RELEASES.md

   1 Version 1.50.0 (2021-02-11)
   2 ============================
   3
   4 Language
   5 -----------------------
   6 - [You can now use `const` values for `x` in `[x; N]` array expressions.][79270]
   7   This has been technically possible since 1.38.0, as it was unintentionally stabilized.
   8 - [Assignments to `ManuallyDrop<T>` union fields are now considered safe.][78068]
   9
  10 Compiler
  11 -----------------------
  12 - [Added tier 3\* support for the `armv5te-unknown-linux-uclibceabi` target.][78142]
  13 - [Added tier 3 support for the `aarch64-apple-ios-macabi` target.][77484]
  14 - [The `x86_64-unknown-freebsd` is now built with the full toolset.][79484]
  15
  16 \* Refer to Rust's [platform support page][forge-platform-support] for more
  17 information on Rust's tiered platform support.
  18
  19 Libraries
  20 -----------------------
  21
  22 - [`proc_macro::Punct` now implements `PartialEq<char>`.][78636]
  23 - [`ops::{Index, IndexMut}` are now implemented for fixed sized arrays of any length.][74989]
  24 - [On Unix platforms, the `std::fs::File` type now has a "niche" of `-1`.][74699]
  25   This value cannot be a valid file descriptor, and now means `Option<File>` takes
  26   up the same amount of space as `File`.
  27
  28 Stabilized APIs
  29 ---------------
  30
  31 - [`bool::then`]
  32 - [`btree_map::Entry::or_insert_with_key`]
  33 - [`f32::clamp`]
  34 - [`f64::clamp`]
  35 - [`hash_map::Entry::or_insert_with_key`]
  36 - [`Ord::clamp`]
  37 - [`RefCell::take`]
  38 - [`slice::fill`]
  39 - [`UnsafeCell::get_mut`]
  40
  41 The following previously stable methods are now `const`.
  42
  43 - [`IpAddr::is_ipv4`]
  44 - [`IpAddr::is_ipv6`]
  45 - [`Layout::size`]
  46 - [`Layout::align`]
  47 - [`Layout::from_size_align`]
  48 - `pow` for all integer types.
  49 - `checked_pow` for all integer types.
  50 - `saturating_pow` for all integer types.
  51 - `wrapping_pow` for all integer types.
  52 - `next_power_of_two` for all unsigned integer types.
  53 - `checked_power_of_two` for all unsigned integer types.
  54
  55 Cargo
  56 -----------------------
  57
  58 - [Added the `[build.rustc-workspace-wrapper]` option.][cargo/8976]
  59   This option sets a wrapper to execute instead of `rustc`, for workspace members only.
  60 - [`cargo:rerun-if-changed` will now, if provided a directory, scan the entire
  61   contents of that directory for changes.][cargo/8973]
  62 - [Added the `--workspace` flag to the `cargo update` command.][cargo/8725]
  63
  64 Misc
  65 ----
  66
  67 - [The search results tab and the help button are focusable with keyboard in rustdoc.][79896]
  68 - [Running tests will now print the total time taken to execute.][75752]
  69
  70 Compatibility Notes
  71 -------------------
  72
  73 - [The `compare_and_swap` method on atomics has been deprecated.][79261] It's
  74   recommended to use the `compare_exchange` and `compare_exchange_weak` methods instead.
  75 - [Changes in how `TokenStream`s are checked have fixed some cases where you could write
  76   unhygenic `macro_rules!` macros.][79472]
  77 - [`#![test]` as an inner attribute is now considered unstable like other inner macro
  78   attributes, and reports an error by default through the `soft_unstable` lint.][79003]
  79 - [Overriding a `forbid` lint at the same level that it was set is now a hard error.][78864]
  80 - [Dropped support for all cloudabi targets.][78439]
  81 - [You can no longer intercept `panic!` calls by supplying your own macro.][78343] It's
  82   recommended to use the `#[panic_handler]` attribute to provide your own implementation.
  83 - [Semi-colons after item statements (e.g. `struct Foo {};`) now produce a warning.][78296]
  84
  85 [74989]: https://github.com/rust-lang/rust/pull/74989
  86 [79261]: https://github.com/rust-lang/rust/pull/79261
  87 [79896]: https://github.com/rust-lang/rust/pull/79896
  88 [79484]: https://github.com/rust-lang/rust/pull/79484
  89 [79472]: https://github.com/rust-lang/rust/pull/79472
  90 [79270]: https://github.com/rust-lang/rust/pull/79270
  91 [79003]: https://github.com/rust-lang/rust/pull/79003
  92 [78864]: https://github.com/rust-lang/rust/pull/78864
  93 [78636]: https://github.com/rust-lang/rust/pull/78636
  94 [78439]: https://github.com/rust-lang/rust/pull/78439
  95 [78343]: https://github.com/rust-lang/rust/pull/78343
  96 [78296]: https://github.com/rust-lang/rust/pull/78296
  97 [78068]: https://github.com/rust-lang/rust/pull/78068
  98 [75752]: https://github.com/rust-lang/rust/pull/75752
  99 [74699]: https://github.com/rust-lang/rust/pull/74699
 100 [78142]: https://github.com/rust-lang/rust/pull/78142
 101 [77484]: https://github.com/rust-lang/rust/pull/77484
 102 [cargo/8976]: https://github.com/rust-lang/cargo/pull/8976
 103 [cargo/8973]: https://github.com/rust-lang/cargo/pull/8973
 104 [cargo/8725]: https://github.com/rust-lang/cargo/pull/8725
 105 [`IpAddr::is_ipv4`]: https://doc.rust-lang.org/stable/std/net/enum.IpAddr.html#method.is_ipv4
 106 [`IpAddr::is_ipv6`]: https://doc.rust-lang.org/stable/std/net/enum.IpAddr.html#method.is_ipv6
 107 [`Layout::align`]: https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.align
 108 [`Layout::from_size_align`]: https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.from_size_align
 109 [`Layout::size`]: https://doc.rust-lang.org/stable/std/alloc/struct.Layout.html#method.size
 110 [`Ord::clamp`]: https://doc.rust-lang.org/stable/std/cmp/trait.Ord.html#method.clamp
 111 [`RefCell::take`]: https://doc.rust-lang.org/stable/std/cell/struct.RefCell.html#method.take
 112 [`UnsafeCell::get_mut`]: https://doc.rust-lang.org/stable/std/cell/struct.UnsafeCell.html#method.get_mut
 113 [`bool::then`]: https://doc.rust-lang.org/stable/std/primitive.bool.html#method.then
 114 [`btree_map::Entry::or_insert_with_key`]: https://doc.rust-lang.org/stable/std/collections/btree_map/enum.Entry.html#method.or_insert_with_key
 115 [`f32::clamp`]: https://doc.rust-lang.org/stable/std/primitive.f32.html#method.clamp
 116 [`f64::clamp`]: https://doc.rust-lang.org/stable/std/primitive.f64.html#method.clamp
 117 [`hash_map::Entry::or_insert_with_key`]: https://doc.rust-lang.org/stable/std/collections/hash_map/enum.Entry.html#method.or_insert_with_key
 118 [`slice::fill`]: https://doc.rust-lang.org/stable/std/primitive.slice.html#method.fill
 119
 120
 121 Version 1.49.0 (2020-12-31)
 122 ============================
 123
 124 Language
 125 -----------------------
 126
 127 - [Unions can now implement `Drop`, and you can now have a field in a union
 128   with `ManuallyDrop<T>`.][77547]
 129 - [You can now cast uninhabited enums to integers.][76199]
 130 - [You can now bind by reference and by move in patterns.][76119] This
 131   allows you to selectively borrow individual components of a type. E.g.
 132   ```rust
 133   #[derive(Debug)]
 134   struct Person {
 135       name: String,
 136       age: u8,
 137   }
 138
 139   let person = Person {
 140       name: String::from("Alice"),
 141       age: 20,
 142   };
 143
 144   // `name` is moved out of person, but `age` is referenced.
 145   let Person { name, ref age } = person;
 146   println!("{} {}", name, age);
 147   ```
 148
 149 Compiler
 150 -----------------------
 151
 152 - [Added tier 1\* support for `aarch64-unknown-linux-gnu`.][78228]
 153 - [Added tier 2 support for `aarch64-apple-darwin`.][75991]
 154 - [Added tier 2 support for `aarch64-pc-windows-msvc`.][75914]
 155 - [Added tier 3 support for `mipsel-unknown-none`.][78676]
 156 - [Raised the minimum supported LLVM version to LLVM 9.][78848]
 157 - [Output from threads spawned in tests is now captured.][78227]
 158 - [Change os and vendor values to "none" and "unknown" for some targets][78951]
 159
 160 \* Refer to Rust's [platform support page][forge-platform-support] for more
 161 information on Rust's tiered platform support.
 162
 163 Libraries
 164 -----------------------
 165
 166 - [`RangeInclusive` now checks for exhaustion when calling `contains` and indexing.][78109]
 167 - [`ToString::to_string` now no longer shrinks the internal buffer in the default implementation.][77997]
 168
 169 Stabilized APIs
 170 ---------------
 171
 172 - [`slice::select_nth_unstable`]
 173 - [`slice::select_nth_unstable_by`]
 174 - [`slice::select_nth_unstable_by_key`]
 175
 176 The following previously stable methods are now `const`.
 177
 178 - [`Poll::is_ready`]
 179 - [`Poll::is_pending`]
 180
 181 Cargo
 182 -----------------------
 183 - [Building a crate with `cargo-package` should now be independently reproducible.][cargo/8864]
 184 - [`cargo-tree` now marks proc-macro crates.][cargo/8765]
 185 - [Added `CARGO_PRIMARY_PACKAGE` build-time environment variable.][cargo/8758] This
 186   variable will be set if the crate being built is one the user selected to build, either
 187   with `-p` or through defaults.
 188 - [You can now use glob patterns when specifying packages & targets.][cargo/8752]
 189
 190
 191 Compatibility Notes
 192 -------------------
 193
 194 - [Demoted `i686-unknown-freebsd` from host tier 2 to target tier 2 support.][78746]
 195 - [Macros that end with a semi-colon are now treated as statements even if they expand to nothing.][78376]
 196 - [Rustc will now check for the validity of some built-in attributes on enum variants.][77015]
 197   Previously such invalid or unused attributes could be ignored.
 198 - Leading whitespace is stripped more uniformly in documentation comments, which may change behavior. You
 199   read [this post about the changes][rustdoc-ws-post] for more details.
 200 - [Trait bounds are no longer inferred for associated types.][79904]
 201
 202 Internal Only
 203 -------------
 204 These changes provide no direct user facing benefits, but represent significant
 205 improvements to the internals and overall performance of rustc and
 206 related tools.
 207
 208 - [rustc's internal crates are now compiled using the `initial-exec` Thread
 209   Local Storage model.][78201]
 210 - [Calculate visibilities once in resolve.][78077]
 211 - [Added `system` to the `llvm-libunwind` bootstrap config option.][77703]
 212 - [Added `--color` for configuring terminal color support to bootstrap.][79004]
 213
 214
 215 [75991]: https://github.com/rust-lang/rust/pull/75991
 216 [78951]: https://github.com/rust-lang/rust/pull/78951
 217 [78848]: https://github.com/rust-lang/rust/pull/78848
 218 [78746]: https://github.com/rust-lang/rust/pull/78746
 219 [78376]: https://github.com/rust-lang/rust/pull/78376
 220 [78228]: https://github.com/rust-lang/rust/pull/78228
 221 [78227]: https://github.com/rust-lang/rust/pull/78227
 222 [78201]: https://github.com/rust-lang/rust/pull/78201
 223 [78109]: https://github.com/rust-lang/rust/pull/78109
 224 [78077]: https://github.com/rust-lang/rust/pull/78077
 225 [77997]: https://github.com/rust-lang/rust/pull/77997
 226 [77703]: https://github.com/rust-lang/rust/pull/77703
 227 [77547]: https://github.com/rust-lang/rust/pull/77547
 228 [77015]: https://github.com/rust-lang/rust/pull/77015
 229 [76199]: https://github.com/rust-lang/rust/pull/76199
 230 [76119]: https://github.com/rust-lang/rust/pull/76119
 231 [75914]: https://github.com/rust-lang/rust/pull/75914
 232 [79004]: https://github.com/rust-lang/rust/pull/79004
 233 [78676]: https://github.com/rust-lang/rust/pull/78676
 234 [79904]: https://github.com/rust-lang/rust/issues/79904
 235 [cargo/8864]: https://github.com/rust-lang/cargo/pull/8864
 236 [cargo/8765]: https://github.com/rust-lang/cargo/pull/8765
 237 [cargo/8758]: https://github.com/rust-lang/cargo/pull/8758
 238 [cargo/8752]: https://github.com/rust-lang/cargo/pull/8752
 239 [`slice::select_nth_unstable`]: https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.select_nth_unstable
 240 [`slice::select_nth_unstable_by`]: https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.select_nth_unstable_by
 241 [`slice::select_nth_unstable_by_key`]: https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.select_nth_unstable_by_key
 242 [`hint::spin_loop`]: https://doc.rust-lang.org/stable/std/hint/fn.spin_loop.html
 243 [`Poll::is_ready`]: https://doc.rust-lang.org/stable/std/task/enum.Poll.html#method.is_ready
 244 [`Poll::is_pending`]: https://doc.rust-lang.org/stable/std/task/enum.Poll.html#method.is_pending
 245 [rustdoc-ws-post]: https://blog.guillaume-gomez.fr/articles/2020-11-11+New+doc+comment+handling+in+rustdoc
 246
 247 Version 1.48.0 (2020-11-19)
 248 ==========================
 249
 250 Language
 251 --------
 252
 253 - [The `unsafe` keyword is now syntactically permitted on modules.][75857] This
 254   is still rejected *semantically*, but can now be parsed by procedural macros.
 255
 256 Compiler
 257 --------
 258 - [Stabilised the `-C link-self-contained=<yes|no>` compiler flag.][76158] This tells
 259   `rustc` whether to link its own C runtime and libraries or to rely on a external
 260   linker to find them. (Supported only on `windows-gnu`, `linux-musl`, and `wasi` platforms.)
 261 - [You can now use `-C target-feature=+crt-static` on `linux-gnu` targets.][77386]
 262   Note: If you're using cargo you must explicitly pass the `--target` flag.
 263 - [Added tier 2\* support for `aarch64-unknown-linux-musl`.][76420]
 264
 265 \* Refer to Rust's [platform support page][forge-platform-support] for more
 266 information on Rust's tiered platform support.
 267
 268 Libraries
 269 ---------
 270 - [`io::Write` is now implemented for `&ChildStdin` `&Sink`, `&Stdout`,
 271   and `&Stderr`.][76275]
 272 - [All arrays of any length now implement `TryFrom<Vec<T>>`.][76310]
 273 - [The `matches!` macro now supports having a trailing comma.][74880]
 274 - [`Vec<A>` now implements `PartialEq<[B]>` where `A: PartialEq<B>`.][74194]
 275 - [The `RefCell::{replace, replace_with, clone}` methods now all use `#[track_caller]`.][77055]
 276
 277 Stabilized APIs
 278 ---------------
 279 - [`slice::as_ptr_range`]
 280 - [`slice::as_mut_ptr_range`]
 281 - [`VecDeque::make_contiguous`]
 282 - [`future::pending`]
 283 - [`future::ready`]
 284
 285 The following previously stable methods are now `const fn`'s:
 286
 287 - [`Option::is_some`]
 288 - [`Option::is_none`]
 289 - [`Option::as_ref`]
 290 - [`Result::is_ok`]
 291 - [`Result::is_err`]
 292 - [`Result::as_ref`]
 293 - [`Ordering::reverse`]
 294 - [`Ordering::then`]
 295
 296 Cargo
 297 -----
 298
 299 Rustdoc
 300 -------
 301 - [You can now link to items in `rustdoc` using the intra-doc link
 302   syntax.][74430] E.g. ``/// Uses [`std::future`]`` will automatically generate
 303   a link to `std::future`'s documentation. See ["Linking to items by
 304   name"][intradoc-links] for more information.
 305 - [You can now specify `#[doc(alias = "<alias>")]` on items to add search aliases
 306   when searching through `rustdoc`'s UI.][75740]
 307
 308 Compatibility Notes
 309 -------------------
 310 - [Promotion of references to `'static` lifetime inside `const fn` now follows the
 311   same rules as inside a `fn` body.][75502] In particular, `&foo()` will not be
 312   promoted to `'static` lifetime any more inside `const fn`s.
 313 - [Associated type bindings on trait objects are now verified to meet the bounds
 314   declared on the trait when checking that they implement the trait.][27675]
 315 - [When trait bounds on associated types or opaque types are ambiguous, the
 316   compiler no longer makes an arbitrary choice on which bound to use.][54121]
 317 - [Fixed recursive nonterminals not being expanded in macros during
 318   pretty-print/reparse check.][77153] This may cause errors if your macro wasn't
 319   correctly handling recursive nonterminal tokens.
 320 - [`&mut` references to non zero-sized types are no longer promoted.][75585]
 321 - [`rustc` will now warn if you use attributes like `#[link_name]` or `#[cold]`
 322   in places where they have no effect.][73461]
 323 - [Updated `_mm256_extract_epi8` and `_mm256_extract_epi16` signatures in
 324   `arch::{x86, x86_64}` to return `i32` to match the vendor signatures.][73166]
 325 - [`mem::uninitialized` will now panic if any inner types inside a struct or enum
 326   disallow zero-initialization.][71274]
 327 - [`#[target_feature]` will now error if used in a place where it has no effect.][78143]
 328 - [Foreign exceptions are now caught by `catch_unwind` and will cause an abort.][70212]
 329   Note: This behaviour is not guaranteed and is still considered undefined behaviour,
 330   see the [`catch_unwind`] documentation for further information.
 331
 332
 333
 334 Internal Only
 335 -------------
 336 These changes provide no direct user facing benefits, but represent significant
 337 improvements to the internals and overall performance of rustc and
 338 related tools.
 339
 340 - [Building `rustc` from source now uses `ninja` by default over `make`.][74922]
 341   You can continue building with `make` by setting `ninja=false` in
 342   your `config.toml`.
 343 - [cg_llvm: `fewer_names` in `uncached_llvm_type`][76030]
 344 - [Made `ensure_sufficient_stack()` non-generic][76680]
 345
 346 [78143]: https://github.com/rust-lang/rust/issues/78143
 347 [76680]: https://github.com/rust-lang/rust/pull/76680/
 348 [76030]: https://github.com/rust-lang/rust/pull/76030/
 349 [70212]: https://github.com/rust-lang/rust/pull/70212/
 350 [27675]: https://github.com/rust-lang/rust/issues/27675/
 351 [54121]: https://github.com/rust-lang/rust/issues/54121/
 352 [71274]: https://github.com/rust-lang/rust/pull/71274/
 353 [77386]: https://github.com/rust-lang/rust/pull/77386/
 354 [77153]: https://github.com/rust-lang/rust/pull/77153/
 355 [77055]: https://github.com/rust-lang/rust/pull/77055/
 356 [76275]: https://github.com/rust-lang/rust/pull/76275/
 357 [76310]: https://github.com/rust-lang/rust/pull/76310/
 358 [76420]: https://github.com/rust-lang/rust/pull/76420/
 359 [76158]: https://github.com/rust-lang/rust/pull/76158/
 360 [75857]: https://github.com/rust-lang/rust/pull/75857/
 361 [75585]: https://github.com/rust-lang/rust/pull/75585/
 362 [75740]: https://github.com/rust-lang/rust/pull/75740/
 363 [75502]: https://github.com/rust-lang/rust/pull/75502/
 364 [74880]: https://github.com/rust-lang/rust/pull/74880/
 365 [74922]: https://github.com/rust-lang/rust/pull/74922/
 366 [74430]: https://github.com/rust-lang/rust/pull/74430/
 367 [74194]: https://github.com/rust-lang/rust/pull/74194/
 368 [73461]: https://github.com/rust-lang/rust/pull/73461/
 369 [73166]: https://github.com/rust-lang/rust/pull/73166/
 370 [intradoc-links]: https://doc.rust-lang.org/rustdoc/linking-to-items-by-name.html
 371 [`catch_unwind`]: https://doc.rust-lang.org/std/panic/fn.catch_unwind.html
 372 [`Option::is_some`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.is_some
 373 [`Option::is_none`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.is_none
 374 [`Option::as_ref`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.as_ref
 375 [`Result::is_ok`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_ok
 376 [`Result::is_err`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.is_err
 377 [`Result::as_ref`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.as_ref
 378 [`Ordering::reverse`]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.reverse
 379 [`Ordering::then`]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.then
 380 [`slice::as_ptr_range`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_ptr_range
 381 [`slice::as_mut_ptr_range`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_mut_ptr_range
 382 [`VecDeque::make_contiguous`]: https://doc.rust-lang.org/std/collections/struct.VecDeque.html#method.make_contiguous
 383 [`future::pending`]: https://doc.rust-lang.org/std/future/fn.pending.html
 384 [`future::ready`]: https://doc.rust-lang.org/std/future/fn.ready.html
 385
 386
 387 Version 1.47.0 (2020-10-08)
 388 ==========================
 389
 390 Language
 391 --------
 392 - [Closures will now warn when not used.][74869]
 393
 394 Compiler
 395 --------
 396 - [Stabilized the `-C control-flow-guard` codegen option][73893], which enables
 397   [Control Flow Guard][1.47.0-cfg] for Windows platforms, and is ignored on other
 398   platforms.
 399 - [Upgraded to LLVM 11.][73526]
 400 - [Added tier 3\* support for the `thumbv4t-none-eabi` target.][74419]
 401 - [Upgrade the FreeBSD toolchain to version 11.4][75204]
 402 - [`RUST_BACKTRACE`'s output is now more compact.][75048]
 403
 404 \* Refer to Rust's [platform support page][forge-platform-support] for more
 405 information on Rust's tiered platform support.
 406
 407 Libraries
 408 ---------
 409 - [`CStr` now implements `Index<RangeFrom<usize>>`.][74021]
 410 - [Traits in `std`/`core` are now implemented for arrays of any length, not just
 411   those of length less than 33.][74060]
 412 - [`ops::RangeFull` and `ops::Range` now implement Default.][73197]
 413 - [`panic::Location` now implements `Copy`, `Clone`, `Eq`, `Hash`, `Ord`,
 414   `PartialEq`, and `PartialOrd`.][73583]
 415
 416 Stabilized APIs
 417 ---------------
 418 - [`Ident::new_raw`]
 419 - [`Range::is_empty`]
 420 - [`RangeInclusive::is_empty`]
 421 - [`Result::as_deref`]
 422 - [`Result::as_deref_mut`]
 423 - [`Vec::leak`]
 424 - [`pointer::offset_from`]
 425 - [`f32::TAU`]
 426 - [`f64::TAU`]
 427
 428 The following previously stable APIs have now been made const.
 429
 430 - [The `new` method for all `NonZero` integers.][73858]
 431 - [The `checked_add`,`checked_sub`,`checked_mul`,`checked_neg`, `checked_shl`,
 432   `checked_shr`, `saturating_add`, `saturating_sub`, and `saturating_mul`
 433   methods for all integers.][73858]
 434 - [The `checked_abs`, `saturating_abs`, `saturating_neg`, and `signum`  for all
 435   signed integers.][73858]
 436 - [The `is_ascii_alphabetic`, `is_ascii_uppercase`, `is_ascii_lowercase`,
 437   `is_ascii_alphanumeric`, `is_ascii_digit`, `is_ascii_hexdigit`,
 438   `is_ascii_punctuation`, `is_ascii_graphic`, `is_ascii_whitespace`, and
 439   `is_ascii_control` methods for `char` and `u8`.][73858]
 440
 441 Cargo
 442 -----
 443 - [`build-dependencies` are now built with opt-level 0 by default.][cargo/8500]
 444   You can override this by setting the following in your `Cargo.toml`.
 445   ```toml
 446   [profile.release.build-override]
 447   opt-level = 3
 448   ```
 449 - [`cargo-help` will now display man pages for commands rather just the
 450   `--help` text.][cargo/8456]
 451 - [`cargo-metadata` now emits a `test` field indicating if a target has
 452   tests enabled.][cargo/8478]
 453 - [`workspace.default-members` now respects `workspace.exclude`.][cargo/8485]
 454 - [`cargo-publish` will now use an alternative registry by default if it's the
 455   only registry specified in `package.publish`.][cargo/8571]
 456
 457 Misc
 458 ----
 459 - [Added a help button beside Rustdoc's searchbar that explains rustdoc's
 460   type based search.][75366]
 461 - [Added the Ayu theme to rustdoc.][71237]
 462
 463 Compatibility Notes
 464 -------------------
 465 - [Bumped the minimum supported Emscripten version to 1.39.20.][75716]
 466 - [Fixed a regression parsing `{} && false` in tail expressions.][74650]
 467 - [Added changes to how proc-macros are expanded in `macro_rules!` that should
 468   help to preserve more span information.][73084] These changes may cause
 469   compiliation errors if your macro was unhygenic or didn't correctly handle
 470   `Delimiter::None`.
 471 - [Moved support for the CloudABI target to tier 3.][75568]
 472 - [`linux-gnu` targets now require minimum kernel 2.6.32 and glibc 2.11.][74163]
 473 - [Added the `rustc-docs` component.][75560] This allows you to install
 474   and read the documentation for the compiler internal APIs. (Currently only
 475   available for `x86_64-unknown-linux-gnu`.)
 476
 477 Internal Only
 478 --------
 479
 480 - [Improved default settings for bootstrapping in `x.py`.][73964] You can read details about this change in the ["Changes to `x.py` defaults"](https://blog.rust-lang.org/inside-rust/2020/08/30/changes-to-x-py-defaults.html) post on the Inside Rust blog.
 481
 482 [1.47.0-cfg]: https://docs.microsoft.com/en-us/windows/win32/secbp/control-flow-guard
 483 [75048]: https://github.com/rust-lang/rust/pull/75048/
 484 [74163]: https://github.com/rust-lang/rust/pull/74163/
 485 [71237]: https://github.com/rust-lang/rust/pull/71237/
 486 [74869]: https://github.com/rust-lang/rust/pull/74869/
 487 [73858]: https://github.com/rust-lang/rust/pull/73858/
 488 [75716]: https://github.com/rust-lang/rust/pull/75716/
 489 [75908]: https://github.com/rust-lang/rust/pull/75908/
 490 [75516]: https://github.com/rust-lang/rust/pull/75516/
 491 [75560]: https://github.com/rust-lang/rust/pull/75560/
 492 [75568]: https://github.com/rust-lang/rust/pull/75568/
 493 [75366]: https://github.com/rust-lang/rust/pull/75366/
 494 [75204]: https://github.com/rust-lang/rust/pull/75204/
 495 [74650]: https://github.com/rust-lang/rust/pull/74650/
 496 [74419]: https://github.com/rust-lang/rust/pull/74419/
 497 [73964]: https://github.com/rust-lang/rust/pull/73964/
 498 [74021]: https://github.com/rust-lang/rust/pull/74021/
 499 [74060]: https://github.com/rust-lang/rust/pull/74060/
 500 [73893]: https://github.com/rust-lang/rust/pull/73893/
 501 [73526]: https://github.com/rust-lang/rust/pull/73526/
 502 [73583]: https://github.com/rust-lang/rust/pull/73583/
 503 [73084]: https://github.com/rust-lang/rust/pull/73084/
 504 [73197]: https://github.com/rust-lang/rust/pull/73197/
 505 [72488]: https://github.com/rust-lang/rust/pull/72488/
 506 [cargo/8456]: https://github.com/rust-lang/cargo/pull/8456/
 507 [cargo/8478]: https://github.com/rust-lang/cargo/pull/8478/
 508 [cargo/8485]: https://github.com/rust-lang/cargo/pull/8485/
 509 [cargo/8500]: https://github.com/rust-lang/cargo/pull/8500/
 510 [cargo/8571]: https://github.com/rust-lang/cargo/pull/8571/
 511 [`Ident::new_raw`]:  https://doc.rust-lang.org/nightly/proc_macro/struct.Ident.html#method.new_raw
 512 [`Range::is_empty`]: https://doc.rust-lang.org/nightly/std/ops/struct.Range.html#method.is_empty
 513 [`RangeInclusive::is_empty`]: https://doc.rust-lang.org/nightly/std/ops/struct.RangeInclusive.html#method.is_empty
 514 [`Result::as_deref_mut`]: https://doc.rust-lang.org/nightly/std/result/enum.Result.html#method.as_deref_mut
 515 [`Result::as_deref`]: https://doc.rust-lang.org/nightly/std/result/enum.Result.html#method.as_deref
 516 [`TypeId::of`]: https://doc.rust-lang.org/nightly/std/any/struct.TypeId.html#method.of
 517 [`Vec::leak`]: https://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#method.leak
 518 [`f32::TAU`]: https://doc.rust-lang.org/nightly/std/f32/consts/constant.TAU.html
 519 [`f64::TAU`]: https://doc.rust-lang.org/nightly/std/f64/consts/constant.TAU.html
 520 [`pointer::offset_from`]: https://doc.rust-lang.org/nightly/std/primitive.pointer.html#method.offset_from
 521
 522
 523 Version 1.46.0 (2020-08-27)
 524 ==========================
 525
 526 Language
 527 --------
 528 - [`if`, `match`, and `loop` expressions can now be used in const functions.][72437]
 529 - [Additionally you are now also able to coerce and cast to slices (`&[T]`) in
 530   const functions.][73862]
 531 - [The `#[track_caller]` attribute can now be added to functions to use the
 532   function's caller's location information for panic messages.][72445]
 533 - [Recursively indexing into tuples no longer needs parentheses.][71322] E.g.
 534   `x.0.0` over `(x.0).0`.
 535 - [`mem::transmute` can now be used in statics and constants.][72920] **Note**
 536   You currently can't use `mem::transmute` in constant functions.
 537
 538 Compiler
 539 --------
 540 - [You can now use the `cdylib` target on Apple iOS and tvOS platforms.][73516]
 541 - [Enabled static "Position Independent Executables" by default
 542   for `x86_64-unknown-linux-musl`.][70740]
 543
 544 Libraries
 545 ---------
 546 - [`mem::forget` is now a `const fn`.][73887]
 547 - [`String` now implements `From<char>`.][73466]
 548 - [The `leading_ones`, and `trailing_ones` methods have been stabilised for all
 549   integer types.][73032]
 550 - [`vec::IntoIter<T>` now implements `AsRef<[T]>`.][72583]
 551 - [All non-zero integer types (`NonZeroU8`) now implement `TryFrom` for their
 552   zero-able equivalent (e.g. `TryFrom<u8>`).][72717]
 553 - [`&[T]` and `&mut [T]` now implement `PartialEq<Vec<T>>`.][71660]
 554 - [`(String, u16)` now implements `ToSocketAddrs`.][73007]
 555 - [`vec::Drain<'_, T>` now implements `AsRef<[T]>`.][72584]
 556
 557 Stabilized APIs
 558 ---------------
 559 - [`Option::zip`]
 560 - [`vec::Drain::as_slice`]
 561
 562 Cargo
 563 -----
 564 Added a number of new environment variables that are now available when
 565 compiling your crate.
 566
 567 - [`CARGO_BIN_NAME` and `CARGO_CRATE_NAME`][cargo/8270] Providing the name of
 568   the specific binary being compiled and the name of the crate.
 569 - [`CARGO_PKG_LICENSE`][cargo/8325] The license from the manifest of the package.
 570 - [`CARGO_PKG_LICENSE_FILE`][cargo/8387] The path to the license file.
 571
 572 Compatibility Notes
 573 -------------------
 574 - [The target configuration option `abi_blacklist` has been renamed
 575   to `unsupported_abis`.][74150] The old name will still continue to work.
 576 - [Rustc will now warn if you cast a C-like enum that implements `Drop`.][72331]
 577   This was previously accepted but will become a hard error in a future release.
 578 - [Rustc will fail to compile if you have a struct with
 579   `#[repr(i128)]` or `#[repr(u128)]`.][74109] This representation is currently only
 580   allowed on `enum`s.
 581 - [Tokens passed to `macro_rules!` are now always captured.][73293] This helps
 582   ensure that spans have the correct information, and may cause breakage if you
 583   were relying on receiving spans with dummy information.
 584 - [The InnoSetup installer for Windows is no longer available.][72569] This was
 585   a legacy installer that was replaced by a MSI installer a few years ago but
 586   was still being built.
 587 - [`{f32, f64}::asinh` now returns the correct values for negative numbers.][72486]
 588 - [Rustc will no longer accept overlapping trait implementations that only
 589   differ in how the lifetime was bound.][72493]
 590 - [Rustc now correctly relates the lifetime of an existential associated
 591   type.][71896] This fixes some edge cases where `rustc` would erroneously allow
 592   you to pass a shorter lifetime than expected.
 593 - [Rustc now dynamically links to `libz` (also called `zlib`) on Linux.][74420]
 594   The library will need to be installed for `rustc` to work, even though we
 595   expect it to be already available on most systems.
 596 - [Tests annotated with `#[should_panic]` are broken on ARMv7 while running
 597   under QEMU.][74820]
 598 - [Pretty printing of some tokens in procedural macros changed.][75453] The
 599   exact output returned by rustc's pretty printing is an unstable
 600   implementation detail: we recommend any macro relying on it to switch to a
 601   more robust parsing system.
 602
 603 [75453]: https://github.com/rust-lang/rust/issues/75453/
 604 [74820]: https://github.com/rust-lang/rust/issues/74820/
 605 [74420]: https://github.com/rust-lang/rust/issues/74420/
 606 [74109]: https://github.com/rust-lang/rust/pull/74109/
 607 [74150]: https://github.com/rust-lang/rust/pull/74150/
 608 [73862]: https://github.com/rust-lang/rust/pull/73862/
 609 [73887]: https://github.com/rust-lang/rust/pull/73887/
 610 [73466]: https://github.com/rust-lang/rust/pull/73466/
 611 [73516]: https://github.com/rust-lang/rust/pull/73516/
 612 [73293]: https://github.com/rust-lang/rust/pull/73293/
 613 [73007]: https://github.com/rust-lang/rust/pull/73007/
 614 [73032]: https://github.com/rust-lang/rust/pull/73032/
 615 [72920]: https://github.com/rust-lang/rust/pull/72920/
 616 [72569]: https://github.com/rust-lang/rust/pull/72569/
 617 [72583]: https://github.com/rust-lang/rust/pull/72583/
 618 [72584]: https://github.com/rust-lang/rust/pull/72584/
 619 [72717]: https://github.com/rust-lang/rust/pull/72717/
 620 [72437]: https://github.com/rust-lang/rust/pull/72437/
 621 [72445]: https://github.com/rust-lang/rust/pull/72445/
 622 [72486]: https://github.com/rust-lang/rust/pull/72486/
 623 [72493]: https://github.com/rust-lang/rust/pull/72493/
 624 [72331]: https://github.com/rust-lang/rust/pull/72331/
 625 [71896]: https://github.com/rust-lang/rust/pull/71896/
 626 [71660]: https://github.com/rust-lang/rust/pull/71660/
 627 [71322]: https://github.com/rust-lang/rust/pull/71322/
 628 [70740]: https://github.com/rust-lang/rust/pull/70740/
 629 [cargo/8270]: https://github.com/rust-lang/cargo/pull/8270/
 630 [cargo/8325]: https://github.com/rust-lang/cargo/pull/8325/
 631 [cargo/8387]: https://github.com/rust-lang/cargo/pull/8387/
 632 [`Option::zip`]: https://doc.rust-lang.org/stable/std/option/enum.Option.html#method.zip
 633 [`vec::Drain::as_slice`]: https://doc.rust-lang.org/stable/std/vec/struct.Drain.html#method.as_slice
 634
 635
 636 Version 1.45.2 (2020-08-03)
 637 ==========================
 638
 639 * [Fix bindings in tuple struct patterns][74954]
 640 * [Fix track_caller integration with trait objects][74784]
 641
 642 [74954]: https://github.com/rust-lang/rust/issues/74954
 643 [74784]: https://github.com/rust-lang/rust/issues/74784
 644
 645
 646 Version 1.45.1 (2020-07-30)
 647 ==========================
 648
 649 * [Fix const propagation with references.][73613]
 650 * [rustfmt accepts rustfmt_skip in cfg_attr again.][73078]
 651 * [Avoid spurious implicit region bound.][74509]
 652 * [Install clippy on x.py install][74457]
 653
 654 [73613]: https://github.com/rust-lang/rust/pull/73613
 655 [73078]: https://github.com/rust-lang/rust/issues/73078
 656 [74509]: https://github.com/rust-lang/rust/pull/74509
 657 [74457]: https://github.com/rust-lang/rust/pull/74457
 658
 659
 660 Version 1.45.0 (2020-07-16)
 661 ==========================
 662
 663 Language
 664 --------
 665 - [Out of range float to int conversions using `as` has been defined as a saturating
 666   conversion.][71269] This was previously undefined behaviour, but you can use the
 667    `{f64, f32}::to_int_unchecked` methods to continue using the current behaviour, which
 668    may be desirable in rare performance sensitive situations.
 669 - [`mem::Discriminant<T>` now uses `T`'s discriminant type instead of always
 670   using `u64`.][70705]
 671 - [Function like procedural macros can now be used in expression, pattern, and  statement
 672   positions.][68717] This means you can now use a function-like procedural macro
 673   anywhere you can use a declarative (`macro_rules!`) macro.
 674
 675 Compiler
 676 --------
 677 - [You can now override individual target features through the `target-feature`
 678   flag.][72094] E.g. `-C target-feature=+avx2 -C target-feature=+fma` is now
 679   equivalent to `-C target-feature=+avx2,+fma`.
 680 - [Added the `force-unwind-tables` flag.][69984] This option allows
 681   rustc to always generate unwind tables regardless of panic strategy.
 682 - [Added the `embed-bitcode` flag.][71716] This codegen flag allows rustc
 683   to include LLVM bitcode into generated `rlib`s (this is on by default).
 684 - [Added the `tiny` value to the `code-model` codegen flag.][72397]
 685 - [Added tier 3 support\* for the `mipsel-sony-psp` target.][72062]
 686 - [Added tier 3 support for the `thumbv7a-uwp-windows-msvc` target.][72133]
 687 - [Upgraded to LLVM 10.][67759]
 688
 689 \* Refer to Rust's [platform support page][forge-platform-support] for more
 690 information on Rust's tiered platform support.
 691
 692
 693 Libraries
 694 ---------
 695 - [`net::{SocketAddr, SocketAddrV4, SocketAddrV6}` now implements `PartialOrd`
 696   and `Ord`.][72239]
 697 - [`proc_macro::TokenStream` now implements `Default`.][72234]
 698 - [You can now use `char` with
 699   `ops::{Range, RangeFrom, RangeFull, RangeInclusive, RangeTo}` to iterate over
 700   a range of codepoints.][72413] E.g.
 701   you can now write the following;
 702   ```rust
 703   for ch in 'a'..='z' {
 704       print!("{}", ch);
 705   }
 706   println!();
 707   // Prints "abcdefghijklmnopqrstuvwxyz"
 708   ```
 709 - [`OsString` now implements `FromStr`.][71662]
 710 - [The `saturating_neg` method has been added to all signed integer primitive
 711   types, and the `saturating_abs` method has been added for all integer
 712   primitive types.][71886]
 713 - [`Arc<T>`, `Rc<T>` now implement  `From<Cow<'_, T>>`, and `Box` now
 714   implements `From<Cow>` when `T` is `[T: Copy]`, `str`, `CStr`, `OsStr`,
 715   or `Path`.][71447]
 716 - [`Box<[T]>` now implements `From<[T; N]>`.][71095]
 717 - [`BitOr` and `BitOrAssign` are implemented for all `NonZero`
 718   integer types.][69813]
 719 - [The `fetch_min`, and `fetch_max` methods have been added to all atomic
 720   integer types.][72324]
 721 - [The `fetch_update` method has been added to all atomic integer types.][71843]
 722
 723 Stabilized APIs
 724 ---------------
 725 - [`Arc::as_ptr`]
 726 - [`BTreeMap::remove_entry`]
 727 - [`Rc::as_ptr`]
 728 - [`rc::Weak::as_ptr`]
 729 - [`rc::Weak::from_raw`]
 730 - [`rc::Weak::into_raw`]
 731 - [`str::strip_prefix`]
 732 - [`str::strip_suffix`]
 733 - [`sync::Weak::as_ptr`]
 734 - [`sync::Weak::from_raw`]
 735 - [`sync::Weak::into_raw`]
 736 - [`char::UNICODE_VERSION`]
 737 - [`Span::resolved_at`]
 738 - [`Span::located_at`]
 739 - [`Span::mixed_site`]
 740 - [`unix::process::CommandExt::arg0`]
 741
 742 Cargo
 743 -----
 744
 745 - [Cargo uses the `embed-bitcode` flag to optimize disk usage and build
 746   time.][cargo/8066]
 747
 748 Misc
 749 ----
 750 - [Rustdoc now supports strikethrough text in Markdown.][71928] E.g.
 751   `~~outdated information~~` becomes "~~outdated information~~".
 752 - [Added an emoji to Rustdoc's deprecated API message.][72014]
 753
 754 Compatibility Notes
 755 -------------------
 756 - [Trying to self initialize a static value (that is creating a value using
 757   itself) is unsound and now causes a compile error.][71140]
 758 - [`{f32, f64}::powi` now returns a slightly different value on Windows.][73420]
 759   This is due to changes in LLVM's intrinsics which `{f32, f64}::powi` uses.
 760 - [Rustdoc's CLI's extra error exit codes have been removed.][71900] These were
 761   previously undocumented and not intended for public use. Rustdoc still provides
 762   a non-zero exit code on errors.
 763 - [Rustc's `lto` flag is incompatible with the new `embed-bitcode=no`.][71848]
 764   This may cause issues if LTO is enabled through `RUSTFLAGS` or `cargo rustc`
 765   flags while cargo is adding `embed-bitcode` itself. The recommended way to
 766   control LTO is with Cargo profiles, either in `Cargo.toml` or `.cargo/config`,
 767   or by setting `CARGO_PROFILE_<name>_LTO` in the environment.
 768
 769 Internals Only
 770 --------------
 771 - [Make clippy a git subtree instead of a git submodule][70655]
 772 - [Unify the undo log of all snapshot types][69464]
 773
 774 [71848]: https://github.com/rust-lang/rust/issues/71848/
 775 [73420]: https://github.com/rust-lang/rust/issues/73420/
 776 [72324]: https://github.com/rust-lang/rust/pull/72324/
 777 [71843]: https://github.com/rust-lang/rust/pull/71843/
 778 [71886]: https://github.com/rust-lang/rust/pull/71886/
 779 [72234]: https://github.com/rust-lang/rust/pull/72234/
 780 [72239]: https://github.com/rust-lang/rust/pull/72239/
 781 [72397]: https://github.com/rust-lang/rust/pull/72397/
 782 [72413]: https://github.com/rust-lang/rust/pull/72413/
 783 [72014]: https://github.com/rust-lang/rust/pull/72014/
 784 [72062]: https://github.com/rust-lang/rust/pull/72062/
 785 [72094]: https://github.com/rust-lang/rust/pull/72094/
 786 [72133]: https://github.com/rust-lang/rust/pull/72133/
 787 [67759]: https://github.com/rust-lang/rust/pull/67759/
 788 [71900]: https://github.com/rust-lang/rust/pull/71900/
 789 [71928]: https://github.com/rust-lang/rust/pull/71928/
 790 [71662]: https://github.com/rust-lang/rust/pull/71662/
 791 [71716]: https://github.com/rust-lang/rust/pull/71716/
 792 [71447]: https://github.com/rust-lang/rust/pull/71447/
 793 [71269]: https://github.com/rust-lang/rust/pull/71269/
 794 [71095]: https://github.com/rust-lang/rust/pull/71095/
 795 [71140]: https://github.com/rust-lang/rust/pull/71140/
 796 [70655]: https://github.com/rust-lang/rust/pull/70655/
 797 [70705]: https://github.com/rust-lang/rust/pull/70705/
 798 [69984]: https://github.com/rust-lang/rust/pull/69984/
 799 [69813]: https://github.com/rust-lang/rust/pull/69813/
 800 [69464]: https://github.com/rust-lang/rust/pull/69464/
 801 [68717]: https://github.com/rust-lang/rust/pull/68717/
 802 [cargo/8066]: https://github.com/rust-lang/cargo/pull/8066
 803 [`Arc::as_ptr`]: https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.as_ptr
 804 [`BTreeMap::remove_entry`]: https://doc.rust-lang.org/stable/std/collections/struct.BTreeMap.html#method.remove_entry
 805 [`Rc::as_ptr`]: https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.as_ptr
 806 [`rc::Weak::as_ptr`]: https://doc.rust-lang.org/stable/std/rc/struct.Weak.html#method.as_ptr
 807 [`rc::Weak::from_raw`]: https://doc.rust-lang.org/stable/std/rc/struct.Weak.html#method.from_raw
 808 [`rc::Weak::into_raw`]: https://doc.rust-lang.org/stable/std/rc/struct.Weak.html#method.into_raw
 809 [`sync::Weak::as_ptr`]: https://doc.rust-lang.org/stable/std/sync/struct.Weak.html#method.as_ptr
 810 [`sync::Weak::from_raw`]: https://doc.rust-lang.org/stable/std/sync/struct.Weak.html#method.from_raw
 811 [`sync::Weak::into_raw`]: https://doc.rust-lang.org/stable/std/sync/struct.Weak.html#method.into_raw
 812 [`str::strip_prefix`]: https://doc.rust-lang.org/stable/std/primitive.str.html#method.strip_prefix
 813 [`str::strip_suffix`]: https://doc.rust-lang.org/stable/std/primitive.str.html#method.strip_suffix
 814 [`char::UNICODE_VERSION`]: https://doc.rust-lang.org/stable/std/char/constant.UNICODE_VERSION.html
 815 [`Span::resolved_at`]: https://doc.rust-lang.org/stable/proc_macro/struct.Span.html#method.resolved_at
 816 [`Span::located_at`]: https://doc.rust-lang.org/stable/proc_macro/struct.Span.html#method.located_at
 817 [`Span::mixed_site`]: https://doc.rust-lang.org/stable/proc_macro/struct.Span.html#method.mixed_site
 818 [`unix::process::CommandExt::arg0`]: https://doc.rust-lang.org/std/os/unix/process/trait.CommandExt.html#tymethod.arg0
 819
 820
 821 Version 1.44.1 (2020-06-18)
 822 ===========================
 823
 824 * [rustfmt accepts rustfmt_skip in cfg_attr again.][73078]
 825 * [Don't hash executable filenames on apple platforms, fixing backtraces.][cargo/8329]
 826 * [Fix crashes when finding backtrace on macOS.][71397]
 827 * [Clippy applies lint levels into different files.][clippy/5356]
 828
 829 [71397]: https://github.com/rust-lang/rust/issues/71397
 830 [73078]: https://github.com/rust-lang/rust/issues/73078
 831 [cargo/8329]: https://github.com/rust-lang/cargo/pull/8329
 832 [clippy/5356]: https://github.com/rust-lang/rust-clippy/issues/5356
 833
 834
 835 Version 1.44.0 (2020-06-04)
 836 ==========================
 837
 838 Language
 839 --------
 840 - [You can now use `async/.await` with `#[no_std]` enabled.][69033]
 841 - [Added the `unused_braces` lint.][70081]
 842
 843 **Syntax-only changes**
 844
 845 - [Expansion-driven outline module parsing][69838]
 846 ```rust
 847 #[cfg(FALSE)]
 848 mod foo {
 849     mod bar {
 850         mod baz; // `foo/bar/baz.rs` doesn't exist, but no error!
 851     }
 852 }
 853 ```
 854
 855 These are still rejected semantically, so you will likely receive an error but
 856 these changes can be seen and parsed by macros and conditional compilation.
 857
 858 Compiler
 859 --------
 860 - [Rustc now respects the `-C codegen-units` flag in incremental mode.][70156]
 861   Additionally when in incremental mode rustc defaults to 256 codegen units.
 862 - [Refactored `catch_unwind` to have zero-cost, unless unwinding is enabled and
 863   a panic is thrown.][67502]
 864 - [Added tier 3\* support for the `aarch64-unknown-none` and
 865   `aarch64-unknown-none-softfloat` targets.][68334]
 866 - [Added tier 3 support for `arm64-apple-tvos` and
 867   `x86_64-apple-tvos` targets.][68191]
 868
 869
 870 Libraries
 871 ---------
 872 - [Special cased `vec![]` to map directly to `Vec::new()`.][70632] This allows
 873   `vec![]` to be able to be used in `const` contexts.
 874 - [`convert::Infallible` now implements `Hash`.][70281]
 875 - [`OsString` now implements `DerefMut` and `IndexMut` returning
 876   a `&mut OsStr`.][70048]
 877 - [Unicode 13 is now supported.][69929]
 878 - [`String` now implements `From<&mut str>`.][69661]
 879 - [`IoSlice` now implements `Copy`.][69403]
 880 - [`Vec<T>` now implements `From<[T; N]>`.][68692] Where `N` is at most 32.
 881 - [`proc_macro::LexError` now implements `fmt::Display` and `Error`.][68899]
 882 - [`from_le_bytes`, `to_le_bytes`, `from_be_bytes`, `to_be_bytes`,
 883   `from_ne_bytes`, and `to_ne_bytes` methods are now `const` for all
 884   integer types.][69373]
 885
 886 Stabilized APIs
 887 ---------------
 888 - [`PathBuf::with_capacity`]
 889 - [`PathBuf::capacity`]
 890 - [`PathBuf::clear`]
 891 - [`PathBuf::reserve`]
 892 - [`PathBuf::reserve_exact`]
 893 - [`PathBuf::shrink_to_fit`]
 894 - [`f32::to_int_unchecked`]
 895 - [`f64::to_int_unchecked`]
 896 - [`Layout::align_to`]
 897 - [`Layout::pad_to_align`]
 898 - [`Layout::array`]
 899 - [`Layout::extend`]
 900
 901 Cargo
 902 -----
 903 - [Added the `cargo tree` command which will print a tree graph of
 904   your dependencies.][cargo/8062] E.g.
 905   ```
 906     mdbook v0.3.2 (/Users/src/rust/mdbook)
 907   ├── ammonia v3.0.0
 908   │   ├── html5ever v0.24.0
 909   │   │   ├── log v0.4.8
 910   │   │   │   └── cfg-if v0.1.9
 911   │   │   ├── mac v0.1.1
 912   │   │   └── markup5ever v0.9.0
 913   │   │       ├── log v0.4.8 (*)
 914   │   │       ├── phf v0.7.24
 915   │   │       │   └── phf_shared v0.7.24
 916   │   │       │       ├── siphasher v0.2.3
 917   │   │       │       └── unicase v1.4.2
 918   │   │       │           [build-dependencies]
 919   │   │       │           └── version_check v0.1.5
 920   ...
 921   ```
 922   You can also display dependencies on multiple versions of the same crate with
 923   `cargo tree -d` (short for `cargo tree --duplicates`).
 924
 925 Misc
 926 ----
 927 - [Rustdoc now allows you to specify `--crate-version` to have rustdoc include
 928   the version in the sidebar.][69494]
 929
 930 Compatibility Notes
 931 -------------------
 932 - [Rustc now correctly generates static libraries on Windows GNU targets with
 933   the `.a` extension, rather than the previous `.lib`.][70937]
 934 - [Removed the `-C no_integrated_as` flag from rustc.][70345]
 935 - [The `file_name` property in JSON output of macro errors now points the actual
 936   source file rather than the previous format of `<NAME macros>`.][70969]
 937   **Note:** this may not point to a file that actually exists on the user's system.
 938 - [The minimum required external LLVM version has been bumped to LLVM 8.][71147]
 939 - [`mem::{zeroed, uninitialised}` will now panic when used with types that do
 940   not allow zero initialization such as `NonZeroU8`.][66059] This was
 941   previously a warning.
 942 - [In 1.45.0 (the next release) converting a `f64` to `u32` using the `as`
 943   operator has been defined as a saturating operation.][71269] This was previously
 944   undefined behaviour, but you can use the `{f64, f32}::to_int_unchecked` methods to
 945   continue using the current behaviour, which may be desirable in rare performance
 946   sensitive situations.
 947
 948 Internal Only
 949 -------------
 950 These changes provide no direct user facing benefits, but represent significant
 951 improvements to the internals and overall performance of rustc and
 952 related tools.
 953
 954 - [dep_graph Avoid allocating a set on when the number reads are small.][69778]
 955 - [Replace big JS dict with JSON parsing.][71250]
 956
 957 [69373]: https://github.com/rust-lang/rust/pull/69373/
 958 [66059]: https://github.com/rust-lang/rust/pull/66059/
 959 [68191]: https://github.com/rust-lang/rust/pull/68191/
 960 [68899]: https://github.com/rust-lang/rust/pull/68899/
 961 [71147]: https://github.com/rust-lang/rust/pull/71147/
 962 [71250]: https://github.com/rust-lang/rust/pull/71250/
 963 [70937]: https://github.com/rust-lang/rust/pull/70937/
 964 [70969]: https://github.com/rust-lang/rust/pull/70969/
 965 [70632]: https://github.com/rust-lang/rust/pull/70632/
 966 [70281]: https://github.com/rust-lang/rust/pull/70281/
 967 [70345]: https://github.com/rust-lang/rust/pull/70345/
 968 [70048]: https://github.com/rust-lang/rust/pull/70048/
 969 [70081]: https://github.com/rust-lang/rust/pull/70081/
 970 [70156]: https://github.com/rust-lang/rust/pull/70156/
 971 [71269]: https://github.com/rust-lang/rust/pull/71269/
 972 [69838]: https://github.com/rust-lang/rust/pull/69838/
 973 [69929]: https://github.com/rust-lang/rust/pull/69929/
 974 [69661]: https://github.com/rust-lang/rust/pull/69661/
 975 [69778]: https://github.com/rust-lang/rust/pull/69778/
 976 [69494]: https://github.com/rust-lang/rust/pull/69494/
 977 [69403]: https://github.com/rust-lang/rust/pull/69403/
 978 [69033]: https://github.com/rust-lang/rust/pull/69033/
 979 [68692]: https://github.com/rust-lang/rust/pull/68692/
 980 [68334]: https://github.com/rust-lang/rust/pull/68334/
 981 [67502]: https://github.com/rust-lang/rust/pull/67502/
 982 [cargo/8062]: https://github.com/rust-lang/cargo/pull/8062/
 983 [`PathBuf::with_capacity`]: https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.with_capacity
 984 [`PathBuf::capacity`]: https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.capacity
 985 [`PathBuf::clear`]: https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.clear
 986 [`PathBuf::reserve`]: https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.reserve
 987 [`PathBuf::reserve_exact`]: https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.reserve_exact
 988 [`PathBuf::shrink_to_fit`]: https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.shrink_to_fit
 989 [`f32::to_int_unchecked`]: https://doc.rust-lang.org/std/primitive.f32.html#method.to_int_unchecked
 990 [`f64::to_int_unchecked`]: https://doc.rust-lang.org/std/primitive.f64.html#method.to_int_unchecked
 991 [`Layout::align_to`]: https://doc.rust-lang.org/std/alloc/struct.Layout.html#method.align_to
 992 [`Layout::pad_to_align`]: https://doc.rust-lang.org/std/alloc/struct.Layout.html#method.pad_to_align
 993 [`Layout::array`]: https://doc.rust-lang.org/std/alloc/struct.Layout.html#method.array
 994 [`Layout::extend`]: https://doc.rust-lang.org/std/alloc/struct.Layout.html#method.extend
 995
 996
 997 Version 1.43.1 (2020-05-07)
 998 ===========================
 999
1000 * [Updated openssl-src to 1.1.1g for CVE-2020-1967.][71430]
1001 * [Fixed the stabilization of AVX-512 features.][71473]
1002 * [Fixed `cargo package --list` not working with unpublished dependencies.][cargo/8151]
1003
1004 [71430]: https://github.com/rust-lang/rust/pull/71430
1005 [71473]: https://github.com/rust-lang/rust/issues/71473
1006 [cargo/8151]: https://github.com/rust-lang/cargo/issues/8151
1007
1008
1009 Version 1.43.0 (2020-04-23)
1010 ==========================
1011
1012 Language
1013 --------
1014 - [Fixed using binary operations with `&{number}` (e.g. `&1.0`) not having
1015   the type inferred correctly.][68129]
1016 - [Attributes such as `#[cfg()]` can now be used on `if` expressions.][69201]
1017
1018 **Syntax only changes**
1019 - [Allow `type Foo: Ord` syntactically.][69361]
1020 - [Fuse associated and extern items up to defaultness.][69194]
1021 - [Syntactically allow `self` in all `fn` contexts.][68764]
1022 - [Merge `fn` syntax + cleanup item parsing.][68728]
1023 - [`item` macro fragments can be interpolated into `trait`s, `impl`s, and `extern` blocks.][69366]
1024   For example, you may now write:
1025   ```rust
1026   macro_rules! mac_trait {
1027       ($i:item) => {
1028           trait T { $i }
1029       }
1030   }
1031   mac_trait! {
1032       fn foo() {}
1033   }
1034   ```
1035
1036 These are still rejected *semantically*, so you will likely receive an error but
1037 these changes can be seen and parsed by macros and
1038 conditional compilation.
1039
1040
1041 Compiler
1042 --------
1043 - [You can now pass multiple lint flags to rustc to override the previous
1044   flags.][67885] For example; `rustc -D unused -A unused-variables` denies
1045   everything in the `unused` lint group except `unused-variables` which
1046   is explicitly allowed. However, passing `rustc -A unused-variables -D unused` denies
1047   everything in the `unused` lint group **including** `unused-variables` since
1048   the allow flag is specified before the deny flag (and therefore overridden).
1049 - [rustc will now prefer your system MinGW libraries over its bundled libraries
1050   if they are available on `windows-gnu`.][67429]
1051 - [rustc now buffers errors/warnings printed in JSON.][69227]
1052
1053 Libraries
1054 ---------
1055 - [`Arc<[T; N]>`, `Box<[T; N]>`, and `Rc<[T; N]>`, now implement
1056   `TryFrom<Arc<[T]>>`,`TryFrom<Box<[T]>>`, and `TryFrom<Rc<[T]>>`
1057   respectively.][69538] **Note** These conversions are only available when `N`
1058   is `0..=32`.
1059 - [You can now use associated constants on floats and integers directly, rather
1060   than having to import the module.][68952] e.g. You can now write `u32::MAX` or
1061   `f32::NAN` with no imports.
1062 - [`u8::is_ascii` is now `const`.][68984]
1063 - [`String` now implements `AsMut<str>`.][68742]
1064 - [Added the `primitive` module to `std` and `core`.][67637] This module
1065   reexports Rust's primitive types. This is mainly useful in macros
1066   where you want avoid these types being shadowed.
1067 - [Relaxed some of the trait bounds on `HashMap` and `HashSet`.][67642]
1068 - [`string::FromUtf8Error` now implements `Clone + Eq`.][68738]
1069
1070 Stabilized APIs
1071 ---------------
1072 - [`Once::is_completed`]
1073 - [`f32::LOG10_2`]
1074 - [`f32::LOG2_10`]
1075 - [`f64::LOG10_2`]
1076 - [`f64::LOG2_10`]
1077 - [`iter::once_with`]
1078
1079 Cargo
1080 -----
1081 - [You can now set config `[profile]`s in your `.cargo/config`, or through
1082   your environment.][cargo/7823]
1083 - [Cargo will now set `CARGO_BIN_EXE_<name>` pointing to a binary's
1084   executable path when running integration tests or benchmarks.][cargo/7697]
1085   `<name>` is the name of your binary as-is e.g. If you wanted the executable
1086   path for a binary named `my-program`you would use `env!("CARGO_BIN_EXE_my-program")`.
1087
1088 Misc
1089 ----
1090 - [Certain checks in the `const_err` lint were deemed unrelated to const
1091   evaluation][69185], and have been moved to the `unconditional_panic` and
1092   `arithmetic_overflow` lints.
1093
1094 Compatibility Notes
1095 -------------------
1096
1097 - [Having trailing syntax in the `assert!` macro is now a hard error.][69548] This
1098   has been a warning since 1.36.0.
1099 - [Fixed `Self` not having the correctly inferred type.][69340] This incorrectly
1100   led to some instances being accepted, and now correctly emits a hard error.
1101
1102 [69340]: https://github.com/rust-lang/rust/pull/69340
1103
1104 Internal Only
1105 -------------
1106 These changes provide no direct user facing benefits, but represent significant
1107 improvements to the internals and overall performance of `rustc` and
1108 related tools.
1109
1110 - [All components are now built with `opt-level=3` instead of `2`.][67878]
1111 - [Improved how rustc generates drop code.][67332]
1112 - [Improved performance from `#[inline]`-ing certain hot functions.][69256]
1113 - [traits: preallocate 2 Vecs of known initial size][69022]
1114 - [Avoid exponential behaviour when relating types][68772]
1115 - [Skip `Drop` terminators for enum variants without drop glue][68943]
1116 - [Improve performance of coherence checks][68966]
1117 - [Deduplicate types in the generator witness][68672]
1118 - [Invert control in struct_lint_level.][68725]
1119
1120 [67332]: https://github.com/rust-lang/rust/pull/67332/
1121 [67429]: https://github.com/rust-lang/rust/pull/67429/
1122 [67637]: https://github.com/rust-lang/rust/pull/67637/
1123 [67642]: https://github.com/rust-lang/rust/pull/67642/
1124 [67878]: https://github.com/rust-lang/rust/pull/67878/
1125 [67885]: https://github.com/rust-lang/rust/pull/67885/
1126 [68129]: https://github.com/rust-lang/rust/pull/68129/
1127 [68672]: https://github.com/rust-lang/rust/pull/68672/
1128 [68725]: https://github.com/rust-lang/rust/pull/68725/
1129 [68728]: https://github.com/rust-lang/rust/pull/68728/
1130 [68738]: https://github.com/rust-lang/rust/pull/68738/
1131 [68742]: https://github.com/rust-lang/rust/pull/68742/
1132 [68764]: https://github.com/rust-lang/rust/pull/68764/
1133 [68772]: https://github.com/rust-lang/rust/pull/68772/
1134 [68943]: https://github.com/rust-lang/rust/pull/68943/
1135 [68952]: https://github.com/rust-lang/rust/pull/68952/
1136 [68966]: https://github.com/rust-lang/rust/pull/68966/
1137 [68984]: https://github.com/rust-lang/rust/pull/68984/
1138 [69022]: https://github.com/rust-lang/rust/pull/69022/
1139 [69185]: https://github.com/rust-lang/rust/pull/69185/
1140 [69194]: https://github.com/rust-lang/rust/pull/69194/
1141 [69201]: https://github.com/rust-lang/rust/pull/69201/
1142 [69227]: https://github.com/rust-lang/rust/pull/69227/
1143 [69548]: https://github.com/rust-lang/rust/pull/69548/
1144 [69256]: https://github.com/rust-lang/rust/pull/69256/
1145 [69361]: https://github.com/rust-lang/rust/pull/69361/
1146 [69366]: https://github.com/rust-lang/rust/pull/69366/
1147 [69538]: https://github.com/rust-lang/rust/pull/69538/
1148 [cargo/7823]: https://github.com/rust-lang/cargo/pull/7823
1149 [cargo/7697]: https://github.com/rust-lang/cargo/pull/7697
1150 [`Once::is_completed`]: https://doc.rust-lang.org/std/sync/struct.Once.html#method.is_completed
1151 [`f32::LOG10_2`]: https://doc.rust-lang.org/std/f32/consts/constant.LOG10_2.html
1152 [`f32::LOG2_10`]: https://doc.rust-lang.org/std/f32/consts/constant.LOG2_10.html
1153 [`f64::LOG10_2`]: https://doc.rust-lang.org/std/f64/consts/constant.LOG10_2.html
1154 [`f64::LOG2_10`]: https://doc.rust-lang.org/std/f64/consts/constant.LOG2_10.html
1155 [`iter::once_with`]: https://doc.rust-lang.org/std/iter/fn.once_with.html
1156
1157
1158 Version 1.42.0 (2020-03-12)
1159 ==========================
1160
1161 Language
1162 --------
1163 - [You can now use the slice pattern syntax with subslices.][67712] e.g.
1164   ```rust
1165   fn foo(words: &[&str]) {
1166       match words {
1167           ["Hello", "World", "!", ..] => println!("Hello World!"),
1168           ["Foo", "Bar", ..] => println!("Baz"),
1169           rest => println!("{:?}", rest),
1170       }
1171   }
1172   ```
1173 - [You can now use `#[repr(transparent)]` on univariant `enum`s.][68122] Meaning
1174   that you can create an enum that has the exact layout and ABI of the type
1175   it contains.
1176 - [There are some *syntax-only* changes:][67131]
1177    - `default` is syntactically allowed before items in `trait` definitions.
1178    - Items in `impl`s (i.e. `const`s, `type`s, and `fn`s) may syntactically
1179      leave out their bodies in favor of `;`.
1180    - Bounds on associated types in `impl`s are now syntactically allowed
1181      (e.g. `type Foo: Ord;`).
1182    - `...` (the C-variadic type) may occur syntactically directly as the type of
1183       any function parameter.
1184
1185   These are still rejected *semantically*, so you will likely receive an error
1186   but these changes can be seen and parsed by procedural macros and
1187   conditional compilation.
1188
1189 Compiler
1190 --------
1191 - [Added tier 2\* support for `armv7a-none-eabi`.][68253]
1192 - [Added tier 2 support for `riscv64gc-unknown-linux-gnu`.][68339]
1193 - [`Option::{expect,unwrap}` and
1194    `Result::{expect, expect_err, unwrap, unwrap_err}` now produce panic messages
1195    pointing to the location where they were called, rather than
1196    `core`'s internals. ][67887]
1197
1198 \* Refer to Rust's [platform support page][forge-platform-support] for more
1199 information on Rust's tiered platform support.
1200
1201 Libraries
1202 ---------
1203 - [`iter::Empty<T>` now implements `Send` and `Sync` for any `T`.][68348]
1204 - [`Pin::{map_unchecked, map_unchecked_mut}` no longer require the return type
1205    to implement `Sized`.][67935]
1206 - [`io::Cursor` now derives `PartialEq` and `Eq`.][67233]
1207 - [`Layout::new` is now `const`.][66254]
1208 - [Added Standard Library support for `riscv64gc-unknown-linux-gnu`.][66899]
1209
1210
1211 Stabilized APIs
1212 ---------------
1213 - [`CondVar::wait_while`]
1214 - [`CondVar::wait_timeout_while`]
1215 - [`DebugMap::key`]
1216 - [`DebugMap::value`]
1217 - [`ManuallyDrop::take`]
1218 - [`matches!`]
1219 - [`ptr::slice_from_raw_parts_mut`]
1220 - [`ptr::slice_from_raw_parts`]
1221
1222 Cargo
1223 -----
1224 - [You no longer need to include `extern crate proc_macro;` to be able to
1225   `use proc_macro;` in the `2018` edition.][cargo/7700]
1226
1227 Compatibility Notes
1228 -------------------
1229 - [`Error::description` has been deprecated, and its use will now produce a
1230   warning.][66919] It's recommended to use `Display`/`to_string` instead.
1231
1232 [68253]: https://github.com/rust-lang/rust/pull/68253/
1233 [68348]: https://github.com/rust-lang/rust/pull/68348/
1234 [67935]: https://github.com/rust-lang/rust/pull/67935/
1235 [68339]: https://github.com/rust-lang/rust/pull/68339/
1236 [68122]: https://github.com/rust-lang/rust/pull/68122/
1237 [67712]: https://github.com/rust-lang/rust/pull/67712/
1238 [67887]: https://github.com/rust-lang/rust/pull/67887/
1239 [67131]: https://github.com/rust-lang/rust/pull/67131/
1240 [67233]: https://github.com/rust-lang/rust/pull/67233/
1241 [66899]: https://github.com/rust-lang/rust/pull/66899/
1242 [66919]: https://github.com/rust-lang/rust/pull/66919/
1243 [66254]: https://github.com/rust-lang/rust/pull/66254/
1244 [cargo/7700]: https://github.com/rust-lang/cargo/pull/7700
1245 [`DebugMap::key`]: https://doc.rust-lang.org/stable/std/fmt/struct.DebugMap.html#method.key
1246 [`DebugMap::value`]: https://doc.rust-lang.org/stable/std/fmt/struct.DebugMap.html#method.value
1247 [`ManuallyDrop::take`]: https://doc.rust-lang.org/stable/std/mem/struct.ManuallyDrop.html#method.take
1248 [`matches!`]: https://doc.rust-lang.org/stable/std/macro.matches.html
1249 [`ptr::slice_from_raw_parts_mut`]: https://doc.rust-lang.org/stable/std/ptr/fn.slice_from_raw_parts_mut.html
1250 [`ptr::slice_from_raw_parts`]: https://doc.rust-lang.org/stable/std/ptr/fn.slice_from_raw_parts.html
1251 [`CondVar::wait_while`]: https://doc.rust-lang.org/stable/std/sync/struct.Condvar.html#method.wait_while
1252 [`CondVar::wait_timeout_while`]: https://doc.rust-lang.org/stable/std/sync/struct.Condvar.html#method.wait_timeout_while
1253
1254
1255 Version 1.41.1 (2020-02-27)
1256 ===========================
1257
1258 * [Always check types of static items][69145]
1259 * [Always check lifetime bounds of `Copy` impls][69145]
1260 * [Fix miscompilation in callers of `Layout::repeat`][69225]
1261
1262 [69225]: https://github.com/rust-lang/rust/issues/69225
1263 [69145]: https://github.com/rust-lang/rust/pull/69145
1264
1265
1266 Version 1.41.0 (2020-01-30)
1267 ===========================
1268
1269 Language
1270 --------
1271
1272 - [You can now pass type parameters to foreign items when implementing
1273   traits.][65879] E.g. You can now write `impl<T> From<Foo> for Vec<T> {}`.
1274 - [You can now arbitrarily nest receiver types in the `self` position.][64325] E.g. you can
1275   now write `fn foo(self: Box<Box<Self>>) {}`. Previously only `Self`, `&Self`,
1276   `&mut Self`, `Arc<Self>`, `Rc<Self>`, and `Box<Self>` were allowed.
1277 - [You can now use any valid identifier in a `format_args` macro.][66847]
1278   Previously identifiers starting with an underscore were not allowed.
1279 - [Visibility modifiers (e.g. `pub`) are now syntactically allowed on trait items and
1280   enum variants.][66183] These are still rejected semantically, but
1281   can be seen and parsed by procedural macros and conditional compilation.
1282
1283 Compiler
1284 --------
1285
1286 - [Rustc will now warn if you have unused loop `'label`s.][66325]
1287 - [Removed support for the `i686-unknown-dragonfly` target.][67255]
1288 - [Added tier 3 support\* for the `riscv64gc-unknown-linux-gnu` target.][66661]
1289 - [You can now pass an arguments file passing the `@path` syntax
1290   to rustc.][66172] Note that the format differs somewhat from what is
1291   found in other tooling; please see [the documentation][argfile-docs] for
1292   more information.
1293 - [You can now provide `--extern` flag without a path, indicating that it is
1294   available from the search path or specified with an `-L` flag.][64882]
1295
1296 \* Refer to Rust's [platform support page][forge-platform-support] for more
1297 information on Rust's tiered platform support.
1298
1299 [argfile-docs]: https://doc.rust-lang.org/nightly/rustc/command-line-arguments.html#path-load-command-line-flags-from-a-path
1300
1301 Libraries
1302 ---------
1303
1304 - [The `core::panic` module is now stable.][66771] It was already stable
1305   through `std`.
1306 - [`NonZero*` numerics now implement `From<NonZero*>` if it's a smaller integer
1307   width.][66277] E.g. `NonZeroU16` now implements `From<NonZeroU8>`.
1308 - [`MaybeUninit<T>` now implements `fmt::Debug`.][65013]
1309
1310 Stabilized APIs
1311 ---------------
1312
1313 - [`Result::map_or`]
1314 - [`Result::map_or_else`]
1315 - [`std::rc::Weak::weak_count`]
1316 - [`std::rc::Weak::strong_count`]
1317 - [`std::sync::Weak::weak_count`]
1318 - [`std::sync::Weak::strong_count`]
1319
1320 Cargo
1321 -----
1322
1323 - [Cargo will now document all the private items for binary crates
1324   by default.][cargo/7593]
1325 - [`cargo-install` will now reinstall the package if it detects that it is out
1326   of date.][cargo/7560]
1327 - [Cargo.lock now uses a more git friendly format that should help to reduce
1328   merge conflicts.][cargo/7579]
1329 - [You can now override specific dependencies's build settings][cargo/7591] E.g.
1330   `[profile.dev.package.image] opt-level = 2` sets the `image` crate's
1331   optimisation level to `2` for debug builds. You can also use
1332   `[profile.<profile>.build-override]` to override build scripts and
1333   their dependencies.
1334
1335 Misc
1336 ----
1337
1338 - [You can now specify `edition` in documentation code blocks to compile the block
1339   for that edition.][66238] E.g. `edition2018` tells rustdoc that the code sample
1340   should be compiled the 2018 edition of Rust.
1341 - [You can now provide custom themes to rustdoc with `--theme`, and check the
1342   current theme with `--check-theme`.][54733]
1343 - [You can use `#[cfg(doc)]` to compile an item when building documentation.][61351]
1344
1345 Compatibility Notes
1346 -------------------
1347
1348 - [As previously announced 1.41.0 will be the last tier 1 release for 32-bit
1349   Apple targets.][apple-32bit-drop] This means that the source code is still
1350   available to build, but the targets are no longer being tested and release
1351   binaries for those platforms will no longer be distributed by the Rust project.
1352   Please refer to the linked blog post for more information.
1353
1354 [54733]: https://github.com/rust-lang/rust/pull/54733/
1355 [61351]: https://github.com/rust-lang/rust/pull/61351/
1356 [67255]: https://github.com/rust-lang/rust/pull/67255/
1357 [66661]: https://github.com/rust-lang/rust/pull/66661/
1358 [66771]: https://github.com/rust-lang/rust/pull/66771/
1359 [66847]: https://github.com/rust-lang/rust/pull/66847/
1360 [66238]: https://github.com/rust-lang/rust/pull/66238/
1361 [66277]: https://github.com/rust-lang/rust/pull/66277/
1362 [66325]: https://github.com/rust-lang/rust/pull/66325/
1363 [66172]: https://github.com/rust-lang/rust/pull/66172/
1364 [66183]: https://github.com/rust-lang/rust/pull/66183/
1365 [65879]: https://github.com/rust-lang/rust/pull/65879/
1366 [65013]: https://github.com/rust-lang/rust/pull/65013/
1367 [64882]: https://github.com/rust-lang/rust/pull/64882/
1368 [64325]: https://github.com/rust-lang/rust/pull/64325/
1369 [cargo/7560]: https://github.com/rust-lang/cargo/pull/7560/
1370 [cargo/7579]: https://github.com/rust-lang/cargo/pull/7579/
1371 [cargo/7591]: https://github.com/rust-lang/cargo/pull/7591/
1372 [cargo/7593]: https://github.com/rust-lang/cargo/pull/7593/
1373 [`Result::map_or_else`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.map_or_else
1374 [`Result::map_or`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.map_or
1375 [`std::rc::Weak::weak_count`]: https://doc.rust-lang.org/std/rc/struct.Weak.html#method.weak_count
1376 [`std::rc::Weak::strong_count`]: https://doc.rust-lang.org/std/rc/struct.Weak.html#method.strong_count
1377 [`std::sync::Weak::weak_count`]: https://doc.rust-lang.org/std/sync/struct.Weak.html#method.weak_count
1378 [`std::sync::Weak::strong_count`]: https://doc.rust-lang.org/std/sync/struct.Weak.html#method.strong_count
1379 [apple-32bit-drop]: https://blog.rust-lang.org/2020/01/03/reducing-support-for-32-bit-apple-targets.html
1380
1381 Version 1.40.0 (2019-12-19)
1382 ===========================
1383
1384 Language
1385 --------
1386 - [You can now use tuple `struct`s and tuple `enum` variant's constructors in
1387   `const` contexts.][65188] e.g.
1388
1389   ```rust
1390   pub struct Point(i32, i32);
1391
1392   const ORIGIN: Point = {
1393       let constructor = Point;
1394
1395       constructor(0, 0)
1396   };
1397   ```
1398
1399 - [You can now mark `struct`s, `enum`s, and `enum` variants with the `#[non_exhaustive]` attribute to
1400   indicate that there may be variants or fields added in the future.][64639]
1401   For example this requires adding a wild-card branch (`_ => {}`) to any match
1402   statements on a non-exhaustive `enum`. [(RFC 2008)]
1403 - [You can now use function-like procedural macros in `extern` blocks and in
1404   type positions.][63931] e.g. `type Generated = macro!();`
1405 - [Function-like and attribute procedural macros can now emit
1406   `macro_rules!` items, so you can now have your macros generate macros.][64035]
1407 - [The `meta` pattern matcher in `macro_rules!` now correctly matches the modern
1408   attribute syntax.][63674] For example `(#[$m:meta])` now matches `#[attr]`,
1409   `#[attr{tokens}]`, `#[attr[tokens]]`, and `#[attr(tokens)]`.
1410
1411 Compiler
1412 --------
1413 - [Added tier 3 support\* for the
1414   `thumbv7neon-unknown-linux-musleabihf` target.][66103]
1415 - [Added tier 3 support for the
1416   `aarch64-unknown-none-softfloat` target.][64589]
1417 - [Added tier 3 support for the `mips64-unknown-linux-muslabi64`, and
1418   `mips64el-unknown-linux-muslabi64` targets.][65843]
1419
1420 \* Refer to Rust's [platform support page][forge-platform-support] for more
1421   information on Rust's tiered platform support.
1422
1423 Libraries
1424 ---------
1425 - [The `is_power_of_two` method on unsigned numeric types is now a `const` function.][65092]
1426
1427 Stabilized APIs
1428 ---------------
1429 - [`BTreeMap::get_key_value`]
1430 - [`HashMap::get_key_value`]
1431 - [`Option::as_deref_mut`]
1432 - [`Option::as_deref`]
1433 - [`Option::flatten`]
1434 - [`UdpSocket::peer_addr`]
1435 - [`f32::to_be_bytes`]
1436 - [`f32::to_le_bytes`]
1437 - [`f32::to_ne_bytes`]
1438 - [`f64::to_be_bytes`]
1439 - [`f64::to_le_bytes`]
1440 - [`f64::to_ne_bytes`]
1441 - [`f32::from_be_bytes`]
1442 - [`f32::from_le_bytes`]
1443 - [`f32::from_ne_bytes`]
1444 - [`f64::from_be_bytes`]
1445 - [`f64::from_le_bytes`]
1446 - [`f64::from_ne_bytes`]
1447 - [`mem::take`]
1448 - [`slice::repeat`]
1449 - [`todo!`]
1450
1451 Cargo
1452 -----
1453 - [Cargo will now always display warnings, rather than only on
1454   fresh builds.][cargo/7450]
1455 - [Feature flags (except `--all-features`) passed to a virtual workspace will
1456   now produce an error.][cargo/7507] Previously these flags were ignored.
1457 - [You can now publish `dev-dependencies` without including
1458   a `version`.][cargo/7333]
1459
1460 Misc
1461 ----
1462 - [You can now specify the `#[cfg(doctest)]` attribute to include an item only
1463   when running documentation tests with `rustdoc`.][63803]
1464
1465 Compatibility Notes
1466 -------------------
1467 - [As previously announced, any previous NLL warnings in the 2015 edition are
1468   now hard errors.][64221]
1469 - [The `include!` macro will now warn if it failed to include the
1470   entire file.][64284] The `include!` macro unintentionally only includes the
1471   first _expression_ in a file, and this can be unintuitive. This will become
1472   either a hard error in a future release, or the behavior may be fixed to include all expressions as expected.
1473 - [Using `#[inline]` on function prototypes and consts now emits a warning under
1474   `unused_attribute` lint.][65294] Using `#[inline]` anywhere else inside traits
1475   or `extern` blocks now correctly emits a hard error.
1476
1477 [65294]: https://github.com/rust-lang/rust/pull/65294/
1478 [66103]: https://github.com/rust-lang/rust/pull/66103/
1479 [65843]: https://github.com/rust-lang/rust/pull/65843/
1480 [65188]: https://github.com/rust-lang/rust/pull/65188/
1481 [65092]: https://github.com/rust-lang/rust/pull/65092/
1482 [64589]: https://github.com/rust-lang/rust/pull/64589/
1483 [64639]: https://github.com/rust-lang/rust/pull/64639/
1484 [64221]: https://github.com/rust-lang/rust/pull/64221/
1485 [64284]: https://github.com/rust-lang/rust/pull/64284/
1486 [63931]: https://github.com/rust-lang/rust/pull/63931/
1487 [64035]: https://github.com/rust-lang/rust/pull/64035/
1488 [63674]: https://github.com/rust-lang/rust/pull/63674/
1489 [63803]: https://github.com/rust-lang/rust/pull/63803/
1490 [cargo/7450]: https://github.com/rust-lang/cargo/pull/7450/
1491 [cargo/7507]: https://github.com/rust-lang/cargo/pull/7507/
1492 [cargo/7525]: https://github.com/rust-lang/cargo/pull/7525/
1493 [cargo/7333]: https://github.com/rust-lang/cargo/pull/7333/
1494 [(rfc 2008)]: https://rust-lang.github.io/rfcs/2008-non-exhaustive.html
1495 [`f32::to_be_bytes`]: https://doc.rust-lang.org/std/primitive.f32.html#method.to_be_bytes
1496 [`f32::to_le_bytes`]: https://doc.rust-lang.org/std/primitive.f32.html#method.to_le_bytes
1497 [`f32::to_ne_bytes`]: https://doc.rust-lang.org/std/primitive.f32.html#method.to_ne_bytes
1498 [`f64::to_be_bytes`]: https://doc.rust-lang.org/std/primitive.f64.html#method.to_be_bytes
1499 [`f64::to_le_bytes`]: https://doc.rust-lang.org/std/primitive.f64.html#method.to_le_bytes
1500 [`f64::to_ne_bytes`]: https://doc.rust-lang.org/std/primitive.f64.html#method.to_ne_bytes
1501 [`f32::from_be_bytes`]: https://doc.rust-lang.org/std/primitive.f32.html#method.from_be_bytes
1502 [`f32::from_le_bytes`]: https://doc.rust-lang.org/std/primitive.f32.html#method.from_le_bytes
1503 [`f32::from_ne_bytes`]: https://doc.rust-lang.org/std/primitive.f32.html#method.from_ne_bytes
1504 [`f64::from_be_bytes`]: https://doc.rust-lang.org/std/primitive.f64.html#method.from_be_bytes
1505 [`f64::from_le_bytes`]: https://doc.rust-lang.org/std/primitive.f64.html#method.from_le_bytes
1506 [`f64::from_ne_bytes`]: https://doc.rust-lang.org/std/primitive.f64.html#method.from_ne_bytes
1507 [`option::flatten`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.flatten
1508 [`option::as_deref`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.as_deref
1509 [`option::as_deref_mut`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.as_deref_mut
1510 [`hashmap::get_key_value`]: https://doc.rust-lang.org/std/collections/struct.HashMap.html#method.get_key_value
1511 [`btreemap::get_key_value`]: https://doc.rust-lang.org/std/collections/struct.BTreeMap.html#method.get_key_value
1512 [`slice::repeat`]: https://doc.rust-lang.org/std/primitive.slice.html#method.repeat
1513 [`mem::take`]: https://doc.rust-lang.org/std/mem/fn.take.html
1514 [`udpsocket::peer_addr`]: https://doc.rust-lang.org/std/net/struct.UdpSocket.html#method.peer_addr
1515 [`todo!`]: https://doc.rust-lang.org/std/macro.todo.html
1516
1517
1518 Version 1.39.0 (2019-11-07)
1519 ===========================
1520
1521 Language
1522 --------
1523 - [You can now create `async` functions and blocks with `async fn`, `async move {}`, and
1524   `async {}` respectively, and you can now call `.await` on async expressions.][63209]
1525 - [You can now use certain attributes on function, closure, and function pointer
1526   parameters.][64010] These attributes include `cfg`, `cfg_attr`, `allow`, `warn`,
1527   `deny`, `forbid` as well as inert helper attributes used by procedural macro
1528   attributes applied to items. e.g.
1529   ```rust
1530   fn len(
1531       #[cfg(windows)] slice: &[u16],
1532       #[cfg(not(windows))] slice: &[u8],
1533   ) -> usize {
1534       slice.len()
1535   }
1536   ```
1537 - [You can now take shared references to bind-by-move patterns in the `if` guards
1538   of `match` arms.][63118] e.g.
1539   ```rust
1540   fn main() {
1541       let array: Box<[u8; 4]> = Box::new([1, 2, 3, 4]);
1542
1543       match array {
1544           nums
1545   //      ---- `nums` is bound by move.
1546               if nums.iter().sum::<u8>() == 10
1547   //                 ^------ `.iter()` implicitly takes a reference to `nums`.
1548           => {
1549               drop(nums);
1550   //          ----------- Legal as `nums` was bound by move and so we have ownership.
1551           }
1552           _ => unreachable!(),
1553       }
1554   }
1555   ```
1556
1557
1558
1559 Compiler
1560 --------
1561 - [Added tier 3\* support for the `i686-unknown-uefi` target.][64334]
1562 - [Added tier 3 support for the `sparc64-unknown-openbsd` target.][63595]
1563 - [rustc will now trim code snippets in diagnostics to fit in your terminal.][63402]
1564   **Note** Cargo currently doesn't use this feature. Refer to
1565   [cargo#7315][cargo/7315] to track this feature's progress.
1566 - [You can now pass `--show-output` argument to test binaries to print the
1567   output of successful tests.][62600]
1568
1569
1570 \* Refer to Rust's [platform support page][forge-platform-support] for more
1571 information on Rust's tiered platform support.
1572
1573 Libraries
1574 ---------
1575 - [`Vec::new` and `String::new` are now `const` functions.][64028]
1576 - [`LinkedList::new` is now a `const` function.][63684]
1577 - [`str::len`, `[T]::len` and `str::as_bytes` are now `const` functions.][63770]
1578 - [The `abs`, `wrapping_abs`, and `overflowing_abs` numeric functions are
1579   now `const`.][63786]
1580
1581 Stabilized APIs
1582 ---------------
1583 - [`Pin::into_inner`]
1584 - [`Instant::checked_duration_since`]
1585 - [`Instant::saturating_duration_since`]
1586
1587 Cargo
1588 -----
1589 - [You can now publish git dependencies if supplied with a `version`.][cargo/7237]
1590 - [The `--all` flag has been renamed to `--workspace`.][cargo/7241] Using
1591   `--all` is now deprecated.
1592
1593 Misc
1594 ----
1595 - [You can now pass `-Clinker` to rustdoc to control the linker used
1596   for compiling doctests.][63834]
1597
1598 Compatibility Notes
1599 -------------------
1600 - [Code that was previously accepted by the old borrow checker, but rejected by
1601   the NLL borrow checker is now a hard error in Rust 2018.][63565] This was
1602   previously a warning, and will also become a hard error in the Rust 2015
1603   edition in the 1.40.0 release.
1604 - [`rustdoc` now requires `rustc` to be installed and in the same directory to
1605   run tests.][63827] This should improve performance when running a large
1606   amount of doctests.
1607 - [The `try!` macro will now issue a deprecation warning.][62672] It is
1608   recommended to use the `?` operator instead.
1609 - [`asinh(-0.0)` now correctly returns `-0.0`.][63698] Previously this
1610   returned `0.0`.
1611
1612 [62600]: https://github.com/rust-lang/rust/pull/62600/
1613 [62672]: https://github.com/rust-lang/rust/pull/62672/
1614 [63118]: https://github.com/rust-lang/rust/pull/63118/
1615 [63209]: https://github.com/rust-lang/rust/pull/63209/
1616 [63402]: https://github.com/rust-lang/rust/pull/63402/
1617 [63565]: https://github.com/rust-lang/rust/pull/63565/
1618 [63595]: https://github.com/rust-lang/rust/pull/63595/
1619 [63684]: https://github.com/rust-lang/rust/pull/63684/
1620 [63698]: https://github.com/rust-lang/rust/pull/63698/
1621 [63770]: https://github.com/rust-lang/rust/pull/63770/
1622 [63786]: https://github.com/rust-lang/rust/pull/63786/
1623 [63827]: https://github.com/rust-lang/rust/pull/63827/
1624 [63834]: https://github.com/rust-lang/rust/pull/63834/
1625 [63927]: https://github.com/rust-lang/rust/pull/63927/
1626 [63933]: https://github.com/rust-lang/rust/pull/63933/
1627 [63934]: https://github.com/rust-lang/rust/pull/63934/
1628 [63938]: https://github.com/rust-lang/rust/pull/63938/
1629 [63940]: https://github.com/rust-lang/rust/pull/63940/
1630 [63941]: https://github.com/rust-lang/rust/pull/63941/
1631 [63945]: https://github.com/rust-lang/rust/pull/63945/
1632 [64010]: https://github.com/rust-lang/rust/pull/64010/
1633 [64028]: https://github.com/rust-lang/rust/pull/64028/
1634 [64334]: https://github.com/rust-lang/rust/pull/64334/
1635 [cargo/7237]: https://github.com/rust-lang/cargo/pull/7237/
1636 [cargo/7241]: https://github.com/rust-lang/cargo/pull/7241/
1637 [cargo/7315]: https://github.com/rust-lang/cargo/pull/7315/
1638 [`Pin::into_inner`]: https://doc.rust-lang.org/std/pin/struct.Pin.html#method.into_inner
1639 [`Instant::checked_duration_since`]: https://doc.rust-lang.org/std/time/struct.Instant.html#method.checked_duration_since
1640 [`Instant::saturating_duration_since`]: https://doc.rust-lang.org/std/time/struct.Instant.html#method.saturating_duration_since
1641
1642 Version 1.38.0 (2019-09-26)
1643 ==========================
1644
1645 Language
1646 --------
1647 - [The `#[global_allocator]` attribute can now be used in submodules.][62735]
1648 - [The `#[deprecated]` attribute can now be used on macros.][62042]
1649
1650 Compiler
1651 --------
1652 - [Added pipelined compilation support to `rustc`.][62766] This will
1653   improve compilation times in some cases. For further information please refer
1654   to the [_"Evaluating pipelined rustc compilation"_][pipeline-internals] thread.
1655 - [Added tier 3\* support for the `aarch64-uwp-windows-msvc`, `i686-uwp-windows-gnu`,
1656   `i686-uwp-windows-msvc`, `x86_64-uwp-windows-gnu`, and
1657   `x86_64-uwp-windows-msvc` targets.][60260]
1658 - [Added tier 3 support for the `armv7-unknown-linux-gnueabi` and
1659   `armv7-unknown-linux-musleabi` targets.][63107]
1660 - [Added tier 3 support for the `hexagon-unknown-linux-musl` target.][62814]
1661 - [Added tier 3 support for the `riscv32i-unknown-none-elf` target.][62784]
1662 - [Upgraded to LLVM 9.][62592]
1663
1664 \* Refer to Rust's [platform support page][forge-platform-support] for more
1665 information on Rust's tiered platform support.
1666
1667 Libraries
1668 ---------
1669 - [`ascii::EscapeDefault` now implements `Clone` and `Display`.][63421]
1670 - [Derive macros for prelude traits (e.g. `Clone`, `Debug`, `Hash`) are now
1671   available at the same path as the trait.][63056] (e.g. The `Clone` derive macro
1672   is available at `std::clone::Clone`). This also makes all built-in macros
1673   available in `std`/`core` root. e.g. `std::include_bytes!`.
1674 - [`str::Chars` now implements `Debug`.][63000]
1675 - [`slice::{concat, connect, join}` now accepts `&[T]` in addition to `&T`.][62528]
1676 - [`*const T` and `*mut T` now implement `marker::Unpin`.][62583]
1677 - [`Arc<[T]>` and `Rc<[T]>` now implement `FromIterator<T>`.][61953]
1678 - [Added euclidean remainder and division operations (`div_euclid`,
1679   `rem_euclid`) to all numeric primitives.][61884] Additionally `checked`,
1680   `overflowing`, and `wrapping` versions are available for all
1681   integer primitives.
1682 - [`thread::AccessError` now implements `Clone`, `Copy`, `Eq`, `Error`, and
1683   `PartialEq`.][61491]
1684 - [`iter::{StepBy, Peekable, Take}` now implement `DoubleEndedIterator`.][61457]
1685
1686 Stabilized APIs
1687 ---------------
1688 - [`<*const T>::cast`]
1689 - [`<*mut T>::cast`]
1690 - [`Duration::as_secs_f32`]
1691 - [`Duration::as_secs_f64`]
1692 - [`Duration::div_f32`]
1693 - [`Duration::div_f64`]
1694 - [`Duration::from_secs_f32`]
1695 - [`Duration::from_secs_f64`]
1696 - [`Duration::mul_f32`]
1697 - [`Duration::mul_f64`]
1698 - [`any::type_name`]
1699
1700 Cargo
1701 -----
1702 - [Added pipelined compilation support to `cargo`.][cargo/7143]
1703 - [You can now pass the `--features` option multiple times to enable
1704   multiple features.][cargo/7084]
1705
1706 Misc
1707 ----
1708 - [`rustc` will now warn about some incorrect uses of
1709   `mem::{uninitialized, zeroed}` that are known to cause undefined behaviour.][63346]
1710
1711 Compatibility Notes
1712 -------------------
1713 - The [`x86_64-unknown-uefi` platform can not be built][62785] with rustc
1714   1.38.0.
1715 - The [`armv7-unknown-linux-gnueabihf` platform is known to have
1716   issues][62896] with certain crates such as libc.
1717
1718 [60260]: https://github.com/rust-lang/rust/pull/60260/
1719 [61457]: https://github.com/rust-lang/rust/pull/61457/
1720 [61491]: https://github.com/rust-lang/rust/pull/61491/
1721 [61884]: https://github.com/rust-lang/rust/pull/61884/
1722 [61953]: https://github.com/rust-lang/rust/pull/61953/
1723 [62042]: https://github.com/rust-lang/rust/pull/62042/
1724 [62528]: https://github.com/rust-lang/rust/pull/62528/
1725 [62583]: https://github.com/rust-lang/rust/pull/62583/
1726 [62735]: https://github.com/rust-lang/rust/pull/62735/
1727 [62766]: https://github.com/rust-lang/rust/pull/62766/
1728 [62784]: https://github.com/rust-lang/rust/pull/62784/
1729 [62592]: https://github.com/rust-lang/rust/pull/62592/
1730 [62785]: https://github.com/rust-lang/rust/issues/62785/
1731 [62814]: https://github.com/rust-lang/rust/pull/62814/
1732 [62896]: https://github.com/rust-lang/rust/issues/62896/
1733 [63000]: https://github.com/rust-lang/rust/pull/63000/
1734 [63056]: https://github.com/rust-lang/rust/pull/63056/
1735 [63107]: https://github.com/rust-lang/rust/pull/63107/
1736 [63346]: https://github.com/rust-lang/rust/pull/63346/
1737 [63421]: https://github.com/rust-lang/rust/pull/63421/
1738 [cargo/7084]: https://github.com/rust-lang/cargo/pull/7084/
1739 [cargo/7143]: https://github.com/rust-lang/cargo/pull/7143/
1740 [`<*const T>::cast`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.cast
1741 [`<*mut T>::cast`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.cast
1742 [`Duration::as_secs_f32`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.as_secs_f32
1743 [`Duration::as_secs_f64`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.as_secs_f64
1744 [`Duration::div_f32`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.div_f32
1745 [`Duration::div_f64`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.div_f64
1746 [`Duration::from_secs_f32`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.from_secs_f32
1747 [`Duration::from_secs_f64`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.from_secs_f64
1748 [`Duration::mul_f32`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.mul_f32
1749 [`Duration::mul_f64`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.mul_f64
1750 [`any::type_name`]: https://doc.rust-lang.org/std/any/fn.type_name.html
1751 [forge-platform-support]: https://forge.rust-lang.org/release/platform-support.html
1752 [pipeline-internals]: https://internals.rust-lang.org/t/evaluating-pipelined-rustc-compilation/10199
1753
1754 Version 1.37.0 (2019-08-15)
1755 ==========================
1756
1757 Language
1758 --------
1759 - `#[must_use]` will now warn if the type is contained in a [tuple][61100],
1760   [`Box`][62228], or an [array][62235] and unused.
1761 - [You can now use the `cfg` and `cfg_attr` attributes on
1762   generic parameters.][61547]
1763 - [You can now use enum variants through type alias.][61682] e.g. You can
1764   write the following:
1765   ```rust
1766   type MyOption = Option<u8>;
1767
1768   fn increment_or_zero(x: MyOption) -> u8 {
1769       match x {
1770           MyOption::Some(y) => y + 1,
1771           MyOption::None => 0,
1772       }
1773   }
1774   ```
1775 - [You can now use `_` as an identifier for consts.][61347] e.g. You can write
1776   `const _: u32 = 5;`.
1777 - [You can now use `#[repr(align(X)]` on enums.][61229]
1778 - [The  `?` Kleene macro operator is now available in the
1779   2015 edition.][60932]
1780
1781 Compiler
1782 --------
1783 - [You can now enable Profile-Guided Optimization with the `-C profile-generate`
1784   and `-C profile-use` flags.][61268] For more information on how to use profile
1785   guided optimization, please refer to the [rustc book][rustc-book-pgo].
1786 - [The `rust-lldb` wrapper script should now work again.][61827]
1787
1788 Libraries
1789 ---------
1790 - [`mem::MaybeUninit<T>` is now ABI-compatible with `T`.][61802]
1791
1792 Stabilized APIs
1793 ---------------
1794 - [`BufReader::buffer`]
1795 - [`BufWriter::buffer`]
1796 - [`Cell::from_mut`]
1797 - [`Cell<[T]>::as_slice_of_cells`][`Cell<slice>::as_slice_of_cells`]
1798 - [`DoubleEndedIterator::nth_back`]
1799 - [`Option::xor`]
1800 - [`Wrapping::reverse_bits`]
1801 - [`i128::reverse_bits`]
1802 - [`i16::reverse_bits`]
1803 - [`i32::reverse_bits`]
1804 - [`i64::reverse_bits`]
1805 - [`i8::reverse_bits`]
1806 - [`isize::reverse_bits`]
1807 - [`slice::copy_within`]
1808 - [`u128::reverse_bits`]
1809 - [`u16::reverse_bits`]
1810 - [`u32::reverse_bits`]
1811 - [`u64::reverse_bits`]
1812 - [`u8::reverse_bits`]
1813 - [`usize::reverse_bits`]
1814
1815 Cargo
1816 -----
1817 - [`Cargo.lock` files are now included by default when publishing executable crates
1818   with executables.][cargo/7026]
1819 - [You can now specify `default-run="foo"` in `[package]` to specify the
1820   default executable to use for `cargo run`.][cargo/7056]
1821
1822 Misc
1823 ----
1824
1825 Compatibility Notes
1826 -------------------
1827 - [Using `...` for inclusive range patterns will now warn by default.][61342]
1828   Please transition your code to using the `..=` syntax for inclusive
1829   ranges instead.
1830 - [Using a trait object without the `dyn` will now warn by default.][61203]
1831   Please transition your code to use `dyn Trait` for trait objects instead.
1832
1833 [62228]: https://github.com/rust-lang/rust/pull/62228/
1834 [62235]: https://github.com/rust-lang/rust/pull/62235/
1835 [61802]: https://github.com/rust-lang/rust/pull/61802/
1836 [61827]: https://github.com/rust-lang/rust/pull/61827/
1837 [61547]: https://github.com/rust-lang/rust/pull/61547/
1838 [61682]: https://github.com/rust-lang/rust/pull/61682/
1839 [61268]: https://github.com/rust-lang/rust/pull/61268/
1840 [61342]: https://github.com/rust-lang/rust/pull/61342/
1841 [61347]: https://github.com/rust-lang/rust/pull/61347/
1842 [61100]: https://github.com/rust-lang/rust/pull/61100/
1843 [61203]: https://github.com/rust-lang/rust/pull/61203/
1844 [61229]: https://github.com/rust-lang/rust/pull/61229/
1845 [60932]: https://github.com/rust-lang/rust/pull/60932/
1846 [cargo/7026]: https://github.com/rust-lang/cargo/pull/7026/
1847 [cargo/7056]: https://github.com/rust-lang/cargo/pull/7056/
1848 [`BufReader::buffer`]: https://doc.rust-lang.org/std/io/struct.BufReader.html#method.buffer
1849 [`BufWriter::buffer`]: https://doc.rust-lang.org/std/io/struct.BufWriter.html#method.buffer
1850 [`Cell::from_mut`]: https://doc.rust-lang.org/std/cell/struct.Cell.html#method.from_mut
1851 [`Cell<slice>::as_slice_of_cells`]: https://doc.rust-lang.org/std/cell/struct.Cell.html#method.as_slice_of_cells
1852 [`DoubleEndedIterator::nth_back`]: https://doc.rust-lang.org/std/iter/trait.DoubleEndedIterator.html#method.nth_back
1853 [`Option::xor`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.xor
1854 [`RefCell::try_borrow_unguarded`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.try_borrow_unguarded
1855 [`Wrapping::reverse_bits`]: https://doc.rust-lang.org/std/num/struct.Wrapping.html#method.reverse_bits
1856 [`i128::reverse_bits`]: https://doc.rust-lang.org/std/primitive.i128.html#method.reverse_bits
1857 [`i16::reverse_bits`]: https://doc.rust-lang.org/std/primitive.i16.html#method.reverse_bits
1858 [`i32::reverse_bits`]: https://doc.rust-lang.org/std/primitive.i32.html#method.reverse_bits
1859 [`i64::reverse_bits`]: https://doc.rust-lang.org/std/primitive.i64.html#method.reverse_bits
1860 [`i8::reverse_bits`]: https://doc.rust-lang.org/std/primitive.i8.html#method.reverse_bits
1861 [`isize::reverse_bits`]: https://doc.rust-lang.org/std/primitive.isize.html#method.reverse_bits
1862 [`slice::copy_within`]: https://doc.rust-lang.org/std/primitive.slice.html#method.copy_within
1863 [`u128::reverse_bits`]: https://doc.rust-lang.org/std/primitive.u128.html#method.reverse_bits
1864 [`u16::reverse_bits`]: https://doc.rust-lang.org/std/primitive.u16.html#method.reverse_bits
1865 [`u32::reverse_bits`]: https://doc.rust-lang.org/std/primitive.u32.html#method.reverse_bits
1866 [`u64::reverse_bits`]: https://doc.rust-lang.org/std/primitive.u64.html#method.reverse_bits
1867 [`u8::reverse_bits`]: https://doc.rust-lang.org/std/primitive.u8.html#method.reverse_bits
1868 [`usize::reverse_bits`]: https://doc.rust-lang.org/std/primitive.usize.html#method.reverse_bits
1869 [rustc-book-pgo]: https://doc.rust-lang.org/rustc/profile-guided-optimization.html
1870
1871
1872 Version 1.36.0 (2019-07-04)
1873 ==========================
1874
1875 Language
1876 --------
1877 - [Non-Lexical Lifetimes are now enabled on the 2015 edition.][59114]
1878 - [The order of traits in trait objects no longer affects the semantics of that
1879   object.][59445] e.g. `dyn Send + fmt::Debug` is now equivalent to
1880   `dyn fmt::Debug + Send`, where this was previously not the case.
1881
1882 Libraries
1883 ---------
1884 - [`HashMap`'s implementation has been replaced with `hashbrown::HashMap` implementation.][58623]
1885 - [`TryFromSliceError` now implements `From<Infallible>`.][60318]
1886 - [`mem::needs_drop` is now available as a const fn.][60364]
1887 - [`alloc::Layout::from_size_align_unchecked` is now available as a const fn.][60370]
1888 - [`String` now implements `BorrowMut<str>`.][60404]
1889 - [`io::Cursor` now implements `Default`.][60234]
1890 - [Both `NonNull::{dangling, cast}` are now const fns.][60244]
1891 - [The `alloc` crate is now stable.][59675] `alloc` allows you to use a subset
1892   of `std` (e.g. `Vec`, `Box`, `Arc`) in `#![no_std]` environments if the
1893   environment has access to heap memory allocation.
1894 - [`String` now implements `From<&String>`.][59825]
1895 - [You can now pass multiple arguments to the `dbg!` macro.][59826] `dbg!` will
1896   return a tuple of each argument when there is multiple arguments.
1897 - [`Result::{is_err, is_ok}` are now `#[must_use]` and will produce a warning if
1898   not used.][59648]
1899
1900 Stabilized APIs
1901 ---------------
1902 - [`VecDeque::rotate_left`]
1903 - [`VecDeque::rotate_right`]
1904 - [`Iterator::copied`]
1905 - [`io::IoSlice`]
1906 - [`io::IoSliceMut`]
1907 - [`Read::read_vectored`]
1908 - [`Write::write_vectored`]
1909 - [`str::as_mut_ptr`]
1910 - [`mem::MaybeUninit`]
1911 - [`pointer::align_offset`]
1912 - [`future::Future`]
1913 - [`task::Context`]
1914 - [`task::RawWaker`]
1915 - [`task::RawWakerVTable`]
1916 - [`task::Waker`]
1917 - [`task::Poll`]
1918
1919 Cargo
1920 -----
1921 - [Cargo will now produce an error if you attempt to use the name of a required dependency as a feature.][cargo/6860]
1922 - [You can now pass the `--offline` flag to run cargo without accessing the network.][cargo/6934]
1923
1924 You can find further change's in [Cargo's 1.36.0 release notes][cargo-1-36-0].
1925
1926 Clippy
1927 ------
1928 There have been numerous additions and fixes to clippy, see [Clippy's 1.36.0 release notes][clippy-1-36-0] for more details.
1929
1930 Misc
1931 ----
1932
1933 Compatibility Notes
1934 -------------------
1935 - With the stabilisation of `mem::MaybeUninit`, `mem::uninitialized` use is no
1936   longer recommended, and will be deprecated in 1.39.0.
1937
1938 [60318]: https://github.com/rust-lang/rust/pull/60318/
1939 [60364]: https://github.com/rust-lang/rust/pull/60364/
1940 [60370]: https://github.com/rust-lang/rust/pull/60370/
1941 [60404]: https://github.com/rust-lang/rust/pull/60404/
1942 [60234]: https://github.com/rust-lang/rust/pull/60234/
1943 [60244]: https://github.com/rust-lang/rust/pull/60244/
1944 [58623]: https://github.com/rust-lang/rust/pull/58623/
1945 [59648]: https://github.com/rust-lang/rust/pull/59648/
1946 [59675]: https://github.com/rust-lang/rust/pull/59675/
1947 [59825]: https://github.com/rust-lang/rust/pull/59825/
1948 [59826]: https://github.com/rust-lang/rust/pull/59826/
1949 [59445]: https://github.com/rust-lang/rust/pull/59445/
1950 [59114]: https://github.com/rust-lang/rust/pull/59114/
1951 [cargo/6860]: https://github.com/rust-lang/cargo/pull/6860/
1952 [cargo/6934]: https://github.com/rust-lang/cargo/pull/6934/
1953 [`VecDeque::rotate_left`]: https://doc.rust-lang.org/std/collections/struct.VecDeque.html#method.rotate_left
1954 [`VecDeque::rotate_right`]: https://doc.rust-lang.org/std/collections/struct.VecDeque.html#method.rotate_right
1955 [`Iterator::copied`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#tymethod.copied
1956 [`io::IoSlice`]: https://doc.rust-lang.org/std/io/struct.IoSlice.html
1957 [`io::IoSliceMut`]: https://doc.rust-lang.org/std/io/struct.IoSliceMut.html
1958 [`Read::read_vectored`]: https://doc.rust-lang.org/std/io/trait.Read.html#method.read_vectored
1959 [`Write::write_vectored`]: https://doc.rust-lang.org/std/io/trait.Write.html#method.write_vectored
1960 [`str::as_mut_ptr`]: https://doc.rust-lang.org/std/primitive.str.html#method.as_mut_ptr
1961 [`mem::MaybeUninit`]: https://doc.rust-lang.org/std/mem/union.MaybeUninit.html
1962 [`pointer::align_offset`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.align_offset
1963 [`future::Future`]: https://doc.rust-lang.org/std/future/trait.Future.html
1964 [`task::Context`]: https://doc.rust-lang.org/beta/std/task/struct.Context.html
1965 [`task::RawWaker`]: https://doc.rust-lang.org/beta/std/task/struct.RawWaker.html
1966 [`task::RawWakerVTable`]: https://doc.rust-lang.org/beta/std/task/struct.RawWakerVTable.html
1967 [`task::Waker`]: https://doc.rust-lang.org/beta/std/task/struct.Waker.html
1968 [`task::Poll`]: https://doc.rust-lang.org/beta/std/task/enum.Poll.html
1969 [clippy-1-36-0]: https://github.com/rust-lang/rust-clippy/blob/master/CHANGELOG.md#rust-136
1970 [cargo-1-36-0]: https://github.com/rust-lang/cargo/blob/master/CHANGELOG.md#cargo-136-2019-07-04
1971
1972
1973 Version 1.35.0 (2019-05-23)
1974 ==========================
1975
1976 Language
1977 --------
1978 - [`FnOnce`, `FnMut`, and the `Fn` traits are now implemented for `Box<FnOnce>`,
1979   `Box<FnMut>`, and `Box<Fn>` respectively.][59500]
1980 - [You can now coerce closures into unsafe function pointers.][59580] e.g.
1981   ```rust
1982   unsafe fn call_unsafe(func: unsafe fn()) {
1983       func()
1984   }
1985
1986   pub fn main() {
1987       unsafe { call_unsafe(|| {}); }
1988   }
1989   ```
1990
1991
1992 Compiler
1993 --------
1994 - [Added the `armv6-unknown-freebsd-gnueabihf` and
1995   `armv7-unknown-freebsd-gnueabihf` targets.][58080]
1996 - [Added the `wasm32-unknown-wasi` target.][59464]
1997
1998
1999 Libraries
2000 ---------
2001 - [`Thread` will now show its ID in `Debug` output.][59460]
2002 - [`StdinLock`, `StdoutLock`, and `StderrLock` now implement `AsRawFd`.][59512]
2003 - [`alloc::System` now implements `Default`.][59451]
2004 - [Expanded `Debug` output (`{:#?}`) for structs now has a trailing comma on the
2005   last field.][59076]
2006 - [`char::{ToLowercase, ToUppercase}` now
2007   implement `ExactSizeIterator`.][58778]
2008 - [All `NonZero` numeric types now implement `FromStr`.][58717]
2009 - [Removed the `Read` trait bounds
2010   on the `BufReader::{get_ref, get_mut, into_inner}` methods.][58423]
2011 - [You can now call the `dbg!` macro without any parameters to print the file
2012   and line where it is called.][57847]
2013 - [In place ASCII case conversions are now up to 4× faster.][59283]
2014   e.g. `str::make_ascii_lowercase`
2015 - [`hash_map::{OccupiedEntry, VacantEntry}` now implement `Sync`
2016   and `Send`.][58369]
2017
2018 Stabilized APIs
2019 ---------------
2020 - [`f32::copysign`]
2021 - [`f64::copysign`]
2022 - [`RefCell::replace_with`]
2023 - [`RefCell::map_split`]
2024 - [`ptr::hash`]
2025 - [`Range::contains`]
2026 - [`RangeFrom::contains`]
2027 - [`RangeTo::contains`]
2028 - [`RangeInclusive::contains`]
2029 - [`RangeToInclusive::contains`]
2030 - [`Option::copied`]
2031
2032 Cargo
2033 -----
2034 - [You can now set `cargo:rustc-cdylib-link-arg` at build time to pass custom
2035   linker arguments when building a `cdylib`.][cargo/6298] Its usage is highly
2036   platform specific.
2037
2038 Misc
2039 ----
2040 - [The Rust toolchain is now available natively for musl based distros.][58575]
2041
2042 [59460]: https://github.com/rust-lang/rust/pull/59460/
2043 [59464]: https://github.com/rust-lang/rust/pull/59464/
2044 [59500]: https://github.com/rust-lang/rust/pull/59500/
2045 [59512]: https://github.com/rust-lang/rust/pull/59512/
2046 [59580]: https://github.com/rust-lang/rust/pull/59580/
2047 [59283]: https://github.com/rust-lang/rust/pull/59283/
2048 [59451]: https://github.com/rust-lang/rust/pull/59451/
2049 [59076]: https://github.com/rust-lang/rust/pull/59076/
2050 [58778]: https://github.com/rust-lang/rust/pull/58778/
2051 [58717]: https://github.com/rust-lang/rust/pull/58717/
2052 [58369]: https://github.com/rust-lang/rust/pull/58369/
2053 [58423]: https://github.com/rust-lang/rust/pull/58423/
2054 [58080]: https://github.com/rust-lang/rust/pull/58080/
2055 [57847]: https://github.com/rust-lang/rust/pull/57847/
2056 [58575]: https://github.com/rust-lang/rust/pull/58575
2057 [cargo/6298]: https://github.com/rust-lang/cargo/pull/6298/
2058 [`f32::copysign`]: https://doc.rust-lang.org/stable/std/primitive.f32.html#method.copysign
2059 [`f64::copysign`]: https://doc.rust-lang.org/stable/std/primitive.f64.html#method.copysign
2060 [`RefCell::replace_with`]: https://doc.rust-lang.org/stable/std/cell/struct.RefCell.html#method.replace_with
2061 [`RefCell::map_split`]: https://doc.rust-lang.org/stable/std/cell/struct.RefCell.html#method.map_split
2062 [`ptr::hash`]: https://doc.rust-lang.org/stable/std/ptr/fn.hash.html
2063 [`Range::contains`]: https://doc.rust-lang.org/std/ops/struct.Range.html#method.contains
2064 [`RangeFrom::contains`]: https://doc.rust-lang.org/std/ops/struct.RangeFrom.html#method.contains
2065 [`RangeTo::contains`]: https://doc.rust-lang.org/std/ops/struct.RangeTo.html#method.contains
2066 [`RangeInclusive::contains`]: https://doc.rust-lang.org/std/ops/struct.RangeInclusive.html#method.contains
2067 [`RangeToInclusive::contains`]: https://doc.rust-lang.org/std/ops/struct.RangeToInclusive.html#method.contains
2068 [`Option::copied`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.copied
2069
2070 Version 1.34.2 (2019-05-14)
2071 ===========================
2072
2073 * [Destabilize the `Error::type_id` function due to a security
2074    vulnerability][60785] ([CVE-2019-12083])
2075
2076 [60785]: https://github.com/rust-lang/rust/pull/60785
2077 [CVE-2019-12083]: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12083
2078
2079 Version 1.34.1 (2019-04-25)
2080 ===========================
2081
2082 * [Fix false positives for the `redundant_closure` Clippy lint][clippy/3821]
2083 * [Fix false positives for the `missing_const_for_fn` Clippy lint][clippy/3844]
2084 * [Fix Clippy panic when checking some macros][clippy/3805]
2085
2086 [clippy/3821]: https://github.com/rust-lang/rust-clippy/pull/3821
2087 [clippy/3844]: https://github.com/rust-lang/rust-clippy/pull/3844
2088 [clippy/3805]: https://github.com/rust-lang/rust-clippy/pull/3805
2089
2090 Version 1.34.0 (2019-04-11)
2091 ==========================
2092
2093 Language
2094 --------
2095 - [You can now use `#[deprecated = "reason"]`][58166] as a shorthand for
2096   `#[deprecated(note = "reason")]`. This was previously allowed by mistake
2097   but had no effect.
2098 - [You can now accept token streams in `#[attr()]`,`#[attr[]]`, and
2099   `#[attr{}]` procedural macros.][57367]
2100 - [You can now write `extern crate self as foo;`][57407] to import your
2101   crate's root into the extern prelude.
2102
2103
2104 Compiler
2105 --------
2106 - [You can now target `riscv64imac-unknown-none-elf` and
2107   `riscv64gc-unknown-none-elf`.][58406]
2108 - [You can now enable linker plugin LTO optimisations with
2109   `-C linker-plugin-lto`.][58057] This allows rustc to compile your Rust code
2110   into LLVM bitcode allowing LLVM to perform LTO optimisations across C/C++ FFI
2111   boundaries.
2112 - [You can now target `powerpc64-unknown-freebsd`.][57809]
2113
2114
2115 Libraries
2116 ---------
2117 - [The trait bounds have been removed on some of `HashMap<K, V, S>`'s and
2118   `HashSet<T, S>`'s basic methods.][58370] Most notably you no longer require
2119   the `Hash` trait to create an iterator.
2120 - [The `Ord` trait bounds have been removed on some of `BinaryHeap<T>`'s basic
2121   methods.][58421] Most notably you no longer require the `Ord` trait to create
2122   an iterator.
2123 - [The methods `overflowing_neg` and `wrapping_neg` are now `const` functions
2124   for all numeric types.][58044]
2125 - [Indexing a `str` is now generic over all types that
2126   implement `SliceIndex<str>`.][57604]
2127 - [`str::trim`, `str::trim_matches`, `str::trim_{start, end}`, and
2128   `str::trim_{start, end}_matches` are now `#[must_use]`][57106] and will
2129   produce a warning if their returning type is unused.
2130 - [The methods `checked_pow`, `saturating_pow`, `wrapping_pow`, and
2131   `overflowing_pow` are now available for all numeric types.][57873] These are
2132   equivalent to methods such as `wrapping_add` for the `pow` operation.
2133
2134
2135 Stabilized APIs
2136 ---------------
2137
2138 #### std & core
2139 * [`Any::type_id`]
2140 * [`Error::type_id`]
2141 * [`atomic::AtomicI16`]
2142 * [`atomic::AtomicI32`]
2143 * [`atomic::AtomicI64`]
2144 * [`atomic::AtomicI8`]
2145 * [`atomic::AtomicU16`]
2146 * [`atomic::AtomicU32`]
2147 * [`atomic::AtomicU64`]
2148 * [`atomic::AtomicU8`]
2149 * [`convert::Infallible`]
2150 * [`convert::TryFrom`]
2151 * [`convert::TryInto`]
2152 * [`iter::from_fn`]
2153 * [`iter::successors`]
2154 * [`num::NonZeroI128`]
2155 * [`num::NonZeroI16`]
2156 * [`num::NonZeroI32`]
2157 * [`num::NonZeroI64`]
2158 * [`num::NonZeroI8`]
2159 * [`num::NonZeroIsize`]
2160 * [`slice::sort_by_cached_key`]
2161 * [`str::escape_debug`]
2162 * [`str::escape_default`]
2163 * [`str::escape_unicode`]
2164 * [`str::split_ascii_whitespace`]
2165
2166 #### std
2167 * [`Instant::checked_add`]
2168 * [`Instant::checked_sub`]
2169 * [`SystemTime::checked_add`]
2170 * [`SystemTime::checked_sub`]
2171
2172 Cargo
2173 -----
2174 - [You can now use alternative registries to crates.io.][cargo/6654]
2175
2176 Misc
2177 ----
2178 - [You can now use the `?` operator in your documentation tests without manually
2179   adding `fn main() -> Result<(), _> {}`.][56470]
2180
2181 Compatibility Notes
2182 -------------------
2183 - [`Command::before_exec` is being replaced by the unsafe method
2184   `Command::pre_exec`][58059] and will be deprecated with Rust 1.37.0.
2185 - [Use of `ATOMIC_{BOOL, ISIZE, USIZE}_INIT` is now deprecated][57425] as you
2186   can now use `const` functions in `static` variables.
2187
2188 [58370]: https://github.com/rust-lang/rust/pull/58370/
2189 [58406]: https://github.com/rust-lang/rust/pull/58406/
2190 [58421]: https://github.com/rust-lang/rust/pull/58421/
2191 [58166]: https://github.com/rust-lang/rust/pull/58166/
2192 [58044]: https://github.com/rust-lang/rust/pull/58044/
2193 [58057]: https://github.com/rust-lang/rust/pull/58057/
2194 [58059]: https://github.com/rust-lang/rust/pull/58059/
2195 [57809]: https://github.com/rust-lang/rust/pull/57809/
2196 [57873]: https://github.com/rust-lang/rust/pull/57873/
2197 [57604]: https://github.com/rust-lang/rust/pull/57604/
2198 [57367]: https://github.com/rust-lang/rust/pull/57367/
2199 [57407]: https://github.com/rust-lang/rust/pull/57407/
2200 [57425]: https://github.com/rust-lang/rust/pull/57425/
2201 [57106]: https://github.com/rust-lang/rust/pull/57106/
2202 [56470]: https://github.com/rust-lang/rust/pull/56470/
2203 [cargo/6654]: https://github.com/rust-lang/cargo/pull/6654/
2204 [`Any::type_id`]: https://doc.rust-lang.org/std/any/trait.Any.html#tymethod.type_id
2205 [`Error::type_id`]: https://doc.rust-lang.org/std/error/trait.Error.html#method.type_id
2206 [`atomic::AtomicI16`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicI16.html
2207 [`atomic::AtomicI32`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicI32.html
2208 [`atomic::AtomicI64`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicI64.html
2209 [`atomic::AtomicI8`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicI8.html
2210 [`atomic::AtomicU16`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU16.html
2211 [`atomic::AtomicU32`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU32.html
2212 [`atomic::AtomicU64`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU64.html
2213 [`atomic::AtomicU8`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU8.html
2214 [`convert::Infallible`]: https://doc.rust-lang.org/std/convert/enum.Infallible.html
2215 [`convert::TryFrom`]: https://doc.rust-lang.org/std/convert/trait.TryFrom.html
2216 [`convert::TryInto`]: https://doc.rust-lang.org/std/convert/trait.TryInto.html
2217 [`iter::from_fn`]: https://doc.rust-lang.org/std/iter/fn.from_fn.html
2218 [`iter::successors`]: https://doc.rust-lang.org/std/iter/fn.successors.html
2219 [`num::NonZeroI128`]: https://doc.rust-lang.org/std/num/struct.NonZeroI128.html
2220 [`num::NonZeroI16`]: https://doc.rust-lang.org/std/num/struct.NonZeroI16.html
2221 [`num::NonZeroI32`]: https://doc.rust-lang.org/std/num/struct.NonZeroI32.html
2222 [`num::NonZeroI64`]: https://doc.rust-lang.org/std/num/struct.NonZeroI64.html
2223 [`num::NonZeroI8`]: https://doc.rust-lang.org/std/num/struct.NonZeroI8.html
2224 [`num::NonZeroIsize`]: https://doc.rust-lang.org/std/num/struct.NonZeroIsize.html
2225 [`slice::sort_by_cached_key`]: https://doc.rust-lang.org/std/primitive.slice.html#method.sort_by_cached_key
2226 [`str::escape_debug`]: https://doc.rust-lang.org/std/primitive.str.html#method.escape_debug
2227 [`str::escape_default`]: https://doc.rust-lang.org/std/primitive.str.html#method.escape_default
2228 [`str::escape_unicode`]: https://doc.rust-lang.org/std/primitive.str.html#method.escape_unicode
2229 [`str::split_ascii_whitespace`]: https://doc.rust-lang.org/std/primitive.str.html#method.split_ascii_whitespace
2230 [`Instant::checked_add`]: https://doc.rust-lang.org/std/time/struct.Instant.html#method.checked_add
2231 [`Instant::checked_sub`]: https://doc.rust-lang.org/std/time/struct.Instant.html#method.checked_sub
2232 [`SystemTime::checked_add`]: https://doc.rust-lang.org/std/time/struct.SystemTime.html#method.checked_add
2233 [`SystemTime::checked_sub`]: https://doc.rust-lang.org/std/time/struct.SystemTime.html#method.checked_sub
2234
2235
2236 Version 1.33.0 (2019-02-28)
2237 ==========================
2238
2239 Language
2240 --------
2241 - [You can now use the `cfg(target_vendor)` attribute.][57465] E.g.
2242   `#[cfg(target_vendor="apple")] fn main() { println!("Hello Apple!"); }`
2243 - [Integer patterns such as in a match expression can now be exhaustive.][56362]
2244   E.g. You can have match statement on a `u8` that covers `0..=255` and
2245   you would no longer be required to have a `_ => unreachable!()` case.
2246 - [You can now have multiple patterns in `if let` and `while let`
2247   expressions.][57532] You can do this with the same syntax as a `match`
2248   expression. E.g.
2249   ```rust
2250   enum Creature {
2251       Crab(String),
2252       Lobster(String),
2253       Person(String),
2254   }
2255
2256   fn main() {
2257       let state = Creature::Crab("Ferris");
2258
2259       if let Creature::Crab(name) | Creature::Person(name) = state {
2260           println!("This creature's name is: {}", name);
2261       }
2262   }
2263   ```
2264 - [You can now have irrefutable `if let` and `while let` patterns.][57535] Using
2265   this feature will by default produce a warning as this behaviour can be
2266   unintuitive. E.g. `if let _ = 5 {}`
2267 - [You can now use `let` bindings, assignments, expression statements,
2268   and irrefutable pattern destructuring in const functions.][57175]
2269 - [You can now call unsafe const functions.][57067] E.g.
2270   ```rust
2271   const unsafe fn foo() -> i32 { 5 }
2272   const fn bar() -> i32 {
2273       unsafe { foo() }
2274   }
2275   ```
2276 - [You can now specify multiple attributes in a `cfg_attr` attribute.][57332]
2277   E.g. `#[cfg_attr(all(), must_use, optimize)]`
2278 - [You can now specify a specific alignment with the `#[repr(packed)]`
2279   attribute.][57049] E.g. `#[repr(packed(2))] struct Foo(i16, i32);` is a struct
2280   with an alignment of 2 bytes and a size of 6 bytes.
2281 - [You can now import an item from a module as an `_`.][56303] This allows you to
2282   import a trait's impls, and not have the name in the namespace. E.g.
2283   ```rust
2284   use std::io::Read as _;
2285
2286   // Allowed as there is only one `Read` in the module.
2287   pub trait Read {}
2288   ```
2289 - [You may now use `Rc`, `Arc`, and `Pin` as method receivers][56805].
2290
2291 Compiler
2292 --------
2293 - [You can now set a linker flavor for `rustc` with the `-Clinker-flavor`
2294   command line argument.][56351]
2295 - [The minimum required LLVM version has been bumped to 6.0.][56642]
2296 - [Added support for the PowerPC64 architecture on FreeBSD.][57615]
2297 - [The `x86_64-fortanix-unknown-sgx` target support has been upgraded to
2298   tier 2 support.][57130] Visit the [platform support][platform-support] page for
2299   information on Rust's platform support.
2300 - [Added support for the `thumbv7neon-linux-androideabi` and
2301   `thumbv7neon-unknown-linux-gnueabihf` targets.][56947]
2302 - [Added support for the `x86_64-unknown-uefi` target.][56769]
2303
2304 Libraries
2305 ---------
2306 - [The methods `overflowing_{add, sub, mul, shl, shr}` are now `const`
2307   functions for all numeric types.][57566]
2308 - [The methods `rotate_left`, `rotate_right`, and `wrapping_{add, sub, mul, shl, shr}`
2309   are now `const` functions for all numeric types.][57105]
2310 - [The methods `is_positive` and `is_negative` are now `const` functions for
2311   all signed numeric types.][57105]
2312 - [The `get` method for all `NonZero` types is now `const`.][57167]
2313 - [The methods `count_ones`, `count_zeros`, `leading_zeros`, `trailing_zeros`,
2314   `swap_bytes`, `from_be`, `from_le`, `to_be`, `to_le` are now `const` for all
2315   numeric types.][57234]
2316 - [`Ipv4Addr::new` is now a `const` function][57234]
2317
2318 Stabilized APIs
2319 ---------------
2320 - [`unix::FileExt::read_exact_at`]
2321 - [`unix::FileExt::write_all_at`]
2322 - [`Option::transpose`]
2323 - [`Result::transpose`]
2324 - [`convert::identity`]
2325 - [`pin::Pin`]
2326 - [`marker::Unpin`]
2327 - [`marker::PhantomPinned`]
2328 - [`Vec::resize_with`]
2329 - [`VecDeque::resize_with`]
2330 - [`Duration::as_millis`]
2331 - [`Duration::as_micros`]
2332 - [`Duration::as_nanos`]
2333
2334
2335 Cargo
2336 -----
2337 - [You can now publish crates that require a feature flag to compile with
2338   `cargo publish --features` or `cargo publish --all-features`.][cargo/6453]
2339 - [Cargo should now rebuild a crate if a file was modified during the initial
2340   build.][cargo/6484]
2341
2342 Compatibility Notes
2343 -------------------
2344 - The methods `str::{trim_left, trim_right, trim_left_matches, trim_right_matches}`
2345   are now deprecated in the standard library, and their usage will now produce a warning.
2346   Please use the `str::{trim_start, trim_end, trim_start_matches, trim_end_matches}`
2347   methods instead.
2348 - The `Error::cause` method has been deprecated in favor of `Error::source` which supports
2349   downcasting.
2350 - [Libtest no longer creates a new thread for each test when
2351   `--test-threads=1`.  It also runs the tests in deterministic order][56243]
2352
2353 [55982]: https://github.com/rust-lang/rust/pull/55982/
2354 [56243]: https://github.com/rust-lang/rust/pull/56243
2355 [56303]: https://github.com/rust-lang/rust/pull/56303/
2356 [56351]: https://github.com/rust-lang/rust/pull/56351/
2357 [56362]: https://github.com/rust-lang/rust/pull/56362
2358 [56642]: https://github.com/rust-lang/rust/pull/56642/
2359 [56769]: https://github.com/rust-lang/rust/pull/56769/
2360 [56805]: https://github.com/rust-lang/rust/pull/56805
2361 [56947]: https://github.com/rust-lang/rust/pull/56947/
2362 [57049]: https://github.com/rust-lang/rust/pull/57049/
2363 [57067]: https://github.com/rust-lang/rust/pull/57067/
2364 [57105]: https://github.com/rust-lang/rust/pull/57105
2365 [57130]: https://github.com/rust-lang/rust/pull/57130/
2366 [57167]: https://github.com/rust-lang/rust/pull/57167/
2367 [57175]: https://github.com/rust-lang/rust/pull/57175/
2368 [57234]: https://github.com/rust-lang/rust/pull/57234/
2369 [57332]: https://github.com/rust-lang/rust/pull/57332/
2370 [57465]: https://github.com/rust-lang/rust/pull/57465/
2371 [57532]: https://github.com/rust-lang/rust/pull/57532/
2372 [57535]: https://github.com/rust-lang/rust/pull/57535/
2373 [57566]: https://github.com/rust-lang/rust/pull/57566/
2374 [57615]: https://github.com/rust-lang/rust/pull/57615/
2375 [cargo/6453]: https://github.com/rust-lang/cargo/pull/6453/
2376 [cargo/6484]: https://github.com/rust-lang/cargo/pull/6484/
2377 [`unix::FileExt::read_exact_at`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html#method.read_exact_at
2378 [`unix::FileExt::write_all_at`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html#method.write_all_at
2379 [`Option::transpose`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.transpose
2380 [`Result::transpose`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.transpose
2381 [`convert::identity`]: https://doc.rust-lang.org/std/convert/fn.identity.html
2382 [`pin::Pin`]: https://doc.rust-lang.org/std/pin/struct.Pin.html
2383 [`marker::Unpin`]: https://doc.rust-lang.org/stable/std/marker/trait.Unpin.html
2384 [`marker::PhantomPinned`]: https://doc.rust-lang.org/nightly/std/marker/struct.PhantomPinned.html
2385 [`Vec::resize_with`]: https://doc.rust-lang.org/std/vec/struct.Vec.html#method.resize_with
2386 [`VecDeque::resize_with`]: https://doc.rust-lang.org/std/collections/struct.VecDeque.html#method.resize_with
2387 [`Duration::as_millis`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.as_millis
2388 [`Duration::as_micros`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.as_micros
2389 [`Duration::as_nanos`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.as_nanos
2390 [platform-support]: https://forge.rust-lang.org/platform-support.html
2391
2392 Version 1.32.0 (2019-01-17)
2393 ==========================
2394
2395 Language
2396 --------
2397 #### 2018 edition
2398 - [You can now use the `?` operator in macro definitions.][56245] The `?`
2399   operator allows you to specify zero or one repetitions similar to the `*` and
2400   `+` operators.
2401 - [Module paths with no leading keyword like `super`, `self`, or `crate`, will
2402   now always resolve to the item (`enum`, `struct`, etc.) available in the
2403   module if present, before resolving to a external crate or an item the prelude.][56759]
2404   E.g.
2405   ```rust
2406   enum Color { Red, Green, Blue }
2407
2408   use Color::*;
2409   ```
2410
2411 #### All editions
2412 - [You can now match against `PhantomData<T>` types.][55837]
2413 - [You can now match against literals in macros with the `literal`
2414   specifier.][56072] This will match against a literal of any type.
2415   E.g. `1`, `'A'`, `"Hello World"`
2416 - [Self can now be used as a constructor and pattern for unit and tuple structs.][56365] E.g.
2417   ```rust
2418   struct Point(i32, i32);
2419
2420   impl Point {
2421       pub fn new(x: i32, y: i32) -> Self {
2422           Self(x, y)
2423       }
2424
2425       pub fn is_origin(&self) -> bool {
2426           match self {
2427               Self(0, 0) => true,
2428               _ => false,
2429           }
2430       }
2431   }
2432   ```
2433 - [Self can also now be used in type definitions.][56366] E.g.
2434   ```rust
2435   enum List<T>
2436   where
2437       Self: PartialOrd<Self> // can write `Self` instead of `List<T>`
2438   {
2439       Nil,
2440       Cons(T, Box<Self>) // likewise here
2441   }
2442   ```
2443 - [You can now mark traits with `#[must_use]`.][55663] This provides a warning if
2444   a `impl Trait` or `dyn Trait` is returned and unused in the program.
2445
2446 Compiler
2447 --------
2448 - [The default allocator has changed from jemalloc to the default allocator on
2449   your system.][55238] The compiler itself on Linux & macOS will still use
2450   jemalloc, but programs compiled with it will use the system allocator.
2451 - [Added the `aarch64-pc-windows-msvc` target.][55702]
2452
2453 Libraries
2454 ---------
2455 - [`PathBuf` now implements `FromStr`.][55148]
2456 - [`Box<[T]>` now implements `FromIterator<T>`.][55843]
2457 - [The `dbg!` macro has been stabilized.][56395] This macro enables you to
2458   easily debug expressions in your rust program. E.g.
2459   ```rust
2460   let a = 2;
2461   let b = dbg!(a * 2) + 1;
2462   //      ^-- prints: [src/main.rs:4] a * 2 = 4
2463   assert_eq!(b, 5);
2464   ```
2465
2466 The following APIs are now `const` functions and can be used in a
2467 `const` context.
2468
2469 - [`Cell::as_ptr`]
2470 - [`UnsafeCell::get`]
2471 - [`char::is_ascii`]
2472 - [`iter::empty`]
2473 - [`ManuallyDrop::new`]
2474 - [`ManuallyDrop::into_inner`]
2475 - [`RangeInclusive::start`]
2476 - [`RangeInclusive::end`]
2477 - [`NonNull::as_ptr`]
2478 - [`slice::as_ptr`]
2479 - [`str::as_ptr`]
2480 - [`Duration::as_secs`]
2481 - [`Duration::subsec_millis`]
2482 - [`Duration::subsec_micros`]
2483 - [`Duration::subsec_nanos`]
2484 - [`CStr::as_ptr`]
2485 - [`Ipv4Addr::is_unspecified`]
2486 - [`Ipv6Addr::new`]
2487 - [`Ipv6Addr::octets`]
2488
2489 Stabilized APIs
2490 ---------------
2491 - [`i8::to_be_bytes`]
2492 - [`i8::to_le_bytes`]
2493 - [`i8::to_ne_bytes`]
2494 - [`i8::from_be_bytes`]
2495 - [`i8::from_le_bytes`]
2496 - [`i8::from_ne_bytes`]
2497 - [`i16::to_be_bytes`]
2498 - [`i16::to_le_bytes`]
2499 - [`i16::to_ne_bytes`]
2500 - [`i16::from_be_bytes`]
2501 - [`i16::from_le_bytes`]
2502 - [`i16::from_ne_bytes`]
2503 - [`i32::to_be_bytes`]
2504 - [`i32::to_le_bytes`]
2505 - [`i32::to_ne_bytes`]
2506 - [`i32::from_be_bytes`]
2507 - [`i32::from_le_bytes`]
2508 - [`i32::from_ne_bytes`]
2509 - [`i64::to_be_bytes`]
2510 - [`i64::to_le_bytes`]
2511 - [`i64::to_ne_bytes`]
2512 - [`i64::from_be_bytes`]
2513 - [`i64::from_le_bytes`]
2514 - [`i64::from_ne_bytes`]
2515 - [`i128::to_be_bytes`]
2516 - [`i128::to_le_bytes`]
2517 - [`i128::to_ne_bytes`]
2518 - [`i128::from_be_bytes`]
2519 - [`i128::from_le_bytes`]
2520 - [`i128::from_ne_bytes`]
2521 - [`isize::to_be_bytes`]
2522 - [`isize::to_le_bytes`]
2523 - [`isize::to_ne_bytes`]
2524 - [`isize::from_be_bytes`]
2525 - [`isize::from_le_bytes`]
2526 - [`isize::from_ne_bytes`]
2527 - [`u8::to_be_bytes`]
2528 - [`u8::to_le_bytes`]
2529 - [`u8::to_ne_bytes`]
2530 - [`u8::from_be_bytes`]
2531 - [`u8::from_le_bytes`]
2532 - [`u8::from_ne_bytes`]
2533 - [`u16::to_be_bytes`]
2534 - [`u16::to_le_bytes`]
2535 - [`u16::to_ne_bytes`]
2536 - [`u16::from_be_bytes`]
2537 - [`u16::from_le_bytes`]
2538 - [`u16::from_ne_bytes`]
2539 - [`u32::to_be_bytes`]
2540 - [`u32::to_le_bytes`]
2541 - [`u32::to_ne_bytes`]
2542 - [`u32::from_be_bytes`]
2543 - [`u32::from_le_bytes`]
2544 - [`u32::from_ne_bytes`]
2545 - [`u64::to_be_bytes`]
2546 - [`u64::to_le_bytes`]
2547 - [`u64::to_ne_bytes`]
2548 - [`u64::from_be_bytes`]
2549 - [`u64::from_le_bytes`]
2550 - [`u64::from_ne_bytes`]
2551 - [`u128::to_be_bytes`]
2552 - [`u128::to_le_bytes`]
2553 - [`u128::to_ne_bytes`]
2554 - [`u128::from_be_bytes`]
2555 - [`u128::from_le_bytes`]
2556 - [`u128::from_ne_bytes`]
2557 - [`usize::to_be_bytes`]
2558 - [`usize::to_le_bytes`]
2559 - [`usize::to_ne_bytes`]
2560 - [`usize::from_be_bytes`]
2561 - [`usize::from_le_bytes`]
2562 - [`usize::from_ne_bytes`]
2563
2564 Cargo
2565 -----
2566 - [You can now run `cargo c` as an alias for `cargo check`.][cargo/6218]
2567 - [Usernames are now allowed in alt registry URLs.][cargo/6242]
2568
2569 Misc
2570 ----
2571 - [`libproc_macro` has been added to the `rust-src` distribution.][55280]
2572
2573 Compatibility Notes
2574 -------------------
2575 - [The argument types for AVX's
2576   `_mm256_stream_si256`, `_mm256_stream_pd`, `_mm256_stream_ps`][55610] have
2577   been changed from `*const` to `*mut` as the previous implementation
2578   was unsound.
2579
2580
2581 [55148]: https://github.com/rust-lang/rust/pull/55148/
2582 [55238]: https://github.com/rust-lang/rust/pull/55238/
2583 [55280]: https://github.com/rust-lang/rust/pull/55280/
2584 [55610]: https://github.com/rust-lang/rust/pull/55610/
2585 [55663]: https://github.com/rust-lang/rust/pull/55663/
2586 [55702]: https://github.com/rust-lang/rust/pull/55702/
2587 [55837]: https://github.com/rust-lang/rust/pull/55837/
2588 [55843]: https://github.com/rust-lang/rust/pull/55843/
2589 [56072]: https://github.com/rust-lang/rust/pull/56072/
2590 [56245]: https://github.com/rust-lang/rust/pull/56245/
2591 [56365]: https://github.com/rust-lang/rust/pull/56365/
2592 [56366]: https://github.com/rust-lang/rust/pull/56366/
2593 [56395]: https://github.com/rust-lang/rust/pull/56395/
2594 [56759]: https://github.com/rust-lang/rust/pull/56759/
2595 [cargo/6218]: https://github.com/rust-lang/cargo/pull/6218/
2596 [cargo/6242]: https://github.com/rust-lang/cargo/pull/6242/
2597 [`CStr::as_ptr`]: https://doc.rust-lang.org/std/ffi/struct.CStr.html#method.as_ptr
2598 [`Cell::as_ptr`]: https://doc.rust-lang.org/std/cell/struct.Cell.html#method.as_ptr
2599 [`Duration::as_secs`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.as_secs
2600 [`Duration::subsec_micros`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.subsec_micros
2601 [`Duration::subsec_millis`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.subsec_millis
2602 [`Duration::subsec_nanos`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.subsec_nanos
2603 [`Ipv4Addr::is_unspecified`]: https://doc.rust-lang.org/std/net/struct.Ipv4Addr.html#method.is_unspecified
2604 [`Ipv6Addr::new`]: https://doc.rust-lang.org/std/net/struct.Ipv6Addr.html#method.new
2605 [`Ipv6Addr::octets`]: https://doc.rust-lang.org/std/net/struct.Ipv6Addr.html#method.octets
2606 [`ManuallyDrop::into_inner`]: https://doc.rust-lang.org/std/mem/struct.ManuallyDrop.html#method.into_inner
2607 [`ManuallyDrop::new`]: https://doc.rust-lang.org/std/mem/struct.ManuallyDrop.html#method.new
2608 [`NonNull::as_ptr`]: https://doc.rust-lang.org/std/ptr/struct.NonNull.html#method.as_ptr
2609 [`RangeInclusive::end`]: https://doc.rust-lang.org/std/ops/struct.RangeInclusive.html#method.end
2610 [`RangeInclusive::start`]: https://doc.rust-lang.org/std/ops/struct.RangeInclusive.html#method.start
2611 [`UnsafeCell::get`]: https://doc.rust-lang.org/std/cell/struct.UnsafeCell.html#method.get
2612 [`slice::as_ptr`]: https://doc.rust-lang.org/std/primitive.slice.html#method.as_ptr
2613 [`char::is_ascii`]: https://doc.rust-lang.org/std/primitive.char.html#method.is_ascii
2614 [`i128::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i128.html#method.from_be_bytes
2615 [`i128::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i128.html#method.from_le_bytes
2616 [`i128::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i128.html#method.from_ne_bytes
2617 [`i128::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i128.html#method.to_be_bytes
2618 [`i128::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i128.html#method.to_le_bytes
2619 [`i128::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i128.html#method.to_ne_bytes
2620 [`i16::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i16.html#method.from_be_bytes
2621 [`i16::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i16.html#method.from_le_bytes
2622 [`i16::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i16.html#method.from_ne_bytes
2623 [`i16::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i16.html#method.to_be_bytes
2624 [`i16::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i16.html#method.to_le_bytes
2625 [`i16::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i16.html#method.to_ne_bytes
2626 [`i32::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i32.html#method.from_be_bytes
2627 [`i32::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i32.html#method.from_le_bytes
2628 [`i32::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i32.html#method.from_ne_bytes
2629 [`i32::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i32.html#method.to_be_bytes
2630 [`i32::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i32.html#method.to_le_bytes
2631 [`i32::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i32.html#method.to_ne_bytes
2632 [`i64::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i64.html#method.from_be_bytes
2633 [`i64::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i64.html#method.from_le_bytes
2634 [`i64::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i64.html#method.from_ne_bytes
2635 [`i64::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i64.html#method.to_be_bytes
2636 [`i64::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i64.html#method.to_le_bytes
2637 [`i64::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i64.html#method.to_ne_bytes
2638 [`i8::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i8.html#method.from_be_bytes
2639 [`i8::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i8.html#method.from_le_bytes
2640 [`i8::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i8.html#method.from_ne_bytes
2641 [`i8::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i8.html#method.to_be_bytes
2642 [`i8::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i8.html#method.to_le_bytes
2643 [`i8::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.i8.html#method.to_ne_bytes
2644 [`isize::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.isize.html#method.from_be_bytes
2645 [`isize::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.isize.html#method.from_le_bytes
2646 [`isize::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.isize.html#method.from_ne_bytes
2647 [`isize::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.isize.html#method.to_be_bytes
2648 [`isize::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.isize.html#method.to_le_bytes
2649 [`isize::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.isize.html#method.to_ne_bytes
2650 [`iter::empty`]: https://doc.rust-lang.org/std/iter/fn.empty.html
2651 [`str::as_ptr`]: https://doc.rust-lang.org/std/primitive.str.html#method.as_ptr
2652 [`u128::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u128.html#method.from_be_bytes
2653 [`u128::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u128.html#method.from_le_bytes
2654 [`u128::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u128.html#method.from_ne_bytes
2655 [`u128::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u128.html#method.to_be_bytes
2656 [`u128::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u128.html#method.to_le_bytes
2657 [`u128::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u128.html#method.to_ne_bytes
2658 [`u16::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u16.html#method.from_be_bytes
2659 [`u16::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u16.html#method.from_le_bytes
2660 [`u16::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u16.html#method.from_ne_bytes
2661 [`u16::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u16.html#method.to_be_bytes
2662 [`u16::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u16.html#method.to_le_bytes
2663 [`u16::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u16.html#method.to_ne_bytes
2664 [`u32::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u32.html#method.from_be_bytes
2665 [`u32::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u32.html#method.from_le_bytes
2666 [`u32::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u32.html#method.from_ne_bytes
2667 [`u32::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u32.html#method.to_be_bytes
2668 [`u32::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u32.html#method.to_le_bytes
2669 [`u32::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u32.html#method.to_ne_bytes
2670 [`u64::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u64.html#method.from_be_bytes
2671 [`u64::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u64.html#method.from_le_bytes
2672 [`u64::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u64.html#method.from_ne_bytes
2673 [`u64::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u64.html#method.to_be_bytes
2674 [`u64::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u64.html#method.to_le_bytes
2675 [`u64::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u64.html#method.to_ne_bytes
2676 [`u8::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.from_be_bytes
2677 [`u8::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.from_le_bytes
2678 [`u8::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.from_ne_bytes
2679 [`u8::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.to_be_bytes
2680 [`u8::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.to_le_bytes
2681 [`u8::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.u8.html#method.to_ne_bytes
2682 [`usize::from_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.usize.html#method.from_be_bytes
2683 [`usize::from_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.usize.html#method.from_le_bytes
2684 [`usize::from_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.usize.html#method.from_ne_bytes
2685 [`usize::to_be_bytes`]: https://doc.rust-lang.org/stable/std/primitive.usize.html#method.to_be_bytes
2686 [`usize::to_le_bytes`]: https://doc.rust-lang.org/stable/std/primitive.usize.html#method.to_le_bytes
2687 [`usize::to_ne_bytes`]: https://doc.rust-lang.org/stable/std/primitive.usize.html#method.to_ne_bytes
2688
2689
2690 Version 1.31.1 (2018-12-20)
2691 ===========================
2692
2693 - [Fix Rust failing to build on `powerpc-unknown-netbsd`][56562]
2694 - [Fix broken go-to-definition in RLS][rls/1171]
2695 - [Fix infinite loop on hover in RLS][rls/1170]
2696
2697 [56562]: https://github.com/rust-lang/rust/pull/56562
2698 [rls/1171]: https://github.com/rust-lang/rls/issues/1171
2699 [rls/1170]: https://github.com/rust-lang/rls/pull/1170
2700
2701 Version 1.31.0 (2018-12-06)
2702 ==========================
2703
2704 Language
2705 --------
2706 - 🎉 [This version marks the release of the 2018 edition of Rust.][54057] 🎉
2707 - [New lifetime elision rules now allow for eliding lifetimes in functions and
2708   impl headers.][54778] E.g. `impl<'a> Reader for BufReader<'a> {}` can now be
2709   `impl Reader for BufReader<'_> {}`. Lifetimes are still required to be defined
2710   in structs.
2711 - [You can now define and use `const` functions.][54835] These are currently
2712   a strict minimal subset of the [const fn RFC][RFC-911]. Refer to the
2713   [language reference][const-reference] for what exactly is available.
2714 - [You can now use tool lints, which allow you to scope lints from external
2715   tools using attributes.][54870] E.g. `#[allow(clippy::filter_map)]`.
2716 - [`#[no_mangle]` and `#[export_name]` attributes can now be located anywhere in
2717   a crate, not just in exported functions.][54451]
2718 - [You can now use parentheses in pattern matches.][54497]
2719
2720 Compiler
2721 --------
2722 - [Updated musl to 1.1.20][54430]
2723
2724 Libraries
2725 ---------
2726 - [You can now convert `num::NonZero*` types to their raw equivalents using the
2727   `From` trait.][54240] E.g. `u8` now implements `From<NonZeroU8>`.
2728 - [You can now convert a `&Option<T>` into `Option<&T>` and `&mut Option<T>`
2729   into `Option<&mut T>` using the `From` trait.][53218]
2730 - [You can now multiply (`*`) a `time::Duration` by a `u32`.][52813]
2731
2732
2733 Stabilized APIs
2734 ---------------
2735 - [`slice::align_to`]
2736 - [`slice::align_to_mut`]
2737 - [`slice::chunks_exact`]
2738 - [`slice::chunks_exact_mut`]
2739 - [`slice::rchunks`]
2740 - [`slice::rchunks_mut`]
2741 - [`slice::rchunks_exact`]
2742 - [`slice::rchunks_exact_mut`]
2743 - [`Option::replace`]
2744
2745 Cargo
2746 -----
2747 - [Cargo will now download crates in parallel using HTTP/2.][cargo/6005]
2748 - [You can now rename packages in your Cargo.toml][cargo/6319] We have a guide
2749   on [how to use the `package` key in your dependencies.][cargo-rename-reference]
2750
2751 [52813]: https://github.com/rust-lang/rust/pull/52813/
2752 [53218]: https://github.com/rust-lang/rust/pull/53218/
2753 [53555]: https://github.com/rust-lang/rust/issues/53555/
2754 [54057]: https://github.com/rust-lang/rust/pull/54057/
2755 [54240]: https://github.com/rust-lang/rust/pull/54240/
2756 [54430]: https://github.com/rust-lang/rust/pull/54430/
2757 [54451]: https://github.com/rust-lang/rust/pull/54451/
2758 [54497]: https://github.com/rust-lang/rust/pull/54497/
2759 [54778]: https://github.com/rust-lang/rust/pull/54778/
2760 [54835]: https://github.com/rust-lang/rust/pull/54835/
2761 [54870]: https://github.com/rust-lang/rust/pull/54870/
2762 [RFC-911]: https://github.com/rust-lang/rfcs/pull/911
2763 [`Option::replace`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.replace
2764 [`slice::align_to_mut`]: https://doc.rust-lang.org/std/primitive.slice.html#method.align_to_mut
2765 [`slice::align_to`]: https://doc.rust-lang.org/std/primitive.slice.html#method.align_to
2766 [`slice::chunks_exact_mut`]: https://doc.rust-lang.org/std/primitive.slice.html#method.chunks_exact_mut
2767 [`slice::chunks_exact`]: https://doc.rust-lang.org/std/primitive.slice.html#method.chunks_exact
2768 [`slice::rchunks_exact_mut`]: https://doc.rust-lang.org/std/primitive.slice.html#method.rchunks_mut
2769 [`slice::rchunks_exact`]: https://doc.rust-lang.org/std/primitive.slice.html#method.rchunks_exact
2770 [`slice::rchunks_mut`]: https://doc.rust-lang.org/std/primitive.slice.html#method.rchunks_mut
2771 [`slice::rchunks`]: https://doc.rust-lang.org/std/primitive.slice.html#method.rchunks
2772 [cargo/6005]: https://github.com/rust-lang/cargo/pull/6005/
2773 [cargo/6319]: https://github.com/rust-lang/cargo/pull/6319/
2774 [cargo-rename-reference]: https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#renaming-dependencies-in-cargotoml
2775 [const-reference]: https://doc.rust-lang.org/reference/items/functions.html#const-functions
2776
2777 Version 1.30.1 (2018-11-08)
2778 ===========================
2779
2780 - [Fixed overflow ICE in rustdoc][54199]
2781 - [Cap Cargo progress bar width at 60 in MSYS terminals][cargo/6122]
2782
2783 [54199]: https://github.com/rust-lang/rust/pull/54199
2784 [cargo/6122]: https://github.com/rust-lang/cargo/pull/6122
2785
2786 Version 1.30.0 (2018-10-25)
2787 ==========================
2788
2789 Language
2790 --------
2791 - [Procedural macros are now available.][52081] These kinds of macros allow for
2792   more powerful code generation. There is a [new chapter available][proc-macros]
2793   in the Rust Programming Language book that goes further in depth.
2794 - [You can now use keywords as identifiers using the raw identifiers
2795   syntax (`r#`),][53236] e.g. `let r#for = true;`
2796 - [Using anonymous parameters in traits is now deprecated with a warning and
2797   will be a hard error in the 2018 edition.][53272]
2798 - [You can now use `crate` in paths.][54404] This allows you to refer to the
2799   crate root in the path, e.g. `use crate::foo;` refers to `foo` in `src/lib.rs`.
2800 - [Using a external crate no longer requires being prefixed with `::`.][54404]
2801   Previously, using a external crate in a module without a use statement
2802   required `let json = ::serde_json::from_str(foo);` but can now be written
2803   as `let json = serde_json::from_str(foo);`.
2804 - [You can now apply the `#[used]` attribute to static items to prevent the
2805   compiler from optimising them away, even if they appear to be unused,][51363]
2806   e.g. `#[used] static FOO: u32 = 1;`
2807 - [You can now import and reexport macros from other crates with the `use`
2808   syntax.][50911] Macros exported with `#[macro_export]` are now placed into
2809   the root module of the crate. If your macro relies on calling other local
2810   macros, it is recommended to export with the
2811   `#[macro_export(local_inner_macros)]` attribute so users won't have to import
2812   those macros.
2813 - [You can now catch visibility keywords (e.g. `pub`, `pub(crate)`) in macros
2814   using the `vis` specifier.][53370]
2815 - [Non-macro attributes now allow all forms of literals, not just
2816   strings.][53044] Previously, you would write `#[attr("true")]`, and you can now
2817   write `#[attr(true)]`.
2818 - [You can now specify a function to handle a panic in the Rust runtime with the
2819   `#[panic_handler]` attribute.][51366]
2820
2821 Compiler
2822 --------
2823 - [Added the `riscv32imc-unknown-none-elf` target.][53822]
2824 - [Added the `aarch64-unknown-netbsd` target][53165]
2825 - [Upgraded to LLVM 8.][53611]
2826
2827 Libraries
2828 ---------
2829 - [`ManuallyDrop` now allows the inner type to be unsized.][53033]
2830
2831 Stabilized APIs
2832 ---------------
2833 - [`Ipv4Addr::BROADCAST`]
2834 - [`Ipv4Addr::LOCALHOST`]
2835 - [`Ipv4Addr::UNSPECIFIED`]
2836 - [`Ipv6Addr::LOCALHOST`]
2837 - [`Ipv6Addr::UNSPECIFIED`]
2838 - [`Iterator::find_map`]
2839
2840   The following methods are replacement methods for `trim_left`, `trim_right`,
2841   `trim_left_matches`, and `trim_right_matches`, which will be deprecated
2842   in 1.33.0:
2843 - [`str::trim_end_matches`]
2844 - [`str::trim_end`]
2845 - [`str::trim_start_matches`]
2846 - [`str::trim_start`]
2847
2848 Cargo
2849 ----
2850 - [`cargo run` doesn't require specifying a package in workspaces.][cargo/5877]
2851 - [`cargo doc` now supports `--message-format=json`.][cargo/5878] This is
2852   equivalent to calling `rustdoc --error-format=json`.
2853 - [Cargo will now provide a progress bar for builds.][cargo/5995]
2854
2855 Misc
2856 ----
2857 - [`rustdoc` allows you to specify what edition to treat your code as with the
2858   `--edition` option.][54057]
2859 - [`rustdoc` now has the `--color` (specify whether to output color) and
2860   `--error-format` (specify error format, e.g. `json`) options.][53003]
2861 - [We now distribute a `rust-gdbgui` script that invokes `gdbgui` with Rust
2862   debug symbols.][53774]
2863 - [Attributes from Rust tools such as `rustfmt` or `clippy` are now
2864   available,][53459] e.g. `#[rustfmt::skip]` will skip formatting the next item.
2865
2866 [50911]: https://github.com/rust-lang/rust/pull/50911/
2867 [51363]: https://github.com/rust-lang/rust/pull/51363/
2868 [51366]: https://github.com/rust-lang/rust/pull/51366/
2869 [52081]: https://github.com/rust-lang/rust/pull/52081/
2870 [53003]: https://github.com/rust-lang/rust/pull/53003/
2871 [53033]: https://github.com/rust-lang/rust/pull/53033/
2872 [53044]: https://github.com/rust-lang/rust/pull/53044/
2873 [53165]: https://github.com/rust-lang/rust/pull/53165/
2874 [53611]: https://github.com/rust-lang/rust/pull/53611/
2875 [53213]: https://github.com/rust-lang/rust/pull/53213/
2876 [53236]: https://github.com/rust-lang/rust/pull/53236/
2877 [53272]: https://github.com/rust-lang/rust/pull/53272/
2878 [53370]: https://github.com/rust-lang/rust/pull/53370/
2879 [53459]: https://github.com/rust-lang/rust/pull/53459/
2880 [53774]: https://github.com/rust-lang/rust/pull/53774/
2881 [53822]: https://github.com/rust-lang/rust/pull/53822/
2882 [54057]: https://github.com/rust-lang/rust/pull/54057/
2883 [54146]: https://github.com/rust-lang/rust/pull/54146/
2884 [54404]: https://github.com/rust-lang/rust/pull/54404/
2885 [cargo/5877]: https://github.com/rust-lang/cargo/pull/5877/
2886 [cargo/5878]: https://github.com/rust-lang/cargo/pull/5878/
2887 [cargo/5995]: https://github.com/rust-lang/cargo/pull/5995/
2888 [proc-macros]: https://doc.rust-lang.org/nightly/book/2018-edition/ch19-06-macros.html
2889
2890 [`Ipv4Addr::BROADCAST`]: https://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#associatedconstant.BROADCAST
2891 [`Ipv4Addr::LOCALHOST`]: https://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#associatedconstant.LOCALHOST
2892 [`Ipv4Addr::UNSPECIFIED`]: https://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#associatedconstant.UNSPECIFIED
2893 [`Ipv6Addr::LOCALHOST`]: https://doc.rust-lang.org/nightly/std/net/struct.Ipv6Addr.html#associatedconstant.LOCALHOST
2894 [`Ipv6Addr::UNSPECIFIED`]: https://doc.rust-lang.org/nightly/std/net/struct.Ipv6Addr.html#associatedconstant.UNSPECIFIED
2895 [`Iterator::find_map`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.find_map
2896 [`str::trim_end_matches`]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.trim_end_matches
2897 [`str::trim_end`]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.trim_end
2898 [`str::trim_start_matches`]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.trim_start_matches
2899 [`str::trim_start`]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.trim_start
2900
2901
2902 Version 1.29.2 (2018-10-11)
2903 ===========================
2904
2905 - [Workaround for an aliasing-related LLVM bug, which caused miscompilation.][54639]
2906 - The `rls-preview` component on the windows-gnu targets has been restored.
2907
2908 [54639]: https://github.com/rust-lang/rust/pull/54639
2909
2910
2911 Version 1.29.1 (2018-09-25)
2912 ===========================
2913
2914 Security Notes
2915 --------------
2916
2917 - The standard library's `str::repeat` function contained an out of bounds write
2918   caused by an integer overflow. This has been fixed by deterministically
2919   panicking when an overflow happens.
2920
2921   Thank you to Scott McMurray for responsibly disclosing this vulnerability to
2922   us.
2923
2924
2925 Version 1.29.0 (2018-09-13)
2926 ==========================
2927
2928 Compiler
2929 --------
2930 - [Bumped minimum LLVM version to 5.0.][51899]
2931 - [Added `powerpc64le-unknown-linux-musl` target.][51619]
2932 - [Added `aarch64-unknown-hermit` and `x86_64-unknown-hermit` targets.][52861]
2933 - [Upgraded to LLVM 7.][51966]
2934
2935 Libraries
2936 ---------
2937 - [`Once::call_once` no longer requires `Once` to be `'static`.][52239]
2938 - [`BuildHasherDefault` now implements `PartialEq` and `Eq`.][52402]
2939 - [`Box<CStr>`, `Box<OsStr>`, and `Box<Path>` now implement `Clone`.][51912]
2940 - [Implemented `PartialEq<&str>` for `OsString` and `PartialEq<OsString>`
2941   for `&str`.][51178]
2942 - [`Cell<T>` now allows `T` to be unsized.][50494]
2943 - [`SocketAddr` is now stable on Redox.][52656]
2944
2945 Stabilized APIs
2946 ---------------
2947 - [`Arc::downcast`]
2948 - [`Iterator::flatten`]
2949 - [`Rc::downcast`]
2950
2951 Cargo
2952 -----
2953 - [Cargo can silently fix some bad lockfiles.][cargo/5831] You can use
2954   `--locked` to disable this behavior.
2955 - [`cargo-install` will now allow you to cross compile an install
2956   using `--target`.][cargo/5614]
2957 - [Added the `cargo-fix` subcommand to automatically move project code from
2958   2015 edition to 2018.][cargo/5723]
2959 - [`cargo doc` can now optionally document private types using the
2960   `--document-private-items` flag.][cargo/5543]
2961
2962 Misc
2963 ----
2964 - [`rustdoc` now has the `--cap-lints` option which demotes all lints above
2965   the specified level to that level.][52354] For example `--cap-lints warn`
2966   will demote `deny` and `forbid` lints to `warn`.
2967 - [`rustc` and `rustdoc` will now have the exit code of `1` if compilation
2968   fails and `101` if there is a panic.][52197]
2969 - [A preview of clippy has been made available through rustup.][51122]
2970   You can install the preview with `rustup component add clippy-preview`.
2971
2972 Compatibility Notes
2973 -------------------
2974 - [`str::{slice_unchecked, slice_unchecked_mut}` are now deprecated.][51807]
2975   Use `str::get_unchecked(begin..end)` instead.
2976 - [`std::env::home_dir` is now deprecated for its unintuitive behavior.][51656]
2977   Consider using the `home_dir` function from
2978   https://crates.io/crates/dirs instead.
2979 - [`rustc` will no longer silently ignore invalid data in target spec.][52330]
2980 - [`cfg` attributes and `--cfg` command line flags are now more
2981   strictly validated.][53893]
2982
2983 [53893]: https://github.com/rust-lang/rust/pull/53893/
2984 [52861]: https://github.com/rust-lang/rust/pull/52861/
2985 [51966]: https://github.com/rust-lang/rust/pull/51966/
2986 [52656]: https://github.com/rust-lang/rust/pull/52656/
2987 [52239]: https://github.com/rust-lang/rust/pull/52239/
2988 [52330]: https://github.com/rust-lang/rust/pull/52330/
2989 [52354]: https://github.com/rust-lang/rust/pull/52354/
2990 [52402]: https://github.com/rust-lang/rust/pull/52402/
2991 [52103]: https://github.com/rust-lang/rust/pull/52103/
2992 [52197]: https://github.com/rust-lang/rust/pull/52197/
2993 [51807]: https://github.com/rust-lang/rust/pull/51807/
2994 [51899]: https://github.com/rust-lang/rust/pull/51899/
2995 [51912]: https://github.com/rust-lang/rust/pull/51912/
2996 [51511]: https://github.com/rust-lang/rust/pull/51511/
2997 [51619]: https://github.com/rust-lang/rust/pull/51619/
2998 [51656]: https://github.com/rust-lang/rust/pull/51656/
2999 [51178]: https://github.com/rust-lang/rust/pull/51178/
3000 [51122]: https://github.com/rust-lang/rust/pull/51122
3001 [50494]: https://github.com/rust-lang/rust/pull/50494/
3002 [cargo/5543]: https://github.com/rust-lang/cargo/pull/5543
3003 [cargo/5614]: https://github.com/rust-lang/cargo/pull/5614/
3004 [cargo/5723]: https://github.com/rust-lang/cargo/pull/5723/
3005 [cargo/5831]: https://github.com/rust-lang/cargo/pull/5831/
3006 [`Arc::downcast`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.downcast
3007 [`Iterator::flatten`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.flatten
3008 [`Rc::downcast`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.downcast
3009
3010
3011 Version 1.28.0 (2018-08-02)
3012 ===========================
3013
3014 Language
3015 --------
3016 - [The `#[repr(transparent)]` attribute is now stable.][51562] This attribute
3017   allows a Rust newtype wrapper (`struct NewType<T>(T);`) to be represented as
3018   the inner type across Foreign Function Interface (FFI) boundaries.
3019 - [The keywords `pure`, `sizeof`, `alignof`, and `offsetof` have been unreserved
3020   and can now be used as identifiers.][51196]
3021 - [The `GlobalAlloc` trait and `#[global_allocator]` attribute are now
3022   stable.][51241] This will allow users to specify a global allocator for
3023   their program.
3024 - [Unit test functions marked with the `#[test]` attribute can now return
3025   `Result<(), E: Debug>` in addition to `()`.][51298]
3026 - [The `lifetime` specifier for `macro_rules!` is now stable.][50385] This
3027   allows macros to easily target lifetimes.
3028
3029 Compiler
3030 --------
3031 - [The `s` and `z` optimisation levels are now stable.][50265] These optimisations
3032   prioritise making smaller binary sizes. `z` is the same as `s` with the
3033   exception that it does not vectorise loops, which typically results in an even
3034   smaller binary.
3035 - [The short error format is now stable.][49546] Specified with
3036   `--error-format=short` this option will provide a more compressed output of
3037   rust error messages.
3038 - [Added a lint warning when you have duplicated `macro_export`s.][50143]
3039 - [Reduced the number of allocations in the macro parser.][50855] This can
3040   improve compile times of macro heavy crates on average by 5%.
3041
3042 Libraries
3043 ---------
3044 - [Implemented `Default` for `&mut str`.][51306]
3045 - [Implemented `From<bool>` for all integer and unsigned number types.][50554]
3046 - [Implemented `Extend` for `()`.][50234]
3047 - [The `Debug` implementation of `time::Duration` should now be more easily
3048   human readable.][50364] Previously a `Duration` of one second would printed as
3049   `Duration { secs: 1, nanos: 0 }` and will now be printed as `1s`.
3050 - [Implemented `From<&String>` for `Cow<str>`, `From<&Vec<T>>` for `Cow<[T]>`,
3051   `From<Cow<CStr>>` for `CString`, `From<CString>, From<CStr>, From<&CString>`
3052   for `Cow<CStr>`, `From<OsString>, From<OsStr>, From<&OsString>` for
3053   `Cow<OsStr>`, `From<&PathBuf>` for `Cow<Path>`, and `From<Cow<Path>>`
3054   for `PathBuf`.][50170]
3055 - [Implemented `Shl` and `Shr` for `Wrapping<u128>`
3056   and `Wrapping<i128>`.][50465]
3057 - [`DirEntry::metadata` now uses `fstatat` instead of `lstat` when
3058   possible.][51050] This can provide up to a 40% speed increase.
3059 - [Improved error messages when using `format!`.][50610]
3060
3061 Stabilized APIs
3062 ---------------
3063 - [`Iterator::step_by`]
3064 - [`Path::ancestors`]
3065 - [`SystemTime::UNIX_EPOCH`]
3066 - [`alloc::GlobalAlloc`]
3067 - [`alloc::Layout`]
3068 - [`alloc::LayoutErr`]
3069 - [`alloc::System`]
3070 - [`alloc::alloc`]
3071 - [`alloc::alloc_zeroed`]
3072 - [`alloc::dealloc`]
3073 - [`alloc::realloc`]
3074 - [`alloc::handle_alloc_error`]
3075 - [`btree_map::Entry::or_default`]
3076 - [`fmt::Alignment`]
3077 - [`hash_map::Entry::or_default`]
3078 - [`iter::repeat_with`]
3079 - [`num::NonZeroUsize`]
3080 - [`num::NonZeroU128`]
3081 - [`num::NonZeroU16`]
3082 - [`num::NonZeroU32`]
3083 - [`num::NonZeroU64`]
3084 - [`num::NonZeroU8`]
3085 - [`ops::RangeBounds`]
3086 - [`slice::SliceIndex`]
3087 - [`slice::from_mut`]
3088 - [`slice::from_ref`]
3089 - [`{Any + Send + Sync}::downcast_mut`]
3090 - [`{Any + Send + Sync}::downcast_ref`]
3091 - [`{Any + Send + Sync}::is`]
3092
3093 Cargo
3094 -----
3095 - [Cargo will now no longer allow you to publish crates with build scripts that
3096   modify the `src` directory.][cargo/5584] The `src` directory in a crate should be
3097   considered to be immutable.
3098
3099 Misc
3100 ----
3101 - [The `suggestion_applicability` field in `rustc`'s json output is now
3102   stable.][50486] This will allow dev tools to check whether a code suggestion
3103   would apply to them.
3104
3105 Compatibility Notes
3106 -------------------
3107 - [Rust will consider trait objects with duplicated constraints to be the same
3108   type as without the duplicated constraint.][51276] For example the below code will
3109   now fail to compile.
3110   ```rust
3111   trait Trait {}
3112
3113   impl Trait + Send {
3114       fn test(&self) { println!("one"); } //~ ERROR duplicate definitions with name `test`
3115   }
3116
3117   impl Trait + Send + Send {
3118       fn test(&self) { println!("two"); }
3119   }
3120   ```
3121
3122 [49546]: https://github.com/rust-lang/rust/pull/49546/
3123 [50143]: https://github.com/rust-lang/rust/pull/50143/
3124 [50170]: https://github.com/rust-lang/rust/pull/50170/
3125 [50234]: https://github.com/rust-lang/rust/pull/50234/
3126 [50265]: https://github.com/rust-lang/rust/pull/50265/
3127 [50364]: https://github.com/rust-lang/rust/pull/50364/
3128 [50385]: https://github.com/rust-lang/rust/pull/50385/
3129 [50465]: https://github.com/rust-lang/rust/pull/50465/
3130 [50486]: https://github.com/rust-lang/rust/pull/50486/
3131 [50554]: https://github.com/rust-lang/rust/pull/50554/
3132 [50610]: https://github.com/rust-lang/rust/pull/50610/
3133 [50855]: https://github.com/rust-lang/rust/pull/50855/
3134 [51050]: https://github.com/rust-lang/rust/pull/51050/
3135 [51196]: https://github.com/rust-lang/rust/pull/51196/
3136 [51200]: https://github.com/rust-lang/rust/pull/51200/
3137 [51241]: https://github.com/rust-lang/rust/pull/51241/
3138 [51276]: https://github.com/rust-lang/rust/pull/51276/
3139 [51298]: https://github.com/rust-lang/rust/pull/51298/
3140 [51306]: https://github.com/rust-lang/rust/pull/51306/
3141 [51562]: https://github.com/rust-lang/rust/pull/51562/
3142 [cargo/5584]: https://github.com/rust-lang/cargo/pull/5584/
3143 [`Iterator::step_by`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.step_by
3144 [`Path::ancestors`]: https://doc.rust-lang.org/std/path/struct.Path.html#method.ancestors
3145 [`SystemTime::UNIX_EPOCH`]: https://doc.rust-lang.org/std/time/struct.SystemTime.html#associatedconstant.UNIX_EPOCH
3146 [`alloc::GlobalAlloc`]: https://doc.rust-lang.org/std/alloc/trait.GlobalAlloc.html
3147 [`alloc::Layout`]: https://doc.rust-lang.org/std/alloc/struct.Layout.html
3148 [`alloc::LayoutErr`]: https://doc.rust-lang.org/std/alloc/struct.LayoutErr.html
3149 [`alloc::System`]: https://doc.rust-lang.org/std/alloc/struct.System.html
3150 [`alloc::alloc`]: https://doc.rust-lang.org/std/alloc/fn.alloc.html
3151 [`alloc::alloc_zeroed`]: https://doc.rust-lang.org/std/alloc/fn.alloc_zeroed.html
3152 [`alloc::dealloc`]: https://doc.rust-lang.org/std/alloc/fn.dealloc.html
3153 [`alloc::realloc`]: https://doc.rust-lang.org/std/alloc/fn.realloc.html
3154 [`alloc::handle_alloc_error`]: https://doc.rust-lang.org/std/alloc/fn.handle_alloc_error.html
3155 [`btree_map::Entry::or_default`]: https://doc.rust-lang.org/std/collections/btree_map/enum.Entry.html#method.or_default
3156 [`fmt::Alignment`]: https://doc.rust-lang.org/std/fmt/enum.Alignment.html
3157 [`hash_map::Entry::or_default`]: https://doc.rust-lang.org/std/collections/hash_map/enum.Entry.html#method.or_default
3158 [`iter::repeat_with`]: https://doc.rust-lang.org/std/iter/fn.repeat_with.html
3159 [`num::NonZeroUsize`]: https://doc.rust-lang.org/std/num/struct.NonZeroUsize.html
3160 [`num::NonZeroU128`]: https://doc.rust-lang.org/std/num/struct.NonZeroU128.html
3161 [`num::NonZeroU16`]: https://doc.rust-lang.org/std/num/struct.NonZeroU16.html
3162 [`num::NonZeroU32`]: https://doc.rust-lang.org/std/num/struct.NonZeroU32.html
3163 [`num::NonZeroU64`]: https://doc.rust-lang.org/std/num/struct.NonZeroU64.html
3164 [`num::NonZeroU8`]: https://doc.rust-lang.org/std/num/struct.NonZeroU8.html
3165 [`ops::RangeBounds`]: https://doc.rust-lang.org/std/ops/trait.RangeBounds.html
3166 [`slice::SliceIndex`]: https://doc.rust-lang.org/std/slice/trait.SliceIndex.html
3167 [`slice::from_mut`]: https://doc.rust-lang.org/std/slice/fn.from_mut.html
3168 [`slice::from_ref`]: https://doc.rust-lang.org/std/slice/fn.from_ref.html
3169 [`{Any + Send + Sync}::downcast_mut`]: https://doc.rust-lang.org/std/any/trait.Any.html#method.downcast_mut-2
3170 [`{Any + Send + Sync}::downcast_ref`]: https://doc.rust-lang.org/std/any/trait.Any.html#method.downcast_ref-2
3171 [`{Any + Send + Sync}::is`]: https://doc.rust-lang.org/std/any/trait.Any.html#method.is-2
3172
3173 Version 1.27.2 (2018-07-20)
3174 ===========================
3175
3176 Compatibility Notes
3177 -------------------
3178
3179 - The borrow checker was fixed to avoid potential unsoundness when using
3180   match ergonomics: [#52213][52213].
3181
3182 [52213]: https://github.com/rust-lang/rust/issues/52213
3183
3184 Version 1.27.1 (2018-07-10)
3185 ===========================
3186
3187 Security Notes
3188 --------------
3189
3190 - rustdoc would execute plugins in the /tmp/rustdoc/plugins directory
3191   when running, which enabled executing code as some other user on a
3192   given machine. This release fixes that vulnerability; you can read
3193   more about this on the [blog][rustdoc-sec]. The associated CVE is [CVE-2018-1000622].
3194
3195   Thank you to Red Hat for responsibly disclosing this vulnerability to us.
3196
3197 Compatibility Notes
3198 -------------------
3199
3200 - The borrow checker was fixed to avoid an additional potential unsoundness when using
3201   match ergonomics: [#51415][51415], [#49534][49534].
3202
3203 [51415]: https://github.com/rust-lang/rust/issues/51415
3204 [49534]: https://github.com/rust-lang/rust/issues/49534
3205 [rustdoc-sec]: https://blog.rust-lang.org/2018/07/06/security-advisory-for-rustdoc.html
3206 [CVE-2018-1000622]: https://cve.mitre.org/cgi-bin/cvename.cgi?name=%20CVE-2018-1000622
3207
3208 Version 1.27.0 (2018-06-21)
3209 ==========================
3210
3211 Language
3212 --------
3213 - [Removed 'proc' from the reserved keywords list.][49699] This allows `proc` to
3214   be used as an identifier.
3215 - [The dyn syntax is now available.][49968] This syntax is equivalent to the
3216   bare `Trait` syntax, and should make it clearer when being used in tandem with
3217   `impl Trait` because it is equivalent to the following syntax:
3218   `&Trait == &dyn Trait`, `&mut Trait == &mut dyn Trait`, and
3219   `Box<Trait> == Box<dyn Trait>`.
3220 - [Attributes on generic parameters such as types and lifetimes are
3221   now stable.][48851] e.g.
3222   `fn foo<#[lifetime_attr] 'a, #[type_attr] T: 'a>() {}`
3223 - [The `#[must_use]` attribute can now also be used on functions as well as
3224   types.][48925] It provides a lint that by default warns users when the
3225   value returned by a function has not been used.
3226
3227 Compiler
3228 --------
3229 - [Added the `armv5te-unknown-linux-musleabi` target.][50423]
3230
3231 Libraries
3232 ---------
3233 - [SIMD (Single Instruction Multiple Data) on x86/x86_64 is now stable.][49664]
3234   This includes [`arch::x86`] & [`arch::x86_64`] modules which contain
3235   SIMD intrinsics, a new macro called `is_x86_feature_detected!`, the
3236   `#[target_feature(enable="")]` attribute, and adding `target_feature = ""` to
3237   the `cfg` attribute.
3238 - [A lot of methods for `[u8]`, `f32`, and `f64` previously only available in
3239   std are now available in core.][49896]
3240 - [The generic `Rhs` type parameter on `ops::{Shl, ShlAssign, Shr}` now defaults
3241   to `Self`.][49630]
3242 - [`std::str::replace` now has the `#[must_use]` attribute][50177] to clarify
3243   that the operation isn't done in place.
3244 - [`Clone::clone`, `Iterator::collect`, and `ToOwned::to_owned` now have
3245   the `#[must_use]` attribute][49533] to warn about unused potentially
3246   expensive allocations.
3247
3248 Stabilized APIs
3249 ---------------
3250 - [`DoubleEndedIterator::rfind`]
3251 - [`DoubleEndedIterator::rfold`]
3252 - [`DoubleEndedIterator::try_rfold`]
3253 - [`Duration::from_micros`]
3254 - [`Duration::from_nanos`]
3255 - [`Duration::subsec_micros`]
3256 - [`Duration::subsec_millis`]
3257 - [`HashMap::remove_entry`]
3258 - [`Iterator::try_fold`]
3259 - [`Iterator::try_for_each`]
3260 - [`NonNull::cast`]
3261 - [`Option::filter`]
3262 - [`String::replace_range`]
3263 - [`Take::set_limit`]
3264 - [`hint::unreachable_unchecked`]
3265 - [`os::unix::process::parent_id`]
3266 - [`ptr::swap_nonoverlapping`]
3267 - [`slice::rsplit_mut`]
3268 - [`slice::rsplit`]
3269 - [`slice::swap_with_slice`]
3270
3271 Cargo
3272 -----
3273 - [`cargo-metadata` now includes `authors`, `categories`, `keywords`,
3274   `readme`, and `repository` fields.][cargo/5386]
3275 - [`cargo-metadata` now includes a package's `metadata` table.][cargo/5360]
3276 - [Added the `--target-dir` optional argument.][cargo/5393] This allows you to specify
3277   a different directory than `target` for placing compilation artifacts.
3278 - [Cargo will be adding automatic target inference for binaries, benchmarks,
3279   examples, and tests in the Rust 2018 edition.][cargo/5335] If your project specifies
3280   specific targets, e.g. using `[[bin]]`, and have other binaries in locations
3281   where cargo would infer a binary, Cargo will produce a warning. You can
3282   disable this feature ahead of time by setting any of the following to false:
3283   `autobins`, `autobenches`, `autoexamples`, `autotests`.
3284 - [Cargo will now cache compiler information.][cargo/5359] This can be disabled by
3285   setting `CARGO_CACHE_RUSTC_INFO=0` in your environment.
3286
3287 Misc
3288 ----
3289 - [Added “The Rustc book” into the official documentation.][49707]
3290   [“The Rustc book”] documents and teaches how to use the rustc compiler.
3291 - [All books available on `doc.rust-lang.org` are now searchable.][49623]
3292
3293 Compatibility Notes
3294 -------------------
3295 - [Calling a `CharExt` or `StrExt` method directly on core will no longer
3296   work.][49896] e.g. `::core::prelude::v1::StrExt::is_empty("")` will not
3297   compile, `"".is_empty()` will still compile.
3298 - [`Debug` output on `atomic::{AtomicBool, AtomicIsize, AtomicPtr, AtomicUsize}`
3299   will only print the inner type.][48553] E.g.
3300   `print!("{:?}", AtomicBool::new(true))` will print `true`,
3301   not `AtomicBool(true)`.
3302 - [The maximum number for `repr(align(N))` is now 2²⁹.][50378] Previously you
3303   could enter higher numbers but they were not supported by LLVM. Up to 512MB
3304   alignment should cover all use cases.
3305 - The `.description()` method on the `std::error::Error` trait
3306   [has been soft-deprecated][50163]. It is no longer required to implement it.
3307
3308 [48553]: https://github.com/rust-lang/rust/pull/48553/
3309 [48851]: https://github.com/rust-lang/rust/pull/48851/
3310 [48925]: https://github.com/rust-lang/rust/pull/48925/
3311 [49533]: https://github.com/rust-lang/rust/pull/49533/
3312 [49623]: https://github.com/rust-lang/rust/pull/49623/
3313 [49630]: https://github.com/rust-lang/rust/pull/49630/
3314 [49664]: https://github.com/rust-lang/rust/pull/49664/
3315 [49699]: https://github.com/rust-lang/rust/pull/49699/
3316 [49707]: https://github.com/rust-lang/rust/pull/49707/
3317 [49719]: https://github.com/rust-lang/rust/pull/49719/
3318 [49896]: https://github.com/rust-lang/rust/pull/49896/
3319 [49968]: https://github.com/rust-lang/rust/pull/49968/
3320 [50163]: https://github.com/rust-lang/rust/pull/50163
3321 [50177]: https://github.com/rust-lang/rust/pull/50177/
3322 [50378]: https://github.com/rust-lang/rust/pull/50378/
3323 [50398]: https://github.com/rust-lang/rust/pull/50398/
3324 [50423]: https://github.com/rust-lang/rust/pull/50423/
3325 [cargo/5203]: https://github.com/rust-lang/cargo/pull/5203/
3326 [cargo/5335]: https://github.com/rust-lang/cargo/pull/5335/
3327 [cargo/5359]: https://github.com/rust-lang/cargo/pull/5359/
3328 [cargo/5360]: https://github.com/rust-lang/cargo/pull/5360/
3329 [cargo/5386]: https://github.com/rust-lang/cargo/pull/5386/
3330 [cargo/5393]: https://github.com/rust-lang/cargo/pull/5393/
3331 [`DoubleEndedIterator::rfind`]: https://doc.rust-lang.org/std/iter/trait.DoubleEndedIterator.html#method.rfind
3332 [`DoubleEndedIterator::rfold`]: https://doc.rust-lang.org/std/iter/trait.DoubleEndedIterator.html#method.rfold
3333 [`DoubleEndedIterator::try_rfold`]: https://doc.rust-lang.org/std/iter/trait.DoubleEndedIterator.html#method.try_rfold
3334 [`Duration::from_micros`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.from_micros
3335 [`Duration::from_nanos`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.from_nanos
3336 [`Duration::subsec_micros`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.subsec_micros
3337 [`Duration::subsec_millis`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.subsec_millis
3338 [`HashMap::remove_entry`]: https://doc.rust-lang.org/std/collections/struct.HashMap.html#method.remove_entry
3339 [`Iterator::try_fold`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.try_fold
3340 [`Iterator::try_for_each`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.try_for_each
3341 [`NonNull::cast`]: https://doc.rust-lang.org/std/ptr/struct.NonNull.html#method.cast
3342 [`Option::filter`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.filter
3343 [`String::replace_range`]: https://doc.rust-lang.org/std/string/struct.String.html#method.replace_range
3344 [`Take::set_limit`]: https://doc.rust-lang.org/std/io/struct.Take.html#method.set_limit
3345 [`hint::unreachable_unchecked`]: https://doc.rust-lang.org/std/hint/fn.unreachable_unchecked.html
3346 [`os::unix::process::parent_id`]: https://doc.rust-lang.org/std/os/unix/process/fn.parent_id.html
3347 [`process::id`]: https://doc.rust-lang.org/std/process/fn.id.html
3348 [`ptr::swap_nonoverlapping`]: https://doc.rust-lang.org/std/ptr/fn.swap_nonoverlapping.html
3349 [`slice::rsplit_mut`]: https://doc.rust-lang.org/std/primitive.slice.html#method.rsplit_mut
3350 [`slice::rsplit`]: https://doc.rust-lang.org/std/primitive.slice.html#method.rsplit
3351 [`slice::swap_with_slice`]: https://doc.rust-lang.org/std/primitive.slice.html#method.swap_with_slice
3352 [`arch::x86_64`]: https://doc.rust-lang.org/std/arch/x86_64/index.html
3353 [`arch::x86`]: https://doc.rust-lang.org/std/arch/x86/index.html
3354 [“The Rustc book”]: https://doc.rust-lang.org/rustc
3355
3356
3357 Version 1.26.2 (2018-06-05)
3358 ==========================
3359
3360 Compatibility Notes
3361 -------------------
3362
3363 - [The borrow checker was fixed to avoid unsoundness when using match ergonomics.][51117]
3364
3365 [51117]: https://github.com/rust-lang/rust/issues/51117
3366
3367
3368 Version 1.26.1 (2018-05-29)
3369 ==========================
3370
3371 Tools
3372 -----
3373
3374 - [RLS now works on Windows.][50646]
3375 - [Rustfmt stopped badly formatting text in some cases.][rustfmt/2695]
3376
3377
3378 Compatibility Notes
3379 --------
3380
3381 - [`fn main() -> impl Trait` no longer works for non-Termination
3382   trait.][50656]
3383   This reverts an accidental stabilization.
3384 - [`NaN > NaN` no longer returns true in const-fn contexts.][50812]
3385 - [Prohibit using turbofish for `impl Trait` in method arguments.][50950]
3386
3387 [50646]: https://github.com/rust-lang/rust/issues/50646
3388 [50656]: https://github.com/rust-lang/rust/pull/50656
3389 [50812]: https://github.com/rust-lang/rust/pull/50812
3390 [50950]: https://github.com/rust-lang/rust/issues/50950
3391 [rustfmt/2695]: https://github.com/rust-lang-nursery/rustfmt/issues/2695
3392
3393 Version 1.26.0 (2018-05-10)
3394 ==========================
3395
3396 Language
3397 --------
3398 - [Closures now implement `Copy` and/or `Clone` if all captured variables
3399   implement either or both traits.][49299]
3400 - [The inclusive range syntax e.g. `for x in 0..=10` is now stable.][47813]
3401 - [The `'_` lifetime is now stable. The underscore lifetime can be used anywhere a
3402   lifetime can be elided.][49458]
3403 - [`impl Trait` is now stable allowing you to have abstract types in returns
3404    or in function parameters.][49255] E.g. `fn foo() -> impl Iterator<Item=u8>` or
3405   `fn open(path: impl AsRef<Path>)`.
3406 - [Pattern matching will now automatically apply dereferences.][49394]
3407 - [128-bit integers in the form of `u128` and `i128` are now stable.][49101]
3408 - [`main` can now return `Result<(), E: Debug>`][49162] in addition to `()`.
3409 - [A lot of operations are now available in a const context.][46882] E.g. You
3410   can now index into constant arrays, reference and dereference into constants,
3411   and use tuple struct constructors.
3412 - [Fixed entry slice patterns are now stable.][48516] E.g.
3413   ```rust
3414   let points = [1, 2, 3, 4];
3415   match points {
3416       [1, 2, 3, 4] => println!("All points were sequential."),
3417       _ => println!("Not all points were sequential."),
3418   }
3419   ```
3420
3421
3422 Compiler
3423 --------
3424 - [LLD is now used as the default linker for `wasm32-unknown-unknown`.][48125]
3425 - [Fixed exponential projection complexity on nested types.][48296]
3426   This can provide up to a ~12% reduction in compile times for certain crates.
3427 - [Added the `--remap-path-prefix` option to rustc.][48359] Allowing you
3428   to remap path prefixes outputted by the compiler.
3429 - [Added `powerpc-unknown-netbsd` target.][48281]
3430
3431 Libraries
3432 ---------
3433 - [Implemented `From<u16> for usize` & `From<{u8, i16}> for isize`.][49305]
3434 - [Added hexadecimal formatting for integers with fmt::Debug][48978]
3435   e.g. `assert!(format!("{:02x?}", b"Foo\0") == "[46, 6f, 6f, 00]")`
3436 - [Implemented `Default, Hash` for `cmp::Reverse`.][48628]
3437 - [Optimized `str::repeat` being 8x faster in large cases.][48657]
3438 - [`ascii::escape_default` is now available in libcore.][48735]
3439 - [Trailing commas are now supported in std and core macros.][48056]
3440 - [Implemented `Copy, Clone` for `cmp::Reverse`][47379]
3441 - [Implemented `Clone` for `char::{ToLowercase, ToUppercase}`.][48629]
3442
3443 Stabilized APIs
3444 ---------------
3445 - [`*const T::add`]
3446 - [`*const T::copy_to_nonoverlapping`]
3447 - [`*const T::copy_to`]
3448 - [`*const T::read_unaligned`]
3449 - [`*const T::read_volatile`]
3450 - [`*const T::read`]
3451 - [`*const T::sub`]
3452 - [`*const T::wrapping_add`]
3453 - [`*const T::wrapping_sub`]
3454 - [`*mut T::add`]
3455 - [`*mut T::copy_to_nonoverlapping`]
3456 - [`*mut T::copy_to`]
3457 - [`*mut T::read_unaligned`]
3458 - [`*mut T::read_volatile`]
3459 - [`*mut T::read`]
3460 - [`*mut T::replace`]
3461 - [`*mut T::sub`]
3462 - [`*mut T::swap`]
3463 - [`*mut T::wrapping_add`]
3464 - [`*mut T::wrapping_sub`]
3465 - [`*mut T::write_bytes`]
3466 - [`*mut T::write_unaligned`]
3467 - [`*mut T::write_volatile`]
3468 - [`*mut T::write`]
3469 - [`Box::leak`]
3470 - [`FromUtf8Error::as_bytes`]
3471 - [`LocalKey::try_with`]
3472 - [`Option::cloned`]
3473 - [`btree_map::Entry::and_modify`]
3474 - [`fs::read_to_string`]
3475 - [`fs::read`]
3476 - [`fs::write`]
3477 - [`hash_map::Entry::and_modify`]
3478 - [`iter::FusedIterator`]
3479 - [`ops::RangeInclusive`]
3480 - [`ops::RangeToInclusive`]
3481 - [`process::id`]
3482 - [`slice::rotate_left`]
3483 - [`slice::rotate_right`]
3484 - [`String::retain`]
3485
3486
3487 Cargo
3488 -----
3489 - [Cargo will now output path to custom commands when `-v` is
3490   passed with `--list`][cargo/5041]
3491 - [The Cargo binary version is now the same as the Rust version][cargo/5083]
3492
3493 Misc
3494 ----
3495 - [The second edition of "The Rust Programming Language" book is now recommended
3496   over the first.][48404]
3497
3498 Compatibility Notes
3499 -------------------
3500
3501 - [aliasing a `Fn` trait as `dyn` no longer works.][48481] E.g. the following
3502   syntax is now invalid.
3503   ```
3504   use std::ops::Fn as dyn;
3505   fn g(_: Box<dyn(std::fmt::Debug)>) {}
3506   ```
3507 - [The result of dereferences are no longer promoted to `'static`.][47408]
3508   e.g.
3509   ```rust
3510   fn main() {
3511       const PAIR: &(i32, i32) = &(0, 1);
3512       let _reversed_pair: &'static _ = &(PAIR.1, PAIR.0); // Doesn't work
3513   }
3514   ```
3515 - [Deprecate `AsciiExt` trait in favor of inherent methods.][49109]
3516 - [`".e0"` will now no longer parse as `0.0` and will instead cause
3517   an error.][48235]
3518 - [Removed hoedown from rustdoc.][48274]
3519 - [Bounds on higher-kinded lifetimes a hard error.][48326]
3520
3521 [46882]: https://github.com/rust-lang/rust/pull/46882
3522 [47379]: https://github.com/rust-lang/rust/pull/47379
3523 [47408]: https://github.com/rust-lang/rust/pull/47408
3524 [47813]: https://github.com/rust-lang/rust/pull/47813
3525 [48056]: https://github.com/rust-lang/rust/pull/48056
3526 [48125]: https://github.com/rust-lang/rust/pull/48125
3527 [48166]: https://github.com/rust-lang/rust/pull/48166
3528 [48235]: https://github.com/rust-lang/rust/pull/48235
3529 [48274]: https://github.com/rust-lang/rust/pull/48274
3530 [48281]: https://github.com/rust-lang/rust/pull/48281
3531 [48296]: https://github.com/rust-lang/rust/pull/48296
3532 [48326]: https://github.com/rust-lang/rust/pull/48326
3533 [48359]: https://github.com/rust-lang/rust/pull/48359
3534 [48404]: https://github.com/rust-lang/rust/pull/48404
3535 [48481]: https://github.com/rust-lang/rust/pull/48481
3536 [48516]: https://github.com/rust-lang/rust/pull/48516
3537 [48628]: https://github.com/rust-lang/rust/pull/48628
3538 [48629]: https://github.com/rust-lang/rust/pull/48629
3539 [48657]: https://github.com/rust-lang/rust/pull/48657
3540 [48735]: https://github.com/rust-lang/rust/pull/48735
3541 [48978]: https://github.com/rust-lang/rust/pull/48978
3542 [49101]: https://github.com/rust-lang/rust/pull/49101
3543 [49109]: https://github.com/rust-lang/rust/pull/49109
3544 [49121]: https://github.com/rust-lang/rust/pull/49121
3545 [49162]: https://github.com/rust-lang/rust/pull/49162
3546 [49184]: https://github.com/rust-lang/rust/pull/49184
3547 [49234]: https://github.com/rust-lang/rust/pull/49234
3548 [49255]: https://github.com/rust-lang/rust/pull/49255
3549 [49299]: https://github.com/rust-lang/rust/pull/49299
3550 [49305]: https://github.com/rust-lang/rust/pull/49305
3551 [49394]: https://github.com/rust-lang/rust/pull/49394
3552 [49458]: https://github.com/rust-lang/rust/pull/49458
3553 [`*const T::add`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.add
3554 [`*const T::copy_to_nonoverlapping`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.copy_to_nonoverlapping
3555 [`*const T::copy_to`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.copy_to
3556 [`*const T::read_unaligned`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.read_unaligned
3557 [`*const T::read_volatile`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.read_volatile
3558 [`*const T::read`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.read
3559 [`*const T::sub`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.sub
3560 [`*const T::wrapping_add`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.wrapping_add
3561 [`*const T::wrapping_sub`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.wrapping_sub
3562 [`*mut T::add`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.add-1
3563 [`*mut T::copy_to_nonoverlapping`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.copy_to_nonoverlapping-1
3564 [`*mut T::copy_to`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.copy_to-1
3565 [`*mut T::read_unaligned`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.read_unaligned-1
3566 [`*mut T::read_volatile`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.read_volatile-1
3567 [`*mut T::read`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.read-1
3568 [`*mut T::replace`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.replace
3569 [`*mut T::sub`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.sub-1
3570 [`*mut T::swap`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.swap
3571 [`*mut T::wrapping_add`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.wrapping_add-1
3572 [`*mut T::wrapping_sub`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.wrapping_sub-1
3573 [`*mut T::write_bytes`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.write_bytes
3574 [`*mut T::write_unaligned`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.write_unaligned
3575 [`*mut T::write_volatile`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.write_volatile
3576 [`*mut T::write`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.write
3577 [`Box::leak`]: https://doc.rust-lang.org/std/boxed/struct.Box.html#method.leak
3578 [`FromUtf8Error::as_bytes`]: https://doc.rust-lang.org/std/string/struct.FromUtf8Error.html#method.as_bytes
3579 [`LocalKey::try_with`]: https://doc.rust-lang.org/std/thread/struct.LocalKey.html#method.try_with
3580 [`Option::cloned`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.cloned
3581 [`btree_map::Entry::and_modify`]: https://doc.rust-lang.org/std/collections/btree_map/enum.Entry.html#method.and_modify
3582 [`fs::read_to_string`]: https://doc.rust-lang.org/std/fs/fn.read_to_string.html
3583 [`fs::read`]: https://doc.rust-lang.org/std/fs/fn.read.html
3584 [`fs::write`]: https://doc.rust-lang.org/std/fs/fn.write.html
3585 [`hash_map::Entry::and_modify`]: https://doc.rust-lang.org/std/collections/hash_map/enum.Entry.html#method.and_modify
3586 [`iter::FusedIterator`]: https://doc.rust-lang.org/std/iter/trait.FusedIterator.html
3587 [`ops::RangeInclusive`]: https://doc.rust-lang.org/std/ops/struct.RangeInclusive.html
3588 [`ops::RangeToInclusive`]: https://doc.rust-lang.org/std/ops/struct.RangeToInclusive.html
3589 [`process::id`]: https://doc.rust-lang.org/std/process/fn.id.html
3590 [`slice::rotate_left`]: https://doc.rust-lang.org/std/primitive.slice.html#method.rotate_left
3591 [`slice::rotate_right`]: https://doc.rust-lang.org/std/primitive.slice.html#method.rotate_right
3592 [`String::retain`]: https://doc.rust-lang.org/std/string/struct.String.html#method.retain
3593 [cargo/5041]: https://github.com/rust-lang/cargo/pull/5041
3594 [cargo/5083]: https://github.com/rust-lang/cargo/pull/5083
3595
3596
3597 Version 1.25.0 (2018-03-29)
3598 ==========================
3599
3600 Language
3601 --------
3602 - [The `#[repr(align(x))]` attribute is now stable.][47006] [RFC 1358]
3603 - [You can now use nested groups of imports.][47948]
3604   e.g. `use std::{fs::File, io::Read, path::{Path, PathBuf}};`
3605 - [You can now have `|` at the start of a match arm.][47947] e.g.
3606 ```rust
3607 enum Foo { A, B, C }
3608
3609 fn main() {
3610     let x = Foo::A;
3611     match x {
3612         | Foo::A
3613         | Foo::B => println!("AB"),
3614         | Foo::C => println!("C"),
3615     }
3616 }
3617 ```
3618
3619 Compiler
3620 --------
3621 - [Upgraded to LLVM 6.][47828]
3622 - [Added `-C lto=val` option.][47521]
3623 - [Added `i586-unknown-linux-musl` target][47282]
3624
3625 Libraries
3626 ---------
3627 - [Impl Send for `process::Command` on Unix.][47760]
3628 - [Impl PartialEq and Eq for `ParseCharError`.][47790]
3629 - [`UnsafeCell::into_inner` is now safe.][47204]
3630 - [Implement libstd for CloudABI.][47268]
3631 - [`Float::{from_bits, to_bits}` is now available in libcore.][46931]
3632 - [Implement `AsRef<Path>` for Component][46985]
3633 - [Implemented `Write` for `Cursor<&mut Vec<u8>>`][46830]
3634 - [Moved `Duration` to libcore.][46666]
3635
3636 Stabilized APIs
3637 ---------------
3638 - [`Location::column`]
3639 - [`ptr::NonNull`]
3640
3641 The following functions can now be used in a constant expression.
3642 eg. `static MINUTE: Duration = Duration::from_secs(60);`
3643 - [`Duration::new`][47300]
3644 - [`Duration::from_secs`][47300]
3645 - [`Duration::from_millis`][47300]
3646
3647 Cargo
3648 -----
3649 - [`cargo new` no longer removes `rust` or `rs` prefixs/suffixs.][cargo/5013]
3650 - [`cargo new` now defaults to creating a binary crate, instead of a
3651   library crate.][cargo/5029]
3652
3653 Misc
3654 ----
3655 - [Rust by example is now shipped with new releases][46196]
3656
3657 Compatibility Notes
3658 -------------------
3659 - [Deprecated `net::lookup_host`.][47510]
3660 - [`rustdoc` has switched to pulldown as the default markdown renderer.][47398]
3661 - The borrow checker was sometimes incorrectly permitting overlapping borrows
3662   around indexing operations (see [#47349][47349]). This has been fixed (which also
3663   enabled some correct code that used to cause errors (e.g. [#33903][33903] and [#46095][46095]).
3664 - [Removed deprecated unstable attribute `#[simd]`.][47251]
3665
3666 [33903]: https://github.com/rust-lang/rust/pull/33903
3667 [47947]: https://github.com/rust-lang/rust/pull/47947
3668 [47948]: https://github.com/rust-lang/rust/pull/47948
3669 [47760]: https://github.com/rust-lang/rust/pull/47760
3670 [47790]: https://github.com/rust-lang/rust/pull/47790
3671 [47828]: https://github.com/rust-lang/rust/pull/47828
3672 [47398]: https://github.com/rust-lang/rust/pull/47398
3673 [47510]: https://github.com/rust-lang/rust/pull/47510
3674 [47521]: https://github.com/rust-lang/rust/pull/47521
3675 [47204]: https://github.com/rust-lang/rust/pull/47204
3676 [47251]: https://github.com/rust-lang/rust/pull/47251
3677 [47268]: https://github.com/rust-lang/rust/pull/47268
3678 [47282]: https://github.com/rust-lang/rust/pull/47282
3679 [47300]: https://github.com/rust-lang/rust/pull/47300
3680 [47349]: https://github.com/rust-lang/rust/pull/47349
3681 [46931]: https://github.com/rust-lang/rust/pull/46931
3682 [46985]: https://github.com/rust-lang/rust/pull/46985
3683 [47006]: https://github.com/rust-lang/rust/pull/47006
3684 [46830]: https://github.com/rust-lang/rust/pull/46830
3685 [46095]: https://github.com/rust-lang/rust/pull/46095
3686 [46666]: https://github.com/rust-lang/rust/pull/46666
3687 [46196]: https://github.com/rust-lang/rust/pull/46196
3688 [cargo/5013]: https://github.com/rust-lang/cargo/pull/5013
3689 [cargo/5029]: https://github.com/rust-lang/cargo/pull/5029
3690 [RFC 1358]: https://github.com/rust-lang/rfcs/pull/1358
3691 [`Location::column`]: https://doc.rust-lang.org/std/panic/struct.Location.html#method.column
3692 [`ptr::NonNull`]: https://doc.rust-lang.org/std/ptr/struct.NonNull.html
3693
3694
3695 Version 1.24.1 (2018-03-01)
3696 ==========================
3697
3698  - [Do not abort when unwinding through FFI][48251]
3699  - [Emit UTF-16 files for linker arguments on Windows][48318]
3700  - [Make the error index generator work again][48308]
3701  - [Cargo will warn on Windows 7 if an update is needed][cargo/5069].
3702
3703 [48251]: https://github.com/rust-lang/rust/issues/48251
3704 [48308]: https://github.com/rust-lang/rust/issues/48308
3705 [48318]: https://github.com/rust-lang/rust/issues/48318
3706 [cargo/5069]: https://github.com/rust-lang/cargo/pull/5069
3707
3708
3709 Version 1.24.0 (2018-02-15)
3710 ==========================
3711
3712 Language
3713 --------
3714 - [External `sysv64` ffi is now available.][46528]
3715   eg. `extern "sysv64" fn foo () {}`
3716
3717 Compiler
3718 --------
3719 - [rustc now uses 16 codegen units by default for release builds.][46910]
3720   For the fastest builds, utilize `codegen-units=1`.
3721 - [Added `armv4t-unknown-linux-gnueabi` target.][47018]
3722 - [Add `aarch64-unknown-openbsd` support][46760]
3723
3724 Libraries
3725 ---------
3726 - [`str::find::<char>` now uses memchr.][46735] This should lead to a 10x
3727   improvement in performance in the majority of cases.
3728 - [`OsStr`'s `Debug` implementation is now lossless and consistent
3729   with Windows.][46798]
3730 - [`time::{SystemTime, Instant}` now implement `Hash`.][46828]
3731 - [impl `From<bool>` for `AtomicBool`][46293]
3732 - [impl `From<{CString, &CStr}>` for `{Arc<CStr>, Rc<CStr>}`][45990]
3733 - [impl `From<{OsString, &OsStr}>` for `{Arc<OsStr>, Rc<OsStr>}`][45990]
3734 - [impl `From<{PathBuf, &Path}>` for `{Arc<Path>, Rc<Path>}`][45990]
3735 - [float::from_bits now just uses transmute.][46012] This provides
3736   some optimisations from LLVM.
3737 - [Copied `AsciiExt` methods onto `char`][46077]
3738 - [Remove `T: Sized` requirement on `ptr::is_null()`][46094]
3739 - [impl `From<RecvError>` for `{TryRecvError, RecvTimeoutError}`][45506]
3740 - [Optimised `f32::{min, max}` to generate more efficient x86 assembly][47080]
3741 - [`[u8]::contains` now uses memchr which provides a 3x speed improvement][46713]
3742
3743 Stabilized APIs
3744 ---------------
3745 - [`RefCell::replace`]
3746 - [`RefCell::swap`]
3747 - [`atomic::spin_loop_hint`]
3748
3749 The following functions can now be used in a constant expression.
3750 eg. `let buffer: [u8; size_of::<usize>()];`, `static COUNTER: AtomicUsize = AtomicUsize::new(1);`
3751
3752 - [`AtomicBool::new`][46287]
3753 - [`AtomicUsize::new`][46287]
3754 - [`AtomicIsize::new`][46287]
3755 - [`AtomicPtr::new`][46287]
3756 - [`Cell::new`][46287]
3757 - [`{integer}::min_value`][46287]
3758 - [`{integer}::max_value`][46287]
3759 - [`mem::size_of`][46287]
3760 - [`mem::align_of`][46287]
3761 - [`ptr::null`][46287]
3762 - [`ptr::null_mut`][46287]
3763 - [`RefCell::new`][46287]
3764 - [`UnsafeCell::new`][46287]
3765
3766 Cargo
3767 -----
3768 - [Added a `workspace.default-members` config that
3769   overrides implied `--all` in virtual workspaces.][cargo/4743]
3770 - [Enable incremental by default on development builds.][cargo/4817] Also added
3771   configuration keys to `Cargo.toml` and `.cargo/config` to disable on a
3772   per-project or global basis respectively.
3773
3774 Misc
3775 ----
3776
3777 Compatibility Notes
3778 -------------------
3779 - [Floating point types `Debug` impl now always prints a decimal point.][46831]
3780 - [`Ipv6Addr` now rejects superfluous `::`'s in IPv6 addresses][46671] This is
3781   in accordance with IETF RFC 4291 §2.2.
3782 - [Unwinding will no longer go past FFI boundaries, and will instead abort.][46833]
3783 - [`Formatter::flags` method is now deprecated.][46284] The `sign_plus`,
3784   `sign_minus`, `alternate`, and `sign_aware_zero_pad` should be used instead.
3785 - [Leading zeros in tuple struct members is now an error][47084]
3786 - [`column!()` macro is one-based instead of zero-based][46977]
3787 - [`fmt::Arguments` can no longer be shared across threads][45198]
3788 - [Access to `#[repr(packed)]` struct fields is now unsafe][44884]
3789 - [Cargo sets a different working directory for the compiler][cargo/4788]
3790
3791 [44884]: https://github.com/rust-lang/rust/pull/44884
3792 [45198]: https://github.com/rust-lang/rust/pull/45198
3793 [45506]: https://github.com/rust-lang/rust/pull/45506
3794 [45904]: https://github.com/rust-lang/rust/pull/45904
3795 [45990]: https://github.com/rust-lang/rust/pull/45990
3796 [46012]: https://github.com/rust-lang/rust/pull/46012
3797 [46077]: https://github.com/rust-lang/rust/pull/46077
3798 [46094]: https://github.com/rust-lang/rust/pull/46094
3799 [46284]: https://github.com/rust-lang/rust/pull/46284
3800 [46287]: https://github.com/rust-lang/rust/pull/46287
3801 [46293]: https://github.com/rust-lang/rust/pull/46293
3802 [46528]: https://github.com/rust-lang/rust/pull/46528
3803 [46671]: https://github.com/rust-lang/rust/pull/46671
3804 [46713]: https://github.com/rust-lang/rust/pull/46713
3805 [46735]: https://github.com/rust-lang/rust/pull/46735
3806 [46749]: https://github.com/rust-lang/rust/pull/46749
3807 [46760]: https://github.com/rust-lang/rust/pull/46760
3808 [46798]: https://github.com/rust-lang/rust/pull/46798
3809 [46828]: https://github.com/rust-lang/rust/pull/46828
3810 [46831]: https://github.com/rust-lang/rust/pull/46831
3811 [46833]: https://github.com/rust-lang/rust/pull/46833
3812 [46910]: https://github.com/rust-lang/rust/pull/46910
3813 [46977]: https://github.com/rust-lang/rust/pull/46977
3814 [47018]: https://github.com/rust-lang/rust/pull/47018
3815 [47080]: https://github.com/rust-lang/rust/pull/47080
3816 [47084]: https://github.com/rust-lang/rust/pull/47084
3817 [cargo/4743]: https://github.com/rust-lang/cargo/pull/4743
3818 [cargo/4788]: https://github.com/rust-lang/cargo/pull/4788
3819 [cargo/4817]: https://github.com/rust-lang/cargo/pull/4817
3820 [`RefCell::replace`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.replace
3821 [`RefCell::swap`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.swap
3822 [`atomic::spin_loop_hint`]: https://doc.rust-lang.org/std/sync/atomic/fn.spin_loop_hint.html
3823
3824
3825 Version 1.23.0 (2018-01-04)
3826 ==========================
3827
3828 Language
3829 --------
3830 - [Arbitrary `auto` traits are now permitted in trait objects.][45772]
3831 - [rustc now uses subtyping on the left hand side of binary operations.][45435]
3832   Which should fix some confusing errors in some operations.
3833
3834 Compiler
3835 --------
3836 - [Enabled `TrapUnreachable` in LLVM which should mitigate the impact of
3837   undefined behavior.][45920]
3838 - [rustc now suggests renaming import if names clash.][45660]
3839 - [Display errors/warnings correctly when there are zero-width or
3840   wide characters.][45711]
3841 - [rustc now avoids unnecessary copies of arguments that are
3842   simple bindings][45380] This should improve memory usage on average by 5-10%.
3843 - [Updated musl used to build musl rustc to 1.1.17][45393]
3844
3845 Libraries
3846 ---------
3847 - [Allow a trailing comma in `assert_eq/ne` macro][45887]
3848 - [Implement Hash for raw pointers to unsized types][45483]
3849 - [impl `From<*mut T>` for `AtomicPtr<T>`][45610]
3850 - [impl `From<usize/isize>` for `AtomicUsize/AtomicIsize`.][45610]
3851 - [Removed the `T: Sync` requirement for `RwLock<T>: Send`][45267]
3852 - [Removed `T: Sized` requirement for `{<*const T>, <*mut T>}::as_ref`
3853   and `<*mut T>::as_mut`][44932]
3854 - [Optimized `Thread::{park, unpark}` implementation][45524]
3855 - [Improved `SliceExt::binary_search` performance.][45333]
3856 - [impl `FromIterator<()>` for `()`][45379]
3857 - [Copied `AsciiExt` trait methods to primitive types.][44042] Use of `AsciiExt`
3858   is now deprecated.
3859
3860 Stabilized APIs
3861 ---------------
3862
3863 Cargo
3864 -----
3865 - [Cargo now supports uninstallation of multiple packages][cargo/4561]
3866   eg. `cargo uninstall foo bar` uninstalls `foo` and `bar`.
3867 - [Added unit test checking to `cargo check`][cargo/4592]
3868 - [Cargo now lets you install a specific version
3869   using `cargo install --version`][cargo/4637]
3870
3871 Misc
3872 ----
3873 - [Releases now ship with the Cargo book documentation.][45692]
3874 - [rustdoc now prints rendering warnings on every run.][45324]
3875
3876 Compatibility Notes
3877 -------------------
3878 - [Changes have been made to type equality to make it more correct,
3879   in rare cases this could break some code.][45853] [Tracking issue for
3880   further information][45852]
3881 - [`char::escape_debug` now uses Unicode 10 over 9.][45571]
3882 - [Upgraded Android SDK to 27, and NDK to r15c.][45580] This drops support for
3883   Android 9, the minimum supported version is Android 14.
3884 - [Bumped the minimum LLVM to 3.9][45326]
3885
3886 [44042]: https://github.com/rust-lang/rust/pull/44042
3887 [44932]: https://github.com/rust-lang/rust/pull/44932
3888 [45267]: https://github.com/rust-lang/rust/pull/45267
3889 [45324]: https://github.com/rust-lang/rust/pull/45324
3890 [45326]: https://github.com/rust-lang/rust/pull/45326
3891 [45333]: https://github.com/rust-lang/rust/pull/45333
3892 [45379]: https://github.com/rust-lang/rust/pull/45379
3893 [45380]: https://github.com/rust-lang/rust/pull/45380
3894 [45393]: https://github.com/rust-lang/rust/pull/45393
3895 [45435]: https://github.com/rust-lang/rust/pull/45435
3896 [45483]: https://github.com/rust-lang/rust/pull/45483
3897 [45524]: https://github.com/rust-lang/rust/pull/45524
3898 [45571]: https://github.com/rust-lang/rust/pull/45571
3899 [45580]: https://github.com/rust-lang/rust/pull/45580
3900 [45610]: https://github.com/rust-lang/rust/pull/45610
3901 [45660]: https://github.com/rust-lang/rust/pull/45660
3902 [45692]: https://github.com/rust-lang/rust/pull/45692
3903 [45711]: https://github.com/rust-lang/rust/pull/45711
3904 [45772]: https://github.com/rust-lang/rust/pull/45772
3905 [45852]: https://github.com/rust-lang/rust/issues/45852
3906 [45853]: https://github.com/rust-lang/rust/pull/45853
3907 [45887]: https://github.com/rust-lang/rust/pull/45887
3908 [45920]: https://github.com/rust-lang/rust/pull/45920
3909 [cargo/4561]: https://github.com/rust-lang/cargo/pull/4561
3910 [cargo/4592]: https://github.com/rust-lang/cargo/pull/4592
3911 [cargo/4637]: https://github.com/rust-lang/cargo/pull/4637
3912
3913
3914 Version 1.22.1 (2017-11-22)
3915 ==========================
3916
3917 - [Update Cargo to fix an issue with macOS 10.13 "High Sierra"][46183]
3918
3919 [46183]: https://github.com/rust-lang/rust/pull/46183
3920
3921 Version 1.22.0 (2017-11-22)
3922 ==========================
3923
3924 Language
3925 --------
3926 - [`non_snake_case` lint now allows extern no-mangle functions][44966]
3927 - [Now accepts underscores in unicode escapes][43716]
3928 - [`T op= &T` now works for numeric types.][44287] eg. `let mut x = 2; x += &8;`
3929 - [types that impl `Drop` are now allowed in `const` and `static` types][44456]
3930
3931 Compiler
3932 --------
3933 - [rustc now defaults to having 16 codegen units at debug on supported platforms.][45064]
3934 - [rustc will no longer inline in codegen units when compiling for debug][45075]
3935   This should decrease compile times for debug builds.
3936 - [strict memory alignment now enabled on ARMv6][45094]
3937 - [Remove support for the PNaCl target `le32-unknown-nacl`][45041]
3938
3939 Libraries
3940 ---------
3941 - [Allow atomic operations up to 32 bits
3942   on `armv5te_unknown_linux_gnueabi`][44978]
3943 - [`Box<Error>` now impls `From<Cow<str>>`][44466]
3944 - [`std::mem::Discriminant` is now guaranteed to be `Send + Sync`][45095]
3945 - [`fs::copy` now returns the length of the main stream on NTFS.][44895]
3946 - [Properly detect overflow in `Instant += Duration`.][44220]
3947 - [impl `Hasher` for `{&mut Hasher, Box<Hasher>}`][44015]
3948 - [impl `fmt::Debug` for `SplitWhitespace`.][44303]
3949 - [`Option<T>` now impls `Try`][42526] This allows for using `?` with `Option` types.
3950
3951 Stabilized APIs
3952 ---------------
3953
3954 Cargo
3955 -----
3956 - [Cargo will now build multi file examples in subdirectories of the `examples`
3957   folder that have a `main.rs` file.][cargo/4496]
3958 - [Changed `[root]` to `[package]` in `Cargo.lock`][cargo/4571] Packages with
3959   the old format will continue to work and can be updated with `cargo update`.
3960 - [Now supports vendoring git repositories][cargo/3992]
3961
3962 Misc
3963 ----
3964 - [`libbacktrace` is now available on Apple platforms.][44251]
3965 - [Stabilised the `compile_fail` attribute for code fences in doc-comments.][43949]
3966   This now lets you specify that a given code example will fail to compile.
3967
3968 Compatibility Notes
3969 -------------------
3970 - [The minimum Android version that rustc can build for has been bumped
3971   to `4.0` from `2.3`][45656]
3972 - [Allowing `T op= &T` for numeric types has broken some type
3973   inference cases][45480]
3974
3975
3976 [42526]: https://github.com/rust-lang/rust/pull/42526
3977 [43017]: https://github.com/rust-lang/rust/pull/43017
3978 [43716]: https://github.com/rust-lang/rust/pull/43716
3979 [43949]: https://github.com/rust-lang/rust/pull/43949
3980 [44015]: https://github.com/rust-lang/rust/pull/44015
3981 [44220]: https://github.com/rust-lang/rust/pull/44220
3982 [44251]: https://github.com/rust-lang/rust/pull/44251
3983 [44287]: https://github.com/rust-lang/rust/pull/44287
3984 [44303]: https://github.com/rust-lang/rust/pull/44303
3985 [44456]: https://github.com/rust-lang/rust/pull/44456
3986 [44466]: https://github.com/rust-lang/rust/pull/44466
3987 [44895]: https://github.com/rust-lang/rust/pull/44895
3988 [44966]: https://github.com/rust-lang/rust/pull/44966
3989 [44978]: https://github.com/rust-lang/rust/pull/44978
3990 [45041]: https://github.com/rust-lang/rust/pull/45041
3991 [45064]: https://github.com/rust-lang/rust/pull/45064
3992 [45075]: https://github.com/rust-lang/rust/pull/45075
3993 [45094]: https://github.com/rust-lang/rust/pull/45094
3994 [45095]: https://github.com/rust-lang/rust/pull/45095
3995 [45480]: https://github.com/rust-lang/rust/issues/45480
3996 [45656]: https://github.com/rust-lang/rust/pull/45656
3997 [cargo/3992]: https://github.com/rust-lang/cargo/pull/3992
3998 [cargo/4496]: https://github.com/rust-lang/cargo/pull/4496
3999 [cargo/4571]: https://github.com/rust-lang/cargo/pull/4571
4000
4001
4002
4003
4004
4005
4006 Version 1.21.0 (2017-10-12)
4007 ==========================
4008
4009 Language
4010 --------
4011 - [You can now use static references for literals.][43838]
4012   Example:
4013   ```rust
4014   fn main() {
4015       let x: &'static u32 = &0;
4016   }
4017   ```
4018 - [Relaxed path syntax. Optional `::` before `<` is now allowed in all contexts.][43540]
4019   Example:
4020   ```rust
4021   my_macro!(Vec<i32>::new); // Always worked
4022   my_macro!(Vec::<i32>::new); // Now works
4023   ```
4024
4025 Compiler
4026 --------
4027 - [Upgraded jemalloc to 4.5.0][43911]
4028 - [Enabled unwinding panics on Redox][43917]
4029 - [Now runs LLVM in parallel during translation phase.][43506]
4030   This should reduce peak memory usage.
4031
4032 Libraries
4033 ---------
4034 - [Generate builtin impls for `Clone` for all arrays and tuples that
4035   are `T: Clone`][43690]
4036 - [`Stdin`, `Stdout`, and `Stderr` now implement `AsRawFd`.][43459]
4037 - [`Rc` and `Arc` now implement `From<&[T]> where T: Clone`, `From<str>`,
4038   `From<String>`, `From<Box<T>> where T: ?Sized`, and `From<Vec<T>>`.][42565]
4039
4040 Stabilized APIs
4041 ---------------
4042
4043 [`std::mem::discriminant`]
4044
4045 Cargo
4046 -----
4047 - [You can now call `cargo install` with multiple package names][cargo/4216]
4048 - [Cargo commands inside a virtual workspace will now implicitly
4049   pass `--all`][cargo/4335]
4050 - [Added a `[patch]` section to `Cargo.toml` to handle
4051   prepublication dependencies][cargo/4123] [RFC 1969]
4052 - [`include` & `exclude` fields in `Cargo.toml` now accept gitignore
4053   like patterns][cargo/4270]
4054 - [Added the `--all-targets` option][cargo/4400]
4055 - [Using required dependencies as a feature is now deprecated and emits
4056   a warning][cargo/4364]
4057
4058
4059 Misc
4060 ----
4061 - [Cargo docs are moving][43916]
4062   to [doc.rust-lang.org/cargo](https://doc.rust-lang.org/cargo)
4063 - [The rustdoc book is now available][43863]
4064   at [doc.rust-lang.org/rustdoc](https://doc.rust-lang.org/rustdoc)
4065 - [Added a preview of RLS has been made available through rustup][44204]
4066   Install with `rustup component add rls-preview`
4067 - [`std::os` documentation for Unix, Linux, and Windows now appears on doc.rust-lang.org][43348]
4068   Previously only showed `std::os::unix`.
4069
4070 Compatibility Notes
4071 -------------------
4072 - [Changes in method matching against higher-ranked types][43880] This may cause
4073   breakage in subtyping corner cases. [A more in-depth explanation is available.][info/43880]
4074 - [rustc's JSON error output's byte position start at top of file.][42973]
4075   Was previously relative to the rustc's internal `CodeMap` struct which
4076   required the unstable library `libsyntax` to correctly use.
4077 - [`unused_results` lint no longer ignores booleans][43728]
4078
4079 [42565]: https://github.com/rust-lang/rust/pull/42565
4080 [42973]: https://github.com/rust-lang/rust/pull/42973
4081 [43348]: https://github.com/rust-lang/rust/pull/43348
4082 [43459]: https://github.com/rust-lang/rust/pull/43459
4083 [43506]: https://github.com/rust-lang/rust/pull/43506
4084 [43540]: https://github.com/rust-lang/rust/pull/43540
4085 [43690]: https://github.com/rust-lang/rust/pull/43690
4086 [43728]: https://github.com/rust-lang/rust/pull/43728
4087 [43838]: https://github.com/rust-lang/rust/pull/43838
4088 [43863]: https://github.com/rust-lang/rust/pull/43863
4089 [43880]: https://github.com/rust-lang/rust/pull/43880
4090 [43911]: https://github.com/rust-lang/rust/pull/43911
4091 [43916]: https://github.com/rust-lang/rust/pull/43916
4092 [43917]: https://github.com/rust-lang/rust/pull/43917
4093 [44204]: https://github.com/rust-lang/rust/pull/44204
4094 [cargo/4123]: https://github.com/rust-lang/cargo/pull/4123
4095 [cargo/4216]: https://github.com/rust-lang/cargo/pull/4216
4096 [cargo/4270]: https://github.com/rust-lang/cargo/pull/4270
4097 [cargo/4335]: https://github.com/rust-lang/cargo/pull/4335
4098 [cargo/4364]: https://github.com/rust-lang/cargo/pull/4364
4099 [cargo/4400]: https://github.com/rust-lang/cargo/pull/4400
4100 [RFC 1969]: https://github.com/rust-lang/rfcs/pull/1969
4101 [info/43880]: https://github.com/rust-lang/rust/issues/44224#issuecomment-330058902
4102 [`std::mem::discriminant`]: https://doc.rust-lang.org/std/mem/fn.discriminant.html
4103
4104 Version 1.20.0 (2017-08-31)
4105 ===========================
4106
4107 Language
4108 --------
4109 - [Associated constants are now stabilised.][42809]
4110 - [A lot of macro bugs are now fixed.][42913]
4111
4112 Compiler
4113 --------
4114
4115 - [Struct fields are now properly coerced to the expected field type.][42807]
4116 - [Enabled wasm LLVM backend][42571] WASM can now be built with the
4117   `wasm32-experimental-emscripten` target.
4118 - [Changed some of the error messages to be more helpful.][42033]
4119 - [Add support for RELRO(RELocation Read-Only) for platforms that support
4120   it.][43170]
4121 - [rustc now reports the total number of errors on compilation failure][43015]
4122   previously this was only the number of errors in the pass that failed.
4123 - [Expansion in rustc has been sped up 29x.][42533]
4124 - [added `msp430-none-elf` target.][43099]
4125 - [rustc will now suggest one-argument enum variant to fix type mismatch when
4126   applicable][43178]
4127 - [Fixes backtraces on Redox][43228]
4128 - [rustc now identifies different versions of same crate when absolute paths of
4129   different types match in an error message.][42826]
4130
4131 Libraries
4132 ---------
4133
4134
4135 - [Relaxed Debug constraints on `{HashMap,BTreeMap}::{Keys,Values}`.][42854]
4136 - [Impl `PartialEq`, `Eq`, `PartialOrd`, `Ord`, `Debug`, `Hash` for unsized
4137   tuples.][43011]
4138 - [Impl `fmt::{Display, Debug}` for `Ref`, `RefMut`, `MutexGuard`,
4139   `RwLockReadGuard`, `RwLockWriteGuard`][42822]
4140 - [Impl `Clone` for `DefaultHasher`.][42799]
4141 - [Impl `Sync` for `SyncSender`.][42397]
4142 - [Impl `FromStr` for `char`][42271]
4143 - [Fixed how `{f32, f64}::{is_sign_negative, is_sign_positive}` handles
4144   NaN.][42431]
4145 - [allow messages in the `unimplemented!()` macro.][42155]
4146   ie. `unimplemented!("Waiting for 1.21 to be stable")`
4147 - [`pub(restricted)` is now supported in the `thread_local!` macro.][43185]
4148 - [Upgrade to Unicode 10.0.0][42999]
4149 - [Reimplemented `{f32, f64}::{min, max}` in Rust instead of using CMath.][42430]
4150 - [Skip the main thread's manual stack guard on Linux][43072]
4151 - [Iterator::nth for `ops::{Range, RangeFrom}` is now done in O(1) time][43077]
4152 - [`#[repr(align(N))]` attribute max number is now 2^31 - 1.][43097] This was
4153   previously 2^15.
4154 - [`{OsStr, Path}::Display` now avoids allocations where possible][42613]
4155
4156 Stabilized APIs
4157 ---------------
4158
4159 - [`CStr::into_c_string`]
4160 - [`CString::as_c_str`]
4161 - [`CString::into_boxed_c_str`]
4162 - [`Chain::get_mut`]
4163 - [`Chain::get_ref`]
4164 - [`Chain::into_inner`]
4165 - [`Option::get_or_insert_with`]
4166 - [`Option::get_or_insert`]
4167 - [`OsStr::into_os_string`]
4168 - [`OsString::into_boxed_os_str`]
4169 - [`Take::get_mut`]
4170 - [`Take::get_ref`]
4171 - [`Utf8Error::error_len`]
4172 - [`char::EscapeDebug`]
4173 - [`char::escape_debug`]
4174 - [`compile_error!`]
4175 - [`f32::from_bits`]
4176 - [`f32::to_bits`]
4177 - [`f64::from_bits`]
4178 - [`f64::to_bits`]
4179 - [`mem::ManuallyDrop`]
4180 - [`slice::sort_unstable_by_key`]
4181 - [`slice::sort_unstable_by`]
4182 - [`slice::sort_unstable`]
4183 - [`str::from_boxed_utf8_unchecked`]
4184 - [`str::as_bytes_mut`]
4185 - [`str::as_bytes_mut`]
4186 - [`str::from_utf8_mut`]
4187 - [`str::from_utf8_unchecked_mut`]
4188 - [`str::get_mut`]
4189 - [`str::get_unchecked_mut`]
4190 - [`str::get_unchecked`]
4191 - [`str::get`]
4192 - [`str::into_boxed_bytes`]
4193
4194
4195 Cargo
4196 -----
4197 - [Cargo API token location moved from `~/.cargo/config` to
4198   `~/.cargo/credentials`.][cargo/3978]
4199 - [Cargo will now build `main.rs` binaries that are in sub-directories of
4200   `src/bin`.][cargo/4214] ie. Having `src/bin/server/main.rs` and
4201   `src/bin/client/main.rs` generates `target/debug/server` and `target/debug/client`
4202 - [You can now specify version of a binary when installed through
4203   `cargo install` using `--vers`.][cargo/4229]
4204 - [Added `--no-fail-fast` flag to cargo to run all benchmarks regardless of
4205   failure.][cargo/4248]
4206 - [Changed the convention around which file is the crate root.][cargo/4259]
4207 - [The `include`/`exclude` property in `Cargo.toml` now accepts gitignore paths
4208   instead of glob patterns][cargo/4270]. Glob patterns are now deprecated.
4209
4210 Compatibility Notes
4211 -------------------
4212
4213 - [Functions with `'static` in their return types will now not be as usable as
4214   if they were using lifetime parameters instead.][42417]
4215 - [The reimplementation of `{f32, f64}::is_sign_{negative, positive}` now
4216   takes the sign of NaN into account where previously didn't.][42430]
4217
4218 [42033]: https://github.com/rust-lang/rust/pull/42033
4219 [42155]: https://github.com/rust-lang/rust/pull/42155
4220 [42271]: https://github.com/rust-lang/rust/pull/42271
4221 [42397]: https://github.com/rust-lang/rust/pull/42397
4222 [42417]: https://github.com/rust-lang/rust/pull/42417
4223 [42430]: https://github.com/rust-lang/rust/pull/42430
4224 [42431]: https://github.com/rust-lang/rust/pull/42431
4225 [42533]: https://github.com/rust-lang/rust/pull/42533
4226 [42571]: https://github.com/rust-lang/rust/pull/42571
4227 [42613]: https://github.com/rust-lang/rust/pull/42613
4228 [42799]: https://github.com/rust-lang/rust/pull/42799
4229 [42807]: https://github.com/rust-lang/rust/pull/42807
4230 [42809]: https://github.com/rust-lang/rust/pull/42809
4231 [42822]: https://github.com/rust-lang/rust/pull/42822
4232 [42826]: https://github.com/rust-lang/rust/pull/42826
4233 [42854]: https://github.com/rust-lang/rust/pull/42854
4234 [42913]: https://github.com/rust-lang/rust/pull/42913
4235 [42999]: https://github.com/rust-lang/rust/pull/42999
4236 [43011]: https://github.com/rust-lang/rust/pull/43011
4237 [43015]: https://github.com/rust-lang/rust/pull/43015
4238 [43072]: https://github.com/rust-lang/rust/pull/43072
4239 [43077]: https://github.com/rust-lang/rust/pull/43077
4240 [43097]: https://github.com/rust-lang/rust/pull/43097
4241 [43099]: https://github.com/rust-lang/rust/pull/43099
4242 [43170]: https://github.com/rust-lang/rust/pull/43170
4243 [43178]: https://github.com/rust-lang/rust/pull/43178
4244 [43185]: https://github.com/rust-lang/rust/pull/43185
4245 [43228]: https://github.com/rust-lang/rust/pull/43228
4246 [cargo/3978]: https://github.com/rust-lang/cargo/pull/3978
4247 [cargo/4214]: https://github.com/rust-lang/cargo/pull/4214
4248 [cargo/4229]: https://github.com/rust-lang/cargo/pull/4229
4249 [cargo/4248]: https://github.com/rust-lang/cargo/pull/4248
4250 [cargo/4259]: https://github.com/rust-lang/cargo/pull/4259
4251 [cargo/4270]: https://github.com/rust-lang/cargo/pull/4270
4252 [`CStr::into_c_string`]: https://doc.rust-lang.org/std/ffi/struct.CStr.html#method.into_c_string
4253 [`CString::as_c_str`]: https://doc.rust-lang.org/std/ffi/struct.CString.html#method.as_c_str
4254 [`CString::into_boxed_c_str`]: https://doc.rust-lang.org/std/ffi/struct.CString.html#method.into_boxed_c_str
4255 [`Chain::get_mut`]: https://doc.rust-lang.org/std/io/struct.Chain.html#method.get_mut
4256 [`Chain::get_ref`]: https://doc.rust-lang.org/std/io/struct.Chain.html#method.get_ref
4257 [`Chain::into_inner`]: https://doc.rust-lang.org/std/io/struct.Chain.html#method.into_inner
4258 [`Option::get_or_insert_with`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.get_or_insert_with
4259 [`Option::get_or_insert`]: https://doc.rust-lang.org/std/option/enum.Option.html#method.get_or_insert
4260 [`OsStr::into_os_string`]: https://doc.rust-lang.org/std/ffi/struct.OsStr.html#method.into_os_string
4261 [`OsString::into_boxed_os_str`]: https://doc.rust-lang.org/std/ffi/struct.OsString.html#method.into_boxed_os_str
4262 [`Take::get_mut`]: https://doc.rust-lang.org/std/io/struct.Take.html#method.get_mut
4263 [`Take::get_ref`]: https://doc.rust-lang.org/std/io/struct.Take.html#method.get_ref
4264 [`Utf8Error::error_len`]: https://doc.rust-lang.org/std/str/struct.Utf8Error.html#method.error_len
4265 [`char::EscapeDebug`]: https://doc.rust-lang.org/std/char/struct.EscapeDebug.html
4266 [`char::escape_debug`]: https://doc.rust-lang.org/std/primitive.char.html#method.escape_debug
4267 [`compile_error!`]: https://doc.rust-lang.org/std/macro.compile_error.html
4268 [`f32::from_bits`]: https://doc.rust-lang.org/std/primitive.f32.html#method.from_bits
4269 [`f32::to_bits`]: https://doc.rust-lang.org/std/primitive.f32.html#method.to_bits
4270 [`f64::from_bits`]: https://doc.rust-lang.org/std/primitive.f64.html#method.from_bits
4271 [`f64::to_bits`]: https://doc.rust-lang.org/std/primitive.f64.html#method.to_bits
4272 [`mem::ManuallyDrop`]: https://doc.rust-lang.org/std/mem/union.ManuallyDrop.html
4273 [`slice::sort_unstable_by_key`]: https://doc.rust-lang.org/std/primitive.slice.html#method.sort_unstable_by_key
4274 [`slice::sort_unstable_by`]: https://doc.rust-lang.org/std/primitive.slice.html#method.sort_unstable_by
4275 [`slice::sort_unstable`]: https://doc.rust-lang.org/std/primitive.slice.html#method.sort_unstable
4276 [`str::from_boxed_utf8_unchecked`]: https://doc.rust-lang.org/std/str/fn.from_boxed_utf8_unchecked.html
4277 [`str::as_bytes_mut`]: https://doc.rust-lang.org/std/primitive.str.html#method.as_bytes_mut
4278 [`str::from_utf8_mut`]: https://doc.rust-lang.org/std/str/fn.from_utf8_mut.html
4279 [`str::from_utf8_unchecked_mut`]: https://doc.rust-lang.org/std/str/fn.from_utf8_unchecked_mut.html
4280 [`str::get_mut`]: https://doc.rust-lang.org/std/primitive.str.html#method.get_mut
4281 [`str::get_unchecked_mut`]: https://doc.rust-lang.org/std/primitive.str.html#method.get_unchecked_mut
4282 [`str::get_unchecked`]: https://doc.rust-lang.org/std/primitive.str.html#method.get_unchecked
4283 [`str::get`]: https://doc.rust-lang.org/std/primitive.str.html#method.get
4284 [`str::into_boxed_bytes`]: https://doc.rust-lang.org/std/primitive.str.html#method.into_boxed_bytes
4285
4286
4287 Version 1.19.0 (2017-07-20)
4288 ===========================
4289
4290 Language
4291 --------
4292
4293 - [Numeric fields can now be used for creating tuple structs.][41145] [RFC 1506]
4294   For example `struct Point(u32, u32); let x = Point { 0: 7, 1: 0 };`.
4295 - [Macro recursion limit increased to 1024 from 64.][41676]
4296 - [Added lint for detecting unused macros.][41907]
4297 - [`loop` can now return a value with `break`.][42016] [RFC 1624]
4298   For example: `let x = loop { break 7; };`
4299 - [C compatible `union`s are now available.][42068] [RFC 1444] They can only
4300   contain `Copy` types and cannot have a `Drop` implementation.
4301   Example: `union Foo { bar: u8, baz: usize }`
4302 - [Non capturing closures can now be coerced into `fn`s,][42162] [RFC 1558]
4303   Example: `let foo: fn(u8) -> u8 = |v: u8| { v };`
4304
4305 Compiler
4306 --------
4307
4308 - [Add support for bootstrapping the Rust compiler toolchain on Android.][41370]
4309 - [Change `arm-linux-androideabi` to correspond to the `armeabi`
4310   official ABI.][41656] If you wish to continue targeting the `armeabi-v7a` ABI
4311   you should use `--target armv7-linux-androideabi`.
4312 - [Fixed ICE when removing a source file between compilation sessions.][41873]
4313 - [Minor optimisation of string operations.][42037]
4314 - [Compiler error message is now `aborting due to previous error(s)` instead of
4315   `aborting due to N previous errors`][42150] This was previously inaccurate and
4316   would only count certain kinds of errors.
4317 - [The compiler now supports Visual Studio 2017][42225]
4318 - [The compiler is now built against LLVM 4.0.1 by default][42948]
4319 - [Added a lot][42264] of [new error codes][42302]
4320 - [Added `target-feature=+crt-static` option][37406] [RFC 1721] Which allows
4321   libraries with C Run-time Libraries(CRT) to be statically linked.
4322 - [Fixed various ARM codegen bugs][42740]
4323
4324 Libraries
4325 ---------
4326
4327 - [`String` now implements `FromIterator<Cow<'a, str>>` and
4328   `Extend<Cow<'a, str>>`][41449]
4329 - [`Vec` now implements `From<&mut [T]>`][41530]
4330 - [`Box<[u8]>` now implements `From<Box<str>>`][41258]
4331 - [`SplitWhitespace` now implements `Clone`][41659]
4332 - [`[u8]::reverse` is now 5x faster and `[u16]::reverse` is now
4333   1.5x faster][41764]
4334 - [`eprint!` and `eprintln!` macros added to prelude.][41192] Same as the `print!`
4335   macros, but for printing to stderr.
4336
4337 Stabilized APIs
4338 ---------------
4339
4340 - [`OsString::shrink_to_fit`]
4341 - [`cmp::Reverse`]
4342 - [`Command::envs`]
4343 - [`thread::ThreadId`]
4344
4345 Cargo
4346 -----
4347
4348 - [Build scripts can now add environment variables to the environment
4349   the crate is being compiled in.
4350   Example: `println!("cargo:rustc-env=FOO=bar");`][cargo/3929]
4351 - [Subcommands now replace the current process rather than spawning a new
4352   child process][cargo/3970]
4353 - [Workspace members can now accept glob file patterns][cargo/3979]
4354 - [Added `--all` flag to the `cargo bench` subcommand to run benchmarks of all
4355   the members in a given workspace.][cargo/3988]
4356 - [Updated `libssh2-sys` to 0.2.6][cargo/4008]
4357 - [Target directory path is now in the cargo metadata][cargo/4022]
4358 - [Cargo no longer checks out a local working directory for the
4359   crates.io index][cargo/4026] This should provide smaller file size for the
4360   registry, and improve cloning times, especially on Windows machines.
4361 - [Added an `--exclude` option for excluding certain packages when using the
4362   `--all` option][cargo/4031]
4363 - [Cargo will now automatically retry when receiving a 5xx error
4364   from crates.io][cargo/4032]
4365 - [The `--features` option now accepts multiple comma or space
4366   delimited values.][cargo/4084]
4367 - [Added support for custom target specific runners][cargo/3954]
4368
4369 Misc
4370 ----
4371
4372 - [Added `rust-windbg.cmd`][39983] for loading rust `.natvis` files in the
4373   Windows Debugger.
4374 - [Rust will now release XZ compressed packages][rust-installer/57]
4375 - [rustup will now prefer to download rust packages with
4376   XZ compression][rustup/1100] over GZip packages.
4377 - [Added the ability to escape `#` in rust documentation][41785] By adding
4378   additional `#`'s ie. `##` is now `#`
4379
4380 Compatibility Notes
4381 -------------------
4382
4383 - [`MutexGuard<T>` may only be `Sync` if `T` is `Sync`.][41624]
4384 - [`-Z` flags are now no longer allowed to be used on the stable
4385   compiler.][41751] This has been a warning for a year previous to this.
4386 - [As a result of the `-Z` flag change, the `cargo-check` plugin no
4387   longer works][42844]. Users should migrate to the built-in `check`
4388   command, which has been available since 1.16.
4389 - [Ending a float literal with `._` is now a hard error.
4390   Example: `42._` .][41946]
4391 - [Any use of a private `extern crate` outside of its module is now a
4392   hard error.][36886] This was previously a warning.
4393 - [`use ::self::foo;` is now a hard error.][36888] `self` paths are always
4394   relative while the `::` prefix makes a path absolute, but was ignored and the
4395   path was relative regardless.
4396 - [Floating point constants in match patterns is now a hard error][36890]
4397   This was previously a warning.
4398 - [Struct or enum constants that don't derive `PartialEq` & `Eq` used
4399   match patterns is now a hard error][36891] This was previously a warning.
4400 - [Lifetimes named `'_` are no longer allowed.][36892] This was previously
4401   a warning.
4402 - [From the pound escape, lines consisting of multiple `#`s are
4403   now visible][41785]
4404 - [It is an error to re-export private enum variants][42460]. This is
4405   known to break a number of crates that depend on an older version of
4406   mustache.
4407 - [On Windows, if `VCINSTALLDIR` is set incorrectly, `rustc` will try
4408   to use it to find the linker, and the build will fail where it did
4409   not previously][42607]
4410
4411 [36886]: https://github.com/rust-lang/rust/issues/36886
4412 [36888]: https://github.com/rust-lang/rust/issues/36888
4413 [36890]: https://github.com/rust-lang/rust/issues/36890
4414 [36891]: https://github.com/rust-lang/rust/issues/36891
4415 [36892]: https://github.com/rust-lang/rust/issues/36892
4416 [37406]: https://github.com/rust-lang/rust/issues/37406
4417 [39983]: https://github.com/rust-lang/rust/pull/39983
4418 [41145]: https://github.com/rust-lang/rust/pull/41145
4419 [41192]: https://github.com/rust-lang/rust/pull/41192
4420 [41258]: https://github.com/rust-lang/rust/pull/41258
4421 [41370]: https://github.com/rust-lang/rust/pull/41370
4422 [41449]: https://github.com/rust-lang/rust/pull/41449
4423 [41530]: https://github.com/rust-lang/rust/pull/41530
4424 [41624]: https://github.com/rust-lang/rust/pull/41624
4425 [41656]: https://github.com/rust-lang/rust/pull/41656
4426 [41659]: https://github.com/rust-lang/rust/pull/41659
4427 [41676]: https://github.com/rust-lang/rust/pull/41676
4428 [41751]: https://github.com/rust-lang/rust/pull/41751
4429 [41764]: https://github.com/rust-lang/rust/pull/41764
4430 [41785]: https://github.com/rust-lang/rust/pull/41785
4431 [41873]: https://github.com/rust-lang/rust/pull/41873
4432 [41907]: https://github.com/rust-lang/rust/pull/41907
4433 [41946]: https://github.com/rust-lang/rust/pull/41946
4434 [42016]: https://github.com/rust-lang/rust/pull/42016
4435 [42037]: https://github.com/rust-lang/rust/pull/42037
4436 [42068]: https://github.com/rust-lang/rust/pull/42068
4437 [42150]: https://github.com/rust-lang/rust/pull/42150
4438 [42162]: https://github.com/rust-lang/rust/pull/42162
4439 [42225]: https://github.com/rust-lang/rust/pull/42225
4440 [42264]: https://github.com/rust-lang/rust/pull/42264
4441 [42302]: https://github.com/rust-lang/rust/pull/42302
4442 [42460]: https://github.com/rust-lang/rust/issues/42460
4443 [42607]: https://github.com/rust-lang/rust/issues/42607
4444 [42740]: https://github.com/rust-lang/rust/pull/42740
4445 [42844]: https://github.com/rust-lang/rust/issues/42844
4446 [42948]: https://github.com/rust-lang/rust/pull/42948
4447 [RFC 1444]: https://github.com/rust-lang/rfcs/pull/1444
4448 [RFC 1506]: https://github.com/rust-lang/rfcs/pull/1506
4449 [RFC 1558]: https://github.com/rust-lang/rfcs/pull/1558
4450 [RFC 1624]: https://github.com/rust-lang/rfcs/pull/1624
4451 [RFC 1721]: https://github.com/rust-lang/rfcs/pull/1721
4452 [`Command::envs`]: https://doc.rust-lang.org/std/process/struct.Command.html#method.envs
4453 [`OsString::shrink_to_fit`]: https://doc.rust-lang.org/std/ffi/struct.OsString.html#method.shrink_to_fit
4454 [`cmp::Reverse`]: https://doc.rust-lang.org/std/cmp/struct.Reverse.html
4455 [`thread::ThreadId`]: https://doc.rust-lang.org/std/thread/struct.ThreadId.html
4456 [cargo/3929]: https://github.com/rust-lang/cargo/pull/3929
4457 [cargo/3954]: https://github.com/rust-lang/cargo/pull/3954
4458 [cargo/3970]: https://github.com/rust-lang/cargo/pull/3970
4459 [cargo/3979]: https://github.com/rust-lang/cargo/pull/3979
4460 [cargo/3988]: https://github.com/rust-lang/cargo/pull/3988
4461 [cargo/4008]: https://github.com/rust-lang/cargo/pull/4008
4462 [cargo/4022]: https://github.com/rust-lang/cargo/pull/4022
4463 [cargo/4026]: https://github.com/rust-lang/cargo/pull/4026
4464 [cargo/4031]: https://github.com/rust-lang/cargo/pull/4031
4465 [cargo/4032]: https://github.com/rust-lang/cargo/pull/4032
4466 [cargo/4084]: https://github.com/rust-lang/cargo/pull/4084
4467 [rust-installer/57]: https://github.com/rust-lang/rust-installer/pull/57
4468 [rustup/1100]: https://github.com/rust-lang-nursery/rustup.rs/pull/1100
4469
4470
4471 Version 1.18.0 (2017-06-08)
4472 ===========================
4473
4474 Language
4475 --------
4476
4477 - [Stabilize pub(restricted)][40556] `pub` can now accept a module path to
4478   make the item visible to just that module tree. Also accepts the keyword
4479   `crate` to make something public to the whole crate but not users of the
4480   library. Example: `pub(crate) mod utils;`. [RFC 1422].
4481 - [Stabilize `#![windows_subsystem]` attribute][40870] conservative exposure of the
4482   `/SUBSYSTEM` linker flag on Windows platforms. [RFC 1665].
4483 - [Refactor of trait object type parsing][40043] Now `ty` in macros can accept
4484   types like `Write + Send`, trailing `+` are now supported in trait objects,
4485   and better error reporting for trait objects starting with `?Sized`.
4486 - [0e+10 is now a valid floating point literal][40589]
4487 - [Now warns if you bind a lifetime parameter to 'static][40734]
4488 - [Tuples, Enum variant fields, and structs with no `repr` attribute or with
4489   `#[repr(Rust)]` are reordered to minimize padding and produce a smaller
4490   representation in some cases.][40377]
4491
4492 Compiler
4493 --------
4494
4495 - [rustc can now emit mir with `--emit mir`][39891]
4496 - [Improved LLVM IR for trivial functions][40367]
4497 - [Added explanation for E0090(Wrong number of lifetimes are supplied)][40723]
4498 - [rustc compilation is now 15%-20% faster][41469] Thanks to optimisation
4499   opportunities found through profiling
4500 - [Improved backtrace formatting when panicking][38165]
4501
4502 Libraries
4503 ---------
4504
4505 - [Specialized `Vec::from_iter` being passed `vec::IntoIter`][40731] if the
4506   iterator hasn't been advanced the original `Vec` is reassembled with no actual
4507   iteration or reallocation.
4508 - [Simplified HashMap Bucket interface][40561] provides performance
4509   improvements for iterating and cloning.
4510 - [Specialize Vec::from_elem to use calloc][40409]
4511 - [Fixed Race condition in fs::create_dir_all][39799]
4512 - [No longer caching stdio on Windows][40516]
4513 - [Optimized insertion sort in slice][40807] insertion sort in some cases
4514   2.50%~ faster and in one case now 12.50% faster.
4515 - [Optimized `AtomicBool::fetch_nand`][41143]
4516
4517 Stabilized APIs
4518 ---------------
4519
4520 - [`Child::try_wait`]
4521 - [`HashMap::retain`]
4522 - [`HashSet::retain`]
4523 - [`PeekMut::pop`]
4524 - [`TcpStream::peek`]
4525 - [`UdpSocket::peek`]
4526 - [`UdpSocket::peek_from`]
4527
4528 Cargo
4529 -----
4530
4531 - [Added partial Pijul support][cargo/3842] Pijul is a version control system in Rust.
4532   You can now create new cargo projects with Pijul using `cargo new --vcs pijul`
4533 - [Now always emits build script warnings for crates that fail to build][cargo/3847]
4534 - [Added Android build support][cargo/3885]
4535 - [Added `--bins` and `--tests` flags][cargo/3901] now you can build all programs
4536   of a certain type, for example `cargo build --bins` will build all
4537   binaries.
4538 - [Added support for haiku][cargo/3952]
4539
4540 Misc
4541 ----
4542
4543 - [rustdoc can now use pulldown-cmark with the `--enable-commonmark` flag][40338]
4544 - [Added rust-windbg script for better debugging on Windows][39983]
4545 - [Rust now uses the official cross compiler for NetBSD][40612]
4546 - [rustdoc now accepts `#` at the start of files][40828]
4547 - [Fixed jemalloc support for musl][41168]
4548
4549 Compatibility Notes
4550 -------------------
4551
4552 - [Changes to how the `0` flag works in format!][40241] Padding zeroes are now
4553   always placed after the sign if it exists and before the digits. With the `#`
4554   flag the zeroes are placed after the prefix and before the digits.
4555 - [Due to the struct field optimisation][40377], using `transmute` on structs
4556   that have no `repr` attribute or `#[repr(Rust)]` will no longer work. This has
4557   always been undefined behavior, but is now more likely to break in practice.
4558 - [The refactor of trait object type parsing][40043] fixed a bug where `+` was
4559   receiving the wrong priority parsing things like `&for<'a> Tr<'a> + Send` as
4560   `&(for<'a> Tr<'a> + Send)` instead of `(&for<'a> Tr<'a>) + Send`
4561 - [Overlapping inherent `impl`s are now a hard error][40728]
4562 - [`PartialOrd` and `Ord` must agree on the ordering.][41270]
4563 - [`rustc main.rs -o out --emit=asm,llvm-ir`][41085] Now will output
4564   `out.asm` and `out.ll` instead of only one of the filetypes.
4565 - [ calling a function that returns `Self` will no longer work][41805] when
4566   the size of `Self` cannot be statically determined.
4567 - [rustc now builds with a "pthreads" flavour of MinGW for Windows GNU][40805]
4568   this has caused a few regressions namely:
4569
4570   - Changed the link order of local static/dynamic libraries (respecting the
4571     order on given rather than having the compiler reorder).
4572   - Changed how MinGW is linked, native code linked to dynamic libraries
4573     may require manually linking to the gcc support library (for the native
4574     code itself)
4575
4576 [38165]: https://github.com/rust-lang/rust/pull/38165
4577 [39799]: https://github.com/rust-lang/rust/pull/39799
4578 [39891]: https://github.com/rust-lang/rust/pull/39891
4579 [39983]: https://github.com/rust-lang/rust/pull/39983
4580 [40043]: https://github.com/rust-lang/rust/pull/40043
4581 [40241]: https://github.com/rust-lang/rust/pull/40241
4582 [40338]: https://github.com/rust-lang/rust/pull/40338
4583 [40367]: https://github.com/rust-lang/rust/pull/40367
4584 [40377]: https://github.com/rust-lang/rust/pull/40377
4585 [40409]: https://github.com/rust-lang/rust/pull/40409
4586 [40516]: https://github.com/rust-lang/rust/pull/40516
4587 [40556]: https://github.com/rust-lang/rust/pull/40556
4588 [40561]: https://github.com/rust-lang/rust/pull/40561
4589 [40589]: https://github.com/rust-lang/rust/pull/40589
4590 [40612]: https://github.com/rust-lang/rust/pull/40612
4591 [40723]: https://github.com/rust-lang/rust/pull/40723
4592 [40728]: https://github.com/rust-lang/rust/pull/40728
4593 [40731]: https://github.com/rust-lang/rust/pull/40731
4594 [40734]: https://github.com/rust-lang/rust/pull/40734
4595 [40805]: https://github.com/rust-lang/rust/pull/40805
4596 [40807]: https://github.com/rust-lang/rust/pull/40807
4597 [40828]: https://github.com/rust-lang/rust/pull/40828
4598 [40870]: https://github.com/rust-lang/rust/pull/40870
4599 [41085]: https://github.com/rust-lang/rust/pull/41085
4600 [41143]: https://github.com/rust-lang/rust/pull/41143
4601 [41168]: https://github.com/rust-lang/rust/pull/41168
4602 [41270]: https://github.com/rust-lang/rust/issues/41270
4603 [41469]: https://github.com/rust-lang/rust/pull/41469
4604 [41805]: https://github.com/rust-lang/rust/issues/41805
4605 [RFC 1422]: https://github.com/rust-lang/rfcs/blob/master/text/1422-pub-restricted.md
4606 [RFC 1665]: https://github.com/rust-lang/rfcs/blob/master/text/1665-windows-subsystem.md
4607 [`Child::try_wait`]: https://doc.rust-lang.org/std/process/struct.Child.html#method.try_wait
4608 [`HashMap::retain`]: https://doc.rust-lang.org/std/collections/struct.HashMap.html#method.retain
4609 [`HashSet::retain`]: https://doc.rust-lang.org/std/collections/struct.HashSet.html#method.retain
4610 [`PeekMut::pop`]: https://doc.rust-lang.org/std/collections/binary_heap/struct.PeekMut.html#method.pop
4611 [`TcpStream::peek`]: https://doc.rust-lang.org/std/net/struct.TcpStream.html#method.peek
4612 [`UdpSocket::peek_from`]: https://doc.rust-lang.org/std/net/struct.UdpSocket.html#method.peek_from
4613 [`UdpSocket::peek`]: https://doc.rust-lang.org/std/net/struct.UdpSocket.html#method.peek
4614 [cargo/3842]: https://github.com/rust-lang/cargo/pull/3842
4615 [cargo/3847]: https://github.com/rust-lang/cargo/pull/3847
4616 [cargo/3885]: https://github.com/rust-lang/cargo/pull/3885
4617 [cargo/3901]: https://github.com/rust-lang/cargo/pull/3901
4618 [cargo/3952]: https://github.com/rust-lang/cargo/pull/3952
4619
4620
4621 Version 1.17.0 (2017-04-27)
4622 ===========================
4623
4624 Language
4625 --------
4626
4627 * [The lifetime of statics and consts defaults to `'static`][39265]. [RFC 1623]
4628 * [Fields of structs may be initialized without duplicating the field/variable
4629   names][39761]. [RFC 1682]
4630 * [`Self` may be included in the `where` clause of `impls`][38864]. [RFC 1647]
4631 * [When coercing to an unsized type lifetimes must be equal][40319]. That is,
4632   there is no subtyping between `T` and `U` when `T: Unsize<U>`. For example,
4633   coercing `&mut [&'a X; N]` to `&mut [&'b X]` requires `'a` be equal to
4634   `'b`. Soundness fix.
4635 * [Values passed to the indexing operator, `[]`, automatically coerce][40166]
4636 * [Static variables may contain references to other statics][40027]
4637
4638 Compiler
4639 --------
4640
4641 * [Exit quickly on only `--emit dep-info`][40336]
4642 * [Make `-C relocation-model` more correctly determine whether the linker
4643   creates a position-independent executable][40245]
4644 * [Add `-C overflow-checks` to directly control whether integer overflow
4645   panics][40037]
4646 * [The rustc type checker now checks items on demand instead of in a single
4647   in-order pass][40008]. This is mostly an internal refactoring in support of
4648   future work, including incremental type checking, but also resolves [RFC
4649   1647], allowing `Self` to appear in `impl` `where` clauses.
4650 * [Optimize vtable loads][39995]
4651 * [Turn off vectorization for Emscripten targets][39990]
4652 * [Provide suggestions for unknown macros imported with `use`][39953]
4653 * [Fix ICEs in path resolution][39939]
4654 * [Strip exception handling code on Emscripten when `panic=abort`][39193]
4655 * [Add clearer error message using `&str + &str`][39116]
4656
4657 Stabilized APIs
4658 ---------------
4659
4660 * [`Arc::into_raw`]
4661 * [`Arc::from_raw`]
4662 * [`Arc::ptr_eq`]
4663 * [`Rc::into_raw`]
4664 * [`Rc::from_raw`]
4665 * [`Rc::ptr_eq`]
4666 * [`Ordering::then`]
4667 * [`Ordering::then_with`]
4668 * [`BTreeMap::range`]
4669 * [`BTreeMap::range_mut`]
4670 * [`collections::Bound`]
4671 * [`process::abort`]
4672 * [`ptr::read_unaligned`]
4673 * [`ptr::write_unaligned`]
4674 * [`Result::expect_err`]
4675 * [`Cell::swap`]
4676 * [`Cell::replace`]
4677 * [`Cell::into_inner`]
4678 * [`Cell::take`]
4679
4680 Libraries
4681 ---------
4682
4683 * [`BTreeMap` and `BTreeSet` can iterate over ranges][27787]
4684 * [`Cell` can store non-`Copy` types][39793]. [RFC 1651]
4685 * [`String` implements `FromIterator<&char>`][40028]
4686 * `Box` [implements][40009] a number of new conversions:
4687   `From<Box<str>> for String`,
4688   `From<Box<[T]>> for Vec<T>`,
4689   `From<Box<CStr>> for CString`,
4690   `From<Box<OsStr>> for OsString`,
4691   `From<Box<Path>> for PathBuf`,
4692   `Into<Box<str>> for String`,
4693   `Into<Box<[T]>> for Vec<T>`,
4694   `Into<Box<CStr>> for CString`,
4695   `Into<Box<OsStr>> for OsString`,
4696   `Into<Box<Path>> for PathBuf`,
4697   `Default for Box<str>`,
4698   `Default for Box<CStr>`,
4699   `Default for Box<OsStr>`,
4700   `From<&CStr> for Box<CStr>`,
4701   `From<&OsStr> for Box<OsStr>`,
4702   `From<&Path> for Box<Path>`
4703 * [`ffi::FromBytesWithNulError` implements `Error` and `Display`][39960]
4704 * [Specialize `PartialOrd<A> for [A] where A: Ord`][39642]
4705 * [Slightly optimize `slice::sort`][39538]
4706 * [Add `ToString` trait specialization for `Cow<'a, str>` and `String`][39440]
4707 * [`Box<[T]>` implements `From<&[T]> where T: Copy`,
4708   `Box<str>` implements `From<&str>`][39438]
4709 * [`IpAddr` implements `From` for various arrays. `SocketAddr` implements
4710   `From<(I, u16)> where I: Into<IpAddr>`][39372]
4711 * [`format!` estimates the needed capacity before writing a string][39356]
4712 * [Support unprivileged symlink creation in Windows][38921]
4713 * [`PathBuf` implements `Default`][38764]
4714 * [Implement `PartialEq<[A]>` for `VecDeque<A>`][38661]
4715 * [`HashMap` resizes adaptively][38368] to guard against DOS attacks
4716   and poor hash functions.
4717
4718 Cargo
4719 -----
4720
4721 * [Add `cargo check --all`][cargo/3731]
4722 * [Add an option to ignore SSL revocation checking][cargo/3699]
4723 * [Add `cargo run --package`][cargo/3691]
4724 * [Add `required_features`][cargo/3667]
4725 * [Assume `build.rs` is a build script][cargo/3664]
4726 * [Find workspace via `workspace_root` link in containing member][cargo/3562]
4727
4728 Misc
4729 ----
4730
4731 * [Documentation is rendered with mdbook instead of the obsolete, in-tree
4732   `rustbook`][39633]
4733 * [The "Unstable Book" documents nightly-only features][ubook]
4734 * [Improve the style of the sidebar in rustdoc output][40265]
4735 * [Configure build correctly on 64-bit CPU's with the armhf ABI][40261]
4736 * [Fix MSP430 breakage due to `i128`][40257]
4737 * [Preliminary Solaris/SPARCv9 support][39903]
4738 * [`rustc` is linked statically on Windows MSVC targets][39837], allowing it to
4739   run without installing the MSVC runtime.
4740 * [`rustdoc --test` includes file names in test names][39788]
4741 * This release includes builds of `std` for `sparc64-unknown-linux-gnu`,
4742   `aarch64-unknown-linux-fuchsia`, and `x86_64-unknown-linux-fuchsia`.
4743 * [Initial support for `aarch64-unknown-freebsd`][39491]
4744 * [Initial support for `i686-unknown-netbsd`][39426]
4745 * [This release no longer includes the old makefile build system][39431]. Rust
4746   is built with a custom build system, written in Rust, and with Cargo.
4747 * [Add Debug implementations for libcollection structs][39002]
4748 * [`TypeId` implements `PartialOrd` and `Ord`][38981]
4749 * [`--test-threads=0` produces an error][38945]
4750 * [`rustup` installs documentation by default][40526]
4751 * [The Rust source includes NatVis visualizations][39843]. These can be used by
4752   WinDbg and Visual Studio to improve the debugging experience.
4753
4754 Compatibility Notes
4755 -------------------
4756
4757 * [Rust 1.17 does not correctly detect the MSVC 2017 linker][38584]. As a
4758   workaround, either use MSVC 2015 or run vcvars.bat.
4759 * [When coercing to an unsized type lifetimes must be equal][40319]. That is,
4760   disallow subtyping between `T` and `U` when `T: Unsize<U>`, e.g. coercing
4761   `&mut [&'a X; N]` to `&mut [&'b X]` requires `'a` be equal to `'b`. Soundness
4762   fix.
4763 * [`format!` and `Display::to_string` panic if an underlying formatting
4764   implementation returns an error][40117]. Previously the error was silently
4765   ignored. It is incorrect for `write_fmt` to return an error when writing
4766   to a string.
4767 * [In-tree crates are verified to be unstable][39851]. Previously, some minor
4768   crates were marked stable and could be accessed from the stable toolchain.
4769 * [Rust git source no longer includes vendored crates][39728]. Those that need
4770   to build with vendored crates should build from release tarballs.
4771 * [Fix inert attributes from `proc_macro_derives`][39572]
4772 * [During crate resolution, rustc prefers a crate in the sysroot if two crates
4773   are otherwise identical][39518]. Unlikely to be encountered outside the Rust
4774   build system.
4775 * [Fixed bugs around how type inference interacts with dead-code][39485]. The
4776   existing code generally ignores the type of dead-code unless a type-hint is
4777   provided; this can cause surprising inference interactions particularly around
4778   defaulting. The new code uniformly ignores the result type of dead-code.
4779 * [Tuple-struct constructors with private fields are no longer visible][38932]
4780 * [Lifetime parameters that do not appear in the arguments are now considered
4781   early-bound][38897], resolving a soundness bug (#[32330]). The
4782   `hr_lifetime_in_assoc_type` future-compatibility lint has been in effect since
4783   April of 2016.
4784 * [rustdoc: fix doctests with non-feature crate attributes][38161]
4785 * [Make transmuting from fn item types to pointer-sized types a hard
4786   error][34198]
4787
4788 [27787]: https://github.com/rust-lang/rust/issues/27787
4789 [32330]: https://github.com/rust-lang/rust/issues/32330
4790 [34198]: https://github.com/rust-lang/rust/pull/34198
4791 [38161]: https://github.com/rust-lang/rust/pull/38161
4792 [38368]: https://github.com/rust-lang/rust/pull/38368
4793 [38584]: https://github.com/rust-lang/rust/issues/38584
4794 [38661]: https://github.com/rust-lang/rust/pull/38661
4795 [38764]: https://github.com/rust-lang/rust/pull/38764
4796 [38864]: https://github.com/rust-lang/rust/issues/38864
4797 [38897]: https://github.com/rust-lang/rust/pull/38897
4798 [38921]: https://github.com/rust-lang/rust/pull/38921
4799 [38932]: https://github.com/rust-lang/rust/pull/38932
4800 [38945]: https://github.com/rust-lang/rust/pull/38945
4801 [38981]: https://github.com/rust-lang/rust/pull/38981
4802 [39002]: https://github.com/rust-lang/rust/pull/39002
4803 [39116]: https://github.com/rust-lang/rust/pull/39116
4804 [39193]: https://github.com/rust-lang/rust/pull/39193
4805 [39265]: https://github.com/rust-lang/rust/pull/39265
4806 [39356]: https://github.com/rust-lang/rust/pull/39356
4807 [39372]: https://github.com/rust-lang/rust/pull/39372
4808 [39426]: https://github.com/rust-lang/rust/pull/39426
4809 [39431]: https://github.com/rust-lang/rust/pull/39431
4810 [39438]: https://github.com/rust-lang/rust/pull/39438
4811 [39440]: https://github.com/rust-lang/rust/pull/39440
4812 [39485]: https://github.com/rust-lang/rust/pull/39485
4813 [39491]: https://github.com/rust-lang/rust/pull/39491
4814 [39518]: https://github.com/rust-lang/rust/pull/39518
4815 [39538]: https://github.com/rust-lang/rust/pull/39538
4816 [39572]: https://github.com/rust-lang/rust/pull/39572
4817 [39633]: https://github.com/rust-lang/rust/pull/39633
4818 [39642]: https://github.com/rust-lang/rust/pull/39642
4819 [39728]: https://github.com/rust-lang/rust/pull/39728
4820 [39761]: https://github.com/rust-lang/rust/pull/39761
4821 [39788]: https://github.com/rust-lang/rust/pull/39788
4822 [39793]: https://github.com/rust-lang/rust/pull/39793
4823 [39837]: https://github.com/rust-lang/rust/pull/39837
4824 [39843]: https://github.com/rust-lang/rust/pull/39843
4825 [39851]: https://github.com/rust-lang/rust/pull/39851
4826 [39903]: https://github.com/rust-lang/rust/pull/39903
4827 [39939]: https://github.com/rust-lang/rust/pull/39939
4828 [39953]: https://github.com/rust-lang/rust/pull/39953
4829 [39960]: https://github.com/rust-lang/rust/pull/39960
4830 [39990]: https://github.com/rust-lang/rust/pull/39990
4831 [39995]: https://github.com/rust-lang/rust/pull/39995
4832 [40008]: https://github.com/rust-lang/rust/pull/40008
4833 [40009]: https://github.com/rust-lang/rust/pull/40009
4834 [40027]: https://github.com/rust-lang/rust/pull/40027
4835 [40028]: https://github.com/rust-lang/rust/pull/40028
4836 [40037]: https://github.com/rust-lang/rust/pull/40037
4837 [40117]: https://github.com/rust-lang/rust/pull/40117
4838 [40166]: https://github.com/rust-lang/rust/pull/40166
4839 [40245]: https://github.com/rust-lang/rust/pull/40245
4840 [40257]: https://github.com/rust-lang/rust/pull/40257
4841 [40261]: https://github.com/rust-lang/rust/pull/40261
4842 [40265]: https://github.com/rust-lang/rust/pull/40265
4843 [40319]: https://github.com/rust-lang/rust/pull/40319
4844 [40336]: https://github.com/rust-lang/rust/pull/40336
4845 [40526]: https://github.com/rust-lang/rust/pull/40526
4846 [RFC 1623]: https://github.com/rust-lang/rfcs/blob/master/text/1623-static.md
4847 [RFC 1647]: https://github.com/rust-lang/rfcs/blob/master/text/1647-allow-self-in-where-clauses.md
4848 [RFC 1651]: https://github.com/rust-lang/rfcs/blob/master/text/1651-movecell.md
4849 [RFC 1682]: https://github.com/rust-lang/rfcs/blob/master/text/1682-field-init-shorthand.md
4850 [`Arc::from_raw`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.from_raw
4851 [`Arc::into_raw`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.into_raw
4852 [`Arc::ptr_eq`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.ptr_eq
4853 [`BTreeMap::range_mut`]: https://doc.rust-lang.org/std/collections/btree_map/struct.BTreeMap.html#method.range_mut
4854 [`BTreeMap::range`]: https://doc.rust-lang.org/std/collections/btree_map/struct.BTreeMap.html#method.range
4855 [`Cell::into_inner`]: https://doc.rust-lang.org/std/cell/struct.Cell.html#method.into_inner
4856 [`Cell::replace`]: https://doc.rust-lang.org/std/cell/struct.Cell.html#method.replace
4857 [`Cell::swap`]: https://doc.rust-lang.org/std/cell/struct.Cell.html#method.swap
4858 [`Cell::take`]: https://doc.rust-lang.org/std/cell/struct.Cell.html#method.take
4859 [`Ordering::then_with`]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.then_with
4860 [`Ordering::then`]: https://doc.rust-lang.org/std/cmp/enum.Ordering.html#method.then
4861 [`Rc::from_raw`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.from_raw
4862 [`Rc::into_raw`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.into_raw
4863 [`Rc::ptr_eq`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.ptr_eq
4864 [`Result::expect_err`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.expect_err
4865 [`collections::Bound`]: https://doc.rust-lang.org/std/collections/enum.Bound.html
4866 [`process::abort`]: https://doc.rust-lang.org/std/process/fn.abort.html
4867 [`ptr::read_unaligned`]: https://doc.rust-lang.org/std/ptr/fn.read_unaligned.html
4868 [`ptr::write_unaligned`]: https://doc.rust-lang.org/std/ptr/fn.write_unaligned.html
4869 [cargo/3562]: https://github.com/rust-lang/cargo/pull/3562
4870 [cargo/3664]: https://github.com/rust-lang/cargo/pull/3664
4871 [cargo/3667]: https://github.com/rust-lang/cargo/pull/3667
4872 [cargo/3691]: https://github.com/rust-lang/cargo/pull/3691
4873 [cargo/3699]: https://github.com/rust-lang/cargo/pull/3699
4874 [cargo/3731]: https://github.com/rust-lang/cargo/pull/3731
4875 [mdbook]: https://crates.io/crates/mdbook
4876 [ubook]: https://doc.rust-lang.org/unstable-book/
4877
4878
4879 Version 1.16.0 (2017-03-16)
4880 ===========================
4881
4882 Language
4883 --------
4884
4885 * [The compiler's `dead_code` lint now accounts for type aliases][38051].
4886 * [Uninhabitable enums (those without any variants) no longer permit wildcard
4887   match patterns][38069]
4888 * [Clean up semantics of `self` in an import list][38313]
4889 * [`Self` may appear in `impl` headers][38920]
4890 * [`Self` may appear in struct expressions][39282]
4891
4892 Compiler
4893 --------
4894
4895 * [`rustc` now supports `--emit=metadata`, which causes rustc to emit
4896   a `.rmeta` file containing only crate metadata][38571]. This can be
4897   used by tools like the Rust Language Service to perform
4898   metadata-only builds.
4899 * [Levenshtein based typo suggestions now work in most places, while
4900   previously they worked only for fields and sometimes for local
4901   variables][38927]. Together with the overhaul of "no
4902   resolution"/"unexpected resolution" errors (#[38154]) they result in
4903   large and systematic improvement in resolution diagnostics.
4904 * [Fix `transmute::<T, U>` where `T` requires a bigger alignment than
4905   `U`][38670]
4906 * [rustc: use -Xlinker when specifying an rpath with ',' in it][38798]
4907 * [`rustc` no longer attempts to provide "consider using an explicit
4908   lifetime" suggestions][37057]. They were inaccurate.
4909
4910 Stabilized APIs
4911 ---------------
4912
4913 * [`VecDeque::truncate`]
4914 * [`VecDeque::resize`]
4915 * [`String::insert_str`]
4916 * [`Duration::checked_add`]
4917 * [`Duration::checked_sub`]
4918 * [`Duration::checked_div`]
4919 * [`Duration::checked_mul`]
4920 * [`str::replacen`]
4921 * [`str::repeat`]
4922 * [`SocketAddr::is_ipv4`]
4923 * [`SocketAddr::is_ipv6`]
4924 * [`IpAddr::is_ipv4`]
4925 * [`IpAddr::is_ipv6`]
4926 * [`Vec::dedup_by`]
4927 * [`Vec::dedup_by_key`]
4928 * [`Result::unwrap_or_default`]
4929 * [`<*const T>::wrapping_offset`]
4930 * [`<*mut T>::wrapping_offset`]
4931 * `CommandExt::creation_flags`
4932 * [`File::set_permissions`]
4933 * [`String::split_off`]
4934
4935 Libraries
4936 ---------
4937
4938 * [`[T]::binary_search` and `[T]::binary_search_by_key` now take
4939   their argument by `Borrow` parameter][37761]
4940 * [All public types in std implement `Debug`][38006]
4941 * [`IpAddr` implements `From<Ipv4Addr>` and `From<Ipv6Addr>`][38327]
4942 * [`Ipv6Addr` implements `From<[u16; 8]>`][38131]
4943 * [Ctrl-Z returns from `Stdin.read()` when reading from the console on
4944   Windows][38274]
4945 * [std: Fix partial writes in `LineWriter`][38062]
4946 * [std: Clamp max read/write sizes on Unix][38062]
4947 * [Use more specific panic message for `&str` slicing errors][38066]
4948 * [`TcpListener::set_only_v6` is deprecated][38304]. This
4949   functionality cannot be achieved in std currently.
4950 * [`writeln!`, like `println!`, now accepts a form with no string
4951   or formatting arguments, to just print a newline][38469]
4952 * [Implement `iter::Sum` and `iter::Product` for `Result`][38580]
4953 * [Reduce the size of static data in `std_unicode::tables`][38781]
4954 * [`char::EscapeDebug`, `EscapeDefault`, `EscapeUnicode`,
4955   `CaseMappingIter`, `ToLowercase`, `ToUppercase`, implement
4956   `Display`][38909]
4957 * [`Duration` implements `Sum`][38712]
4958 * [`String` implements `ToSocketAddrs`][39048]
4959
4960 Cargo
4961 -----
4962
4963 * [The `cargo check` command does a type check of a project without
4964   building it][cargo/3296]
4965 * [crates.io will display CI badges from Travis and AppVeyor, if
4966   specified in Cargo.toml][cargo/3546]
4967 * [crates.io will display categories listed in Cargo.toml][cargo/3301]
4968 * [Compilation profiles accept integer values for `debug`, in addition
4969   to `true` and `false`. These are passed to `rustc` as the value to
4970   `-C debuginfo`][cargo/3534]
4971 * [Implement `cargo --version --verbose`][cargo/3604]
4972 * [All builds now output 'dep-info' build dependencies compatible with
4973   make and ninja][cargo/3557]
4974 * [Build all workspace members with `build --all`][cargo/3511]
4975 * [Document all workspace members with `doc --all`][cargo/3515]
4976 * [Path deps outside workspace are not members][cargo/3443]
4977
4978 Misc
4979 ----
4980
4981 * [`rustdoc` has a `--sysroot` argument that, like `rustc`, specifies
4982   the path to the Rust implementation][38589]
4983 * [The `armv7-linux-androideabi` target no longer enables NEON
4984   extensions, per Google's ABI guide][38413]
4985 * [The stock standard library can be compiled for Redox OS][38401]
4986 * [Rust has initial SPARC support][38726]. Tier 3. No builds
4987   available.
4988 * [Rust has experimental support for Nvidia PTX][38559]. Tier 3. No
4989   builds available.
4990 * [Fix backtraces on i686-pc-windows-gnu by disabling FPO][39379]
4991
4992 Compatibility Notes
4993 -------------------
4994
4995 * [Uninhabitable enums (those without any variants) no longer permit wildcard
4996   match patterns][38069]
4997 * In this release, references to uninhabited types can not be
4998   pattern-matched. This was accidentally allowed in 1.15.
4999 * [The compiler's `dead_code` lint now accounts for type aliases][38051].
5000 * [Ctrl-Z returns from `Stdin.read()` when reading from the console on
5001   Windows][38274]
5002 * [Clean up semantics of `self` in an import list][38313]
5003 * Reimplemented lifetime elision. This change was almost entirely compatible
5004   with existing code, but it did close a number of small bugs and loopholes,
5005   as well as being more accepting in some other [cases][41105].
5006
5007 [37057]: https://github.com/rust-lang/rust/pull/37057
5008 [37761]: https://github.com/rust-lang/rust/pull/37761
5009 [38006]: https://github.com/rust-lang/rust/pull/38006
5010 [38051]: https://github.com/rust-lang/rust/pull/38051
5011 [38062]: https://github.com/rust-lang/rust/pull/38062
5012 [38062]: https://github.com/rust-lang/rust/pull/38622
5013 [38066]: https://github.com/rust-lang/rust/pull/38066
5014 [38069]: https://github.com/rust-lang/rust/pull/38069
5015 [38131]: https://github.com/rust-lang/rust/pull/38131
5016 [38154]: https://github.com/rust-lang/rust/pull/38154
5017 [38274]: https://github.com/rust-lang/rust/pull/38274
5018 [38304]: https://github.com/rust-lang/rust/pull/38304
5019 [38313]: https://github.com/rust-lang/rust/pull/38313
5020 [38314]: https://github.com/rust-lang/rust/pull/38314
5021 [38327]: https://github.com/rust-lang/rust/pull/38327
5022 [38401]: https://github.com/rust-lang/rust/pull/38401
5023 [38413]: https://github.com/rust-lang/rust/pull/38413
5024 [38469]: https://github.com/rust-lang/rust/pull/38469
5025 [38559]: https://github.com/rust-lang/rust/pull/38559
5026 [38571]: https://github.com/rust-lang/rust/pull/38571
5027 [38580]: https://github.com/rust-lang/rust/pull/38580
5028 [38589]: https://github.com/rust-lang/rust/pull/38589
5029 [38670]: https://github.com/rust-lang/rust/pull/38670
5030 [38712]: https://github.com/rust-lang/rust/pull/38712
5031 [38726]: https://github.com/rust-lang/rust/pull/38726
5032 [38781]: https://github.com/rust-lang/rust/pull/38781
5033 [38798]: https://github.com/rust-lang/rust/pull/38798
5034 [38909]: https://github.com/rust-lang/rust/pull/38909
5035 [38920]: https://github.com/rust-lang/rust/pull/38920
5036 [38927]: https://github.com/rust-lang/rust/pull/38927
5037 [39048]: https://github.com/rust-lang/rust/pull/39048
5038 [39282]: https://github.com/rust-lang/rust/pull/39282
5039 [39379]: https://github.com/rust-lang/rust/pull/39379
5040 [41105]: https://github.com/rust-lang/rust/issues/41105
5041 [`<*const T>::wrapping_offset`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.wrapping_offset
5042 [`<*mut T>::wrapping_offset`]: https://doc.rust-lang.org/std/primitive.pointer.html#method.wrapping_offset
5043 [`Duration::checked_add`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.checked_add
5044 [`Duration::checked_div`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.checked_div
5045 [`Duration::checked_mul`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.checked_mul
5046 [`Duration::checked_sub`]: https://doc.rust-lang.org/std/time/struct.Duration.html#method.checked_sub
5047 [`File::set_permissions`]: https://doc.rust-lang.org/std/fs/struct.File.html#method.set_permissions
5048 [`IpAddr::is_ipv4`]: https://doc.rust-lang.org/std/net/enum.IpAddr.html#method.is_ipv4
5049 [`IpAddr::is_ipv6`]: https://doc.rust-lang.org/std/net/enum.IpAddr.html#method.is_ipv6
5050 [`Result::unwrap_or_default`]: https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_or_default
5051 [`SocketAddr::is_ipv4`]: https://doc.rust-lang.org/std/net/enum.SocketAddr.html#method.is_ipv4
5052 [`SocketAddr::is_ipv6`]: https://doc.rust-lang.org/std/net/enum.SocketAddr.html#method.is_ipv6
5053 [`String::insert_str`]: https://doc.rust-lang.org/std/string/struct.String.html#method.insert_str
5054 [`String::split_off`]: https://doc.rust-lang.org/std/string/struct.String.html#method.split_off
5055 [`Vec::dedup_by_key`]: https://doc.rust-lang.org/std/vec/struct.Vec.html#method.dedup_by_key
5056 [`Vec::dedup_by`]: https://doc.rust-lang.org/std/vec/struct.Vec.html#method.dedup_by
5057 [`VecDeque::resize`]:  https://doc.rust-lang.org/std/collections/vec_deque/struct.VecDeque.html#method.resize
5058 [`VecDeque::truncate`]: https://doc.rust-lang.org/std/collections/vec_deque/struct.VecDeque.html#method.truncate
5059 [`str::repeat`]: https://doc.rust-lang.org/std/primitive.str.html#method.repeat
5060 [`str::replacen`]: https://doc.rust-lang.org/std/primitive.str.html#method.replacen
5061 [cargo/3296]: https://github.com/rust-lang/cargo/pull/3296
5062 [cargo/3301]: https://github.com/rust-lang/cargo/pull/3301
5063 [cargo/3443]: https://github.com/rust-lang/cargo/pull/3443
5064 [cargo/3511]: https://github.com/rust-lang/cargo/pull/3511
5065 [cargo/3515]: https://github.com/rust-lang/cargo/pull/3515
5066 [cargo/3534]: https://github.com/rust-lang/cargo/pull/3534
5067 [cargo/3546]: https://github.com/rust-lang/cargo/pull/3546
5068 [cargo/3557]: https://github.com/rust-lang/cargo/pull/3557
5069 [cargo/3604]: https://github.com/rust-lang/cargo/pull/3604
5070 [RFC 1623]: https://github.com/rust-lang/rfcs/blob/master/text/1623-static.md
5071
5072
5073 Version 1.15.1 (2017-02-09)
5074 ===========================
5075
5076 * [Fix IntoIter::as_mut_slice's signature][39466]
5077 * [Compile compiler builtins with `-fPIC` on 32-bit platforms][39523]
5078
5079 [39466]: https://github.com/rust-lang/rust/pull/39466
5080 [39523]: https://github.com/rust-lang/rust/pull/39523
5081
5082
5083 Version 1.15.0 (2017-02-02)
5084 ===========================
5085
5086 Language
5087 --------
5088
5089 * Basic procedural macros allowing custom `#[derive]`, aka "macros 1.1", are
5090   stable. This allows popular code-generating crates like Serde and Diesel to
5091   work ergonomically. [RFC 1681].
5092 * [Tuple structs may be empty. Unary and empty tuple structs may be instantiated
5093   with curly braces][36868]. Part of [RFC 1506].
5094 * [A number of minor changes to name resolution have been activated][37127].
5095   They add up to more consistent semantics, allowing for future evolution of
5096   Rust macros. Specified in [RFC 1560], see its section on ["changes"] for
5097   details of what is different. The breaking changes here have been transitioned
5098   through the [`legacy_imports`] lint since 1.14, with no known regressions.
5099 * [In `macro_rules`, `path` fragments can now be parsed as type parameter
5100   bounds][38279]
5101 * [`?Sized` can be used in `where` clauses][37791]
5102 * [There is now a limit on the size of monomorphized types and it can be
5103   modified with the `#![type_size_limit]` crate attribute, similarly to
5104   the `#![recursion_limit]` attribute][37789]
5105
5106 Compiler
5107 --------
5108
5109 * [On Windows, the compiler will apply dllimport attributes when linking to
5110   extern functions][37973]. Additional attributes and flags can control which
5111   library kind is linked and its name. [RFC 1717].
5112 * [Rust-ABI symbols are no longer exported from cdylibs][38117]
5113 * [The `--test` flag works with procedural macro crates][38107]
5114 * [Fix `extern "aapcs" fn` ABI][37814]
5115 * [The `-C no-stack-check` flag is deprecated][37636]. It does nothing.
5116 * [The `format!` expander recognizes incorrect `printf` and shell-style
5117   formatting directives and suggests the correct format][37613].
5118 * [Only report one error for all unused imports in an import list][37456]
5119
5120 Compiler Performance
5121 --------------------
5122
5123 * [Avoid unnecessary `mk_ty` calls in `Ty::super_fold_with`][37705]
5124 * [Avoid more unnecessary `mk_ty` calls in `Ty::super_fold_with`][37979]
5125 * [Don't clone in `UnificationTable::probe`][37848]
5126 * [Remove `scope_auxiliary` to cut RSS by 10%][37764]
5127 * [Use small vectors in type walker][37760]
5128 * [Macro expansion performance was improved][37701]
5129 * [Change `HirVec<P<T>>` to `HirVec<T>` in `hir::Expr`][37642]
5130 * [Replace FNV with a faster hash function][37229]
5131
5132 Stabilized APIs
5133 ---------------
5134
5135 * [`std::iter::Iterator::min_by`]
5136 * [`std::iter::Iterator::max_by`]
5137 * [`std::os::*::fs::FileExt`]
5138 * [`std::sync::atomic::Atomic*::get_mut`]
5139 * [`std::sync::atomic::Atomic*::into_inner`]
5140 * [`std::vec::IntoIter::as_slice`]
5141 * [`std::vec::IntoIter::as_mut_slice`]
5142 * [`std::sync::mpsc::Receiver::try_iter`]
5143 * [`std::os::unix::process::CommandExt::before_exec`]
5144 * [`std::rc::Rc::strong_count`]
5145 * [`std::rc::Rc::weak_count`]
5146 * [`std::sync::Arc::strong_count`]
5147 * [`std::sync::Arc::weak_count`]
5148 * [`std::char::encode_utf8`]
5149 * [`std::char::encode_utf16`]
5150 * [`std::cell::Ref::clone`]
5151 * [`std::io::Take::into_inner`]
5152
5153 Libraries
5154 ---------
5155
5156 * [The standard sorting algorithm has been rewritten for dramatic performance
5157   improvements][38192]. It is a hybrid merge sort, drawing influences from
5158   Timsort. Previously it was a naive merge sort.
5159 * [`Iterator::nth` no longer has a `Sized` bound][38134]
5160 * [`Extend<&T>` is specialized for `Vec` where `T: Copy`][38182] to improve
5161   performance.
5162 * [`chars().count()` is much faster][37888] and so are [`chars().last()`
5163   and `char_indices().last()`][37882]
5164 * [Fix ARM Objective-C ABI in `std::env::args`][38146]
5165 * [Chinese characters display correctly in `fmt::Debug`][37855]
5166 * [Derive `Default` for `Duration`][37699]
5167 * [Support creation of anonymous pipes on WinXP/2k][37677]
5168 * [`mpsc::RecvTimeoutError` implements `Error`][37527]
5169 * [Don't pass overlapped handles to processes][38835]
5170
5171 Cargo
5172 -----
5173
5174 * [In this release, Cargo build scripts no longer have access to the `OUT_DIR`
5175   environment variable at build time via `env!("OUT_DIR")`][cargo/3368]. They
5176   should instead check the variable at runtime with `std::env`. That the value
5177   was set at build time was a bug, and incorrect when cross-compiling. This
5178   change is known to cause breakage.
5179 * [Add `--all` flag to `cargo test`][cargo/3221]
5180 * [Compile statically against the MSVC CRT][cargo/3363]
5181 * [Mix feature flags into fingerprint/metadata shorthash][cargo/3102]
5182 * [Link OpenSSL statically on OSX][cargo/3311]
5183 * [Apply new fingerprinting to build dir outputs][cargo/3310]
5184 * [Test for bad path overrides with summaries][cargo/3336]
5185 * [Require `cargo install --vers` to take a semver version][cargo/3338]
5186 * [Fix retrying crate downloads for network errors][cargo/3348]
5187 * [Implement string lookup for `build.rustflags` config key][cargo/3356]
5188 * [Emit more info on --message-format=json][cargo/3319]
5189 * [Assume `build.rs` in the same directory as `Cargo.toml` is a build script][cargo/3361]
5190 * [Don't ignore errors in workspace manifest][cargo/3409]
5191 * [Fix `--message-format JSON` when rustc emits non-JSON warnings][cargo/3410]
5192
5193 Tooling
5194 -------
5195
5196 * [Test runners (binaries built with `--test`) now support a `--list` argument
5197   that lists the tests it contains][38185]
5198 * [Test runners now support a `--exact` argument that makes the test filter
5199   match exactly, instead of matching only a substring of the test name][38181]
5200 * [rustdoc supports a `--playground-url` flag][37763]
5201 * [rustdoc provides more details about `#[should_panic]` errors][37749]
5202
5203 Misc
5204 ----
5205
5206 * [The Rust build system is now written in Rust][37817]. The Makefiles may
5207   continue to be used in this release by passing `--disable-rustbuild` to the
5208   configure script, but they will be deleted soon. Note that the new build
5209   system uses a different on-disk layout that will likely affect any scripts
5210   building Rust.
5211 * [Rust supports i686-unknown-openbsd][38086]. Tier 3 support. No testing or
5212   releases.
5213 * [Rust supports the MSP430][37627]. Tier 3 support. No testing or releases.
5214 * [Rust supports the ARMv5TE architecture][37615]. Tier 3 support. No testing or
5215   releases.
5216
5217 Compatibility Notes
5218 -------------------
5219
5220 * [A number of minor changes to name resolution have been activated][37127].
5221   They add up to more consistent semantics, allowing for future evolution of
5222   Rust macros. Specified in [RFC 1560], see its section on ["changes"] for
5223   details of what is different. The breaking changes here have been transitioned
5224   through the [`legacy_imports`] lint since 1.14, with no known regressions.
5225 * [In this release, Cargo build scripts no longer have access to the `OUT_DIR`
5226   environment variable at build time via `env!("OUT_DIR")`][cargo/3368]. They
5227   should instead check the variable at runtime with `std::env`. That the value
5228   was set at build time was a bug, and incorrect when cross-compiling. This
5229   change is known to cause breakage.
5230 * [Higher-ranked lifetimes are no longer allowed to appear _only_ in associated
5231   types][33685]. The [`hr_lifetime_in_assoc_type` lint] has been a warning since
5232   1.10 and is now an error by default. It will become a hard error in the near
5233   future.
5234 * [The semantics relating modules to file system directories are changing in
5235   minor ways][37602]. This is captured in the new `legacy_directory_ownership`
5236   lint, which is a warning in this release, and will become a hard error in the
5237   future.
5238 * [Rust-ABI symbols are no longer exported from cdylibs][38117]
5239 * [Once `Peekable` peeks a `None` it will return that `None` without re-querying
5240   the underlying iterator][37834]
5241
5242 ["changes"]: https://github.com/rust-lang/rfcs/blob/master/text/1560-name-resolution.md#changes-to-name-resolution-rules
5243 [33685]: https://github.com/rust-lang/rust/issues/33685
5244 [36868]: https://github.com/rust-lang/rust/pull/36868
5245 [37127]: https://github.com/rust-lang/rust/pull/37127
5246 [37229]: https://github.com/rust-lang/rust/pull/37229
5247 [37456]: https://github.com/rust-lang/rust/pull/37456
5248 [37527]: https://github.com/rust-lang/rust/pull/37527
5249 [37602]: https://github.com/rust-lang/rust/pull/37602
5250 [37613]: https://github.com/rust-lang/rust/pull/37613
5251 [37615]: https://github.com/rust-lang/rust/pull/37615
5252 [37636]: https://github.com/rust-lang/rust/pull/37636
5253 [37627]: https://github.com/rust-lang/rust/pull/37627
5254 [37642]: https://github.com/rust-lang/rust/pull/37642
5255 [37677]: https://github.com/rust-lang/rust/pull/37677
5256 [37699]: https://github.com/rust-lang/rust/pull/37699
5257 [37701]: https://github.com/rust-lang/rust/pull/37701
5258 [37705]: https://github.com/rust-lang/rust/pull/37705
5259 [37749]: https://github.com/rust-lang/rust/pull/37749
5260 [37760]: https://github.com/rust-lang/rust/pull/37760
5261 [37763]: https://github.com/rust-lang/rust/pull/37763
5262 [37764]: https://github.com/rust-lang/rust/pull/37764
5263 [37789]: https://github.com/rust-lang/rust/pull/37789
5264 [37791]: https://github.com/rust-lang/rust/pull/37791
5265 [37814]: https://github.com/rust-lang/rust/pull/37814
5266 [37817]: https://github.com/rust-lang/rust/pull/37817
5267 [37834]: https://github.com/rust-lang/rust/pull/37834
5268 [37848]: https://github.com/rust-lang/rust/pull/37848
5269 [37855]: https://github.com/rust-lang/rust/pull/37855
5270 [37882]: https://github.com/rust-lang/rust/pull/37882
5271 [37888]: https://github.com/rust-lang/rust/pull/37888
5272 [37973]: https://github.com/rust-lang/rust/pull/37973
5273 [37979]: https://github.com/rust-lang/rust/pull/37979
5274 [38086]: https://github.com/rust-lang/rust/pull/38086
5275 [38107]: https://github.com/rust-lang/rust/pull/38107
5276 [38117]: https://github.com/rust-lang/rust/pull/38117
5277 [38134]: https://github.com/rust-lang/rust/pull/38134
5278 [38146]: https://github.com/rust-lang/rust/pull/38146
5279 [38181]: https://github.com/rust-lang/rust/pull/38181
5280 [38182]: https://github.com/rust-lang/rust/pull/38182
5281 [38185]: https://github.com/rust-lang/rust/pull/38185
5282 [38192]: https://github.com/rust-lang/rust/pull/38192
5283 [38279]: https://github.com/rust-lang/rust/pull/38279
5284 [38835]: https://github.com/rust-lang/rust/pull/38835
5285 [RFC 1492]: https://github.com/rust-lang/rfcs/blob/master/text/1492-dotdot-in-patterns.md
5286 [RFC 1506]: https://github.com/rust-lang/rfcs/blob/master/text/1506-adt-kinds.md
5287 [RFC 1560]: https://github.com/rust-lang/rfcs/blob/master/text/1560-name-resolution.md
5288 [RFC 1681]: https://github.com/rust-lang/rfcs/blob/master/text/1681-macros-1.1.md
5289 [RFC 1717]: https://github.com/rust-lang/rfcs/blob/master/text/1717-dllimport.md
5290 [`hr_lifetime_in_assoc_type` lint]: https://github.com/rust-lang/rust/issues/33685
5291 [`legacy_imports`]: https://github.com/rust-lang/rust/pull/38271
5292 [cargo/3102]: https://github.com/rust-lang/cargo/pull/3102
5293 [cargo/3221]: https://github.com/rust-lang/cargo/pull/3221
5294 [cargo/3310]: https://github.com/rust-lang/cargo/pull/3310
5295 [cargo/3311]: https://github.com/rust-lang/cargo/pull/3311
5296 [cargo/3319]: https://github.com/rust-lang/cargo/pull/3319
5297 [cargo/3336]: https://github.com/rust-lang/cargo/pull/3336
5298 [cargo/3338]: https://github.com/rust-lang/cargo/pull/3338
5299 [cargo/3348]: https://github.com/rust-lang/cargo/pull/3348
5300 [cargo/3356]: https://github.com/rust-lang/cargo/pull/3356
5301 [cargo/3361]: https://github.com/rust-lang/cargo/pull/3361
5302 [cargo/3363]: https://github.com/rust-lang/cargo/pull/3363
5303 [cargo/3368]: https://github.com/rust-lang/cargo/issues/3368
5304 [cargo/3409]: https://github.com/rust-lang/cargo/pull/3409
5305 [cargo/3410]: https://github.com/rust-lang/cargo/pull/3410
5306 [`std::iter::Iterator::min_by`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.min_by
5307 [`std::iter::Iterator::max_by`]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.max_by
5308 [`std::os::*::fs::FileExt`]: https://doc.rust-lang.org/std/os/unix/fs/trait.FileExt.html
5309 [`std::sync::atomic::Atomic*::get_mut`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU8.html#method.get_mut
5310 [`std::sync::atomic::Atomic*::into_inner`]: https://doc.rust-lang.org/std/sync/atomic/struct.AtomicU8.html#method.into_inner
5311 [`std::vec::IntoIter::as_slice`]: https://doc.rust-lang.org/std/vec/struct.IntoIter.html#method.as_slice
5312 [`std::vec::IntoIter::as_mut_slice`]: https://doc.rust-lang.org/std/vec/struct.IntoIter.html#method.as_mut_slice
5313 [`std::sync::mpsc::Receiver::try_iter`]: https://doc.rust-lang.org/std/sync/mpsc/struct.Receiver.html#method.try_iter
5314 [`std::os::unix::process::CommandExt::before_exec`]: https://doc.rust-lang.org/std/os/unix/process/trait.CommandExt.html#tymethod.before_exec
5315 [`std::rc::Rc::strong_count`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.strong_count
5316 [`std::rc::Rc::weak_count`]: https://doc.rust-lang.org/std/rc/struct.Rc.html#method.weak_count
5317 [`std::sync::Arc::strong_count`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.strong_count
5318 [`std::sync::Arc::weak_count`]: https://doc.rust-lang.org/std/sync/struct.Arc.html#method.weak_count
5319 [`std::char::encode_utf8`]: https://doc.rust-lang.org/std/primitive.char.html#method.encode_utf8
5320 [`std::char::encode_utf16`]: https://doc.rust-lang.org/std/primitive.char.html#method.encode_utf16
5321 [`std::cell::Ref::clone`]: https://doc.rust-lang.org/std/cell/struct.Ref.html#method.clone
5322 [`std::io::Take::into_inner`]: https://doc.rust-lang.org/std/io/struct.Take.html#method.into_inner
5323
5324
5325 Version 1.14.0 (2016-12-22)
5326 ===========================
5327
5328 Language
5329 --------
5330
5331 * [`..` matches multiple tuple fields in enum variants, structs
5332   and tuples][36843]. [RFC 1492].
5333 * [Safe `fn` items can be coerced to `unsafe fn` pointers][37389]
5334 * [`use *` and `use ::*` both glob-import from the crate root][37367]
5335 * [It's now possible to call a `Vec<Box<Fn()>>` without explicit
5336   dereferencing][36822]
5337
5338 Compiler
5339 --------
5340
5341 * [Mark enums with non-zero discriminant as non-zero][37224]
5342 * [Lower-case `static mut` names are linted like other
5343   statics and consts][37162]
5344 * [Fix ICE on some macros in const integer positions
5345    (e.g. `[u8; m!()]`)][36819]
5346 * [Improve error message and snippet for "did you mean `x`"][36798]
5347 * [Add a panic-strategy field to the target specification][36794]
5348 * [Include LLVM version in `--version --verbose`][37200]
5349
5350 Compile-time Optimizations
5351 --------------------------
5352
5353 * [Improve macro expansion performance][37569]
5354 * [Shrink `Expr_::ExprInlineAsm`][37445]
5355 * [Replace all uses of SHA-256 with BLAKE2b][37439]
5356 * [Reduce the number of bytes hashed by `IchHasher`][37427]
5357 * [Avoid more allocations when compiling html5ever][37373]
5358 * [Use `SmallVector` in `CombineFields::instantiate`][37322]
5359 * [Avoid some allocations in the macro parser][37318]
5360 * [Use a faster deflate setting][37298]
5361 * [Add `ArrayVec` and `AccumulateVec` to reduce heap allocations
5362   during interning of slices][37270]
5363 * [Optimize `write_metadata`][37267]
5364 * [Don't process obligation forest cycles when stalled][37231]
5365 * [Avoid many `CrateConfig` clones][37161]
5366 * [Optimize `Substs::super_fold_with`][37108]
5367 * [Optimize `ObligationForest`'s `NodeState` handling][36993]
5368 * [Speed up `plug_leaks`][36917]
5369
5370 Libraries
5371 ---------
5372
5373 * [`println!()`, with no arguments, prints newline][36825].
5374   Previously, an empty string was required to achieve the same.
5375 * [`Wrapping` impls standard binary and unary operators, as well as
5376    the `Sum` and `Product` iterators][37356]
5377 * [Implement `From<Cow<str>> for String` and `From<Cow<[T]>> for
5378   Vec<T>`][37326]
5379 * [Improve `fold` performance for `chain`, `cloned`, `map`, and
5380   `VecDeque` iterators][37315]
5381 * [Improve `SipHasher` performance on small values][37312]
5382 * [Add Iterator trait TrustedLen to enable better FromIterator /
5383   Extend][37306]
5384 * [Expand `.zip()` specialization to `.map()` and `.cloned()`][37230]
5385 * [`ReadDir` implements `Debug`][37221]
5386 * [Implement `RefUnwindSafe` for atomic types][37178]
5387 * [Specialize `Vec::extend` to `Vec::extend_from_slice`][37094]
5388 * [Avoid allocations in `Decoder::read_str`][37064]
5389 * [`io::Error` implements `From<io::ErrorKind>`][37037]
5390 * [Impl `Debug` for raw pointers to unsized data][36880]
5391 * [Don't reuse `HashMap` random seeds][37470]
5392 * [The internal memory layout of `HashMap` is more cache-friendly, for
5393   significant improvements in some operations][36692]
5394 * [`HashMap` uses less memory on 32-bit architectures][36595]
5395 * [Impl `Add<{str, Cow<str>}>` for `Cow<str>`][36430]
5396
5397 Cargo
5398 -----
5399
5400 * [Expose rustc cfg values to build scripts][cargo/3243]
5401 * [Allow cargo to work with read-only `CARGO_HOME`][cargo/3259]
5402 * [Fix passing --features when testing multiple packages][cargo/3280]
5403 * [Use a single profile set per workspace][cargo/3249]
5404 * [Load `replace` sections from lock files][cargo/3220]
5405 * [Ignore `panic` configuration for test/bench profiles][cargo/3175]
5406
5407 Tooling
5408 -------
5409
5410 * [rustup is the recommended Rust installation method][1.14rustup]
5411 * This release includes host (rustc) builds for Linux on MIPS, PowerPC, and
5412   S390x. These are [tier 2] platforms and may have major defects. Follow the
5413   instructions on the website to install, or add the targets to an existing
5414   installation with `rustup target add`. The new target triples are:
5415   - `mips-unknown-linux-gnu`
5416   - `mipsel-unknown-linux-gnu`
5417   - `mips64-unknown-linux-gnuabi64`
5418   - `mips64el-unknown-linux-gnuabi64 `
5419   - `powerpc-unknown-linux-gnu`
5420   - `powerpc64-unknown-linux-gnu`
5421   - `powerpc64le-unknown-linux-gnu`
5422   - `s390x-unknown-linux-gnu `
5423 * This release includes target (std) builds for ARM Linux running MUSL
5424   libc. These are [tier 2] platforms and may have major defects. Add the
5425   following triples to an existing rustup installation with `rustup target add`:
5426   - `arm-unknown-linux-musleabi`
5427   - `arm-unknown-linux-musleabihf`
5428   - `armv7-unknown-linux-musleabihf`
5429 * This release includes [experimental support for WebAssembly][1.14wasm], via
5430   the `wasm32-unknown-emscripten` target. This target is known to have major
5431   defects. Please test, report, and fix.
5432 * rustup no longer installs documentation by default. Run `rustup
5433   component add rust-docs` to install.
5434 * [Fix line stepping in debugger][37310]
5435 * [Enable line number debuginfo in releases][37280]
5436
5437 Misc
5438 ----
5439
5440 * [Disable jemalloc on aarch64/powerpc/mips][37392]
5441 * [Add support for Fuchsia OS][37313]
5442 * [Detect local-rebuild by only MAJOR.MINOR version][37273]
5443
5444 Compatibility Notes
5445 -------------------
5446
5447 * [A number of forward-compatibility lints used by the compiler
5448   to gradually introduce language changes have been converted
5449   to deny by default][36894]:
5450   - ["use of inaccessible extern crate erroneously allowed"][36886]
5451   - ["type parameter default erroneously allowed in invalid location"][36887]
5452   - ["detects super or self keywords at the beginning of global path"][36888]
5453   - ["two overlapping inherent impls define an item with the same name
5454     were erroneously allowed"][36889]
5455   - ["floating-point constants cannot be used in patterns"][36890]
5456   - ["constants of struct or enum type can only be used in a pattern if
5457      the struct or enum has `#[derive(PartialEq, Eq)]`"][36891]
5458   - ["lifetimes or labels named `'_` were erroneously allowed"][36892]
5459 * [Prohibit patterns in trait methods without bodies][37378]
5460 * [The atomic `Ordering` enum may not be matched exhaustively][37351]
5461 * [Future-proofing `#[no_link]` breaks some obscure cases][37247]
5462 * [The `$crate` macro variable is accepted in fewer locations][37213]
5463 * [Impls specifying extra region requirements beyond the trait
5464   they implement are rejected][37167]
5465 * [Enums may not be unsized][37111]. Unsized enums are intended to
5466   work but never have. For now they are forbidden.
5467 * [Enforce the shadowing restrictions from RFC 1560 for today's macros][36767]
5468
5469 [tier 2]: https://forge.rust-lang.org/platform-support.html
5470 [1.14rustup]: https://internals.rust-lang.org/t/beta-testing-rustup-rs/3316/204
5471 [1.14wasm]: https://users.rust-lang.org/t/compiling-to-the-web-with-rust-and-emscripten/7627
5472 [36430]: https://github.com/rust-lang/rust/pull/36430
5473 [36595]: https://github.com/rust-lang/rust/pull/36595
5474 [36595]: https://github.com/rust-lang/rust/pull/36595
5475 [36692]: https://github.com/rust-lang/rust/pull/36692
5476 [36767]: https://github.com/rust-lang/rust/pull/36767
5477 [36794]: https://github.com/rust-lang/rust/pull/36794
5478 [36798]: https://github.com/rust-lang/rust/pull/36798
5479 [36819]: https://github.com/rust-lang/rust/pull/36819
5480 [36822]: https://github.com/rust-lang/rust/pull/36822
5481 [36825]: https://github.com/rust-lang/rust/pull/36825
5482 [36843]: https://github.com/rust-lang/rust/pull/36843
5483 [36880]: https://github.com/rust-lang/rust/pull/36880
5484 [36886]: https://github.com/rust-lang/rust/issues/36886
5485 [36887]: https://github.com/rust-lang/rust/issues/36887
5486 [36888]: https://github.com/rust-lang/rust/issues/36888
5487 [36889]: https://github.com/rust-lang/rust/issues/36889
5488 [36890]: https://github.com/rust-lang/rust/issues/36890
5489 [36891]: https://github.com/rust-lang/rust/issues/36891
5490 [36892]: https://github.com/rust-lang/rust/issues/36892
5491 [36894]: https://github.com/rust-lang/rust/pull/36894
5492 [36917]: https://github.com/rust-lang/rust/pull/36917
5493 [36993]: https://github.com/rust-lang/rust/pull/36993
5494 [37037]: https://github.com/rust-lang/rust/pull/37037
5495 [37064]: https://github.com/rust-lang/rust/pull/37064
5496 [37094]: https://github.com/rust-lang/rust/pull/37094
5497 [37108]: https://github.com/rust-lang/rust/pull/37108
5498 [37111]: https://github.com/rust-lang/rust/pull/37111
5499 [37161]: https://github.com/rust-lang/rust/pull/37161
5500 [37162]: https://github.com/rust-lang/rust/pull/37162
5501 [37167]: https://github.com/rust-lang/rust/pull/37167
5502 [37178]: https://github.com/rust-lang/rust/pull/37178
5503 [37200]: https://github.com/rust-lang/rust/pull/37200
5504 [37213]: https://github.com/rust-lang/rust/pull/37213
5505 [37221]: https://github.com/rust-lang/rust/pull/37221
5506 [37224]: https://github.com/rust-lang/rust/pull/37224
5507 [37230]: https://github.com/rust-lang/rust/pull/37230
5508 [37231]: https://github.com/rust-lang/rust/pull/37231
5509 [37247]: https://github.com/rust-lang/rust/pull/37247
5510 [37267]: https://github.com/rust-lang/rust/pull/37267
5511 [37270]: https://github.com/rust-lang/rust/pull/37270
5512 [37273]: https://github.com/rust-lang/rust/pull/37273
5513 [37280]: https://github.com/rust-lang/rust/pull/37280
5514 [37298]: https://github.com/rust-lang/rust/pull/37298
5515 [37306]: https://github.com/rust-lang/rust/pull/37306
5516 [37310]: https://github.com/rust-lang/rust/pull/37310
5517 [37312]: https://github.com/rust-lang/rust/pull/37312
5518 [37313]: https://github.com/rust-lang/rust/pull/37313
5519 [37315]: https://github.com/rust-lang/rust/pull/37315
5520 [37318]: https://github.com/rust-lang/rust/pull/37318
5521 [37322]: https://github.com/rust-lang/rust/pull/37322
5522 [37326]: https://github.com/rust-lang/rust/pull/37326
5523 [37351]: https://github.com/rust-lang/rust/pull/37351
5524 [37356]: https://github.com/rust-lang/rust/pull/37356
5525 [37367]: https://github.com/rust-lang/rust/pull/37367
5526 [37373]: https://github.com/rust-lang/rust/pull/37373
5527 [37378]: https://github.com/rust-lang/rust/pull/37378
5528 [37389]: https://github.com/rust-lang/rust/pull/37389
5529 [37392]: https://github.com/rust-lang/rust/pull/37392
5530 [37427]: https://github.com/rust-lang/rust/pull/37427
5531 [37439]: https://github.com/rust-lang/rust/pull/37439
5532 [37445]: https://github.com/rust-lang/rust/pull/37445
5533 [37470]: https://github.com/rust-lang/rust/pull/37470
5534 [37569]: https://github.com/rust-lang/rust/pull/37569
5535 [RFC 1492]: https://github.com/rust-lang/rfcs/blob/master/text/1492-dotdot-in-patterns.md
5536 [cargo/3175]: https://github.com/rust-lang/cargo/pull/3175
5537 [cargo/3220]: https://github.com/rust-lang/cargo/pull/3220
5538 [cargo/3243]: https://github.com/rust-lang/cargo/pull/3243
5539 [cargo/3249]: https://github.com/rust-lang/cargo/pull/3249
5540 [cargo/3259]: https://github.com/rust-lang/cargo/pull/3259
5541 [cargo/3280]: https://github.com/rust-lang/cargo/pull/3280
5542
5543
5544 Version 1.13.0 (2016-11-10)
5545 ===========================
5546
5547 Language
5548 --------
5549
5550 * [Stabilize the `?` operator][36995]. `?` is a simple way to propagate
5551   errors, like the `try!` macro, described in [RFC 0243].
5552 * [Stabilize macros in type position][36014]. Described in [RFC 873].
5553 * [Stabilize attributes on statements][36995]. Described in [RFC 0016].
5554 * [Fix `#[derive]` for empty tuple structs/variants][35728]
5555 * [Fix lifetime rules for 'if' conditions][36029]
5556 * [Avoid loading and parsing unconfigured non-inline modules][36482]
5557
5558 Compiler
5559 --------
5560
5561 * [Add the `-C link-arg` argument][36574]
5562 * [Remove the old AST-based backend from rustc_trans][35764]
5563 * [Don't enable NEON by default on armv7 Linux][35814]
5564 * [Fix debug line number info for macro expansions][35238]
5565 * [Do not emit "class method" debuginfo for types that are not
5566   DICompositeType][36008]
5567 * [Warn about multiple conflicting #[repr] hints][34623]
5568 * [When sizing DST, don't double-count nested struct prefixes][36351]
5569 * [Default RUST_MIN_STACK to 16MiB for now][36505]
5570 * [Improve rlib metadata format][36551]. Reduces rlib size significantly.
5571 * [Reject macros with empty repetitions to avoid infinite loop][36721]
5572 * [Expand macros without recursing to avoid stack overflows][36214]
5573
5574 Diagnostics
5575 -----------
5576
5577 * [Replace macro backtraces with labeled local uses][35702]
5578 * [Improve error message for misplaced doc comments][33922]
5579 * [Buffer unix and lock windows to prevent message interleaving][35975]
5580 * [Update lifetime errors to specifically note temporaries][36171]
5581 * [Special case a few colors for Windows][36178]
5582 * [Suggest `use self` when such an import resolves][36289]
5583 * [Be more specific when type parameter shadows primitive type][36338]
5584 * Many minor improvements
5585
5586 Compile-time Optimizations
5587 --------------------------
5588
5589 * [Compute and cache HIR hashes at beginning][35854]
5590 * [Don't hash types in loan paths][36004]
5591 * [Cache projections in trans][35761]
5592 * [Optimize the parser's last token handling][36527]
5593 * [Only instantiate #[inline] functions in codegen units referencing
5594   them][36524]. This leads to big improvements in cases where crates export
5595   define many inline functions without using them directly.
5596 * [Lazily allocate TypedArena's first chunk][36592]
5597 * [Don't allocate during default HashSet creation][36734]
5598
5599 Stabilized APIs
5600 ---------------
5601
5602 * [`checked_abs`]
5603 * [`wrapping_abs`]
5604 * [`overflowing_abs`]
5605 * [`RefCell::try_borrow`]
5606 * [`RefCell::try_borrow_mut`]
5607
5608 Libraries
5609 ---------
5610
5611 * [Add `assert_ne!` and `debug_assert_ne!`][35074]
5612 * [Make `vec_deque::Drain`, `hash_map::Drain`, and `hash_set::Drain`
5613   covariant][35354]
5614 * [Implement `AsRef<[T]>` for `std::slice::Iter`][35559]
5615 * [Implement `Debug` for `std::vec::IntoIter`][35707]
5616 * [`CString`: avoid excessive growth just to 0-terminate][35871]
5617 * [Implement `CoerceUnsized` for `{Cell, RefCell, UnsafeCell}`][35627]
5618 * [Use arc4rand on FreeBSD][35884]
5619 * [memrchr: Correct aligned offset computation][35969]
5620 * [Improve Demangling of Rust Symbols][36059]
5621 * [Use monotonic time in condition variables][35048]
5622 * [Implement `Debug` for `std::path::{Components,Iter}`][36101]
5623 * [Implement conversion traits for `char`][35755]
5624 * [Fix illegal instruction caused by overflow in channel cloning][36104]
5625 * [Zero first byte of CString on drop][36264]
5626 * [Inherit overflow checks for sum and product][36372]
5627 * [Add missing Eq implementations][36423]
5628 * [Implement `Debug` for `DirEntry`][36631]
5629 * [When `getaddrinfo` returns `EAI_SYSTEM` retrieve actual error from
5630   `errno`][36754]
5631 * [`SipHasher`] is deprecated. Use [`DefaultHasher`].
5632 * [Implement more traits for `std::io::ErrorKind`][35911]
5633 * [Optimize BinaryHeap bounds checking][36072]
5634 * [Work around pointer aliasing issue in `Vec::extend_from_slice`,
5635   `extend_with_element`][36355]
5636 * [Fix overflow checking in unsigned pow()][34942]
5637
5638 Cargo
5639 -----
5640
5641 * This release includes security fixes to both curl and OpenSSL.
5642 * [Fix transitive doctests when panic=abort][cargo/3021]
5643 * [Add --all-features flag to cargo][cargo/3038]
5644 * [Reject path-based dependencies in `cargo package`][cargo/3060]
5645 * [Don't parse the home directory more than once][cargo/3078]
5646 * [Don't try to generate Cargo.lock on empty workspaces][cargo/3092]
5647 * [Update OpenSSL to 1.0.2j][cargo/3121]
5648 * [Add license and license_file to cargo metadata output][cargo/3110]
5649 * [Make crates-io registry URL optional in config; ignore all changes to
5650   source.crates-io][cargo/3089]
5651 * [Don't download dependencies from other platforms][cargo/3123]
5652 * [Build transitive dev-dependencies when needed][cargo/3125]
5653 * [Add support for per-target rustflags in .cargo/config][cargo/3157]
5654 * [Avoid updating registry when adding existing deps][cargo/3144]
5655 * [Warn about path overrides that won't work][cargo/3136]
5656 * [Use workspaces during `cargo install`][cargo/3146]
5657 * [Leak mspdbsrv.exe processes on Windows][cargo/3162]
5658 * [Add --message-format flag][cargo/3000]
5659 * [Pass target environment for rustdoc][cargo/3205]
5660 * [Use `CommandExt::exec` for `cargo run` on Unix][cargo/2818]
5661 * [Update curl and curl-sys][cargo/3241]
5662 * [Call rustdoc test with the correct cfg flags of a package][cargo/3242]
5663
5664 Tooling
5665 -------
5666
5667 * [rustdoc: Add the `--sysroot` argument][36586]
5668 * [rustdoc: Fix a couple of issues with the search results][35655]
5669 * [rustdoc: remove the `!` from macro URLs and titles][35234]
5670 * [gdb: Fix pretty-printing special-cased Rust types][35585]
5671 * [rustdoc: Filter more incorrect methods inherited through Deref][36266]
5672
5673 Misc
5674 ----
5675
5676 * [Remove unmaintained style guide][35124]
5677 * [Add s390x support][36369]
5678 * [Initial work at Haiku OS support][36727]
5679 * [Add mips-uclibc targets][35734]
5680 * [Crate-ify compiler-rt into compiler-builtins][35021]
5681 * [Add rustc version info (git hash + date) to dist tarball][36213]
5682 * Many documentation improvements
5683
5684 Compatibility Notes
5685 -------------------
5686
5687 * [`SipHasher`] is deprecated. Use [`DefaultHasher`].
5688 * [Deny (by default) transmuting from fn item types to pointer-sized
5689   types][34923]. Continuing the long transition to zero-sized fn items,
5690   per [RFC 401].
5691 * [Fix `#[derive]` for empty tuple structs/variants][35728].
5692   Part of [RFC 1506].
5693 * [Issue deprecation warnings for safe accesses to extern statics][36173]
5694 * [Fix lifetime rules for 'if' conditions][36029].
5695 * [Inherit overflow checks for sum and product][36372].
5696 * [Forbid user-defined macros named "macro_rules"][36730].
5697
5698 [33922]: https://github.com/rust-lang/rust/pull/33922
5699 [34623]: https://github.com/rust-lang/rust/pull/34623
5700 [34923]: https://github.com/rust-lang/rust/pull/34923
5701 [34942]: https://github.com/rust-lang/rust/pull/34942
5702 [34982]: https://github.com/rust-lang/rust/pull/34982
5703 [35021]: https://github.com/rust-lang/rust/pull/35021
5704 [35048]: https://github.com/rust-lang/rust/pull/35048
5705 [35074]: https://github.com/rust-lang/rust/pull/35074
5706 [35124]: https://github.com/rust-lang/rust/pull/35124
5707 [35234]: https://github.com/rust-lang/rust/pull/35234
5708 [35238]: https://github.com/rust-lang/rust/pull/35238
5709 [35354]: https://github.com/rust-lang/rust/pull/35354
5710 [35559]: https://github.com/rust-lang/rust/pull/35559
5711 [35585]: https://github.com/rust-lang/rust/pull/35585
5712 [35627]: https://github.com/rust-lang/rust/pull/35627
5713 [35655]: https://github.com/rust-lang/rust/pull/35655
5714 [35702]: https://github.com/rust-lang/rust/pull/35702
5715 [35707]: https://github.com/rust-lang/rust/pull/35707
5716 [35728]: https://github.com/rust-lang/rust/pull/35728
5717 [35734]: https://github.com/rust-lang/rust/pull/35734
5718 [35755]: https://github.com/rust-lang/rust/pull/35755
5719 [35761]: https://github.com/rust-lang/rust/pull/35761
5720 [35764]: https://github.com/rust-lang/rust/pull/35764
5721 [35814]: https://github.com/rust-lang/rust/pull/35814
5722 [35854]: https://github.com/rust-lang/rust/pull/35854
5723 [35871]: https://github.com/rust-lang/rust/pull/35871
5724 [35884]: https://github.com/rust-lang/rust/pull/35884
5725 [35911]: https://github.com/rust-lang/rust/pull/35911
5726 [35969]: https://github.com/rust-lang/rust/pull/35969
5727 [35975]: https://github.com/rust-lang/rust/pull/35975
5728 [36004]: https://github.com/rust-lang/rust/pull/36004
5729 [36008]: https://github.com/rust-lang/rust/pull/36008
5730 [36014]: https://github.com/rust-lang/rust/pull/36014
5731 [36029]: https://github.com/rust-lang/rust/pull/36029
5732 [36059]: https://github.com/rust-lang/rust/pull/36059
5733 [36072]: https://github.com/rust-lang/rust/pull/36072
5734 [36101]: https://github.com/rust-lang/rust/pull/36101
5735 [36104]: https://github.com/rust-lang/rust/pull/36104
5736 [36171]: https://github.com/rust-lang/rust/pull/36171
5737 [36173]: https://github.com/rust-lang/rust/pull/36173
5738 [36178]: https://github.com/rust-lang/rust/pull/36178
5739 [36213]: https://github.com/rust-lang/rust/pull/36213
5740 [36214]: https://github.com/rust-lang/rust/pull/36214
5741 [36264]: https://github.com/rust-lang/rust/pull/36264
5742 [36266]: https://github.com/rust-lang/rust/pull/36266
5743 [36289]: https://github.com/rust-lang/rust/pull/36289
5744 [36338]: https://github.com/rust-lang/rust/pull/36338
5745 [36351]: https://github.com/rust-lang/rust/pull/36351
5746 [36355]: https://github.com/rust-lang/rust/pull/36355
5747 [36369]: https://github.com/rust-lang/rust/pull/36369
5748 [36372]: https://github.com/rust-lang/rust/pull/36372
5749 [36423]: https://github.com/rust-lang/rust/pull/36423
5750 [36482]: https://github.com/rust-lang/rust/pull/36482
5751 [36505]: https://github.com/rust-lang/rust/pull/36505
5752 [36524]: https://github.com/rust-lang/rust/pull/36524
5753 [36527]: https://github.com/rust-lang/rust/pull/36527
5754 [36551]: https://github.com/rust-lang/rust/pull/36551
5755 [36574]: https://github.com/rust-lang/rust/pull/36574
5756 [36586]: https://github.com/rust-lang/rust/pull/36586
5757 [36592]: https://github.com/rust-lang/rust/pull/36592
5758 [36631]: https://github.com/rust-lang/rust/pull/36631
5759 [36639]: https://github.com/rust-lang/rust/pull/36639
5760 [36721]: https://github.com/rust-lang/rust/pull/36721
5761 [36727]: https://github.com/rust-lang/rust/pull/36727
5762 [36730]: https://github.com/rust-lang/rust/pull/36730
5763 [36734]: https://github.com/rust-lang/rust/pull/36734
5764 [36754]: https://github.com/rust-lang/rust/pull/36754
5765 [36995]: https://github.com/rust-lang/rust/pull/36995
5766 [RFC 0016]: https://github.com/rust-lang/rfcs/blob/master/text/0016-more-attributes.md
5767 [RFC 0243]: https://github.com/rust-lang/rfcs/blob/master/text/0243-trait-based-exception-handling.md
5768 [RFC 1506]: https://github.com/rust-lang/rfcs/blob/master/text/1506-adt-kinds.md
5769 [RFC 401]: https://github.com/rust-lang/rfcs/blob/master/text/0401-coercions.md
5770 [RFC 873]: https://github.com/rust-lang/rfcs/blob/master/text/0873-type-macros.md
5771 [cargo/2818]: https://github.com/rust-lang/cargo/pull/2818
5772 [cargo/3000]: https://github.com/rust-lang/cargo/pull/3000
5773 [cargo/3021]: https://github.com/rust-lang/cargo/pull/3021
5774 [cargo/3038]: https://github.com/rust-lang/cargo/pull/3038
5775 [cargo/3060]: https://github.com/rust-lang/cargo/pull/3060
5776 [cargo/3078]: https://github.com/rust-lang/cargo/pull/3078
5777 [cargo/3089]: https://github.com/rust-lang/cargo/pull/3089
5778 [cargo/3092]: https://github.com/rust-lang/cargo/pull/3092
5779 [cargo/3110]: https://github.com/rust-lang/cargo/pull/3110
5780 [cargo/3121]: https://github.com/rust-lang/cargo/pull/3121
5781 [cargo/3123]: https://github.com/rust-lang/cargo/pull/3123
5782 [cargo/3125]: https://github.com/rust-lang/cargo/pull/3125
5783 [cargo/3136]: https://github.com/rust-lang/cargo/pull/3136
5784 [cargo/3144]: https://github.com/rust-lang/cargo/pull/3144
5785 [cargo/3146]: https://github.com/rust-lang/cargo/pull/3146
5786 [cargo/3157]: https://github.com/rust-lang/cargo/pull/3157
5787 [cargo/3162]: https://github.com/rust-lang/cargo/pull/3162
5788 [cargo/3205]: https://github.com/rust-lang/cargo/pull/3205
5789 [cargo/3241]: https://github.com/rust-lang/cargo/pull/3241
5790 [cargo/3242]: https://github.com/rust-lang/cargo/pull/3242
5791 [rustup]: https://www.rustup.rs
5792 [`checked_abs`]: https://doc.rust-lang.org/std/primitive.i32.html#method.checked_abs
5793 [`wrapping_abs`]: https://doc.rust-lang.org/std/primitive.i32.html#method.wrapping_abs
5794 [`overflowing_abs`]: https://doc.rust-lang.org/std/primitive.i32.html#method.overflowing_abs
5795 [`RefCell::try_borrow`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.try_borrow
5796 [`RefCell::try_borrow_mut`]: https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.try_borrow_mut
5797 [`SipHasher`]: https://doc.rust-lang.org/std/hash/struct.SipHasher.html
5798 [`DefaultHasher`]: https://doc.rust-lang.org/std/collections/hash_map/struct.DefaultHasher.html
5799
5800
5801 Version 1.12.1 (2016-10-20)
5802 ===========================
5803
5804 Regression Fixes
5805 ----------------
5806
5807 * [ICE: 'rustc' panicked at 'assertion failed: concrete_substs.is_normalized_for_trans()' #36381][36381]
5808 * [Confusion with double negation and booleans][36856]
5809 * [rustc 1.12.0 fails with SIGSEGV in release mode (syn crate 0.8.0)][36875]
5810 * [Rustc 1.12.0 Windows build of `ethcore` crate fails with LLVM error][36924]
5811 * [1.12.0: High memory usage when linking in release mode with debug info][36926]
5812 * [Corrupted memory after updated to 1.12][36936]
5813 * ["Let NullaryConstructor = something;" causes internal compiler error: "tried to overwrite interned AdtDef"][37026]
5814 * [Fix ICE: inject bitcast if types mismatch for invokes/calls/stores][37112]
5815 * [debuginfo: Handle spread_arg case in MIR-trans in a more stable way.][37153]
5816
5817 [36381]: https://github.com/rust-lang/rust/issues/36381
5818 [36856]: https://github.com/rust-lang/rust/issues/36856
5819 [36875]: https://github.com/rust-lang/rust/issues/36875
5820 [36924]: https://github.com/rust-lang/rust/issues/36924
5821 [36926]: https://github.com/rust-lang/rust/issues/36926
5822 [36936]: https://github.com/rust-lang/rust/issues/36936
5823 [37026]: https://github.com/rust-lang/rust/issues/37026
5824 [37112]: https://github.com/rust-lang/rust/issues/37112
5825 [37153]: https://github.com/rust-lang/rust/issues/37153
5826
5827
5828 Version 1.12.0 (2016-09-29)
5829 ===========================
5830
5831 Highlights
5832 ----------
5833
5834 * [`rustc` translates code to LLVM IR via its own "middle" IR (MIR)](https://github.com/rust-lang/rust/pull/34096).
5835   This translation pass is far simpler than the previous AST->LLVM pass, and
5836   creates opportunities to perform new optimizations directly on the MIR. It
5837   was previously described [on the Rust blog](https://blog.rust-lang.org/2016/04/19/MIR.html).
5838 * [`rustc` presents a new, more readable error format, along with
5839   machine-readable JSON error output for use by IDEs](https://github.com/rust-lang/rust/pull/35401).
5840   Most common editors supporting Rust have been updated to work with it. It was
5841   previously described [on the Rust blog](https://blog.rust-lang.org/2016/08/10/Shape-of-errors-to-come.html).
5842
5843 Compiler
5844 --------
5845
5846 * [`rustc` translates code to LLVM IR via its own "middle" IR (MIR)](https://github.com/rust-lang/rust/pull/34096).
5847   This translation pass is far simpler than the previous AST->LLVM pass, and
5848   creates opportunities to perform new optimizations directly on the MIR. It
5849   was previously described [on the Rust blog](https://blog.rust-lang.org/2016/04/19/MIR.html).
5850 * [Print the Rust target name, not the LLVM target name, with
5851   `--print target-list`](https://github.com/rust-lang/rust/pull/35489)
5852 * [The computation of `TypeId` is correct in some cases where it was previously
5853   producing inconsistent results](https://github.com/rust-lang/rust/pull/35267)
5854 * [The `mips-unknown-linux-gnu` target uses hardware floating point by default](https://github.com/rust-lang/rust/pull/34910)
5855 * [The `rustc` arguments, `--print target-cpus`, `--print target-features`,
5856   `--print relocation-models`, and `--print code-models` print the available
5857   options to the `-C target-cpu`, `-C target-feature`, `-C relocation-model` and
5858   `-C code-model` code generation arguments](https://github.com/rust-lang/rust/pull/34845)
5859 * [`rustc` supports three new MUSL targets on ARM: `arm-unknown-linux-musleabi`,
5860   `arm-unknown-linux-musleabihf`, and `armv7-unknown-linux-musleabihf`](https://github.com/rust-lang/rust/pull/35060).
5861   These targets produce statically-linked binaries. There are no binary release
5862   builds yet though.
5863
5864 Diagnostics
5865 -----------
5866
5867 * [`rustc` presents a new, more readable error format, along with
5868   machine-readable JSON error output for use by IDEs](https://github.com/rust-lang/rust/pull/35401).
5869   Most common editors supporting Rust have been updated to work with it. It was
5870   previously described [on the Rust blog](https://blog.rust-lang.org/2016/08/10/Shape-of-errors-to-come.html).
5871 * [In error descriptions, references are now described in plain English,
5872   instead of as "&-ptr"](https://github.com/rust-lang/rust/pull/35611)
5873 * [In error type descriptions, unknown numeric types are named `{integer}` or
5874   `{float}` instead of `_`](https://github.com/rust-lang/rust/pull/35080)
5875 * [`rustc` emits a clearer error when inner attributes follow a doc comment](https://github.com/rust-lang/rust/pull/34676)
5876
5877 Language
5878 --------
5879
5880 * [`macro_rules!` invocations can be made within `macro_rules!` invocations](https://github.com/rust-lang/rust/pull/34925)
5881 * [`macro_rules!` meta-variables are hygienic](https://github.com/rust-lang/rust/pull/35453)
5882 * [`macro_rules!` `tt` matchers can be reparsed correctly, making them much more
5883   useful](https://github.com/rust-lang/rust/pull/34908)
5884 * [`macro_rules!` `stmt` matchers correctly consume the entire contents when
5885   inside non-braces invocations](https://github.com/rust-lang/rust/pull/34886)
5886 * [Semicolons are properly required as statement delimiters inside
5887   `macro_rules!` invocations](https://github.com/rust-lang/rust/pull/34660)
5888 * [`cfg_attr` works on `path` attributes](https://github.com/rust-lang/rust/pull/34546)
5889
5890 Stabilized APIs
5891 ---------------
5892
5893 * [`Cell::as_ptr`](https://doc.rust-lang.org/std/cell/struct.Cell.html#method.as_ptr)
5894 * [`RefCell::as_ptr`](https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.as_ptr)
5895 * [`IpAddr::is_unspecified`](https://doc.rust-lang.org/std/net/enum.IpAddr.html#method.is_unspecified)
5896 * [`IpAddr::is_loopback`](https://doc.rust-lang.org/std/net/enum.IpAddr.html#method.is_loopback)
5897 * [`IpAddr::is_multicast`](https://doc.rust-lang.org/std/net/enum.IpAddr.html#method.is_multicast)
5898 * [`Ipv4Addr::is_unspecified`](https://doc.rust-lang.org/std/net/struct.Ipv4Addr.html#method.is_unspecified)
5899 * [`Ipv6Addr::octets`](https://doc.rust-lang.org/std/net/struct.Ipv6Addr.html#method.octets)
5900 * [`LinkedList::contains`](https://doc.rust-lang.org/std/collections/linked_list/struct.LinkedList.html#method.contains)
5901 * [`VecDeque::contains`](https://doc.rust-lang.org/std/collections/vec_deque/struct.VecDeque.html#method.contains)
5902 * [`ExitStatusExt::from_raw`](https://doc.rust-lang.org/std/os/unix/process/trait.ExitStatusExt.html#tymethod.from_raw).
5903   Both on Unix and Windows.
5904 * [`Receiver::recv_timeout`](https://doc.rust-lang.org/std/sync/mpsc/struct.Receiver.html#method.recv_timeout)
5905 * [`RecvTimeoutError`](https://doc.rust-lang.org/std/sync/mpsc/enum.RecvTimeoutError.html)
5906 * [`BinaryHeap::peek_mut`](https://doc.rust-lang.org/std/collections/binary_heap/struct.BinaryHeap.html#method.peek_mut)
5907 * [`PeekMut`](https://doc.rust-lang.org/std/collections/binary_heap/struct.PeekMut.html)
5908 * [`iter::Product`](https://doc.rust-lang.org/std/iter/trait.Product.html)
5909 * [`iter::Sum`](https://doc.rust-lang.org/std/iter/trait.Sum.html)
5910 * [`OccupiedEntry::remove_entry`](https://doc.rust-lang.org/std/collections/btree_map/struct.OccupiedEntry.html#method.remove_entry)
5911 * [`VacantEntry::into_key`](https://doc.rust-lang.org/std/collections/btree_map/struct.VacantEntry.html#method.into_key)
5912
5913 Libraries
5914 ---------
5915
5916 * [The `format!` macro and friends now allow a single argument to be formatted
5917   in multiple styles](https://github.com/rust-lang/rust/pull/33642)
5918 * [The lifetime bounds on `[T]::binary_search_by` and
5919   `[T]::binary_search_by_key` have been adjusted to be more flexible](https://github.com/rust-lang/rust/pull/34762)
5920 * [`Option` implements `From` for its contained type](https://github.com/rust-lang/rust/pull/34828)
5921 * [`Cell`, `RefCell` and `UnsafeCell` implement `From` for their contained type](https://github.com/rust-lang/rust/pull/35392)
5922 * [`RwLock` panics if the reader count overflows](https://github.com/rust-lang/rust/pull/35378)
5923 * [`vec_deque::Drain`, `hash_map::Drain` and `hash_set::Drain` are covariant](https://github.com/rust-lang/rust/pull/35354)
5924 * [`vec::Drain` and `binary_heap::Drain` are covariant](https://github.com/rust-lang/rust/pull/34951)
5925 * [`Cow<str>` implements `FromIterator` for `char`, `&str` and `String`](https://github.com/rust-lang/rust/pull/35064)
5926 * [Sockets on Linux are correctly closed in subprocesses via `SOCK_CLOEXEC`](https://github.com/rust-lang/rust/pull/34946)
5927 * [`hash_map::Entry`, `hash_map::VacantEntry` and `hash_map::OccupiedEntry`
5928   implement `Debug`](https://github.com/rust-lang/rust/pull/34937)
5929 * [`btree_map::Entry`, `btree_map::VacantEntry` and `btree_map::OccupiedEntry`
5930   implement `Debug`](https://github.com/rust-lang/rust/pull/34885)
5931 * [`String` implements `AddAssign`](https://github.com/rust-lang/rust/pull/34890)
5932 * [Variadic `extern fn` pointers implement the `Clone`, `PartialEq`, `Eq`,
5933   `PartialOrd`, `Ord`, `Hash`, `fmt::Pointer`, and `fmt::Debug` traits](https://github.com/rust-lang/rust/pull/34879)
5934 * [`FileType` implements `Debug`](https://github.com/rust-lang/rust/pull/34757)
5935 * [References to `Mutex` and `RwLock` are unwind-safe](https://github.com/rust-lang/rust/pull/34756)
5936 * [`mpsc::sync_channel` `Receiver`s return any available message before
5937   reporting a disconnect](https://github.com/rust-lang/rust/pull/34731)
5938 * [Unicode definitions have been updated to 9.0](https://github.com/rust-lang/rust/pull/34599)
5939 * [`env` iterators implement `DoubleEndedIterator`](https://github.com/rust-lang/rust/pull/33312)
5940
5941 Cargo
5942 -----
5943
5944 * [Support local mirrors of registries](https://github.com/rust-lang/cargo/pull/2857)
5945 * [Add support for command aliases](https://github.com/rust-lang/cargo/pull/2679)
5946 * [Allow `opt-level="s"` / `opt-level="z"` in profile overrides](https://github.com/rust-lang/cargo/pull/3007)
5947 * [Make `cargo doc --open --target` work as expected](https://github.com/rust-lang/cargo/pull/2988)
5948 * [Speed up noop registry updates](https://github.com/rust-lang/cargo/pull/2974)
5949 * [Update OpenSSL](https://github.com/rust-lang/cargo/pull/2971)
5950 * [Fix `--panic=abort` with plugins](https://github.com/rust-lang/cargo/pull/2954)
5951 * [Always pass `-C metadata` to the compiler](https://github.com/rust-lang/cargo/pull/2946)
5952 * [Fix depending on git repos with workspaces](https://github.com/rust-lang/cargo/pull/2938)
5953 * [Add a `--lib` flag to `cargo new`](https://github.com/rust-lang/cargo/pull/2921)
5954 * [Add `http.cainfo` for custom certs](https://github.com/rust-lang/cargo/pull/2917)
5955 * [Indicate the compilation profile after compiling](https://github.com/rust-lang/cargo/pull/2909)
5956 * [Allow enabling features for dependencies with `--features`](https://github.com/rust-lang/cargo/pull/2876)
5957 * [Add `--jobs` flag to `cargo package`](https://github.com/rust-lang/cargo/pull/2867)
5958 * [Add `--dry-run` to `cargo publish`](https://github.com/rust-lang/cargo/pull/2849)
5959 * [Add support for `RUSTDOCFLAGS`](https://github.com/rust-lang/cargo/pull/2794)
5960
5961 Performance
5962 -----------
5963
5964 * [`panic::catch_unwind` is more optimized](https://github.com/rust-lang/rust/pull/35444)
5965 * [`panic::catch_unwind` no longer accesses thread-local storage on entry](https://github.com/rust-lang/rust/pull/34866)
5966
5967 Tooling
5968 -------
5969
5970 * [Test binaries now support a `--test-threads` argument to specify the number
5971   of threads used to run tests, and which acts the same as the
5972   `RUST_TEST_THREADS` environment variable](https://github.com/rust-lang/rust/pull/35414)
5973 * [The test runner now emits a warning when tests run over 60 seconds](https://github.com/rust-lang/rust/pull/35405)
5974 * [rustdoc: Fix methods in search results](https://github.com/rust-lang/rust/pull/34752)
5975 * [`rust-lldb` warns about unsupported versions of LLDB](https://github.com/rust-lang/rust/pull/34646)
5976 * [Rust releases now come with source packages that can be installed by rustup
5977   via `rustup component add rust-src`](https://github.com/rust-lang/rust/pull/34366).
5978   The resulting source code can be used by tools and IDES, located in the
5979   sysroot under `lib/rustlib/src`.
5980
5981 Misc
5982 ----
5983
5984 * [The compiler can now be built against LLVM 3.9](https://github.com/rust-lang/rust/pull/35594)
5985 * Many minor improvements to the documentation.
5986 * [The Rust exception handling "personality" routine is now written in Rust](https://github.com/rust-lang/rust/pull/34832)
5987
5988 Compatibility Notes
5989 -------------------
5990
5991 * [When printing Windows `OsStr`s, unpaired surrogate codepoints are escaped
5992   with the lowercase format instead of the uppercase](https://github.com/rust-lang/rust/pull/35084)
5993 * [When formatting strings, if "precision" is specified, the "fill",
5994   "align" and "width" specifiers are no longer ignored](https://github.com/rust-lang/rust/pull/34544)
5995 * [The `Debug` impl for strings no longer escapes all non-ASCII characters](https://github.com/rust-lang/rust/pull/34485)
5996
5997
5998 Version 1.11.0 (2016-08-18)
5999 ===========================
6000
6001 Language
6002 --------
6003
6004 * [Support nested `cfg_attr` attributes](https://github.com/rust-lang/rust/pull/34216)
6005 * [Allow statement-generating braced macro invocations at the end of blocks](https://github.com/rust-lang/rust/pull/34436)
6006 * [Macros can be expanded inside of trait definitions](https://github.com/rust-lang/rust/pull/34213)
6007 * [`#[macro_use]` works properly when it is itself expanded from a macro](https://github.com/rust-lang/rust/pull/34032)
6008
6009 Stabilized APIs
6010 ---------------
6011
6012 * [`BinaryHeap::append`](https://doc.rust-lang.org/std/collections/binary_heap/struct.BinaryHeap.html#method.append)
6013 * [`BTreeMap::append`](https://doc.rust-lang.org/std/collections/btree_map/struct.BTreeMap.html#method.append)
6014 * [`BTreeMap::split_off`](https://doc.rust-lang.org/std/collections/btree_map/struct.BTreeMap.html#method.split_off)
6015 * [`BTreeSet::append`](https://doc.rust-lang.org/std/collections/btree_set/struct.BTreeSet.html#method.append)
6016 * [`BTreeSet::split_off`](https://doc.rust-lang.org/std/collections/btree_set/struct.BTreeSet.html#method.split_off)
6017 * [`f32::to_degrees`](https://doc.rust-lang.org/std/primitive.f32.html#method.to_degrees)
6018   (in libcore - previously stabilized in libstd)
6019 * [`f32::to_radians`](https://doc.rust-lang.org/std/primitive.f32.html#method.to_radians)
6020   (in libcore - previously stabilized in libstd)
6021 * [`f64::to_degrees`](https://doc.rust-lang.org/std/primitive.f64.html#method.to_degrees)
6022   (in libcore - previously stabilized in libstd)
6023 * [`f64::to_radians`](https://doc.rust-lang.org/std/primitive.f64.html#method.to_radians)
6024   (in libcore - previously stabilized in libstd)
6025 * [`Iterator::sum`](https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.sum)
6026 * [`Iterator::product`](https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.sum)
6027 * [`Cell::get_mut`](https://doc.rust-lang.org/std/cell/struct.Cell.html#method.get_mut)
6028 * [`RefCell::get_mut`](https://doc.rust-lang.org/std/cell/struct.RefCell.html#method.get_mut)
6029
6030 Libraries
6031 ---------
6032
6033 * [The `thread_local!` macro supports multiple definitions in a single
6034    invocation, and can apply attributes](https://github.com/rust-lang/rust/pull/34077)
6035 * [`Cow` implements `Default`](https://github.com/rust-lang/rust/pull/34305)
6036 * [`Wrapping` implements binary, octal, lower-hex and upper-hex
6037   `Display` formatting](https://github.com/rust-lang/rust/pull/34190)
6038 * [The range types implement `Hash`](https://github.com/rust-lang/rust/pull/34180)
6039 * [`lookup_host` ignores unknown address types](https://github.com/rust-lang/rust/pull/34067)
6040 * [`assert_eq!` accepts a custom error message, like `assert!` does](https://github.com/rust-lang/rust/pull/33976)
6041 * [The main thread is now called "main" instead of "&lt;main&gt;"](https://github.com/rust-lang/rust/pull/33803)
6042
6043 Cargo
6044 -----
6045
6046 * [Disallow specifying features of transitive deps](https://github.com/rust-lang/cargo/pull/2821)
6047 * [Add color support for Windows consoles](https://github.com/rust-lang/cargo/pull/2804)
6048 * [Fix `harness = false` on `[lib]` sections](https://github.com/rust-lang/cargo/pull/2795)
6049 * [Don't panic when `links` contains a '.'](https://github.com/rust-lang/cargo/pull/2787)
6050 * [Build scripts can emit warnings](https://github.com/rust-lang/cargo/pull/2630),
6051   and `-vv` prints warnings for all crates.
6052 * [Ignore file locks on OS X NFS mounts](https://github.com/rust-lang/cargo/pull/2720)
6053 * [Don't warn about `package.metadata` keys](https://github.com/rust-lang/cargo/pull/2668).
6054   This provides room for expansion by arbitrary tools.
6055 * [Add support for cdylib crate types](https://github.com/rust-lang/cargo/pull/2741)
6056 * [Prevent publishing crates when files are dirty](https://github.com/rust-lang/cargo/pull/2781)
6057 * [Don't fetch all crates on clean](https://github.com/rust-lang/cargo/pull/2704)
6058 * [Propagate --color option to rustc](https://github.com/rust-lang/cargo/pull/2779)
6059 * [Fix `cargo doc --open` on Windows](https://github.com/rust-lang/cargo/pull/2780)
6060 * [Improve autocompletion](https://github.com/rust-lang/cargo/pull/2772)
6061 * [Configure colors of stderr as well as stdout](https://github.com/rust-lang/cargo/pull/2739)
6062
6063 Performance
6064 -----------
6065
6066 * [Caching projections speeds up type check dramatically for some
6067   workloads](https://github.com/rust-lang/rust/pull/33816)
6068 * [The default `HashMap` hasher is SipHash 1-3 instead of SipHash 2-4](https://github.com/rust-lang/rust/pull/33940)
6069   This hasher is faster, but is believed to provide sufficient
6070   protection from collision attacks.
6071 * [Comparison of `Ipv4Addr` is 10x faster](https://github.com/rust-lang/rust/pull/33891)
6072
6073 Rustdoc
6074 -------
6075
6076 * [Fix empty implementation section on some module pages](https://github.com/rust-lang/rust/pull/34536)
6077 * [Fix inlined renamed re-exports in import lists](https://github.com/rust-lang/rust/pull/34479)
6078 * [Fix search result layout for enum variants and struct fields](https://github.com/rust-lang/rust/pull/34477)
6079 * [Fix issues with source links to external crates](https://github.com/rust-lang/rust/pull/34387)
6080 * [Fix redirect pages for renamed re-exports](https://github.com/rust-lang/rust/pull/34245)
6081
6082 Tooling
6083 -------
6084
6085 * [rustc is better at finding the MSVC toolchain](https://github.com/rust-lang/rust/pull/34492)
6086 * [When emitting debug info, rustc emits frame pointers for closures,
6087   shims and glue, as it does for all other functions](https://github.com/rust-lang/rust/pull/33909)
6088 * [rust-lldb warns about unsupported versions of LLDB](https://github.com/rust-lang/rust/pull/34646)
6089 * Many more errors have been given error codes and extended
6090   explanations
6091 * API documentation continues to be improved, with many new examples
6092
6093 Misc
6094 ----
6095
6096 * [rustc no longer hangs when dependencies recursively re-export
6097   submodules](https://github.com/rust-lang/rust/pull/34542)
6098 * [rustc requires LLVM 3.7+](https://github.com/rust-lang/rust/pull/34104)
6099 * [The 'How Safe and Unsafe Interact' chapter of The Rustonomicon was
6100   rewritten](https://github.com/rust-lang/rust/pull/33895)
6101 * [rustc support 16-bit pointer sizes](https://github.com/rust-lang/rust/pull/33460).
6102   No targets use this yet, but it works toward AVR support.
6103
6104 Compatibility Notes
6105 -------------------
6106
6107 * [`const`s and `static`s may not have unsized types](https://github.com/rust-lang/rust/pull/34443)
6108 * [The new follow-set rules that place restrictions on `macro_rules!`
6109   in order to ensure syntax forward-compatibility have been enabled](https://github.com/rust-lang/rust/pull/33982)
6110   This was an [amendment to RFC 550](https://github.com/rust-lang/rfcs/pull/1384),
6111   and has been a warning since 1.10.
6112 * [`cfg` attribute process has been refactored to fix various bugs](https://github.com/rust-lang/rust/pull/33706).
6113   This causes breakage in some corner cases.
6114
6115
6116 Version 1.10.0 (2016-07-07)
6117 ===========================
6118
6119 Language
6120 --------
6121
6122 * [`Copy` types are required to have a trivial implementation of `Clone`](https://github.com/rust-lang/rust/pull/33420).
6123   [RFC 1521](https://github.com/rust-lang/rfcs/blob/master/text/1521-copy-clone-semantics.md).
6124 * [Single-variant enums support the `#[repr(..)]` attribute](https://github.com/rust-lang/rust/pull/33355).
6125 * [Fix `#[derive(RustcEncodable)]` in the presence of other `encode` methods](https://github.com/rust-lang/rust/pull/32908).
6126 * [`panic!` can be converted to a runtime abort with the
6127   `-C panic=abort` flag](https://github.com/rust-lang/rust/pull/32900).
6128   [RFC 1513](https://github.com/rust-lang/rfcs/blob/master/text/1513-less-unwinding.md).
6129 * [Add a new crate type, 'cdylib'](https://github.com/rust-lang/rust/pull/33553).
6130   cdylibs are dynamic libraries suitable for loading by non-Rust hosts.
6131   [RFC 1510](https://github.com/rust-lang/rfcs/blob/master/text/1510-cdylib.md).
6132   Note that Cargo does not yet directly support cdylibs.
6133
6134 Stabilized APIs
6135 ---------------
6136
6137 * `os::windows::fs::OpenOptionsExt::access_mode`
6138 * `os::windows::fs::OpenOptionsExt::share_mode`
6139 * `os::windows::fs::OpenOptionsExt::custom_flags`
6140 * `os::windows::fs::OpenOptionsExt::attributes`
6141 * `os::windows::fs::OpenOptionsExt::security_qos_flags`
6142 * `os::unix::fs::OpenOptionsExt::custom_flags`
6143 * [`sync::Weak::new`](http://doc.rust-lang.org/alloc/arc/struct.Weak.html#method.new)
6144 * `Default for sync::Weak`
6145 * [`panic::set_hook`](http://doc.rust-lang.org/std/panic/fn.set_hook.html)
6146 * [`panic::take_hook`](http://doc.rust-lang.org/std/panic/fn.take_hook.html)
6147 * [`panic::PanicInfo`](http://doc.rust-lang.org/std/panic/struct.PanicInfo.html)
6148 * [`panic::PanicInfo::payload`](http://doc.rust-lang.org/std/panic/struct.PanicInfo.html#method.payload)
6149 * [`panic::PanicInfo::location`](http://doc.rust-lang.org/std/panic/struct.PanicInfo.html#method.location)
6150 * [`panic::Location`](http://doc.rust-lang.org/std/panic/struct.Location.html)
6151 * [`panic::Location::file`](http://doc.rust-lang.org/std/panic/struct.Location.html#method.file)
6152 * [`panic::Location::line`](http://doc.rust-lang.org/std/panic/struct.Location.html#method.line)
6153 * [`ffi::CStr::from_bytes_with_nul`](http://doc.rust-lang.org/std/ffi/struct.CStr.html#method.from_bytes_with_nul)
6154 * [`ffi::CStr::from_bytes_with_nul_unchecked`](http://doc.rust-lang.org/std/ffi/struct.CStr.html#method.from_bytes_with_nul_unchecked)
6155 * [`ffi::FromBytesWithNulError`](http://doc.rust-lang.org/std/ffi/struct.FromBytesWithNulError.html)
6156 * [`fs::Metadata::modified`](http://doc.rust-lang.org/std/fs/struct.Metadata.html#method.modified)
6157 * [`fs::Metadata::accessed`](http://doc.rust-lang.org/std/fs/struct.Metadata.html#method.accessed)
6158 * [`fs::Metadata::created`](http://doc.rust-lang.org/std/fs/struct.Metadata.html#method.created)
6159 * `sync::atomic::Atomic{Usize,Isize,Bool,Ptr}::compare_exchange`
6160 * `sync::atomic::Atomic{Usize,Isize,Bool,Ptr}::compare_exchange_weak`
6161 * `collections::{btree,hash}_map::{Occupied,Vacant,}Entry::key`
6162 * `os::unix::net::{UnixStream, UnixListener, UnixDatagram, SocketAddr}`
6163 * [`SocketAddr::is_unnamed`](http://doc.rust-lang.org/std/os/unix/net/struct.SocketAddr.html#method.is_unnamed)
6164 * [`SocketAddr::as_pathname`](http://doc.rust-lang.org/std/os/unix/net/struct.SocketAddr.html#method.as_pathname)
6165 * [`UnixStream::connect`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.connect)
6166 * [`UnixStream::pair`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.pair)
6167 * [`UnixStream::try_clone`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.try_clone)
6168 * [`UnixStream::local_addr`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.local_addr)
6169 * [`UnixStream::peer_addr`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.peer_addr)
6170 * [`UnixStream::set_read_timeout`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.read_timeout)
6171 * [`UnixStream::set_write_timeout`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.write_timeout)
6172 * [`UnixStream::read_timeout`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.read_timeout)
6173 * [`UnixStream::write_timeout`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.write_timeout)
6174 * [`UnixStream::set_nonblocking`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.set_nonblocking)
6175 * [`UnixStream::take_error`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.take_error)
6176 * [`UnixStream::shutdown`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixStream.html#method.shutdown)
6177 * Read/Write/RawFd impls for `UnixStream`
6178 * [`UnixListener::bind`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixListener.html#method.bind)
6179 * [`UnixListener::accept`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixListener.html#method.accept)
6180 * [`UnixListener::try_clone`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixListener.html#method.try_clone)
6181 * [`UnixListener::local_addr`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixListener.html#method.local_addr)
6182 * [`UnixListener::set_nonblocking`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixListener.html#method.set_nonblocking)
6183 * [`UnixListener::take_error`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixListener.html#method.take_error)
6184 * [`UnixListener::incoming`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixListener.html#method.incoming)
6185 * RawFd impls for `UnixListener`
6186 * [`UnixDatagram::bind`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.bind)
6187 * [`UnixDatagram::unbound`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.unbound)
6188 * [`UnixDatagram::pair`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.pair)
6189 * [`UnixDatagram::connect`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.connect)
6190 * [`UnixDatagram::try_clone`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.try_clone)
6191 * [`UnixDatagram::local_addr`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.local_addr)
6192 * [`UnixDatagram::peer_addr`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.peer_addr)
6193 * [`UnixDatagram::recv_from`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.recv_from)
6194 * [`UnixDatagram::recv`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.recv)
6195 * [`UnixDatagram::send_to`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.send_to)
6196 * [`UnixDatagram::send`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.send)
6197 * [`UnixDatagram::set_read_timeout`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.set_read_timeout)
6198 * [`UnixDatagram::set_write_timeout`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.set_write_timeout)
6199 * [`UnixDatagram::read_timeout`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.read_timeout)
6200 * [`UnixDatagram::write_timeout`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.write_timeout)
6201 * [`UnixDatagram::set_nonblocking`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.set_nonblocking)
6202 * [`UnixDatagram::take_error`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.take_error)
6203 * [`UnixDatagram::shutdown`](http://doc.rust-lang.org/std/os/unix/net/struct.UnixDatagram.html#method.shutdown)
6204 * RawFd impls for `UnixDatagram`
6205 * `{BTree,Hash}Map::values_mut`
6206 * [`<[_]>::binary_search_by_key`](http://doc.rust-lang.org/std/primitive.slice.html#method.binary_search_by_key)
6207
6208 Libraries
6209 ---------
6210
6211 * [The `abs_sub` method of floats is deprecated](https://github.com/rust-lang/rust/pull/33664).
6212   The semantics of this minor method are subtle and probably not what
6213   most people want.
6214 * [Add implementation of Ord for Cell<T> and RefCell<T> where T: Ord](https://github.com/rust-lang/rust/pull/33306).
6215 * [On Linux, if `HashMap`s can't be initialized with `getrandom` they
6216   will fall back to `/dev/urandom` temporarily to avoid blocking
6217   during early boot](https://github.com/rust-lang/rust/pull/33086).
6218 * [Implemented negation for wrapping numerals](https://github.com/rust-lang/rust/pull/33067).
6219 * [Implement `Clone` for `binary_heap::IntoIter`](https://github.com/rust-lang/rust/pull/33050).
6220 * [Implement `Display` and `Hash` for `std::num::Wrapping`](https://github.com/rust-lang/rust/pull/33023).
6221 * [Add `Default` implementation for `&CStr`, `CString`](https://github.com/rust-lang/rust/pull/32990).
6222 * [Implement `From<Vec<T>>` and `Into<Vec<T>>` for `VecDeque<T>`](https://github.com/rust-lang/rust/pull/32866).
6223 * [Implement `Default` for `UnsafeCell`, `fmt::Error`, `Condvar`,
6224   `Mutex`, `RwLock`](https://github.com/rust-lang/rust/pull/32785).
6225
6226 Cargo
6227 -----
6228 * [Cargo.toml supports the `profile.*.panic` option](https://github.com/rust-lang/cargo/pull/2687).
6229   This controls the runtime behavior of the `panic!` macro
6230   and can be either "unwind" (the default), or "abort".
6231   [RFC 1513](https://github.com/rust-lang/rfcs/blob/master/text/1513-less-unwinding.md).
6232 * [Don't throw away errors with `-p` arguments](https://github.com/rust-lang/cargo/pull/2723).
6233 * [Report status to stderr instead of stdout](https://github.com/rust-lang/cargo/pull/2693).
6234 * [Build scripts are passed a `CARGO_MANIFEST_LINKS` environment
6235   variable that corresponds to the `links` field of the manifest](https://github.com/rust-lang/cargo/pull/2710).
6236 * [Ban keywords from crate names](https://github.com/rust-lang/cargo/pull/2707).
6237 * [Canonicalize `CARGO_HOME` on Windows](https://github.com/rust-lang/cargo/pull/2604).
6238 * [Retry network requests](https://github.com/rust-lang/cargo/pull/2396).
6239   By default they are retried twice, which can be customized with the
6240   `net.retry` value in `.cargo/config`.
6241 * [Don't print extra error info for failing subcommands](https://github.com/rust-lang/cargo/pull/2674).
6242 * [Add `--force` flag to `cargo install`](https://github.com/rust-lang/cargo/pull/2405).
6243 * [Don't use `flock` on NFS mounts](https://github.com/rust-lang/cargo/pull/2623).
6244 * [Prefer building `cargo install` artifacts in temporary directories](https://github.com/rust-lang/cargo/pull/2610).
6245   Makes it possible to install multiple crates in parallel.
6246 * [Add `cargo test --doc`](https://github.com/rust-lang/cargo/pull/2578).
6247 * [Add `cargo --explain`](https://github.com/rust-lang/cargo/pull/2551).
6248 * [Don't print warnings when `-q` is passed](https://github.com/rust-lang/cargo/pull/2576).
6249 * [Add `cargo doc --lib` and `--bin`](https://github.com/rust-lang/cargo/pull/2577).
6250 * [Don't require build script output to be UTF-8](https://github.com/rust-lang/cargo/pull/2560).
6251 * [Correctly attempt multiple git usernames](https://github.com/rust-lang/cargo/pull/2584).
6252
6253 Performance
6254 -----------
6255
6256 * [rustc memory usage was reduced by refactoring the context used for
6257   type checking](https://github.com/rust-lang/rust/pull/33425).
6258 * [Speed up creation of `HashMap`s by caching the random keys used
6259   to initialize the hash state](https://github.com/rust-lang/rust/pull/33318).
6260 * [The `find` implementation for `Chain` iterators is 2x faster](https://github.com/rust-lang/rust/pull/33289).
6261 * [Trait selection optimizations speed up type checking by 15%](https://github.com/rust-lang/rust/pull/33138).
6262 * [Efficient trie lookup for boolean Unicode properties](https://github.com/rust-lang/rust/pull/33098).
6263   10x faster than the previous lookup tables.
6264 * [Special case `#[derive(Copy, Clone)]` to avoid bloat](https://github.com/rust-lang/rust/pull/31414).
6265
6266 Usability
6267 ---------
6268
6269 * Many incremental improvements to documentation and rustdoc.
6270 * [rustdoc: List blanket trait impls](https://github.com/rust-lang/rust/pull/33514).
6271 * [rustdoc: Clean up ABI rendering](https://github.com/rust-lang/rust/pull/33151).
6272 * [Indexing with the wrong type produces a more informative error](https://github.com/rust-lang/rust/pull/33401).
6273 * [Improve diagnostics for constants being used in irrefutable patterns](https://github.com/rust-lang/rust/pull/33406).
6274 * [When many method candidates are in scope limit the suggestions to 10](https://github.com/rust-lang/rust/pull/33338).
6275 * [Remove confusing suggestion when calling a `fn` type](https://github.com/rust-lang/rust/pull/33325).
6276 * [Do not suggest changing `&mut self` to `&mut mut self`](https://github.com/rust-lang/rust/pull/33319).
6277
6278 Misc
6279 ----
6280
6281 * [Update i686-linux-android features to match Android ABI](https://github.com/rust-lang/rust/pull/33651).
6282 * [Update aarch64-linux-android features to match Android ABI](https://github.com/rust-lang/rust/pull/33500).
6283 * [`std` no longer prints backtraces on platforms where the running
6284   module must be loaded with `env::current_exe`, which can't be relied
6285   on](https://github.com/rust-lang/rust/pull/33554).
6286 * This release includes std binaries for the i586-unknown-linux-gnu,
6287   i686-unknown-linux-musl, and armv7-linux-androideabi targets. The
6288   i586 target is for old x86 hardware without SSE2, and the armv7
6289   target is for Android running on modern ARM architectures.
6290 * [The `rust-gdb` and `rust-lldb` scripts are distributed on all
6291   Unix platforms](https://github.com/rust-lang/rust/pull/32835).
6292 * [On Unix the runtime aborts by calling `libc::abort` instead of
6293   generating an illegal instruction](https://github.com/rust-lang/rust/pull/31457).
6294 * [Rust is now bootstrapped from the previous release of Rust,
6295   instead of a snapshot from an arbitrary commit](https://github.com/rust-lang/rust/pull/32942).
6296
6297 Compatibility Notes
6298 -------------------
6299
6300 * [`AtomicBool` is now bool-sized, not word-sized](https://github.com/rust-lang/rust/pull/33579).
6301 * [`target_env` for Linux ARM targets is just `gnu`, not
6302   `gnueabihf`, `gnueabi`, etc](https://github.com/rust-lang/rust/pull/33403).
6303 * [Consistently panic on overflow in `Duration::new`](https://github.com/rust-lang/rust/pull/33072).
6304 * [Change `String::truncate` to panic less](https://github.com/rust-lang/rust/pull/32977).
6305 * [Add `:block` to the follow set for `:ty` and `:path`](https://github.com/rust-lang/rust/pull/32945).
6306   Affects how macros are parsed.
6307 * [Fix macro hygiene bug](https://github.com/rust-lang/rust/pull/32923).
6308 * [Feature-gated attributes on macro-generated macro invocations are
6309   now rejected](https://github.com/rust-lang/rust/pull/32791).
6310 * [Suppress fallback and ambiguity errors during type inference](https://github.com/rust-lang/rust/pull/32258).
6311   This caused some minor changes to type inference.
6312
6313
6314 Version 1.9.0 (2016-05-26)
6315 ==========================
6316
6317 Language
6318 --------
6319
6320 * The `#[deprecated]` attribute when applied to an API will generate
6321   warnings when used. The warnings may be suppressed with
6322   `#[allow(deprecated)]`. [RFC 1270].
6323 * [`fn` item types are zero sized, and each `fn` names a unique
6324   type][1.9fn]. This will break code that transmutes `fn`s, so calling
6325   `transmute` on a `fn` type will generate a warning for a few cycles,
6326   then will be converted to an error.
6327 * [Field and method resolution understand visibility, so private
6328   fields and methods cannot prevent the proper use of public fields
6329   and methods][1.9fv].
6330 * [The parser considers unicode codepoints in the
6331   `PATTERN_WHITE_SPACE` category to be whitespace][1.9ws].
6332
6333 Stabilized APIs
6334 ---------------
6335
6336 * [`std::panic`]
6337 * [`std::panic::catch_unwind`] (renamed from `recover`)
6338 * [`std::panic::resume_unwind`] (renamed from `propagate`)
6339 * [`std::panic::AssertUnwindSafe`] (renamed from `AssertRecoverSafe`)
6340 * [`std::panic::UnwindSafe`] (renamed from `RecoverSafe`)
6341 * [`str::is_char_boundary`]
6342 * [`<*const T>::as_ref`]
6343 * [`<*mut T>::as_ref`]
6344 * [`<*mut T>::as_mut`]
6345 * [`AsciiExt::make_ascii_uppercase`]
6346 * [`AsciiExt::make_ascii_lowercase`]
6347 * [`char::decode_utf16`]
6348 * [`char::DecodeUtf16`]
6349 * [`char::DecodeUtf16Error`]
6350 * [`char::DecodeUtf16Error::unpaired_surrogate`]
6351 * [`BTreeSet::take`]
6352 * [`BTreeSet::replace`]
6353 * [`BTreeSet::get`]
6354 * [`HashSet::take`]
6355 * [`HashSet::replace`]
6356 * [`HashSet::get`]
6357 * [`OsString::with_capacity`]
6358 * [`OsString::clear`]
6359 * [`OsString::capacity`]
6360 * [`OsString::reserve`]
6361 * [`OsString::reserve_exact`]
6362 * [`OsStr::is_empty`]
6363 * [`OsStr::len`]
6364 * [`std::os::unix::thread`]
6365 * [`RawPthread`]
6366 * [`JoinHandleExt`]
6367 * [`JoinHandleExt::as_pthread_t`]
6368 * [`JoinHandleExt::into_pthread_t`]
6369 * [`HashSet::hasher`]
6370 * [`HashMap::hasher`]
6371 * [`CommandExt::exec`]
6372 * [`File::try_clone`]
6373 * [`SocketAddr::set_ip`]
6374 * [`SocketAddr::set_port`]
6375 * [`SocketAddrV4::set_ip`]
6376 * [`SocketAddrV4::set_port`]
6377 * [`SocketAddrV6::set_ip`]
6378 * [`SocketAddrV6::set_port`]
6379 * [`SocketAddrV6::set_flowinfo`]
6380 * [`SocketAddrV6::set_scope_id`]
6381 * [`slice::copy_from_slice`]
6382 * [`ptr::read_volatile`]
6383 * [`ptr::write_volatile`]
6384 * [`OpenOptions::create_new`]
6385 * [`TcpStream::set_nodelay`]
6386 * [`TcpStream::nodelay`]
6387 * [`TcpStream::set_ttl`]
6388 * [`TcpStream::ttl`]
6389 * [`TcpStream::set_only_v6`]
6390 * [`TcpStream::only_v6`]
6391 * [`TcpStream::take_error`]
6392 * [`TcpStream::set_nonblocking`]
6393 * [`TcpListener::set_ttl`]
6394 * [`TcpListener::ttl`]
6395 * [`TcpListener::set_only_v6`]
6396 * [`TcpListener::only_v6`]
6397 * [`TcpListener::take_error`]
6398 * [`TcpListener::set_nonblocking`]
6399 * [`UdpSocket::set_broadcast`]
6400 * [`UdpSocket::broadcast`]
6401 * [`UdpSocket::set_multicast_loop_v4`]
6402 * [`UdpSocket::multicast_loop_v4`]
6403 * [`UdpSocket::set_multicast_ttl_v4`]
6404 * [`UdpSocket::multicast_ttl_v4`]
6405 * [`UdpSocket::set_multicast_loop_v6`]
6406 * [`UdpSocket::multicast_loop_v6`]
6407 * [`UdpSocket::set_multicast_ttl_v6`]
6408 * [`UdpSocket::multicast_ttl_v6`]
6409 * [`UdpSocket::set_ttl`]
6410 * [`UdpSocket::ttl`]
6411 * [`UdpSocket::set_only_v6`]
6412 * [`UdpSocket::only_v6`]
6413 * [`UdpSocket::join_multicast_v4`]
6414 * [`UdpSocket::join_multicast_v6`]
6415 * [`UdpSocket::leave_multicast_v4`]
6416 * [`UdpSocket::leave_multicast_v6`]
6417 * [`UdpSocket::take_error`]
6418 * [`UdpSocket::connect`]
6419 * [`UdpSocket::send`]
6420 * [`UdpSocket::recv`]
6421 * [`UdpSocket::set_nonblocking`]
6422
6423 Libraries
6424 ---------
6425
6426 * [`std::sync::Once` is poisoned if its initialization function
6427   fails][1.9o].
6428 * [`cell::Ref` and `cell::RefMut` can contain unsized types][1.9cu].
6429 * [Most types implement `fmt::Debug`][1.9db].
6430 * [The default buffer size used by `BufReader` and `BufWriter` was
6431   reduced to 8K, from 64K][1.9bf]. This is in line with the buffer size
6432   used by other languages.
6433 * [`Instant`, `SystemTime` and `Duration` implement `+=` and `-=`.
6434   `Duration` additionally implements `*=` and `/=`][1.9ta].
6435 * [`Skip` is a `DoubleEndedIterator`][1.9sk].
6436 * [`From<[u8; 4]>` is implemented for `Ipv4Addr`][1.9fi].
6437 * [`Chain` implements `BufRead`][1.9ch].
6438 * [`HashMap`, `HashSet` and iterators are covariant][1.9hc].
6439
6440 Cargo
6441 -----
6442
6443 * [Cargo can now run concurrently][1.9cc].
6444 * [Top-level overrides allow specific revisions of crates to be
6445   overridden through the entire crate graph][1.9ct].  This is intended
6446   to make upgrades easier for large projects, by allowing crates to be
6447   forked temporarily until they've been upgraded and republished.
6448 * [Cargo exports a `CARGO_PKG_AUTHORS` environment variable][1.9cp].
6449 * [Cargo will pass the contents of the `RUSTFLAGS` variable to `rustc`
6450   on the commandline][1.9cf]. `rustc` arguments can also be specified
6451   in the `build.rustflags` configuration key.
6452
6453 Performance
6454 -----------
6455
6456 * [The time complexity of comparing variables for equivalence during type
6457   unification is reduced from _O_(_n_!) to _O_(_n_)][1.9tu]. This leads
6458   to major compilation time improvement in some scenarios.
6459 * [`ToString` is specialized for `str`, giving it the same performance
6460   as `to_owned`][1.9ts].
6461 * [Spawning processes with `Command::output` no longer creates extra
6462   threads][1.9sp].
6463 * [`#[derive(PartialEq)]` and `#[derive(PartialOrd)]` emit less code
6464   for C-like enums][1.9cl].
6465
6466 Misc
6467 ----
6468
6469 * [Passing the `--quiet` flag to a test runner will produce
6470   much-abbreviated output][1.9q].
6471 * The Rust Project now publishes std binaries for the
6472   `mips-unknown-linux-musl`, `mipsel-unknown-linux-musl`, and
6473   `i586-pc-windows-msvc` targets.
6474
6475 Compatibility Notes
6476 -------------------
6477
6478 * [`std::sync::Once` is poisoned if its initialization function
6479   fails][1.9o].
6480 * [It is illegal to define methods with the same name in overlapping
6481   inherent `impl` blocks][1.9sn].
6482 * [`fn` item types are zero sized, and each `fn` names a unique
6483   type][1.9fn]. This will break code that transmutes `fn`s, so calling
6484   `transmute` on a `fn` type will generate a warning for a few cycles,
6485   then will be converted to an error.
6486 * [Improvements to const evaluation may trigger new errors when integer
6487   literals are out of range][1.9ce].
6488
6489
6490 [1.9bf]: https://github.com/rust-lang/rust/pull/32695
6491 [1.9cc]: https://github.com/rust-lang/cargo/pull/2486
6492 [1.9ce]: https://github.com/rust-lang/rust/pull/30587
6493 [1.9cf]: https://github.com/rust-lang/cargo/pull/2241
6494 [1.9ch]: https://github.com/rust-lang/rust/pull/32541
6495 [1.9cl]: https://github.com/rust-lang/rust/pull/31977
6496 [1.9cp]: https://github.com/rust-lang/cargo/pull/2465
6497 [1.9ct]: https://github.com/rust-lang/cargo/pull/2385
6498 [1.9cu]: https://github.com/rust-lang/rust/pull/32652
6499 [1.9db]: https://github.com/rust-lang/rust/pull/32054
6500 [1.9fi]: https://github.com/rust-lang/rust/pull/32050
6501 [1.9fn]: https://github.com/rust-lang/rust/pull/31710
6502 [1.9fv]: https://github.com/rust-lang/rust/pull/31938
6503 [1.9hc]: https://github.com/rust-lang/rust/pull/32635
6504 [1.9o]: https://github.com/rust-lang/rust/pull/32325
6505 [1.9q]: https://github.com/rust-lang/rust/pull/31887
6506 [1.9sk]: https://github.com/rust-lang/rust/pull/31700
6507 [1.9sn]: https://github.com/rust-lang/rust/pull/31925
6508 [1.9sp]: https://github.com/rust-lang/rust/pull/31618
6509 [1.9ta]: https://github.com/rust-lang/rust/pull/32448
6510 [1.9ts]: https://github.com/rust-lang/rust/pull/32586
6511 [1.9tu]: https://github.com/rust-lang/rust/pull/32062
6512 [1.9ws]: https://github.com/rust-lang/rust/pull/29734
6513 [RFC 1270]: https://github.com/rust-lang/rfcs/blob/master/text/1270-deprecation.md
6514 [`<*const T>::as_ref`]: http://doc.rust-lang.org/nightly/std/primitive.pointer.html#method.as_ref
6515 [`<*mut T>::as_mut`]: http://doc.rust-lang.org/nightly/std/primitive.pointer.html#method.as_mut
6516 [`<*mut T>::as_ref`]: http://doc.rust-lang.org/nightly/std/primitive.pointer.html#method.as_ref
6517 [`slice::copy_from_slice`]: http://doc.rust-lang.org/nightly/std/primitive.slice.html#method.copy_from_slice
6518 [`AsciiExt::make_ascii_lowercase`]: http://doc.rust-lang.org/nightly/std/ascii/trait.AsciiExt.html#tymethod.make_ascii_lowercase
6519 [`AsciiExt::make_ascii_uppercase`]: http://doc.rust-lang.org/nightly/std/ascii/trait.AsciiExt.html#tymethod.make_ascii_uppercase
6520 [`BTreeSet::get`]: http://doc.rust-lang.org/nightly/collections/btree/set/struct.BTreeSet.html#method.get
6521 [`BTreeSet::replace`]: http://doc.rust-lang.org/nightly/collections/btree/set/struct.BTreeSet.html#method.replace
6522 [`BTreeSet::take`]: http://doc.rust-lang.org/nightly/collections/btree/set/struct.BTreeSet.html#method.take
6523 [`CommandExt::exec`]: http://doc.rust-lang.org/nightly/std/os/unix/process/trait.CommandExt.html#tymethod.exec
6524 [`File::try_clone`]: http://doc.rust-lang.org/nightly/std/fs/struct.File.html#method.try_clone
6525 [`HashMap::hasher`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashMap.html#method.hasher
6526 [`HashSet::get`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashSet.html#method.get
6527 [`HashSet::hasher`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashSet.html#method.hasher
6528 [`HashSet::replace`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashSet.html#method.replace
6529 [`HashSet::take`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashSet.html#method.take
6530 [`JoinHandleExt::as_pthread_t`]: http://doc.rust-lang.org/nightly/std/os/unix/thread/trait.JoinHandleExt.html#tymethod.as_pthread_t
6531 [`JoinHandleExt::into_pthread_t`]: http://doc.rust-lang.org/nightly/std/os/unix/thread/trait.JoinHandleExt.html#tymethod.into_pthread_t
6532 [`JoinHandleExt`]: http://doc.rust-lang.org/nightly/std/os/unix/thread/trait.JoinHandleExt.html
6533 [`OpenOptions::create_new`]: http://doc.rust-lang.org/nightly/std/fs/struct.OpenOptions.html#method.create_new
6534 [`OsStr::is_empty`]: http://doc.rust-lang.org/nightly/std/ffi/struct.OsStr.html#method.is_empty
6535 [`OsStr::len`]: http://doc.rust-lang.org/nightly/std/ffi/struct.OsStr.html#method.len
6536 [`OsString::capacity`]: http://doc.rust-lang.org/nightly/std/ffi/struct.OsString.html#method.capacity
6537 [`OsString::clear`]: http://doc.rust-lang.org/nightly/std/ffi/struct.OsString.html#method.clear
6538 [`OsString::reserve_exact`]: http://doc.rust-lang.org/nightly/std/ffi/struct.OsString.html#method.reserve_exact
6539 [`OsString::reserve`]: http://doc.rust-lang.org/nightly/std/ffi/struct.OsString.html#method.reserve
6540 [`OsString::with_capacity`]: http://doc.rust-lang.org/nightly/std/ffi/struct.OsString.html#method.with_capacity
6541 [`RawPthread`]: http://doc.rust-lang.org/nightly/std/os/unix/thread/type.RawPthread.html
6542 [`SocketAddr::set_ip`]: http://doc.rust-lang.org/nightly/std/net/enum.SocketAddr.html#method.set_ip
6543 [`SocketAddr::set_port`]: http://doc.rust-lang.org/nightly/std/net/enum.SocketAddr.html#method.set_port
6544 [`SocketAddrV4::set_ip`]: http://doc.rust-lang.org/nightly/std/net/struct.SocketAddrV4.html#method.set_ip
6545 [`SocketAddrV4::set_port`]: http://doc.rust-lang.org/nightly/std/net/struct.SocketAddrV4.html#method.set_port
6546 [`SocketAddrV6::set_flowinfo`]: http://doc.rust-lang.org/nightly/std/net/struct.SocketAddrV6.html#method.set_flowinfo
6547 [`SocketAddrV6::set_ip`]: http://doc.rust-lang.org/nightly/std/net/struct.SocketAddrV6.html#method.set_ip
6548 [`SocketAddrV6::set_port`]: http://doc.rust-lang.org/nightly/std/net/struct.SocketAddrV6.html#method.set_port
6549 [`SocketAddrV6::set_scope_id`]: http://doc.rust-lang.org/nightly/std/net/struct.SocketAddrV6.html#method.set_scope_id
6550 [`TcpListener::only_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.only_v6
6551 [`TcpListener::set_nonblocking`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_nonblocking
6552 [`TcpListener::set_only_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_only_v6
6553 [`TcpListener::set_ttl`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_ttl
6554 [`TcpListener::take_error`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.take_error
6555 [`TcpListener::ttl`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.ttl
6556 [`TcpStream::nodelay`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.nodelay
6557 [`TcpStream::only_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.only_v6
6558 [`TcpStream::set_nodelay`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_nodelay
6559 [`TcpStream::set_nonblocking`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_nonblocking
6560 [`TcpStream::set_only_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_only_v6
6561 [`TcpStream::set_ttl`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_ttl
6562 [`TcpStream::take_error`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.take_error
6563 [`TcpStream::ttl`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.ttl
6564 [`UdpSocket::broadcast`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.broadcast
6565 [`UdpSocket::connect`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.connect
6566 [`UdpSocket::join_multicast_v4`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.join_multicast_v4
6567 [`UdpSocket::join_multicast_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.join_multicast_v6
6568 [`UdpSocket::leave_multicast_v4`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.leave_multicast_v4
6569 [`UdpSocket::leave_multicast_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.leave_multicast_v6
6570 [`UdpSocket::multicast_loop_v4`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.multicast_loop_v4
6571 [`UdpSocket::multicast_loop_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.multicast_loop_v6
6572 [`UdpSocket::multicast_ttl_v4`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.multicast_ttl_v4
6573 [`UdpSocket::multicast_ttl_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.multicast_ttl_v6
6574 [`UdpSocket::only_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.only_v6
6575 [`UdpSocket::recv`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.recv
6576 [`UdpSocket::send`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.send
6577 [`UdpSocket::set_broadcast`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.set_broadcast
6578 [`UdpSocket::set_multicast_loop_v4`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.set_multicast_loop_v4
6579 [`UdpSocket::set_multicast_loop_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.set_multicast_loop_v6
6580 [`UdpSocket::set_multicast_ttl_v4`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.set_multicast_ttl_v4
6581 [`UdpSocket::set_multicast_ttl_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.set_multicast_ttl_v6
6582 [`UdpSocket::set_nonblocking`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.set_nonblocking
6583 [`UdpSocket::set_only_v6`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.set_only_v6
6584 [`UdpSocket::set_ttl`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.set_ttl
6585 [`UdpSocket::take_error`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.take_error
6586 [`UdpSocket::ttl`]: http://doc.rust-lang.org/nightly/std/net/struct.UdpSocket.html#method.ttl
6587 [`char::DecodeUtf16Error::unpaired_surrogate`]: http://doc.rust-lang.org/nightly/std/char/struct.DecodeUtf16Error.html#method.unpaired_surrogate
6588 [`char::DecodeUtf16Error`]: http://doc.rust-lang.org/nightly/std/char/struct.DecodeUtf16Error.html
6589 [`char::DecodeUtf16`]: http://doc.rust-lang.org/nightly/std/char/struct.DecodeUtf16.html
6590 [`char::decode_utf16`]: http://doc.rust-lang.org/nightly/std/char/fn.decode_utf16.html
6591 [`ptr::read_volatile`]: http://doc.rust-lang.org/nightly/std/ptr/fn.read_volatile.html
6592 [`ptr::write_volatile`]: http://doc.rust-lang.org/nightly/std/ptr/fn.write_volatile.html
6593 [`std::os::unix::thread`]: http://doc.rust-lang.org/nightly/std/os/unix/thread/index.html
6594 [`std::panic::AssertUnwindSafe`]: http://doc.rust-lang.org/nightly/std/panic/struct.AssertUnwindSafe.html
6595 [`std::panic::UnwindSafe`]: http://doc.rust-lang.org/nightly/std/panic/trait.UnwindSafe.html
6596 [`std::panic::catch_unwind`]: http://doc.rust-lang.org/nightly/std/panic/fn.catch_unwind.html
6597 [`std::panic::resume_unwind`]: http://doc.rust-lang.org/nightly/std/panic/fn.resume_unwind.html
6598 [`std::panic`]: http://doc.rust-lang.org/nightly/std/panic/index.html
6599 [`str::is_char_boundary`]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.is_char_boundary
6600
6601
6602 Version 1.8.0 (2016-04-14)
6603 ==========================
6604
6605 Language
6606 --------
6607
6608 * Rust supports overloading of compound assignment statements like
6609   `+=` by implementing the [`AddAssign`], [`SubAssign`],
6610   [`MulAssign`], [`DivAssign`], [`RemAssign`], [`BitAndAssign`],
6611   [`BitOrAssign`], [`BitXorAssign`], [`ShlAssign`], or [`ShrAssign`]
6612   traits. [RFC 953].
6613 * Empty structs can be defined with braces, as in `struct Foo { }`, in
6614   addition to the non-braced form, `struct Foo;`. [RFC 218].
6615
6616 Libraries
6617 ---------
6618
6619 * Stabilized APIs:
6620   * [`str::encode_utf16`] (renamed from `utf16_units`)
6621   * [`str::EncodeUtf16`] (renamed from `Utf16Units`)
6622   * [`Ref::map`]
6623   * [`RefMut::map`]
6624   * [`ptr::drop_in_place`]
6625   * [`time::Instant`]
6626   * [`time::SystemTime`]
6627   * [`Instant::now`]
6628   * [`Instant::duration_since`] (renamed from `duration_from_earlier`)
6629   * [`Instant::elapsed`]
6630   * [`SystemTime::now`]
6631   * [`SystemTime::duration_since`] (renamed from `duration_from_earlier`)
6632   * [`SystemTime::elapsed`]
6633   * Various `Add`/`Sub` impls for `Time` and `SystemTime`
6634   * [`SystemTimeError`]
6635   * [`SystemTimeError::duration`]
6636   * Various impls for `SystemTimeError`
6637   * [`UNIX_EPOCH`]
6638   * [`AddAssign`], [`SubAssign`], [`MulAssign`], [`DivAssign`],
6639     [`RemAssign`], [`BitAndAssign`], [`BitOrAssign`],
6640     [`BitXorAssign`], [`ShlAssign`], [`ShrAssign`].
6641 * [The `write!` and `writeln!` macros correctly emit errors if any of
6642   their arguments can't be formatted][1.8w].
6643 * [Various I/O functions support large files on 32-bit Linux][1.8l].
6644 * [The Unix-specific `raw` modules, which contain a number of
6645   redefined C types are deprecated][1.8r], including `os::raw::unix`,
6646   `os::raw::macos`, and `os::raw::linux`. These modules defined types
6647   such as `ino_t` and `dev_t`. The inconsistency of these definitions
6648   across platforms was making it difficult to implement `std`
6649   correctly. Those that need these definitions should use the `libc`
6650   crate. [RFC 1415].
6651 * The Unix-specific `MetadataExt` traits, including
6652   `os::unix::fs::MetadataExt`, which expose values such as inode
6653   numbers [no longer return platform-specific types][1.8r], but
6654   instead return widened integers. [RFC 1415].
6655 * [`btree_set::{IntoIter, Iter, Range}` are covariant][1.8cv].
6656 * [Atomic loads and stores are not volatile][1.8a].
6657 * [All types in `sync::mpsc` implement `fmt::Debug`][1.8mp].
6658
6659 Performance
6660 -----------
6661
6662 * [Inlining hash functions lead to a 3% compile-time improvement in
6663   some workloads][1.8h].
6664 * When using jemalloc, its symbols are [unprefixed so that it
6665   overrides the libc malloc implementation][1.8h]. This means that for
6666   rustc, LLVM is now using jemalloc, which results in a 6%
6667   compile-time improvement on a specific workload.
6668 * [Avoid quadratic growth in function size due to cleanups][1.8cu].
6669
6670 Misc
6671 ----
6672
6673 * [32-bit MSVC builds finally implement unwinding][1.8ms].
6674   i686-pc-windows-msvc is now considered a tier-1 platform.
6675 * [The `--print targets` flag prints a list of supported targets][1.8t].
6676 * [The `--print cfg` flag prints the `cfg`s defined for the current
6677   target][1.8cf].
6678 * [`rustc` can be built with an new Cargo-based build system, written
6679   in Rust][1.8b].  It will eventually replace Rust's Makefile-based
6680   build system. To enable it configure with `configure --rustbuild`.
6681 * [Errors for non-exhaustive `match` patterns now list up to 3 missing
6682   variants while also indicating the total number of missing variants
6683   if more than 3][1.8m].
6684 * [Executable stacks are disabled on Linux and BSD][1.8nx].
6685 * The Rust Project now publishes binary releases of the standard
6686   library for a number of tier-2 targets:
6687   `armv7-unknown-linux-gnueabihf`, `powerpc-unknown-linux-gnu`,
6688   `powerpc64-unknown-linux-gnu`, `powerpc64le-unknown-linux-gnu`
6689   `x86_64-rumprun-netbsd`. These can be installed with
6690   tools such as [multirust][1.8mr].
6691
6692 Cargo
6693 -----
6694
6695 * [`cargo init` creates a new Cargo project in the current
6696   directory][1.8ci].  It is otherwise like `cargo new`.
6697 * [Cargo has configuration keys for `-v` and
6698   `--color`][1.8cc]. `verbose` and `color`, respectively, go in the
6699   `[term]` section of `.cargo/config`.
6700 * [Configuration keys that evaluate to strings or integers can be set
6701   via environment variables][1.8ce]. For example the `build.jobs` key
6702   can be set via `CARGO_BUILD_JOBS`. Environment variables take
6703   precedence over config files.
6704 * [Target-specific dependencies support Rust `cfg` syntax for
6705   describing targets][1.8cfg] so that dependencies for multiple
6706   targets can be specified together. [RFC 1361].
6707 * [The environment variables `CARGO_TARGET_ROOT`, `RUSTC`, and
6708   `RUSTDOC` take precedence over the `build.target-dir`,
6709   `build.rustc`, and `build.rustdoc` configuration values][1.8cv].
6710 * [The child process tree is killed on Windows when Cargo is
6711   killed][1.8ck].
6712 * [The `build.target` configuration value sets the target platform,
6713   like `--target`][1.8ct].
6714
6715 Compatibility Notes
6716 -------------------
6717
6718 * [Unstable compiler flags have been further restricted][1.8u]. Since
6719   1.0 `-Z` flags have been considered unstable, and other flags that
6720   were considered unstable additionally required passing `-Z
6721   unstable-options` to access. Unlike unstable language and library
6722   features though, these options have been accessible on the stable
6723   release channel. Going forward, *new unstable flags will not be
6724   available on the stable release channel*, and old unstable flags
6725   will warn about their usage. In the future, all unstable flags will
6726   be unavailable on the stable release channel.
6727 * [It is no longer possible to `match` on empty enum variants using
6728   the `Variant(..)` syntax][1.8v]. This has been a warning since 1.6.
6729 * The Unix-specific `MetadataExt` traits, including
6730   `os::unix::fs::MetadataExt`, which expose values such as inode
6731   numbers [no longer return platform-specific types][1.8r], but
6732   instead return widened integers. [RFC 1415].
6733 * [Modules sourced from the filesystem cannot appear within arbitrary
6734   blocks, but only within other modules][1.8mf].
6735 * [`--cfg` compiler flags are parsed strictly as identifiers][1.8c].
6736 * On Unix, [stack overflow triggers a runtime abort instead of a
6737   SIGSEGV][1.8so].
6738 * [`Command::spawn` and its equivalents return an error if any of
6739   its command-line arguments contain interior `NUL`s][1.8n].
6740 * [Tuple and unit enum variants from other crates are in the type
6741   namespace][1.8tn].
6742 * [On Windows `rustc` emits `.lib` files for the `staticlib` library
6743   type instead of `.a` files][1.8st]. Additionally, for the MSVC
6744   toolchain, `rustc` emits import libraries named `foo.dll.lib`
6745   instead of `foo.lib`.
6746
6747
6748 [1.8a]: https://github.com/rust-lang/rust/pull/30962
6749 [1.8b]: https://github.com/rust-lang/rust/pull/31123
6750 [1.8c]: https://github.com/rust-lang/rust/pull/31530
6751 [1.8cc]: https://github.com/rust-lang/cargo/pull/2397
6752 [1.8ce]: https://github.com/rust-lang/cargo/pull/2398
6753 [1.8cf]: https://github.com/rust-lang/rust/pull/31278
6754 [1.8cfg]: https://github.com/rust-lang/cargo/pull/2328
6755 [1.8ci]: https://github.com/rust-lang/cargo/pull/2081
6756 [1.8ck]: https://github.com/rust-lang/cargo/pull/2370
6757 [1.8ct]: https://github.com/rust-lang/cargo/pull/2335
6758 [1.8cu]: https://github.com/rust-lang/rust/pull/31390
6759 [1.8cv]: https://github.com/rust-lang/cargo/issues/2365
6760 [1.8cv]: https://github.com/rust-lang/rust/pull/30998
6761 [1.8h]: https://github.com/rust-lang/rust/pull/31460
6762 [1.8l]: https://github.com/rust-lang/rust/pull/31668
6763 [1.8m]: https://github.com/rust-lang/rust/pull/31020
6764 [1.8mf]: https://github.com/rust-lang/rust/pull/31534
6765 [1.8mp]: https://github.com/rust-lang/rust/pull/30894
6766 [1.8mr]: https://users.rust-lang.org/t/multirust-0-8-with-cross-std-installation/4901
6767 [1.8ms]: https://github.com/rust-lang/rust/pull/30448
6768 [1.8n]: https://github.com/rust-lang/rust/pull/31056
6769 [1.8nx]: https://github.com/rust-lang/rust/pull/30859
6770 [1.8r]: https://github.com/rust-lang/rust/pull/31551
6771 [1.8so]: https://github.com/rust-lang/rust/pull/31333
6772 [1.8st]: https://github.com/rust-lang/rust/pull/29520
6773 [1.8t]: https://github.com/rust-lang/rust/pull/31358
6774 [1.8tn]: https://github.com/rust-lang/rust/pull/30882
6775 [1.8u]: https://github.com/rust-lang/rust/pull/31793
6776 [1.8v]: https://github.com/rust-lang/rust/pull/31757
6777 [1.8w]: https://github.com/rust-lang/rust/pull/31904
6778 [RFC 1361]: https://github.com/rust-lang/rfcs/blob/master/text/1361-cargo-cfg-dependencies.md
6779 [RFC 1415]: https://github.com/rust-lang/rfcs/blob/master/text/1415-trim-std-os.md
6780 [RFC 218]: https://github.com/rust-lang/rfcs/blob/master/text/0218-empty-struct-with-braces.md
6781 [RFC 953]: https://github.com/rust-lang/rfcs/blob/master/text/0953-op-assign.md
6782 [`AddAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.AddAssign.html
6783 [`BitAndAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.BitAndAssign.html
6784 [`BitOrAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.BitOrAssign.html
6785 [`BitXorAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.BitXorAssign.html
6786 [`DivAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.DivAssign.html
6787 [`Instant::duration_since`]: http://doc.rust-lang.org/nightly/std/time/struct.Instant.html#method.duration_since
6788 [`Instant::elapsed`]: http://doc.rust-lang.org/nightly/std/time/struct.Instant.html#method.elapsed
6789 [`Instant::now`]: http://doc.rust-lang.org/nightly/std/time/struct.Instant.html#method.now
6790 [`MulAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.MulAssign.html
6791 [`Ref::map`]: http://doc.rust-lang.org/nightly/std/cell/struct.Ref.html#method.map
6792 [`RefMut::map`]: http://doc.rust-lang.org/nightly/std/cell/struct.RefMut.html#method.map
6793 [`RemAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.RemAssign.html
6794 [`ShlAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.ShlAssign.html
6795 [`ShrAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.ShrAssign.html
6796 [`SubAssign`]: http://doc.rust-lang.org/nightly/std/ops/trait.SubAssign.html
6797 [`SystemTime::duration_since`]: http://doc.rust-lang.org/nightly/std/time/struct.SystemTime.html#method.duration_since
6798 [`SystemTime::elapsed`]: http://doc.rust-lang.org/nightly/std/time/struct.SystemTime.html#method.elapsed
6799 [`SystemTime::now`]: http://doc.rust-lang.org/nightly/std/time/struct.SystemTime.html#method.now
6800 [`SystemTimeError::duration`]: http://doc.rust-lang.org/nightly/std/time/struct.SystemTimeError.html#method.duration
6801 [`SystemTimeError`]: http://doc.rust-lang.org/nightly/std/time/struct.SystemTimeError.html
6802 [`UNIX_EPOCH`]: http://doc.rust-lang.org/nightly/std/time/constant.UNIX_EPOCH.html
6803 [`ptr::drop_in_place`]: http://doc.rust-lang.org/nightly/std/ptr/fn.drop_in_place.html
6804 [`str::EncodeUtf16`]: http://doc.rust-lang.org/nightly/std/str/struct.EncodeUtf16.html
6805 [`str::encode_utf16`]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.encode_utf16
6806 [`time::Instant`]: http://doc.rust-lang.org/nightly/std/time/struct.Instant.html
6807 [`time::SystemTime`]: http://doc.rust-lang.org/nightly/std/time/struct.SystemTime.html
6808
6809
6810 Version 1.7.0 (2016-03-03)
6811 ==========================
6812
6813 Libraries
6814 ---------
6815
6816 * Stabilized APIs
6817   * `Path`
6818     * [`Path::strip_prefix`] (renamed from relative_from)
6819     * [`path::StripPrefixError`] (new error type returned from strip_prefix)
6820   * `Ipv4Addr`
6821     * [`Ipv4Addr::is_loopback`]
6822     * [`Ipv4Addr::is_private`]
6823     * [`Ipv4Addr::is_link_local`]
6824     * [`Ipv4Addr::is_multicast`]
6825     * [`Ipv4Addr::is_broadcast`]
6826     * [`Ipv4Addr::is_documentation`]
6827   * `Ipv6Addr`
6828     * [`Ipv6Addr::is_unspecified`]
6829     * [`Ipv6Addr::is_loopback`]
6830     * [`Ipv6Addr::is_multicast`]
6831   * `Vec`
6832     * [`Vec::as_slice`]
6833     * [`Vec::as_mut_slice`]
6834   * `String`
6835     * [`String::as_str`]
6836     * [`String::as_mut_str`]
6837   * Slices
6838     * `<[T]>::`[`clone_from_slice`], which now requires the two slices to
6839     be the same length
6840     * `<[T]>::`[`sort_by_key`]
6841   * checked, saturated, and overflowing operations
6842     * [`i32::checked_rem`], [`i32::checked_neg`], [`i32::checked_shl`], [`i32::checked_shr`]
6843     * [`i32::saturating_mul`]
6844     * [`i32::overflowing_add`], [`i32::overflowing_sub`], [`i32::overflowing_mul`], [`i32::overflowing_div`]
6845     * [`i32::overflowing_rem`], [`i32::overflowing_neg`], [`i32::overflowing_shl`], [`i32::overflowing_shr`]
6846     * [`u32::checked_rem`], [`u32::checked_neg`], [`u32::checked_shl`], [`u32::checked_shl`]
6847     * [`u32::saturating_mul`]
6848     * [`u32::overflowing_add`], [`u32::overflowing_sub`], [`u32::overflowing_mul`], [`u32::overflowing_div`]
6849     * [`u32::overflowing_rem`], [`u32::overflowing_neg`], [`u32::overflowing_shl`], [`u32::overflowing_shr`]
6850     * and checked, saturated, and overflowing operations for other primitive types
6851   * FFI
6852     * [`ffi::IntoStringError`]
6853     * [`CString::into_string`]
6854     * [`CString::into_bytes`]
6855     * [`CString::into_bytes_with_nul`]
6856     * `From<CString> for Vec<u8>`
6857   * `IntoStringError`
6858     * [`IntoStringError::into_cstring`]
6859     * [`IntoStringError::utf8_error`]
6860     * `Error for IntoStringError`
6861   * Hashing
6862     * [`std::hash::BuildHasher`]
6863     * [`BuildHasher::Hasher`]
6864     * [`BuildHasher::build_hasher`]
6865     * [`std::hash::BuildHasherDefault`]
6866     * [`HashMap::with_hasher`]
6867     * [`HashMap::with_capacity_and_hasher`]
6868     * [`HashSet::with_hasher`]
6869     * [`HashSet::with_capacity_and_hasher`]
6870     * [`std::collections::hash_map::RandomState`]
6871     * [`RandomState::new`]
6872 * [Validating UTF-8 is faster by a factor of between 7 and 14x for
6873   ASCII input][1.7utf8]. This means that creating `String`s and `str`s
6874   from bytes is faster.
6875 * [The performance of `LineWriter` (and thus `io::stdout`) was
6876   improved by using `memchr` to search for newlines][1.7m].
6877 * [`f32::to_degrees` and `f32::to_radians` are stable][1.7f]. The
6878   `f64` variants were stabilized previously.
6879 * [`BTreeMap` was rewritten to use less memory and improve the performance
6880   of insertion and iteration, the latter by as much as 5x][1.7bm].
6881 * [`BTreeSet` and its iterators, `Iter`, `IntoIter`, and `Range` are
6882   covariant over their contained type][1.7bt].
6883 * [`LinkedList` and its iterators, `Iter` and `IntoIter` are covariant
6884   over their contained type][1.7ll].
6885 * [`str::replace` now accepts a `Pattern`][1.7rp], like other string
6886   searching methods.
6887 * [`Any` is implemented for unsized types][1.7a].
6888 * [`Hash` is implemented for `Duration`][1.7h].
6889
6890 Misc
6891 ----
6892
6893 * [When running tests with `--test`, rustdoc will pass `--cfg`
6894   arguments to the compiler][1.7dt].
6895 * [The compiler is built with RPATH information by default][1.7rpa].
6896   This means that it will be possible to run `rustc` when installed in
6897   unusual configurations without configuring the dynamic linker search
6898   path explicitly.
6899 * [`rustc` passes `--enable-new-dtags` to GNU ld][1.7dta]. This makes
6900   any RPATH entries (emitted with `-C rpath`) *not* take precedence
6901   over `LD_LIBRARY_PATH`.
6902
6903 Cargo
6904 -----
6905
6906 * [`cargo rustc` accepts a `--profile` flag that runs `rustc` under
6907   any of the compilation profiles, 'dev', 'bench', or 'test'][1.7cp].
6908 * [The `rerun-if-changed` build script directive no longer causes the
6909   build script to incorrectly run twice in certain scenarios][1.7rr].
6910
6911 Compatibility Notes
6912 -------------------
6913
6914 * Soundness fixes to the interactions between associated types and
6915   lifetimes, specified in [RFC 1214], [now generate errors][1.7sf] for
6916   code that violates the new rules. This is a significant change that
6917   is known to break existing code, so it has emitted warnings for the
6918   new error cases since 1.4 to give crate authors time to adapt. The
6919   details of what is changing are subtle; read the RFC for more.
6920 * [Several bugs in the compiler's visibility calculations were
6921   fixed][1.7v]. Since this was found to break significant amounts of
6922   code, the new errors will be emitted as warnings for several release
6923   cycles, under the `private_in_public` lint.
6924 * Defaulted type parameters were accidentally accepted in positions
6925   that were not intended. In this release, [defaulted type parameters
6926   appearing outside of type definitions will generate a
6927   warning][1.7d], which will become an error in future releases.
6928 * [Parsing "." as a float results in an error instead of 0][1.7p].
6929   That is, `".".parse::<f32>()` returns `Err`, not `Ok(0.0)`.
6930 * [Borrows of closure parameters may not outlive the closure][1.7bc].
6931
6932 [1.7a]: https://github.com/rust-lang/rust/pull/30928
6933 [1.7bc]: https://github.com/rust-lang/rust/pull/30341
6934 [1.7bm]: https://github.com/rust-lang/rust/pull/30426
6935 [1.7bt]: https://github.com/rust-lang/rust/pull/30998
6936 [1.7cp]: https://github.com/rust-lang/cargo/pull/2224
6937 [1.7d]: https://github.com/rust-lang/rust/pull/30724
6938 [1.7dt]: https://github.com/rust-lang/rust/pull/30372
6939 [1.7dta]: https://github.com/rust-lang/rust/pull/30394
6940 [1.7f]: https://github.com/rust-lang/rust/pull/30672
6941 [1.7h]: https://github.com/rust-lang/rust/pull/30818
6942 [1.7ll]: https://github.com/rust-lang/rust/pull/30663
6943 [1.7m]: https://github.com/rust-lang/rust/pull/30381
6944 [1.7p]: https://github.com/rust-lang/rust/pull/30681
6945 [1.7rp]: https://github.com/rust-lang/rust/pull/29498
6946 [1.7rpa]: https://github.com/rust-lang/rust/pull/30353
6947 [1.7rr]: https://github.com/rust-lang/cargo/pull/2279
6948 [1.7sf]: https://github.com/rust-lang/rust/pull/30389
6949 [1.7utf8]: https://github.com/rust-lang/rust/pull/30740
6950 [1.7v]: https://github.com/rust-lang/rust/pull/29973
6951 [RFC 1214]: https://github.com/rust-lang/rfcs/blob/master/text/1214-projections-lifetimes-and-wf.md
6952 [`BuildHasher::Hasher`]: http://doc.rust-lang.org/nightly/std/hash/trait.Hasher.html
6953 [`BuildHasher::build_hasher`]: http://doc.rust-lang.org/nightly/std/hash/trait.BuildHasher.html#tymethod.build_hasher
6954 [`CString::into_bytes_with_nul`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CString.html#method.into_bytes_with_nul
6955 [`CString::into_bytes`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CString.html#method.into_bytes
6956 [`CString::into_string`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CString.html#method.into_string
6957 [`HashMap::with_capacity_and_hasher`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashMap.html#method.with_capacity_and_hasher
6958 [`HashMap::with_hasher`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashMap.html#method.with_hasher
6959 [`HashSet::with_capacity_and_hasher`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashSet.html#method.with_capacity_and_hasher
6960 [`HashSet::with_hasher`]: http://doc.rust-lang.org/nightly/std/collections/struct.HashSet.html#method.with_hasher
6961 [`IntoStringError::into_cstring`]: http://doc.rust-lang.org/nightly/std/ffi/struct.IntoStringError.html#method.into_cstring
6962 [`IntoStringError::utf8_error`]: http://doc.rust-lang.org/nightly/std/ffi/struct.IntoStringError.html#method.utf8_error
6963 [`Ipv4Addr::is_broadcast`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#method.is_broadcast
6964 [`Ipv4Addr::is_documentation`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#method.is_documentation
6965 [`Ipv4Addr::is_link_local`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#method.is_link_local
6966 [`Ipv4Addr::is_loopback`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#method.is_loopback
6967 [`Ipv4Addr::is_multicast`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#method.is_multicast
6968 [`Ipv4Addr::is_private`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv4Addr.html#method.is_private
6969 [`Ipv6Addr::is_loopback`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv6Addr.html#method.is_loopback
6970 [`Ipv6Addr::is_multicast`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv6Addr.html#method.is_multicast
6971 [`Ipv6Addr::is_unspecified`]: http://doc.rust-lang.org/nightly/std/net/struct.Ipv6Addr.html#method.is_unspecified
6972 [`Path::strip_prefix`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.strip_prefix
6973 [`RandomState::new`]: http://doc.rust-lang.org/nightly/std/collections/hash_map/struct.RandomState.html#method.new
6974 [`String::as_mut_str`]: http://doc.rust-lang.org/nightly/std/string/struct.String.html#method.as_mut_str
6975 [`String::as_str`]: http://doc.rust-lang.org/nightly/std/string/struct.String.html#method.as_str
6976 [`Vec::as_mut_slice`]: http://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#method.as_mut_slice
6977 [`Vec::as_slice`]: http://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#method.as_slice
6978 [`clone_from_slice`]: http://doc.rust-lang.org/nightly/std/primitive.slice.html#method.clone_from_slice
6979 [`ffi::IntoStringError`]: http://doc.rust-lang.org/nightly/std/ffi/struct.IntoStringError.html
6980 [`i32::checked_neg`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.checked_neg
6981 [`i32::checked_rem`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.checked_rem
6982 [`i32::checked_shl`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.checked_shl
6983 [`i32::checked_shr`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.checked_shr
6984 [`i32::overflowing_add`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.overflowing_add
6985 [`i32::overflowing_div`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.overflowing_div
6986 [`i32::overflowing_mul`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.overflowing_mul
6987 [`i32::overflowing_neg`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.overflowing_neg
6988 [`i32::overflowing_rem`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.overflowing_rem
6989 [`i32::overflowing_shl`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.overflowing_shl
6990 [`i32::overflowing_shr`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.overflowing_shr
6991 [`i32::overflowing_sub`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.overflowing_sub
6992 [`i32::saturating_mul`]: http://doc.rust-lang.org/nightly/std/primitive.i32.html#method.saturating_mul
6993 [`path::StripPrefixError`]: http://doc.rust-lang.org/nightly/std/path/struct.StripPrefixError.html
6994 [`sort_by_key`]: http://doc.rust-lang.org/nightly/std/primitive.slice.html#method.sort_by_key
6995 [`std::collections::hash_map::RandomState`]: http://doc.rust-lang.org/nightly/std/collections/hash_map/struct.RandomState.html
6996 [`std::hash::BuildHasherDefault`]: http://doc.rust-lang.org/nightly/std/hash/struct.BuildHasherDefault.html
6997 [`std::hash::BuildHasher`]: http://doc.rust-lang.org/nightly/std/hash/trait.BuildHasher.html
6998 [`u32::checked_neg`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.checked_neg
6999 [`u32::checked_rem`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.checked_rem
7000 [`u32::checked_neg`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.checked_neg
7001 [`u32::checked_shl`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.checked_shl
7002 [`u32::overflowing_add`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.overflowing_add
7003 [`u32::overflowing_div`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.overflowing_div
7004 [`u32::overflowing_mul`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.overflowing_mul
7005 [`u32::overflowing_neg`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.overflowing_neg
7006 [`u32::overflowing_rem`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.overflowing_rem
7007 [`u32::overflowing_shl`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.overflowing_shl
7008 [`u32::overflowing_shr`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.overflowing_shr
7009 [`u32::overflowing_sub`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.overflowing_sub
7010 [`u32::saturating_mul`]: http://doc.rust-lang.org/nightly/std/primitive.u32.html#method.saturating_mul
7011
7012
7013 Version 1.6.0 (2016-01-21)
7014 ==========================
7015
7016 Language
7017 --------
7018
7019 * The `#![no_std]` attribute causes a crate to not be linked to the
7020   standard library, but only the [core library][1.6co], as described
7021   in [RFC 1184]. The core library defines common types and traits but
7022   has no platform dependencies whatsoever, and is the basis for Rust
7023   software in environments that cannot support a full port of the
7024   standard library, such as operating systems. Most of the core
7025   library is now stable.
7026
7027 Libraries
7028 ---------
7029
7030 * Stabilized APIs:
7031   [`Read::read_exact`],
7032   [`ErrorKind::UnexpectedEof`] (renamed from `UnexpectedEOF`),
7033   [`fs::DirBuilder`], [`fs::DirBuilder::new`],
7034   [`fs::DirBuilder::recursive`], [`fs::DirBuilder::create`],
7035   [`os::unix::fs::DirBuilderExt`],
7036   [`os::unix::fs::DirBuilderExt::mode`], [`vec::Drain`],
7037   [`vec::Vec::drain`], [`string::Drain`], [`string::String::drain`],
7038   [`vec_deque::Drain`], [`vec_deque::VecDeque::drain`],
7039   [`collections::hash_map::Drain`],
7040   [`collections::hash_map::HashMap::drain`],
7041   [`collections::hash_set::Drain`],
7042   [`collections::hash_set::HashSet::drain`],
7043   [`collections::binary_heap::Drain`],
7044   [`collections::binary_heap::BinaryHeap::drain`],
7045   [`Vec::extend_from_slice`] (renamed from `push_all`),
7046   [`Mutex::get_mut`], [`Mutex::into_inner`], [`RwLock::get_mut`],
7047   [`RwLock::into_inner`],
7048   [`Iterator::min_by_key`] (renamed from `min_by`),
7049   [`Iterator::max_by_key`] (renamed from `max_by`).
7050 * The [core library][1.6co] is stable, as are most of its APIs.
7051 * [The `assert_eq!` macro supports arguments that don't implement
7052   `Sized`][1.6ae], such as arrays. In this way it behaves more like
7053   `assert!`.
7054 * Several timer functions that take duration in milliseconds [are
7055   deprecated in favor of those that take `Duration`][1.6ms]. These
7056   include `Condvar::wait_timeout_ms`, `thread::sleep_ms`, and
7057   `thread::park_timeout_ms`.
7058 * The algorithm by which `Vec` reserves additional elements was
7059   [tweaked to not allocate excessive space][1.6a] while still growing
7060   exponentially.
7061 * `From` conversions are [implemented from integers to floats][1.6f]
7062   in cases where the conversion is lossless. Thus they are not
7063   implemented for 32-bit ints to `f32`, nor for 64-bit ints to `f32`
7064   or `f64`. They are also not implemented for `isize` and `usize`
7065   because the implementations would be platform-specific. `From` is
7066   also implemented from `f32` to `f64`.
7067 * `From<&Path>` and `From<PathBuf>` are implemented for `Cow<Path>`.
7068 * `From<T>` is implemented for `Box<T>`, `Rc<T>` and `Arc<T>`.
7069 * `IntoIterator` is implemented for `&PathBuf` and `&Path`.
7070 * [`BinaryHeap` was refactored][1.6bh] for modest performance
7071   improvements.
7072 * Sorting slices that are already sorted [is 50% faster in some
7073   cases][1.6s].
7074
7075 Cargo
7076 -----
7077
7078 * Cargo will look in `$CARGO_HOME/bin` for subcommands [by default][1.6c].
7079 * Cargo build scripts can specify their dependencies by emitting the
7080   [`rerun-if-changed`][1.6rr] key.
7081 * crates.io will reject publication of crates with dependencies that
7082   have a wildcard version constraint. Crates with wildcard
7083   dependencies were seen to cause a variety of problems, as described
7084   in [RFC 1241]. Since 1.5 publication of such crates has emitted a
7085   warning.
7086 * `cargo clean` [accepts a `--release` flag][1.6cc] to clean the
7087   release folder.  A variety of artifacts that Cargo failed to clean
7088   are now correctly deleted.
7089
7090 Misc
7091 ----
7092
7093 * The `unreachable_code` lint [warns when a function call's argument
7094   diverges][1.6dv].
7095 * The parser indicates [failures that may be caused by
7096   confusingly-similar Unicode characters][1.6uc]
7097 * Certain macro errors [are reported at definition time][1.6m], not
7098   expansion.
7099
7100 Compatibility Notes
7101 -------------------
7102
7103 * The compiler no longer makes use of the [`RUST_PATH`][1.6rp]
7104   environment variable when locating crates. This was a pre-cargo
7105   feature for integrating with the package manager that was
7106   accidentally never removed.
7107 * [A number of bugs were fixed in the privacy checker][1.6p] that
7108   could cause previously-accepted code to break.
7109 * [Modules and unit/tuple structs may not share the same name][1.6ts].
7110 * [Bugs in pattern matching unit structs were fixed][1.6us]. The tuple
7111   struct pattern syntax (`Foo(..)`) can no longer be used to match
7112   unit structs. This is a warning now, but will become an error in
7113   future releases. Patterns that share the same name as a const are
7114   now an error.
7115 * A bug was fixed that causes [rustc not to apply default type
7116   parameters][1.6xc] when resolving certain method implementations of
7117   traits defined in other crates.
7118
7119 [1.6a]: https://github.com/rust-lang/rust/pull/29454
7120 [1.6ae]: https://github.com/rust-lang/rust/pull/29770
7121 [1.6bh]: https://github.com/rust-lang/rust/pull/29811
7122 [1.6c]: https://github.com/rust-lang/cargo/pull/2192
7123 [1.6cc]: https://github.com/rust-lang/cargo/pull/2131
7124 [1.6co]: http://doc.rust-lang.org/core/index.html
7125 [1.6dv]: https://github.com/rust-lang/rust/pull/30000
7126 [1.6f]: https://github.com/rust-lang/rust/pull/29129
7127 [1.6m]: https://github.com/rust-lang/rust/pull/29828
7128 [1.6ms]: https://github.com/rust-lang/rust/pull/29604
7129 [1.6p]: https://github.com/rust-lang/rust/pull/29726
7130 [1.6rp]: https://github.com/rust-lang/rust/pull/30034
7131 [1.6rr]: https://github.com/rust-lang/cargo/pull/2134
7132 [1.6s]: https://github.com/rust-lang/rust/pull/29675
7133 [1.6ts]: https://github.com/rust-lang/rust/issues/21546
7134 [1.6uc]: https://github.com/rust-lang/rust/pull/29837
7135 [1.6us]: https://github.com/rust-lang/rust/pull/29383
7136 [1.6xc]: https://github.com/rust-lang/rust/issues/30123
7137 [RFC 1184]: https://github.com/rust-lang/rfcs/blob/master/text/1184-stabilize-no_std.md
7138 [RFC 1241]: https://github.com/rust-lang/rfcs/blob/master/text/1241-no-wildcard-deps.md
7139 [`ErrorKind::UnexpectedEof`]: http://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html#variant.UnexpectedEof
7140 [`Iterator::max_by_key`]: http://doc.rust-lang.org/nightly/std/iter/trait.Iterator.html#method.max_by_key
7141 [`Iterator::min_by_key`]: http://doc.rust-lang.org/nightly/std/iter/trait.Iterator.html#method.min_by_key
7142 [`Mutex::get_mut`]: http://doc.rust-lang.org/nightly/std/sync/struct.Mutex.html#method.get_mut
7143 [`Mutex::into_inner`]: http://doc.rust-lang.org/nightly/std/sync/struct.Mutex.html#method.into_inner
7144 [`Read::read_exact`]: http://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.read_exact
7145 [`RwLock::get_mut`]: http://doc.rust-lang.org/nightly/std/sync/struct.RwLock.html#method.get_mut
7146 [`RwLock::into_inner`]: http://doc.rust-lang.org/nightly/std/sync/struct.RwLock.html#method.into_inner
7147 [`Vec::extend_from_slice`]: http://doc.rust-lang.org/nightly/collections/vec/struct.Vec.html#method.extend_from_slice
7148 [`collections::binary_heap::BinaryHeap::drain`]: http://doc.rust-lang.org/nightly/std/collections/binary_heap/struct.BinaryHeap.html#method.drain
7149 [`collections::binary_heap::Drain`]: http://doc.rust-lang.org/nightly/std/collections/binary_heap/struct.Drain.html
7150 [`collections::hash_map::Drain`]: http://doc.rust-lang.org/nightly/std/collections/hash_map/struct.Drain.html
7151 [`collections::hash_map::HashMap::drain`]: http://doc.rust-lang.org/nightly/std/collections/hash_map/struct.HashMap.html#method.drain
7152 [`collections::hash_set::Drain`]: http://doc.rust-lang.org/nightly/std/collections/hash_set/struct.Drain.html
7153 [`collections::hash_set::HashSet::drain`]: http://doc.rust-lang.org/nightly/std/collections/hash_set/struct.HashSet.html#method.drain
7154 [`fs::DirBuilder::create`]: http://doc.rust-lang.org/nightly/std/fs/struct.DirBuilder.html#method.create
7155 [`fs::DirBuilder::new`]: http://doc.rust-lang.org/nightly/std/fs/struct.DirBuilder.html#method.new
7156 [`fs::DirBuilder::recursive`]: http://doc.rust-lang.org/nightly/std/fs/struct.DirBuilder.html#method.recursive
7157 [`fs::DirBuilder`]: http://doc.rust-lang.org/nightly/std/fs/struct.DirBuilder.html
7158 [`os::unix::fs::DirBuilderExt::mode`]: http://doc.rust-lang.org/nightly/std/os/unix/fs/trait.DirBuilderExt.html#tymethod.mode
7159 [`os::unix::fs::DirBuilderExt`]: http://doc.rust-lang.org/nightly/std/os/unix/fs/trait.DirBuilderExt.html
7160 [`string::Drain`]: http://doc.rust-lang.org/nightly/std/string/struct.Drain.html
7161 [`string::String::drain`]: http://doc.rust-lang.org/nightly/std/string/struct.String.html#method.drain
7162 [`vec::Drain`]: http://doc.rust-lang.org/nightly/std/vec/struct.Drain.html
7163 [`vec::Vec::drain`]: http://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#method.drain
7164 [`vec_deque::Drain`]: http://doc.rust-lang.org/nightly/std/collections/vec_deque/struct.Drain.html
7165 [`vec_deque::VecDeque::drain`]: http://doc.rust-lang.org/nightly/std/collections/vec_deque/struct.VecDeque.html#method.drain
7166
7167
7168 Version 1.5.0 (2015-12-10)
7169 ==========================
7170
7171 * ~700 changes, numerous bugfixes
7172
7173 Highlights
7174 ----------
7175
7176 * Stabilized APIs:
7177   [`BinaryHeap::from`], [`BinaryHeap::into_sorted_vec`],
7178   [`BinaryHeap::into_vec`], [`Condvar::wait_timeout`],
7179   [`FileTypeExt::is_block_device`], [`FileTypeExt::is_char_device`],
7180   [`FileTypeExt::is_fifo`], [`FileTypeExt::is_socket`],
7181   [`FileTypeExt`], [`Formatter::alternate`], [`Formatter::fill`],
7182   [`Formatter::precision`], [`Formatter::sign_aware_zero_pad`],
7183   [`Formatter::sign_minus`], [`Formatter::sign_plus`],
7184   [`Formatter::width`], [`Iterator::cmp`], [`Iterator::eq`],
7185   [`Iterator::ge`], [`Iterator::gt`], [`Iterator::le`],
7186   [`Iterator::lt`], [`Iterator::ne`], [`Iterator::partial_cmp`],
7187   [`Path::canonicalize`], [`Path::exists`], [`Path::is_dir`],
7188   [`Path::is_file`], [`Path::metadata`], [`Path::read_dir`],
7189   [`Path::read_link`], [`Path::symlink_metadata`],
7190   [`Utf8Error::valid_up_to`], [`Vec::resize`],
7191   [`VecDeque::as_mut_slices`], [`VecDeque::as_slices`],
7192   [`VecDeque::insert`], [`VecDeque::shrink_to_fit`],
7193   [`VecDeque::swap_remove_back`], [`VecDeque::swap_remove_front`],
7194   [`slice::split_first_mut`], [`slice::split_first`],
7195   [`slice::split_last_mut`], [`slice::split_last`],
7196   [`char::from_u32_unchecked`], [`fs::canonicalize`],
7197   [`str::MatchIndices`], [`str::RMatchIndices`],
7198   [`str::match_indices`], [`str::rmatch_indices`],
7199   [`str::slice_mut_unchecked`], [`string::ParseError`].
7200 * Rust applications hosted on crates.io can be installed locally to
7201   `~/.cargo/bin` with the [`cargo install`] command. Among other
7202   things this makes it easier to augment Cargo with new subcommands:
7203   when a binary named e.g. `cargo-foo` is found in `$PATH` it can be
7204   invoked as `cargo foo`.
7205 * Crates with wildcard (`*`) dependencies will [emit warnings when
7206   published][1.5w]. In 1.6 it will no longer be possible to publish
7207   crates with wildcard dependencies.
7208
7209 Breaking Changes
7210 ----------------
7211
7212 * The rules determining when a particular lifetime must outlive
7213   a particular value (known as '[dropck]') have been [modified
7214   to not rely on parametricity][1.5p].
7215 * [Implementations of `AsRef` and `AsMut` were added to `Box`, `Rc`,
7216   and `Arc`][1.5a]. Because these smart pointer types implement
7217   `Deref`, this causes breakage in cases where the interior type
7218   contains methods of the same name.
7219 * [Correct a bug in Rc/Arc][1.5c] that caused [dropck] to be unaware
7220   that they could drop their content. Soundness fix.
7221 * All method invocations are [properly checked][1.5wf1] for
7222   [well-formedness][1.5wf2]. Soundness fix.
7223 * Traits whose supertraits contain `Self` are [not object
7224   safe][1.5o]. Soundness fix.
7225 * Target specifications support a [`no_default_libraries`][1.5nd]
7226   setting that controls whether `-nodefaultlibs` is passed to the
7227   linker, and in turn the `is_like_windows` setting no longer affects
7228   the `-nodefaultlibs` flag.
7229 * `#[derive(Show)]`, long-deprecated, [has been removed][1.5ds].
7230 * The `#[inline]` and `#[repr]` attributes [can only appear
7231   in valid locations][1.5at].
7232 * Native libraries linked from the local crate are [passed to
7233   the linker before native libraries from upstream crates][1.5nl].
7234 * Two rarely-used attributes, `#[no_debug]` and
7235   `#[omit_gdb_pretty_printer_section]` [are feature gated][1.5fg].
7236 * Negation of unsigned integers, which has been a warning for
7237   several releases, [is now behind a feature gate and will
7238   generate errors][1.5nu].
7239 * The parser accidentally accepted visibility modifiers on
7240   enum variants, a bug [which has been fixed][1.5ev].
7241 * [A bug was fixed that allowed `use` statements to import unstable
7242   features][1.5use].
7243
7244 Language
7245 --------
7246
7247 * When evaluating expressions at compile-time that are not
7248   compile-time constants (const-evaluating expressions in non-const
7249   contexts), incorrect code such as overlong bitshifts and arithmetic
7250   overflow will [generate a warning instead of an error][1.5ce],
7251   delaying the error until runtime. This will allow the
7252   const-evaluator to be expanded in the future backwards-compatibly.
7253 * The `improper_ctypes` lint [no longer warns about using `isize` and
7254   `usize` in FFI][1.5ict].
7255
7256 Libraries
7257 ---------
7258
7259 * `Arc<T>` and `Rc<T>` are [covariant with respect to `T` instead of
7260   invariant][1.5c].
7261 * `Default` is [implemented for mutable slices][1.5d].
7262 * `FromStr` is [implemented for `SockAddrV4` and `SockAddrV6`][1.5s].
7263 * There are now `From` conversions [between floating point
7264   types][1.5f] where the conversions are lossless.
7265 * There are now `From` conversions [between integer types][1.5i] where
7266   the conversions are lossless.
7267 * [`fs::Metadata` implements `Clone`][1.5fs].
7268 * The `parse` method [accepts a leading "+" when parsing
7269   integers][1.5pi].
7270 * [`AsMut` is implemented for `Vec`][1.5am].
7271 * The `clone_from` implementations for `String` and `BinaryHeap` [have
7272   been optimized][1.5cf] and no longer rely on the default impl.
7273 * The `extern "Rust"`, `extern "C"`, `unsafe extern "Rust"` and
7274   `unsafe extern "C"` function types now [implement `Clone`,
7275   `PartialEq`, `Eq`, `PartialOrd`, `Ord`, `Hash`, `fmt::Pointer`, and
7276   `fmt::Debug` for up to 12 arguments][1.5fp].
7277 * [Dropping `Vec`s is much faster in unoptimized builds when the
7278   element types don't implement `Drop`][1.5dv].
7279 * A bug that caused in incorrect behavior when [combining `VecDeque`
7280   with zero-sized types][1.5vdz] was resolved.
7281 * [`PartialOrd` for slices is faster][1.5po].
7282
7283 Miscellaneous
7284 -------------
7285
7286 * [Crate metadata size was reduced by 20%][1.5md].
7287 * [Improvements to code generation reduced the size of libcore by 3.3
7288   MB and rustc's memory usage by 18MB][1.5m].
7289 * [Improvements to deref translation increased performance in
7290   unoptimized builds][1.5dr].
7291 * Various errors in trait resolution [are deduplicated to only be
7292   reported once][1.5te].
7293 * Rust has preliminary [support for rumprun kernels][1.5rr].
7294 * Rust has preliminary [support for NetBSD on amd64][1.5na].
7295
7296 [1.5use]: https://github.com/rust-lang/rust/pull/28364
7297 [1.5po]: https://github.com/rust-lang/rust/pull/28436
7298 [1.5ev]: https://github.com/rust-lang/rust/pull/28442
7299 [1.5nu]: https://github.com/rust-lang/rust/pull/28468
7300 [1.5dr]: https://github.com/rust-lang/rust/pull/28491
7301 [1.5vdz]: https://github.com/rust-lang/rust/pull/28494
7302 [1.5md]: https://github.com/rust-lang/rust/pull/28521
7303 [1.5fg]: https://github.com/rust-lang/rust/pull/28522
7304 [1.5dv]: https://github.com/rust-lang/rust/pull/28531
7305 [1.5na]: https://github.com/rust-lang/rust/pull/28543
7306 [1.5fp]: https://github.com/rust-lang/rust/pull/28560
7307 [1.5rr]: https://github.com/rust-lang/rust/pull/28593
7308 [1.5cf]: https://github.com/rust-lang/rust/pull/28602
7309 [1.5nl]: https://github.com/rust-lang/rust/pull/28605
7310 [1.5te]: https://github.com/rust-lang/rust/pull/28645
7311 [1.5at]: https://github.com/rust-lang/rust/pull/28650
7312 [1.5am]: https://github.com/rust-lang/rust/pull/28663
7313 [1.5m]: https://github.com/rust-lang/rust/pull/28778
7314 [1.5ict]: https://github.com/rust-lang/rust/pull/28779
7315 [1.5a]: https://github.com/rust-lang/rust/pull/28811
7316 [1.5pi]: https://github.com/rust-lang/rust/pull/28826
7317 [1.5ce]: https://github.com/rust-lang/rfcs/blob/master/text/1229-compile-time-asserts.md
7318 [1.5p]: https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md
7319 [1.5i]: https://github.com/rust-lang/rust/pull/28921
7320 [1.5fs]: https://github.com/rust-lang/rust/pull/29021
7321 [1.5f]: https://github.com/rust-lang/rust/pull/29129
7322 [1.5ds]: https://github.com/rust-lang/rust/pull/29148
7323 [1.5s]: https://github.com/rust-lang/rust/pull/29190
7324 [1.5d]: https://github.com/rust-lang/rust/pull/29245
7325 [1.5o]: https://github.com/rust-lang/rust/pull/29259
7326 [1.5nd]: https://github.com/rust-lang/rust/pull/28578
7327 [1.5wf2]: https://github.com/rust-lang/rfcs/blob/master/text/1214-projections-lifetimes-and-wf.md
7328 [1.5wf1]: https://github.com/rust-lang/rust/pull/28669
7329 [dropck]: https://doc.rust-lang.org/nightly/nomicon/dropck.html
7330 [1.5c]: https://github.com/rust-lang/rust/pull/29110
7331 [1.5w]: https://github.com/rust-lang/rfcs/blob/master/text/1241-no-wildcard-deps.md
7332 [`cargo install`]: https://github.com/rust-lang/rfcs/blob/master/text/1200-cargo-install.md
7333 [`BinaryHeap::from`]: http://doc.rust-lang.org/nightly/std/convert/trait.From.html#method.from
7334 [`BinaryHeap::into_sorted_vec`]: http://doc.rust-lang.org/nightly/std/collections/struct.BinaryHeap.html#method.into_sorted_vec
7335 [`BinaryHeap::into_vec`]: http://doc.rust-lang.org/nightly/std/collections/struct.BinaryHeap.html#method.into_vec
7336 [`Condvar::wait_timeout`]: http://doc.rust-lang.org/nightly/std/sync/struct.Condvar.html#method.wait_timeout
7337 [`FileTypeExt::is_block_device`]: http://doc.rust-lang.org/nightly/std/os/unix/fs/trait.FileTypeExt.html#tymethod.is_block_device
7338 [`FileTypeExt::is_char_device`]: http://doc.rust-lang.org/nightly/std/os/unix/fs/trait.FileTypeExt.html#tymethod.is_char_device
7339 [`FileTypeExt::is_fifo`]: http://doc.rust-lang.org/nightly/std/os/unix/fs/trait.FileTypeExt.html#tymethod.is_fifo
7340 [`FileTypeExt::is_socket`]: http://doc.rust-lang.org/nightly/std/os/unix/fs/trait.FileTypeExt.html#tymethod.is_socket
7341 [`FileTypeExt`]: http://doc.rust-lang.org/nightly/std/os/unix/fs/trait.FileTypeExt.html
7342 [`Formatter::alternate`]: http://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.alternate
7343 [`Formatter::fill`]: http://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.fill
7344 [`Formatter::precision`]: http://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.precision
7345 [`Formatter::sign_aware_zero_pad`]: http://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.sign_aware_zero_pad
7346 [`Formatter::sign_minus`]: http://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.sign_minus
7347 [`Formatter::sign_plus`]: http://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.sign_plus
7348 [`Formatter::width`]: http://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.width
7349 [`Iterator::cmp`]: http://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html#method.cmp
7350 [`Iterator::eq`]: http://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html#method.eq
7351 [`Iterator::ge`]: http://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html#method.ge
7352 [`Iterator::gt`]: http://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html#method.gt
7353 [`Iterator::le`]: http://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html#method.le
7354 [`Iterator::lt`]: http://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html#method.lt
7355 [`Iterator::ne`]: http://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html#method.ne
7356 [`Iterator::partial_cmp`]: http://doc.rust-lang.org/nightly/core/iter/trait.Iterator.html#method.partial_cmp
7357 [`Path::canonicalize`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.canonicalize
7358 [`Path::exists`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.exists
7359 [`Path::is_dir`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.is_dir
7360 [`Path::is_file`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.is_file
7361 [`Path::metadata`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.metadata
7362 [`Path::read_dir`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.read_dir
7363 [`Path::read_link`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.read_link
7364 [`Path::symlink_metadata`]: http://doc.rust-lang.org/nightly/std/path/struct.Path.html#method.symlink_metadata
7365 [`Utf8Error::valid_up_to`]: http://doc.rust-lang.org/nightly/core/str/struct.Utf8Error.html#method.valid_up_to
7366 [`Vec::resize`]: http://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#method.resize
7367 [`VecDeque::as_mut_slices`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.as_mut_slices
7368 [`VecDeque::as_slices`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.as_slices
7369 [`VecDeque::insert`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.insert
7370 [`VecDeque::shrink_to_fit`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.shrink_to_fit
7371 [`VecDeque::swap_remove_back`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.swap_remove_back
7372 [`VecDeque::swap_remove_front`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.swap_remove_front
7373 [`slice::split_first_mut`]: http://doc.rust-lang.org/nightly/std/primitive.slice.html#method.split_first_mut
7374 [`slice::split_first`]: http://doc.rust-lang.org/nightly/std/primitive.slice.html#method.split_first
7375 [`slice::split_last_mut`]: http://doc.rust-lang.org/nightly/std/primitive.slice.html#method.split_last_mut
7376 [`slice::split_last`]: http://doc.rust-lang.org/nightly/std/primitive.slice.html#method.split_last
7377 [`char::from_u32_unchecked`]: http://doc.rust-lang.org/nightly/std/char/fn.from_u32_unchecked.html
7378 [`fs::canonicalize`]: http://doc.rust-lang.org/nightly/std/fs/fn.canonicalize.html
7379 [`str::MatchIndices`]: http://doc.rust-lang.org/nightly/std/str/struct.MatchIndices.html
7380 [`str::RMatchIndices`]: http://doc.rust-lang.org/nightly/std/str/struct.RMatchIndices.html
7381 [`str::match_indices`]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.match_indices
7382 [`str::rmatch_indices`]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.rmatch_indices
7383 [`str::slice_mut_unchecked`]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.slice_mut_unchecked
7384 [`string::ParseError`]: http://doc.rust-lang.org/nightly/std/string/enum.ParseError.html
7385
7386 Version 1.4.0 (2015-10-29)
7387 ==========================
7388
7389 * ~1200 changes, numerous bugfixes
7390
7391 Highlights
7392 ----------
7393
7394 * Windows builds targeting the 64-bit MSVC ABI and linker (instead of
7395   GNU) are now supported and recommended for use.
7396
7397 Breaking Changes
7398 ----------------
7399
7400 * [Several changes have been made to fix type soundness and improve
7401   the behavior of associated types][sound]. See [RFC 1214]. Although
7402   we have mostly introduced these changes as warnings this release, to
7403   become errors next release, there are still some scenarios that will
7404   see immediate breakage.
7405 * [The `str::lines` and `BufRead::lines` iterators treat `\r\n` as
7406   line breaks in addition to `\n`][crlf].
7407 * [Loans of `'static` lifetime extend to the end of a function][stat].
7408 * [`str::parse` no longer introduces avoidable rounding error when
7409   parsing floating point numbers. Together with earlier changes to
7410   float formatting/output, "round trips" like f.to_string().parse()
7411   now preserve the value of f exactly. Additionally, leading plus
7412   signs are now accepted][fp3].
7413
7414
7415 Language
7416 --------
7417
7418 * `use` statements that import multiple items [can now rename
7419   them][i], as in `use foo::{bar as kitten, baz as puppy}`.
7420 * [Binops work correctly on fat pointers][binfat].
7421 * `pub extern crate`, which does not behave as expected, [issues a
7422   warning][pec] until a better solution is found.
7423
7424 Libraries
7425 ---------
7426
7427 * [Many APIs were stabilized][stab]: `<Box<str>>::into_string`,
7428   [`Arc::downgrade`], [`Arc::get_mut`], [`Arc::make_mut`],
7429   [`Arc::try_unwrap`], [`Box::from_raw`], [`Box::into_raw`], [`CStr::to_str`],
7430   [`CStr::to_string_lossy`], [`CString::from_raw`], [`CString::into_raw`],
7431   [`IntoRawFd::into_raw_fd`], [`IntoRawFd`],
7432   `IntoRawHandle::into_raw_handle`, `IntoRawHandle`,
7433   `IntoRawSocket::into_raw_socket`, `IntoRawSocket`, [`Rc::downgrade`],
7434   [`Rc::get_mut`], [`Rc::make_mut`], [`Rc::try_unwrap`], [`Result::expect`],
7435   [`String::into_boxed_str`], [`TcpStream::read_timeout`],
7436   [`TcpStream::set_read_timeout`], [`TcpStream::set_write_timeout`],
7437   [`TcpStream::write_timeout`], [`UdpSocket::read_timeout`],
7438   [`UdpSocket::set_read_timeout`], [`UdpSocket::set_write_timeout`],
7439   [`UdpSocket::write_timeout`], `Vec::append`, `Vec::split_off`,
7440   [`VecDeque::append`], [`VecDeque::retain`], [`VecDeque::split_off`],
7441   [`rc::Weak::upgrade`], [`rc::Weak`], [`slice::Iter::as_slice`],
7442   [`slice::IterMut::into_slice`], [`str::CharIndices::as_str`],
7443   [`str::Chars::as_str`], [`str::split_at_mut`], [`str::split_at`],
7444   [`sync::Weak::upgrade`], [`sync::Weak`], [`thread::park_timeout`],
7445   [`thread::sleep`].
7446 * [Some APIs were deprecated][dep]: `BTreeMap::with_b`,
7447   `BTreeSet::with_b`, `Option::as_mut_slice`, `Option::as_slice`,
7448   `Result::as_mut_slice`, `Result::as_slice`, `f32::from_str_radix`,
7449   `f64::from_str_radix`.
7450 * [Reverse-searching strings is faster with the 'two-way'
7451   algorithm][s].
7452 * [`std::io::copy` allows `?Sized` arguments][cc].
7453 * The `Windows`, `Chunks`, and `ChunksMut` iterators over slices all
7454   [override `count`, `nth` and `last` with an O(1)
7455   implementation][it].
7456 * [`Default` is implemented for arrays up to `[T; 32]`][d].
7457 * [`IntoRawFd` has been added to the Unix-specific prelude,
7458   `IntoRawSocket` and `IntoRawHandle` to the Windows-specific
7459   prelude][pr].
7460 * [`Extend<String>` and `FromIterator<String` are both implemented for
7461   `String`][es].
7462 * [`IntoIterator` is implemented for references to `Option` and
7463   `Result`][into2].
7464 * [`HashMap` and `HashSet` implement `Extend<&T>` where `T:
7465   Copy`][ext] as part of [RFC 839]. This will cause type inference
7466   breakage in rare situations.
7467 * [`BinaryHeap` implements `Debug`][bh2].
7468 * [`Borrow` and `BorrowMut` are implemented for fixed-size
7469   arrays][bm].
7470 * [`extern fn`s with the "Rust" and "C" ABIs implement common
7471   traits including `Eq`, `Ord`, `Debug`, `Hash`][fp].
7472 * [String comparison is faster][faststr].
7473 * `&mut T` where `T: std::fmt::Write` [also implements
7474   `std::fmt::Write`][mutw].
7475 * [A stable regression in `VecDeque::push_back` and other
7476   capacity-altering methods that caused panics for zero-sized types
7477   was fixed][vd].
7478 * [Function pointers implement traits for up to 12 parameters][fp2].
7479
7480 Miscellaneous
7481 -------------
7482
7483 * The compiler [no longer uses the 'morestack' feature to prevent
7484   stack overflow][mm]. Instead it uses guard pages and stack
7485   probes (though stack probes are not yet implemented on any platform
7486   but Windows).
7487 * [The compiler matches traits faster when projections are involved][p].
7488 * The 'improper_ctypes' lint [no longer warns about use of `isize` and
7489   `usize`][ffi].
7490 * [Cargo now displays useful information about what its doing during
7491   `cargo update`][cu].
7492
7493 [`Arc::downgrade`]: http://doc.rust-lang.org/nightly/alloc/arc/struct.Arc.html#method.downgrade
7494 [`Arc::make_mut`]: http://doc.rust-lang.org/nightly/alloc/arc/struct.Arc.html#method.make_mut
7495 [`Arc::get_mut`]: http://doc.rust-lang.org/nightly/alloc/arc/struct.Arc.html#method.get_mut
7496 [`Arc::try_unwrap`]: http://doc.rust-lang.org/nightly/alloc/arc/struct.Arc.html#method.try_unwrap
7497 [`Box::from_raw`]: http://doc.rust-lang.org/nightly/alloc/boxed/struct.Box.html#method.from_raw
7498 [`Box::into_raw`]: http://doc.rust-lang.org/nightly/alloc/boxed/struct.Box.html#method.into_raw
7499 [`CStr::to_str`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CStr.html#method.to_str
7500 [`CStr::to_string_lossy`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CStr.html#method.to_string_lossy
7501 [`CString::from_raw`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CString.html#method.from_raw
7502 [`CString::into_raw`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CString.html#method.into_raw
7503 [`IntoRawFd::into_raw_fd`]: http://doc.rust-lang.org/nightly/std/os/unix/io/trait.IntoRawFd.html#tymethod.into_raw_fd
7504 [`IntoRawFd`]: http://doc.rust-lang.org/nightly/std/os/unix/io/trait.IntoRawFd.html
7505 [`Rc::downgrade`]: http://doc.rust-lang.org/nightly/alloc/rc/struct.Rc.html#method.downgrade
7506 [`Rc::get_mut`]: http://doc.rust-lang.org/nightly/alloc/rc/struct.Rc.html#method.get_mut
7507 [`Rc::make_mut`]: http://doc.rust-lang.org/nightly/alloc/rc/struct.Rc.html#method.make_mut
7508 [`Rc::try_unwrap`]: http://doc.rust-lang.org/nightly/alloc/rc/struct.Rc.html#method.try_unwrap
7509 [`Result::expect`]: http://doc.rust-lang.org/nightly/core/result/enum.Result.html#method.expect
7510 [`String::into_boxed_str`]: http://doc.rust-lang.org/nightly/collections/string/struct.String.html#method.into_boxed_str
7511 [`TcpStream::read_timeout`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.read_timeout
7512 [`TcpStream::set_read_timeout`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_read_timeout
7513 [`TcpStream::write_timeout`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.write_timeout
7514 [`TcpStream::set_write_timeout`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_write_timeout
7515 [`UdpSocket::read_timeout`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.read_timeout
7516 [`UdpSocket::set_read_timeout`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_read_timeout
7517 [`UdpSocket::write_timeout`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.write_timeout
7518 [`UdpSocket::set_write_timeout`]: http://doc.rust-lang.org/nightly/std/net/struct.TcpStream.html#method.set_write_timeout
7519 [`VecDeque::append`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.append
7520 [`VecDeque::retain`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.retain
7521 [`VecDeque::split_off`]: http://doc.rust-lang.org/nightly/std/collections/struct.VecDeque.html#method.split_off
7522 [`rc::Weak::upgrade`]: http://doc.rust-lang.org/nightly/std/rc/struct.Weak.html#method.upgrade
7523 [`rc::Weak`]: http://doc.rust-lang.org/nightly/std/rc/struct.Weak.html
7524 [`slice::Iter::as_slice`]: http://doc.rust-lang.org/nightly/std/slice/struct.Iter.html#method.as_slice
7525 [`slice::IterMut::into_slice`]: http://doc.rust-lang.org/nightly/std/slice/struct.IterMut.html#method.into_slice
7526 [`str::CharIndices::as_str`]: http://doc.rust-lang.org/nightly/std/str/struct.CharIndices.html#method.as_str
7527 [`str::Chars::as_str`]: http://doc.rust-lang.org/nightly/std/str/struct.Chars.html#method.as_str
7528 [`str::split_at_mut`]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.split_at_mut
7529 [`str::split_at`]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.split_at
7530 [`sync::Weak::upgrade`]: http://doc.rust-lang.org/nightly/std/sync/struct.Weak.html#method.upgrade
7531 [`sync::Weak`]: http://doc.rust-lang.org/nightly/std/sync/struct.Weak.html
7532 [`thread::park_timeout`]: http://doc.rust-lang.org/nightly/std/thread/fn.park_timeout.html
7533 [`thread::sleep`]: http://doc.rust-lang.org/nightly/std/thread/fn.sleep.html
7534 [bh2]: https://github.com/rust-lang/rust/pull/28156
7535 [binfat]: https://github.com/rust-lang/rust/pull/28270
7536 [bm]: https://github.com/rust-lang/rust/pull/28197
7537 [cc]: https://github.com/rust-lang/rust/pull/27531
7538 [crlf]: https://github.com/rust-lang/rust/pull/28034
7539 [cu]: https://github.com/rust-lang/cargo/pull/1931
7540 [d]: https://github.com/rust-lang/rust/pull/27825
7541 [dep]: https://github.com/rust-lang/rust/pull/28339
7542 [es]: https://github.com/rust-lang/rust/pull/27956
7543 [ext]: https://github.com/rust-lang/rust/pull/28094
7544 [faststr]: https://github.com/rust-lang/rust/pull/28338
7545 [ffi]: https://github.com/rust-lang/rust/pull/28779
7546 [fp]: https://github.com/rust-lang/rust/pull/28268
7547 [fp2]: https://github.com/rust-lang/rust/pull/28560
7548 [fp3]: https://github.com/rust-lang/rust/pull/27307
7549 [i]: https://github.com/rust-lang/rust/pull/27451
7550 [into2]: https://github.com/rust-lang/rust/pull/28039
7551 [it]: https://github.com/rust-lang/rust/pull/27652
7552 [mm]: https://github.com/rust-lang/rust/pull/27338
7553 [mutw]: https://github.com/rust-lang/rust/pull/28368
7554 [sound]: https://github.com/rust-lang/rust/pull/27641
7555 [p]: https://github.com/rust-lang/rust/pull/27866
7556 [pec]: https://github.com/rust-lang/rust/pull/28486
7557 [pr]: https://github.com/rust-lang/rust/pull/27896
7558 [RFC 839]: https://github.com/rust-lang/rfcs/blob/master/text/0839-embrace-extend-extinguish.md
7559 [RFC 1214]: https://github.com/rust-lang/rfcs/blob/master/text/1214-projections-lifetimes-and-wf.md
7560 [s]: https://github.com/rust-lang/rust/pull/27474
7561 [stab]: https://github.com/rust-lang/rust/pull/28339
7562 [stat]: https://github.com/rust-lang/rust/pull/28321
7563 [vd]: https://github.com/rust-lang/rust/pull/28494
7564
7565 Version 1.3.0 (2015-09-17)
7566 ==============================
7567
7568 * ~900 changes, numerous bugfixes
7569
7570 Highlights
7571 ----------
7572
7573 * The [new object lifetime defaults][nold] have been [turned
7574   on][nold2] after a cycle of warnings about the change. Now types
7575   like `&'a Box<Trait>` (or `&'a Rc<Trait>`, etc) will change from
7576   being interpreted as `&'a Box<Trait+'a>` to `&'a
7577   Box<Trait+'static>`.
7578 * [The Rustonomicon][nom] is a new book in the official documentation
7579   that dives into writing unsafe Rust.
7580 * The [`Duration`] API, [has been stabilized][ds]. This basic unit of
7581   timekeeping is employed by other std APIs, as well as out-of-tree
7582   time crates.
7583
7584 Breaking Changes
7585 ----------------
7586
7587 * The [new object lifetime defaults][nold] have been [turned
7588   on][nold2] after a cycle of warnings about the change.
7589 * There is a known [regression][lr] in how object lifetime elision is
7590   interpreted, the proper solution for which is undetermined.
7591 * The `#[prelude_import]` attribute, an internal implementation
7592   detail, was accidentally stabilized previously. [It has been put
7593   behind the `prelude_import` feature gate][pi]. This change is
7594   believed to break no existing code.
7595 * The behavior of [`size_of_val`][dst1] and [`align_of_val`][dst2] is
7596   [more sane for dynamically sized types][dst3]. Code that relied on
7597   the previous behavior is thought to be broken.
7598 * The `dropck` rules, which checks that destructors can't access
7599   destroyed values, [have been updated][dropck] to match the
7600   [RFC][dropckrfc]. This fixes some soundness holes, and as such will
7601   cause some previously-compiling code to no longer build.
7602
7603 Language
7604 --------
7605
7606 * The [new object lifetime defaults][nold] have been [turned
7607   on][nold2] after a cycle of warnings about the change.
7608 * Semicolons may [now follow types and paths in
7609   macros](https://github.com/rust-lang/rust/pull/27000).
7610 * The behavior of [`size_of_val`][dst1] and [`align_of_val`][dst2] is
7611   [more sane for dynamically sized types][dst3]. Code that relied on
7612   the previous behavior is not known to exist, and suspected to be
7613   broken.
7614 * `'static` variables [may now be recursive][st].
7615 * `ref` bindings choose between [`Deref`] and [`DerefMut`]
7616   implementations correctly.
7617 * The `dropck` rules, which checks that destructors can't access
7618   destroyed values, [have been updated][dropck] to match the
7619   [RFC][dropckrfc].
7620
7621 Libraries
7622 ---------
7623
7624 * The [`Duration`] API, [has been stabilized][ds], as well as the
7625   `std::time` module, which presently contains only `Duration`.
7626 * `Box<str>` and `Box<[T]>` both implement `Clone`.
7627 * The owned C string, [`CString`], implements [`Borrow`] and the
7628   borrowed C string, [`CStr`], implements [`ToOwned`]. The two of
7629   these allow C strings to be borrowed and cloned in generic code.
7630 * [`CStr`] implements [`Debug`].
7631 * [`AtomicPtr`] implements [`Debug`].
7632 * [`Error`] trait objects [can be downcast to their concrete types][e]
7633   in many common configurations, using the [`is`], [`downcast`],
7634   [`downcast_ref`] and [`downcast_mut`] methods, similarly to the
7635   [`Any`] trait.
7636 * Searching for substrings now [employs the two-way algorithm][search]
7637   instead of doing a naive search. This gives major speedups to a
7638   number of methods, including [`contains`][sc], [`find`][sf],
7639   [`rfind`][srf], [`split`][ss]. [`starts_with`][ssw] and
7640   [`ends_with`][sew] are also faster.
7641 * The performance of `PartialEq` for slices is [much faster][ps].
7642 * The [`Hash`] trait offers the default method, [`hash_slice`], which
7643   is overridden and optimized by the implementations for scalars.
7644 * The [`Hasher`] trait now has a number of specialized `write_*`
7645   methods for primitive types, for efficiency.
7646 * The I/O-specific error type, [`std::io::Error`][ie], gained a set of
7647   methods for accessing the 'inner error', if any: [`get_ref`][iegr],
7648   [`get_mut`][iegm], [`into_inner`][ieii]. As well, the implementation
7649   of [`std::error::Error::cause`][iec] also delegates to the inner
7650   error.
7651 * [`process::Child`][pc] gained the [`id`] method, which returns a
7652   `u32` representing the platform-specific process identifier.
7653 * The [`connect`] method on slices is deprecated, replaced by the new
7654   [`join`] method (note that both of these are on the *unstable*
7655   [`SliceConcatExt`] trait, but through the magic of the prelude are
7656   available to stable code anyway).
7657 * The [`Div`] operator is implemented for [`Wrapping`] types.
7658 * [`DerefMut` is implemented for `String`][dms].
7659 * Performance of SipHash (the default hasher for `HashMap`) is
7660   [better for long data][sh].
7661 * [`AtomicPtr`] implements [`Send`].
7662 * The [`read_to_end`] implementations for [`Stdin`] and [`File`]
7663   are now [specialized to use uninitialized buffers for increased
7664   performance][rte].
7665 * Lifetime parameters of foreign functions [are now resolved
7666   properly][f].
7667
7668 Misc
7669 ----
7670
7671 * Rust can now, with some coercion, [produce programs that run on
7672   Windows XP][xp], though XP is not considered a supported platform.
7673 * Porting Rust on Windows from the GNU toolchain to MSVC continues
7674   ([1][win1], [2][win2], [3][win3], [4][win4]). It is still not
7675   recommended for use in 1.3, though should be fully-functional
7676   in the [64-bit 1.4 beta][b14].
7677 * On Fedora-based systems installation will [properly configure the
7678   dynamic linker][fl].
7679 * The compiler gained many new extended error descriptions, which can
7680   be accessed with the `--explain` flag.
7681 * The `dropck` pass, which checks that destructors can't access
7682   destroyed values, [has been rewritten][dropck]. This fixes some
7683   soundness holes, and as such will cause some previously-compiling
7684   code to no longer build.
7685 * `rustc` now uses [LLVM to write archive files where possible][ar].
7686   Eventually this will eliminate the compiler's dependency on the ar
7687   utility.
7688 * Rust has [preliminary support for i686 FreeBSD][fb] (it has long
7689   supported FreeBSD on x86_64).
7690 * The [`unused_mut`][lum], [`unconditional_recursion`][lur],
7691   [`improper_ctypes`][lic], and [`negate_unsigned`][lnu] lints are
7692   more strict.
7693 * If landing pads are disabled (with `-Z no-landing-pads`), [`panic!`
7694   will kill the process instead of leaking][nlp].
7695
7696 [`Any`]: http://doc.rust-lang.org/nightly/std/any/trait.Any.html
7697 [`AtomicPtr`]: http://doc.rust-lang.org/nightly/std/sync/atomic/struct.AtomicPtr.html
7698 [`Borrow`]: http://doc.rust-lang.org/nightly/std/borrow/trait.Borrow.html
7699 [`CStr`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CStr.html
7700 [`CString`]: http://doc.rust-lang.org/nightly/std/ffi/struct.CString.html
7701 [`Debug`]: http://doc.rust-lang.org/nightly/std/fmt/trait.Debug.html
7702 [`DerefMut`]: http://doc.rust-lang.org/nightly/std/ops/trait.DerefMut.html
7703 [`Deref`]: http://doc.rust-lang.org/nightly/std/ops/trait.Deref.html
7704 [`Div`]: http://doc.rust-lang.org/nightly/std/ops/trait.Div.html
7705 [`Duration`]: http://doc.rust-lang.org/nightly/std/time/struct.Duration.html
7706 [`Error`]: http://doc.rust-lang.org/nightly/std/error/trait.Error.html
7707 [`File`]: http://doc.rust-lang.org/nightly/std/fs/struct.File.html
7708 [`Hash`]: http://doc.rust-lang.org/nightly/std/hash/trait.Hash.html
7709 [`Hasher`]: http://doc.rust-lang.org/nightly/std/hash/trait.Hasher.html
7710 [`Send`]: http://doc.rust-lang.org/nightly/std/marker/trait.Send.html
7711 [`SliceConcatExt`]: http://doc.rust-lang.org/nightly/std/slice/trait.SliceConcatExt.html
7712 [`Stdin`]: http://doc.rust-lang.org/nightly/std/io/struct.Stdin.html
7713 [`ToOwned`]: http://doc.rust-lang.org/nightly/std/borrow/trait.ToOwned.html
7714 [`Wrapping`]: http://doc.rust-lang.org/nightly/std/num/struct.Wrapping.html
7715 [`connect`]: http://doc.rust-lang.org/nightly/std/slice/trait.SliceConcatExt.html#method.connect
7716 [`downcast_mut`]: http://doc.rust-lang.org/nightly/std/error/trait.Error.html#method.downcast_mut
7717 [`downcast_ref`]: http://doc.rust-lang.org/nightly/std/error/trait.Error.html#method.downcast_ref
7718 [`downcast`]: http://doc.rust-lang.org/nightly/std/error/trait.Error.html#method.downcast
7719 [`hash_slice`]: http://doc.rust-lang.org/nightly/std/hash/trait.Hash.html#method.hash_slice
7720 [`id`]: http://doc.rust-lang.org/nightly/std/process/struct.Child.html#method.id
7721 [`is`]: http://doc.rust-lang.org/nightly/std/error/trait.Error.html#method.is
7722 [`join`]: http://doc.rust-lang.org/nightly/std/slice/trait.SliceConcatExt.html#method.join
7723 [`read_to_end`]: http://doc.rust-lang.org/nightly/std/io/trait.Read.html#method.read_to_end
7724 [ar]: https://github.com/rust-lang/rust/pull/26926
7725 [b14]: https://static.rust-lang.org/dist/rust-beta-x86_64-pc-windows-msvc.msi
7726 [dms]: https://github.com/rust-lang/rust/pull/26241
7727 [dropck]: https://github.com/rust-lang/rust/pull/27261
7728 [dropckrfc]: https://github.com/rust-lang/rfcs/blob/master/text/0769-sound-generic-drop.md
7729 [ds]: https://github.com/rust-lang/rust/pull/26818
7730 [dst1]: http://doc.rust-lang.org/nightly/std/mem/fn.size_of_val.html
7731 [dst2]: http://doc.rust-lang.org/nightly/std/mem/fn.align_of_val.html
7732 [dst3]: https://github.com/rust-lang/rust/pull/27351
7733 [e]: https://github.com/rust-lang/rust/pull/24793
7734 [f]: https://github.com/rust-lang/rust/pull/26588
7735 [fb]: https://github.com/rust-lang/rust/pull/26959
7736 [fl]: https://github.com/rust-lang/rust-installer/pull/41
7737 [hs]: http://doc.rust-lang.org/nightly/std/hash/trait.Hash.html#method.hash_slice
7738 [ie]: http://doc.rust-lang.org/nightly/std/io/struct.Error.html
7739 [iec]: http://doc.rust-lang.org/nightly/std/io/struct.Error.html#method.cause
7740 [iegm]: http://doc.rust-lang.org/nightly/std/io/struct.Error.html#method.get_mut
7741 [iegr]: http://doc.rust-lang.org/nightly/std/io/struct.Error.html#method.get_ref
7742 [ieii]: http://doc.rust-lang.org/nightly/std/io/struct.Error.html#method.into_inner
7743 [lic]: https://github.com/rust-lang/rust/pull/26583
7744 [lnu]: https://github.com/rust-lang/rust/pull/27026
7745 [lr]: https://github.com/rust-lang/rust/issues/27248
7746 [lum]: https://github.com/rust-lang/rust/pull/26378
7747 [lur]: https://github.com/rust-lang/rust/pull/26783
7748 [nlp]: https://github.com/rust-lang/rust/pull/27176
7749 [nold2]: https://github.com/rust-lang/rust/pull/27045
7750 [nold]: https://github.com/rust-lang/rfcs/blob/master/text/1156-adjust-default-object-bounds.md
7751 [nom]: http://doc.rust-lang.org/nightly/nomicon/
7752 [pc]: http://doc.rust-lang.org/nightly/std/process/struct.Child.html
7753 [pi]: https://github.com/rust-lang/rust/pull/26699
7754 [ps]: https://github.com/rust-lang/rust/pull/26884
7755 [rte]: https://github.com/rust-lang/rust/pull/26950
7756 [sc]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.contains
7757 [search]: https://github.com/rust-lang/rust/pull/26327
7758 [sew]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.ends_with
7759 [sf]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.find
7760 [sh]: https://github.com/rust-lang/rust/pull/27280
7761 [srf]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.rfind
7762 [ss]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.split
7763 [ssw]: http://doc.rust-lang.org/nightly/std/primitive.str.html#method.starts_with
7764 [st]: https://github.com/rust-lang/rust/pull/26630
7765 [win1]: https://github.com/rust-lang/rust/pull/26569
7766 [win2]: https://github.com/rust-lang/rust/pull/26741
7767 [win3]: https://github.com/rust-lang/rust/pull/26741
7768 [win4]: https://github.com/rust-lang/rust/pull/27210
7769 [xp]: https://github.com/rust-lang/rust/pull/26569
7770
7771 Version 1.2.0 (2015-08-07)
7772 ==========================
7773
7774 * ~1200 changes, numerous bugfixes
7775
7776 Highlights
7777 ----------
7778
7779 * [Dynamically-sized-type coercions][dst] allow smart pointer types
7780   like `Rc` to contain types without a fixed size, arrays and trait
7781   objects, finally enabling use of `Rc<[T]>` and completing the
7782   implementation of DST.
7783 * [Parallel codegen][parcodegen] is now working again, which can
7784   substantially speed up large builds in debug mode; It also gets
7785   another ~33% speedup when bootstrapping on a 4 core machine (using 8
7786   jobs). It's not enabled by default, but will be "in the near
7787   future". It can be activated with the `-C codegen-units=N` flag to
7788   `rustc`.
7789 * This is the first release with [experimental support for linking
7790   with the MSVC linker and lib C on Windows (instead of using the GNU
7791   variants via MinGW)][win]. It is yet recommended only for the most
7792   intrepid Rustaceans.
7793 * Benchmark compilations are showing a 30% improvement in
7794   bootstrapping over 1.1.
7795
7796 Breaking Changes
7797 ----------------
7798
7799 * The [`to_uppercase`] and [`to_lowercase`] methods on `char` now do
7800   unicode case mapping, which is a previously-planned change in
7801   behavior and considered a bugfix.
7802 * [`mem::align_of`] now specifies [the *minimum alignment* for
7803   T][align], which is usually the alignment programs are interested
7804   in, and the same value reported by clang's
7805   `alignof`. [`mem::min_align_of`] is deprecated. This is not known to
7806   break real code.
7807 * [The `#[packed]` attribute is no longer silently accepted by the
7808   compiler][packed]. This attribute did nothing and code that
7809   mentioned it likely did not work as intended.
7810 * Associated type defaults are [now behind the
7811   `associated_type_defaults` feature gate][ad]. In 1.1 associated type
7812   defaults *did not work*, but could be mentioned syntactically. As
7813   such this breakage has minimal impact.
7814
7815 Language
7816 --------
7817
7818 * Patterns with `ref mut` now correctly invoke [`DerefMut`] when
7819   matching against dereferenceable values.
7820
7821 Libraries
7822 ---------
7823
7824 * The [`Extend`] trait, which grows a collection from an iterator, is
7825   implemented over iterators of references, for `String`, `Vec`,
7826   `LinkedList`, `VecDeque`, `EnumSet`, `BinaryHeap`, `VecMap`,
7827   `BTreeSet` and `BTreeMap`. [RFC][extend-rfc].
7828 * The [`iter::once`] function returns an iterator that yields a single
7829   element, and [`iter::empty`] returns an iterator that yields no
7830   elements.
7831 * The [`matches`] and [`rmatches`] methods on `str` return iterators
7832   over substring matches.
7833 * [`Cell`] and [`RefCell`] both implement `Eq`.
7834 * A number of methods for wrapping arithmetic are added to the
7835   integral types, [`wrapping_div`], [`wrapping_rem`],
7836   [`wrapping_neg`], [`wrapping_shl`], [`wrapping_shr`]. These are in
7837   addition to the existing [`wrapping_add`], [`wrapping_sub`], and
7838   [`wrapping_mul`] methods, and alternatives to the [`Wrapping`]
7839   type.. It is illegal for the default arithmetic operations in Rust
7840   to overflow; the desire to wrap must be explicit.
7841 * The `{:#?}` formatting specifier [displays the alternate,
7842   pretty-printed][debugfmt] form of the `Debug` formatter. This
7843   feature was actually introduced prior to 1.0 with little
7844   fanfare.
7845 * [`fmt::Formatter`] implements [`fmt::Write`], a `fmt`-specific trait
7846   for writing data to formatted strings, similar to [`io::Write`].
7847 * [`fmt::Formatter`] adds 'debug builder' methods, [`debug_struct`],
7848   [`debug_tuple`], [`debug_list`], [`debug_set`], [`debug_map`]. These
7849   are used by code generators to emit implementations of [`Debug`].
7850 * `str` has new [`to_uppercase`][strup] and [`to_lowercase`][strlow]
7851   methods that convert case, following Unicode case mapping.
7852 * It is now easier to handle poisoned locks. The [`PoisonError`]
7853   type, returned by failing lock operations, exposes `into_inner`,
7854   `get_ref`, and `get_mut`, which all give access to the inner lock
7855   guard, and allow the poisoned lock to continue to operate. The
7856   `is_poisoned` method of [`RwLock`] and [`Mutex`] can poll for a
7857   poisoned lock without attempting to take the lock.
7858 * On Unix the [`FromRawFd`] trait is implemented for [`Stdio`], and
7859   [`AsRawFd`] for [`ChildStdin`], [`ChildStdout`], [`ChildStderr`].
7860   On Windows the `FromRawHandle` trait is implemented for `Stdio`,
7861   and `AsRawHandle` for `ChildStdin`, `ChildStdout`,
7862   `ChildStderr`.
7863 * [`io::ErrorKind`] has a new variant, `InvalidData`, which indicates
7864   malformed input.
7865
7866 Misc
7867 ----
7868
7869 * `rustc` employs smarter heuristics for guessing at [typos].
7870 * `rustc` emits more efficient code for [no-op conversions between
7871   unsafe pointers][nop].
7872 * Fat pointers are now [passed in pairs of immediate arguments][fat],
7873   resulting in faster compile times and smaller code.
7874
7875 [`Extend`]: https://doc.rust-lang.org/nightly/std/iter/trait.Extend.html
7876 [extend-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0839-embrace-extend-extinguish.md
7877 [`iter::once`]: https://doc.rust-lang.org/nightly/std/iter/fn.once.html
7878 [`iter::empty`]: https://doc.rust-lang.org/nightly/std/iter/fn.empty.html
7879 [`matches`]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.matches
7880 [`rmatches`]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.rmatches
7881 [`Cell`]: https://doc.rust-lang.org/nightly/std/cell/struct.Cell.html
7882 [`RefCell`]: https://doc.rust-lang.org/nightly/std/cell/struct.RefCell.html
7883 [`wrapping_add`]: https://doc.rust-lang.org/nightly/std/primitive.i8.html#method.wrapping_add
7884 [`wrapping_sub`]: https://doc.rust-lang.org/nightly/std/primitive.i8.html#method.wrapping_sub
7885 [`wrapping_mul`]: https://doc.rust-lang.org/nightly/std/primitive.i8.html#method.wrapping_mul
7886 [`wrapping_div`]: https://doc.rust-lang.org/nightly/std/primitive.i8.html#method.wrapping_div
7887 [`wrapping_rem`]: https://doc.rust-lang.org/nightly/std/primitive.i8.html#method.wrapping_rem
7888 [`wrapping_neg`]: https://doc.rust-lang.org/nightly/std/primitive.i8.html#method.wrapping_neg
7889 [`wrapping_shl`]: https://doc.rust-lang.org/nightly/std/primitive.i8.html#method.wrapping_shl
7890 [`wrapping_shr`]: https://doc.rust-lang.org/nightly/std/primitive.i8.html#method.wrapping_shr
7891 [`Wrapping`]: https://doc.rust-lang.org/nightly/std/num/struct.Wrapping.html
7892 [`fmt::Formatter`]: https://doc.rust-lang.org/nightly/std/fmt/struct.Formatter.html
7893 [`fmt::Write`]: https://doc.rust-lang.org/nightly/std/fmt/trait.Write.html
7894 [`io::Write`]: https://doc.rust-lang.org/nightly/std/io/trait.Write.html
7895 [`debug_struct`]: https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.debug_struct
7896 [`debug_tuple`]: https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.debug_tuple
7897 [`debug_list`]: https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.debug_list
7898 [`debug_set`]: https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.debug_set
7899 [`debug_map`]: https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html#method.debug_map
7900 [`Debug`]: https://doc.rust-lang.org/nightly/std/fmt/trait.Debug.html
7901 [strup]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.to_uppercase
7902 [strlow]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.to_lowercase
7903 [`to_uppercase`]: https://doc.rust-lang.org/nightly/std/primitive.char.html#method.to_uppercase
7904 [`to_lowercase`]: https://doc.rust-lang.org/nightly/std/primitive.char.html#method.to_lowercase
7905 [`PoisonError`]: https://doc.rust-lang.org/nightly/std/sync/struct.PoisonError.html
7906 [`RwLock`]: https://doc.rust-lang.org/nightly/std/sync/struct.RwLock.html
7907 [`Mutex`]: https://doc.rust-lang.org/nightly/std/sync/struct.Mutex.html
7908 [`FromRawFd`]: https://doc.rust-lang.org/nightly/std/os/unix/io/trait.FromRawFd.html
7909 [`AsRawFd`]: https://doc.rust-lang.org/nightly/std/os/unix/io/trait.AsRawFd.html
7910 [`Stdio`]: https://doc.rust-lang.org/nightly/std/process/struct.Stdio.html
7911 [`ChildStdin`]: https://doc.rust-lang.org/nightly/std/process/struct.ChildStdin.html
7912 [`ChildStdout`]: https://doc.rust-lang.org/nightly/std/process/struct.ChildStdout.html
7913 [`ChildStderr`]: https://doc.rust-lang.org/nightly/std/process/struct.ChildStderr.html
7914 [`io::ErrorKind`]: https://doc.rust-lang.org/nightly/std/io/enum.ErrorKind.html
7915 [debugfmt]: https://www.reddit.com/r/rust/comments/3ceaui/psa_produces_prettyprinted_debug_output/
7916 [`DerefMut`]: https://doc.rust-lang.org/nightly/std/ops/trait.DerefMut.html
7917 [`mem::align_of`]: https://doc.rust-lang.org/nightly/std/mem/fn.align_of.html
7918 [align]: https://github.com/rust-lang/rust/pull/25646
7919 [`mem::min_align_of`]: https://doc.rust-lang.org/nightly/std/mem/fn.min_align_of.html
7920 [typos]: https://github.com/rust-lang/rust/pull/26087
7921 [nop]: https://github.com/rust-lang/rust/pull/26336
7922 [fat]: https://github.com/rust-lang/rust/pull/26411
7923 [dst]: https://github.com/rust-lang/rfcs/blob/master/text/0982-dst-coercion.md
7924 [parcodegen]: https://github.com/rust-lang/rust/pull/26018
7925 [packed]: https://github.com/rust-lang/rust/pull/25541
7926 [ad]: https://github.com/rust-lang/rust/pull/27382
7927 [win]: https://github.com/rust-lang/rust/pull/25350
7928
7929 Version 1.1.0 (2015-06-25)
7930 =========================
7931
7932 * ~850 changes, numerous bugfixes
7933
7934 Highlights
7935 ----------
7936
7937 * The [`std::fs` module has been expanded][fs] to expand the set of
7938   functionality exposed:
7939   * `DirEntry` now supports optimizations like `file_type` and `metadata` which
7940     don't incur a syscall on some platforms.
7941   * A `symlink_metadata` function has been added.
7942   * The `fs::Metadata` structure now lowers to its OS counterpart, providing
7943     access to all underlying information.
7944 * The compiler now contains extended explanations of many errors. When an error
7945   with an explanation occurs the compiler suggests using the `--explain` flag
7946   to read the explanation. Error explanations are also [available online][err-index].
7947 * Thanks to multiple [improvements][sk] to [type checking][pre], as
7948   well as other work, the time to bootstrap the compiler decreased by
7949   32%.
7950
7951 Libraries
7952 ---------
7953
7954 * The [`str::split_whitespace`] method splits a string on unicode
7955   whitespace boundaries.
7956 * On both Windows and Unix, new extension traits provide conversion of
7957   I/O types to and from the underlying system handles. On Unix, these
7958   traits are [`FromRawFd`] and [`AsRawFd`], on Windows `FromRawHandle`
7959   and `AsRawHandle`. These are implemented for `File`, `TcpStream`,
7960   `TcpListener`, and `UpdSocket`. Further implementations for
7961   `std::process` will be stabilized later.
7962 * On Unix, [`std::os::unix::symlink`] creates symlinks. On
7963   Windows, symlinks can be created with
7964   `std::os::windows::symlink_dir` and
7965   `std::os::windows::symlink_file`.
7966 * The `mpsc::Receiver` type can now be converted into an iterator with
7967   `into_iter` on the [`IntoIterator`] trait.
7968 * `Ipv4Addr` can be created from `u32` with the `From<u32>`
7969   implementation of the [`From`] trait.
7970 * The `Debug` implementation for `RangeFull` [creates output that is
7971   more consistent with other implementations][rf].
7972 * [`Debug` is implemented for `File`][file].
7973 * The `Default` implementation for `Arc` [no longer requires `Sync +
7974   Send`][arc].
7975 * [The `Iterator` methods `count`, `nth`, and `last` have been
7976   overridden for slices to have O(1) performance instead of O(n)][si].
7977 * Incorrect handling of paths on Windows has been improved in both the
7978   compiler and the standard library.
7979 * [`AtomicPtr` gained a `Default` implementation][ap].
7980 * In accordance with Rust's policy on arithmetic overflow `abs` now
7981   [panics on overflow when debug assertions are enabled][abs].
7982 * The [`Cloned`] iterator, which was accidentally left unstable for
7983   1.0 [has been stabilized][c].
7984 * The [`Incoming`] iterator, which iterates over incoming TCP
7985   connections, and which was accidentally unnamable in 1.0, [is now
7986   properly exported][inc].
7987 * [`BinaryHeap`] no longer corrupts itself [when functions called by
7988   `sift_up` or `sift_down` panic][bh].
7989 * The [`split_off`] method of `LinkedList` [no longer corrupts
7990   the list in certain scenarios][ll].
7991
7992 Misc
7993 ----
7994
7995 * Type checking performance [has improved notably][sk] with
7996   [multiple improvements][pre].
7997 * The compiler [suggests code changes][ch] for more errors.
7998 * rustc and it's build system have experimental support for [building
7999   toolchains against MUSL][m] instead of glibc on Linux.
8000 * The compiler defines the `target_env` cfg value, which is used for
8001   distinguishing toolchains that are otherwise for the same
8002   platform. Presently this is set to `gnu` for common GNU Linux
8003   targets and for MinGW targets, and `musl` for MUSL Linux targets.
8004 * The [`cargo rustc`][crc] command invokes a build with custom flags
8005   to rustc.
8006 * [Android executables are always position independent][pie].
8007 * [The `drop_with_repr_extern` lint warns about mixing `repr(C)`
8008   with `Drop`][drop].
8009
8010 [`str::split_whitespace`]: https://doc.rust-lang.org/nightly/std/primitive.str.html#method.split_whitespace
8011 [`FromRawFd`]: https://doc.rust-lang.org/nightly/std/os/unix/io/trait.FromRawFd.html
8012 [`AsRawFd`]: https://doc.rust-lang.org/nightly/std/os/unix/io/trait.AsRawFd.html
8013 [`std::os::unix::symlink`]: https://doc.rust-lang.org/nightly/std/os/unix/fs/fn.symlink.html
8014 [`IntoIterator`]: https://doc.rust-lang.org/nightly/std/iter/trait.IntoIterator.html
8015 [`From`]: https://doc.rust-lang.org/nightly/std/convert/trait.From.html
8016 [rf]: https://github.com/rust-lang/rust/pull/24491
8017 [err-index]: https://doc.rust-lang.org/error-index.html
8018 [sk]: https://github.com/rust-lang/rust/pull/24615
8019 [pre]: https://github.com/rust-lang/rust/pull/25323
8020 [file]: https://github.com/rust-lang/rust/pull/24598
8021 [ch]: https://github.com/rust-lang/rust/pull/24683
8022 [arc]: https://github.com/rust-lang/rust/pull/24695
8023 [si]: https://github.com/rust-lang/rust/pull/24701
8024 [ap]: https://github.com/rust-lang/rust/pull/24834
8025 [m]: https://github.com/rust-lang/rust/pull/24777
8026 [fs]: https://github.com/rust-lang/rfcs/blob/master/text/1044-io-fs-2.1.md
8027 [crc]: https://github.com/rust-lang/cargo/pull/1568
8028 [pie]: https://github.com/rust-lang/rust/pull/24953
8029 [abs]: https://github.com/rust-lang/rust/pull/25441
8030 [c]: https://github.com/rust-lang/rust/pull/25496
8031 [`Cloned`]: https://doc.rust-lang.org/nightly/std/iter/struct.Cloned.html
8032 [`Incoming`]: https://doc.rust-lang.org/nightly/std/net/struct.Incoming.html
8033 [inc]: https://github.com/rust-lang/rust/pull/25522
8034 [bh]: https://github.com/rust-lang/rust/pull/25856
8035 [`BinaryHeap`]: https://doc.rust-lang.org/nightly/std/collections/struct.BinaryHeap.html
8036 [ll]: https://github.com/rust-lang/rust/pull/26022
8037 [`split_off`]: https://doc.rust-lang.org/nightly/collections/linked_list/struct.LinkedList.html#method.split_off
8038 [drop]: https://github.com/rust-lang/rust/pull/24935
8039
8040 Version 1.0.0 (2015-05-15)
8041 ========================
8042
8043 * ~1500 changes, numerous bugfixes
8044
8045 Highlights
8046 ----------
8047
8048 * The vast majority of the standard library is now `#[stable]`. It is
8049   no longer possible to use unstable features with a stable build of
8050   the compiler.
8051 * Many popular crates on [crates.io] now work on the stable release
8052   channel.
8053 * Arithmetic on basic integer types now [checks for overflow in debug
8054   builds][overflow].
8055
8056 Language
8057 --------
8058
8059 * Several [restrictions have been added to trait coherence][coh] in
8060   order to make it easier for upstream authors to change traits
8061   without breaking downstream code.
8062 * Digits of binary and octal literals are [lexed more eagerly][lex] to
8063   improve error messages and macro behavior. For example, `0b1234` is
8064   now lexed as `0b1234` instead of two tokens, `0b1` and `234`.
8065 * Trait bounds [are always invariant][inv], eliminating the need for
8066   the `PhantomFn` and `MarkerTrait` lang items, which have been
8067   removed.
8068 * ["-" is no longer a valid character in crate names][cr], the `extern crate
8069   "foo" as bar` syntax has been replaced with `extern crate foo as
8070   bar`, and Cargo now automatically translates "-" in *package* names
8071   to underscore for the crate name.
8072 * [Lifetime shadowing is an error][lt].
8073 * [`Send` no longer implies `'static`][send-rfc].
8074 * [UFCS now supports trait-less associated paths][moar-ufcs] like
8075   `MyType::default()`.
8076 * Primitive types [now have inherent methods][prim-inherent],
8077   obviating the need for extension traits like `SliceExt`.
8078 * Methods with `Self: Sized` in their `where` clause are [considered
8079   object-safe][self-sized], allowing many extension traits like
8080   `IteratorExt` to be merged into the traits they extended.
8081 * You can now [refer to associated types][assoc-where] whose
8082   corresponding trait bounds appear only in a `where` clause.
8083 * The final bits of [OIBIT landed][oibit-final], meaning that traits
8084   like `Send` and `Sync` are now library-defined.
8085 * A [Reflect trait][reflect] was introduced, which means that
8086   downcasting via the `Any` trait is effectively limited to concrete
8087   types. This helps retain the potentially-important "parametricity"
8088   property: generic code cannot behave differently for different type
8089   arguments except in minor ways.
8090 * The `unsafe_destructor` feature is now deprecated in favor of the
8091   [new `dropck`][dropck]. This change is a major reduction in unsafe
8092   code.
8093
8094 Libraries
8095 ---------
8096
8097 * The `thread_local` module [has been renamed to `std::thread`][th].
8098 * The methods of `IteratorExt` [have been moved to the `Iterator`
8099   trait itself][ie].
8100 * Several traits that implement Rust's conventions for type
8101   conversions, `AsMut`, `AsRef`, `From`, and `Into` have been
8102   [centralized in the `std::convert` module][con].
8103 * The `FromError` trait [was removed in favor of `From`][fe].
8104 * The basic sleep function [has moved to
8105   `std::thread::sleep_ms`][slp].
8106 * The `splitn` function now takes an `n` parameter that represents the
8107   number of items yielded by the returned iterator [instead of the
8108   number of 'splits'][spl].
8109 * [On Unix, all file descriptors are `CLOEXEC` by default][clo].
8110 * [Derived implementations of `PartialOrd` now order enums according
8111   to their explicitly-assigned discriminants][po].
8112 * [Methods for searching strings are generic over `Pattern`s][pat],
8113   implemented presently by `&char`, `&str`, `FnMut(char) -> bool` and
8114   some others.
8115 * [In method resolution, object methods are resolved before inherent
8116   methods][meth].
8117 * [`String::from_str` has been deprecated in favor of the `From` impl,
8118   `String::from`][sf].
8119 * [`io::Error` implements `Sync`][ios].
8120 * [The `words` method on `&str` has been replaced with
8121   `split_whitespace`][sw], to avoid answering the tricky question, 'what is
8122   a word?'
8123 * The new path and IO modules are complete and `#[stable]`. This
8124   was the major library focus for this cycle.
8125 * The path API was [revised][path-normalize] to normalize `.`,
8126   adjusting the tradeoffs in favor of the most common usage.
8127 * A large number of remaining APIs in `std` were also stabilized
8128   during this cycle; about 75% of the non-deprecated API surface
8129   is now stable.
8130 * The new [string pattern API][string-pattern] landed, which makes
8131   the string slice API much more internally consistent and flexible.
8132 * A new set of [generic conversion traits][conversion] replaced
8133   many existing ad hoc traits.
8134 * Generic numeric traits were [completely removed][num-traits]. This
8135   was made possible thanks to inherent methods for primitive types,
8136   and the removal gives maximal flexibility for designing a numeric
8137   hierarchy in the future.
8138 * The `Fn` traits are now related via [inheritance][fn-inherit]
8139   and provide ergonomic [blanket implementations][fn-blanket].
8140 * The `Index` and `IndexMut` traits were changed to
8141   [take the index by value][index-value], enabling code like
8142   `hash_map["string"]` to work.
8143 * `Copy` now [inherits][copy-clone] from `Clone`, meaning that all
8144   `Copy` data is known to be `Clone` as well.
8145
8146 Misc
8147 ----
8148
8149 * Many errors now have extended explanations that can be accessed with
8150   the `--explain` flag to `rustc`.
8151 * Many new examples have been added to the standard library
8152   documentation.
8153 * rustdoc has received a number of improvements focused on completion
8154   and polish.
8155 * Metadata was tuned, shrinking binaries [by 27%][metadata-shrink].
8156 * Much headway was made on ecosystem-wide CI, making it possible
8157   to [compare builds for breakage][ci-compare].
8158
8159
8160 [crates.io]: http://crates.io
8161 [clo]: https://github.com/rust-lang/rust/pull/24034
8162 [coh]: https://github.com/rust-lang/rfcs/blob/master/text/1023-rebalancing-coherence.md
8163 [con]: https://github.com/rust-lang/rust/pull/23875
8164 [cr]: https://github.com/rust-lang/rust/pull/23419
8165 [fe]: https://github.com/rust-lang/rust/pull/23879
8166 [ie]: https://github.com/rust-lang/rust/pull/23300
8167 [inv]: https://github.com/rust-lang/rust/pull/23938
8168 [ios]: https://github.com/rust-lang/rust/pull/24133
8169 [lex]: https://github.com/rust-lang/rfcs/blob/master/text/0879-small-base-lexing.md
8170 [lt]: https://github.com/rust-lang/rust/pull/24057
8171 [meth]: https://github.com/rust-lang/rust/pull/24056
8172 [pat]: https://github.com/rust-lang/rfcs/blob/master/text/0528-string-patterns.md
8173 [po]: https://github.com/rust-lang/rust/pull/24270
8174 [sf]: https://github.com/rust-lang/rust/pull/24517
8175 [slp]: https://github.com/rust-lang/rust/pull/23949
8176 [spl]: https://github.com/rust-lang/rfcs/blob/master/text/0979-align-splitn-with-other-languages.md
8177 [sw]: https://github.com/rust-lang/rfcs/blob/master/text/1054-str-words.md
8178 [th]: https://github.com/rust-lang/rfcs/blob/master/text/0909-move-thread-local-to-std-thread.md
8179 [send-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0458-send-improvements.md
8180 [moar-ufcs]: https://github.com/rust-lang/rust/pull/22172
8181 [prim-inherent]: https://github.com/rust-lang/rust/pull/23104
8182 [overflow]: https://github.com/rust-lang/rfcs/blob/master/text/0560-integer-overflow.md
8183 [metadata-shrink]: https://github.com/rust-lang/rust/pull/22971
8184 [self-sized]: https://github.com/rust-lang/rust/pull/22301
8185 [assoc-where]: https://github.com/rust-lang/rust/pull/22512
8186 [string-pattern]: https://github.com/rust-lang/rust/pull/22466
8187 [oibit-final]: https://github.com/rust-lang/rust/pull/21689
8188 [reflect]: https://github.com/rust-lang/rust/pull/23712
8189 [conversion]: https://github.com/rust-lang/rfcs/pull/529
8190 [num-traits]: https://github.com/rust-lang/rust/pull/23549
8191 [index-value]: https://github.com/rust-lang/rust/pull/23601
8192 [dropck]: https://github.com/rust-lang/rfcs/pull/769
8193 [ci-compare]: https://gist.github.com/brson/a30a77836fbec057cbee
8194 [fn-inherit]: https://github.com/rust-lang/rust/pull/23282
8195 [fn-blanket]: https://github.com/rust-lang/rust/pull/23895
8196 [copy-clone]: https://github.com/rust-lang/rust/pull/23860
8197 [path-normalize]: https://github.com/rust-lang/rust/pull/23229
8198
8199
8200 Version 1.0.0-alpha.2 (2015-02-20)
8201 =====================================
8202
8203 * ~1300 changes, numerous bugfixes
8204
8205 * Highlights
8206
8207     * The various I/O modules were [overhauled][io-rfc] to reduce
8208       unnecessary abstractions and provide better interoperation with
8209       the underlying platform. The old `io` module remains temporarily
8210       at `std::old_io`.
8211     * The standard library now [participates in feature gating][feat],
8212       so use of unstable libraries now requires a `#![feature(...)]`
8213       attribute. The impact of this change is [described on the
8214       forum][feat-forum]. [RFC][feat-rfc].
8215
8216 * Language
8217
8218     * `for` loops [now operate on the `IntoIterator` trait][into],
8219       which eliminates the need to call `.iter()`, etc. to iterate
8220       over collections. There are some new subtleties to remember
8221       though regarding what sort of iterators various types yield, in
8222       particular that `for foo in bar { }` yields values from a move
8223       iterator, destroying the original collection. [RFC][into-rfc].
8224     * Objects now have [default lifetime bounds][obj], so you don't
8225       have to write `Box<Trait+'static>` when you don't care about
8226       storing references. [RFC][obj-rfc].
8227     * In types that implement `Drop`, [lifetimes must outlive the
8228       value][drop]. This will soon make it possible to safely
8229       implement `Drop` for types where `#[unsafe_destructor]` is now
8230       required. Read the [gorgeous RFC][drop-rfc] for details.
8231     * The fully qualified <T as Trait>::X syntax lets you set the Self
8232       type for a trait method or associated type. [RFC][ufcs-rfc].
8233     * References to types that implement `Deref<U>` now [automatically
8234       coerce to references][deref] to the dereferenced type `U`,
8235       e.g. `&T where T: Deref<U>` automatically coerces to `&U`. This
8236       should eliminate many unsightly uses of `&*`, as when converting
8237       from references to vectors into references to
8238       slices. [RFC][deref-rfc].
8239     * The explicit [closure kind syntax][close] (`|&:|`, `|&mut:|`,
8240       `|:|`) is obsolete and closure kind is inferred from context.
8241     * [`Self` is a keyword][Self].
8242
8243 * Libraries
8244
8245     * The `Show` and `String` formatting traits [have been
8246       renamed][fmt] to `Debug` and `Display` to more clearly reflect
8247       their related purposes. Automatically getting a string
8248       conversion to use with `format!("{:?}", something_to_debug)` is
8249       now written `#[derive(Debug)]`.
8250     * Abstract [OS-specific string types][osstr], `std::ff::{OsString,
8251       OsStr}`, provide strings in platform-specific encodings for easier
8252       interop with system APIs. [RFC][osstr-rfc].
8253     * The `boxed::into_raw` and `Box::from_raw` functions [convert
8254       between `Box<T>` and `*mut T`][boxraw], a common pattern for
8255       creating raw pointers.
8256
8257 * Tooling
8258
8259     * Certain long error messages of the form 'expected foo found bar'
8260       are now [split neatly across multiple
8261       lines][multiline]. Examples in the PR.
8262     * On Unix Rust can be [uninstalled][un] by running
8263       `/usr/local/lib/rustlib/uninstall.sh`.
8264     * The `#[rustc_on_unimplemented]` attribute, requiring the
8265       'on_unimplemented' feature, lets rustc [display custom error
8266       messages when a trait is expected to be implemented for a type
8267       but is not][onun].
8268
8269 * Misc
8270
8271     * Rust is tested against a [LALR grammar][lalr], which parses
8272       almost all the Rust files that rustc does.
8273
8274 [boxraw]: https://github.com/rust-lang/rust/pull/21318
8275 [close]: https://github.com/rust-lang/rust/pull/21843
8276 [deref]: https://github.com/rust-lang/rust/pull/21351
8277 [deref-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0241-deref-conversions.md
8278 [drop]: https://github.com/rust-lang/rust/pull/21972
8279 [drop-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0769-sound-generic-drop.md
8280 [feat]: https://github.com/rust-lang/rust/pull/21248
8281 [feat-forum]: https://users.rust-lang.org/t/psa-important-info-about-rustcs-new-feature-staging/82/5
8282 [feat-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0507-release-channels.md
8283 [fmt]: https://github.com/rust-lang/rust/pull/21457
8284 [into]: https://github.com/rust-lang/rust/pull/20790
8285 [into-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0235-collections-conventions.md#intoiterator-and-iterable
8286 [io-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0517-io-os-reform.md
8287 [lalr]: https://github.com/rust-lang/rust/pull/21452
8288 [multiline]: https://github.com/rust-lang/rust/pull/19870
8289 [obj]: https://github.com/rust-lang/rust/pull/22230
8290 [obj-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0599-default-object-bound.md
8291 [onun]: https://github.com/rust-lang/rust/pull/20889
8292 [osstr]: https://github.com/rust-lang/rust/pull/21488
8293 [osstr-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0517-io-os-reform.md
8294 [Self]: https://github.com/rust-lang/rust/pull/22158
8295 [ufcs-rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0132-ufcs.md
8296 [un]: https://github.com/rust-lang/rust/pull/22256
8297
8298
8299 Version 1.0.0-alpha (2015-01-09)
8300 ==================================
8301
8302   * ~2400 changes, numerous bugfixes
8303
8304   * Highlights
8305
8306     * The language itself is considered feature complete for 1.0,
8307       though there will be many usability improvements and bugfixes
8308       before the final release.
8309     * Nearly 50% of the public API surface of the standard library has
8310       been declared 'stable'. Those interfaces are unlikely to change
8311       before 1.0.
8312     * The long-running debate over integer types has been
8313       [settled][ints]: Rust will ship with types named `isize` and
8314       `usize`, rather than `int` and `uint`, for pointer-sized
8315       integers. Guidelines will be rolled out during the alpha cycle.
8316     * Most crates that are not `std` have been moved out of the Rust
8317       distribution into the Cargo ecosystem so they can evolve
8318       separately and don't need to be stabilized as quickly, including
8319       'time', 'getopts', 'num', 'regex', and 'term'.
8320     * Documentation continues to be expanded with more API coverage, more
8321       examples, and more in-depth explanations. The guides have been
8322       consolidated into [The Rust Programming Language][trpl].
8323     * "[Rust By Example][rbe]" is now maintained by the Rust team.
8324     * All official Rust binary installers now come with [Cargo], the
8325       Rust package manager.
8326
8327 * Language
8328
8329     * Closures have been [completely redesigned][unboxed] to be
8330       implemented in terms of traits, can now be used as generic type
8331       bounds and thus monomorphized and inlined, or via an opaque
8332       pointer (boxed) as in the old system. The new system is often
8333       referred to as 'unboxed' closures.
8334     * Traits now support [associated types][assoc], allowing families
8335       of related types to be defined together and used generically in
8336       powerful ways.
8337     * Enum variants are [namespaced by their type names][enum].
8338     * [`where` clauses][where] provide a more versatile and attractive
8339       syntax for specifying generic bounds, though the previous syntax
8340       remains valid.
8341     * Rust again picks a [fallback][fb] (either i32 or f64) for uninferred
8342       numeric types.
8343     * Rust [no longer has a runtime][rt] of any description, and only
8344       supports OS threads, not green threads.
8345     * At long last, Rust has been overhauled for 'dynamically-sized
8346       types' ([DST]), which integrates 'fat pointers' (object types,
8347       arrays, and `str`) more deeply into the type system, making it
8348       more consistent.
8349     * Rust now has a general [range syntax][range], `i..j`, `i..`, and
8350       `..j` that produce range types and which, when combined with the
8351       `Index` operator and multidispatch, leads to a convenient slice
8352       notation, `[i..j]`.
8353     * The new range syntax revealed an ambiguity in the fixed-length
8354       array syntax, so now fixed length arrays [are written `[T;
8355       N]`][arrays].
8356     * The `Copy` trait is no longer implemented automatically. Unsafe
8357       pointers no longer implement `Sync` and `Send` so types
8358       containing them don't automatically either. `Sync` and `Send`
8359       are now 'unsafe traits' so one can "forcibly" implement them via
8360       `unsafe impl` if a type confirms to the requirements for them
8361       even though the internals do not (e.g. structs containing unsafe
8362       pointers like `Arc`). These changes are intended to prevent some
8363       footguns and are collectively known as [opt-in built-in
8364       traits][oibit] (though `Sync` and `Send` will soon become pure
8365       library types unknown to the compiler).
8366     * Operator traits now take their operands [by value][ops], and
8367       comparison traits can use multidispatch to compare one type
8368       against multiple other types, allowing e.g. `String` to be
8369       compared with `&str`.
8370     * `if let` and `while let` are no longer feature-gated.
8371     * Rust has adopted a more [uniform syntax for escaping unicode
8372       characters][unicode].
8373     * `macro_rules!` [has been declared stable][mac]. Though it is a
8374       flawed system it is sufficiently popular that it must be usable
8375       for 1.0. Effort has gone into [future-proofing][mac-future] it
8376       in ways that will allow other macro systems to be developed in
8377       parallel, and won't otherwise impact the evolution of the
8378       language.
8379     * The prelude has been [pared back significantly][prelude] such
8380       that it is the minimum necessary to support the most pervasive
8381       code patterns, and through [generalized where clauses][where]
8382       many of the prelude extension traits have been consolidated.
8383     * Rust's rudimentary reflection [has been removed][refl], as it
8384       incurred too much code generation for little benefit.
8385     * [Struct variants][structvars] are no longer feature-gated.
8386     * Trait bounds can be [polymorphic over lifetimes][hrtb]. Also
8387       known as 'higher-ranked trait bounds', this crucially allows
8388       unboxed closures to work.
8389     * Macros invocations surrounded by parens or square brackets and
8390       not terminated by a semicolon are [parsed as
8391       expressions][macros], which makes expressions like `vec![1i32,
8392       2, 3].len()` work as expected.
8393     * Trait objects now implement their traits automatically, and
8394       traits that can be coerced to objects now must be [object
8395       safe][objsafe].
8396     * Automatically deriving traits is now done with `#[derive(...)]`
8397       not `#[deriving(...)]` for [consistency with other naming
8398       conventions][derive].
8399     * Importing the containing module or enum at the same time as
8400       items or variants they contain is [now done with `self` instead
8401       of `mod`][self], as in use `foo::{self, bar}`
8402     * Glob imports are no longer feature-gated.
8403     * The `box` operator and `box` patterns have been feature-gated
8404       pending a redesign. For now unique boxes should be allocated
8405       like other containers, with `Box::new`.
8406
8407 * Libraries
8408
8409     * A [series][coll1] of [efforts][coll2] to establish
8410       [conventions][coll3] for collections types has resulted in API
8411       improvements throughout the standard library.
8412     * New [APIs for error handling][err] provide ergonomic interop
8413       between error types, and [new conventions][err-conv] describe
8414       more clearly the recommended error handling strategies in Rust.
8415     * The `fail!` macro has been renamed to [`panic!`][panic] so that
8416       it is easier to discuss failure in the context of error handling
8417       without making clarifications as to whether you are referring to
8418       the 'fail' macro or failure more generally.
8419     * On Linux, `OsRng` prefers the new, more reliable `getrandom`
8420       syscall when available.
8421     * The 'serialize' crate has been renamed 'rustc-serialize' and
8422       moved out of the distribution to Cargo. Although it is widely
8423       used now, it is expected to be superseded in the near future.
8424     * The `Show` formatter, typically implemented with
8425       `#[derive(Show)]` is [now requested with the `{:?}`
8426       specifier][show] and is intended for use by all types, for uses
8427       such as `println!` debugging. The new `String` formatter must be
8428       implemented by hand, uses the `{}` specifier, and is intended
8429       for full-fidelity conversions of things that can logically be
8430       represented as strings.
8431
8432 * Tooling
8433
8434     * [Flexible target specification][flex] allows rustc's code
8435       generation to be configured to support otherwise-unsupported
8436       platforms.
8437     * Rust comes with rust-gdb and rust-lldb scripts that launch their
8438       respective debuggers with Rust-appropriate pretty-printing.
8439     * The Windows installation of Rust is distributed with the
8440       MinGW components currently required to link binaries on that
8441       platform.
8442
8443 * Misc
8444
8445     * Nullable enum optimizations have been extended to more types so
8446       that e.g. `Option<Vec<T>>` and `Option<String>` take up no more
8447       space than the inner types themselves.
8448     * Work has begun on supporting AArch64.
8449
8450 [Cargo]: https://crates.io
8451 [unboxed]: http://smallcultfollowing.com/babysteps/blog/2014/11/26/purging-proc/
8452 [enum]: https://github.com/rust-lang/rfcs/blob/master/text/0390-enum-namespacing.md
8453 [flex]: https://github.com/rust-lang/rfcs/blob/master/text/0131-target-specification.md
8454 [err]: https://github.com/rust-lang/rfcs/blob/master/text/0201-error-chaining.md
8455 [err-conv]: https://github.com/rust-lang/rfcs/blob/master/text/0236-error-conventions.md
8456 [rt]: https://github.com/rust-lang/rfcs/blob/master/text/0230-remove-runtime.md
8457 [mac]: https://github.com/rust-lang/rfcs/blob/master/text/0453-macro-reform.md
8458 [mac-future]: https://github.com/rust-lang/rfcs/pull/550
8459 [DST]: http://smallcultfollowing.com/babysteps/blog/2014/01/05/dst-take-5/
8460 [coll1]: https://github.com/rust-lang/rfcs/blob/master/text/0235-collections-conventions.md
8461 [coll2]: https://github.com/rust-lang/rfcs/blob/master/text/0509-collections-reform-part-2.md
8462 [coll3]: https://github.com/rust-lang/rfcs/blob/master/text/0216-collection-views.md
8463 [ops]: https://github.com/rust-lang/rfcs/blob/master/text/0439-cmp-ops-reform.md
8464 [prelude]: https://github.com/rust-lang/rfcs/blob/master/text/0503-prelude-stabilization.md
8465 [where]: https://github.com/rust-lang/rfcs/blob/master/text/0135-where.md
8466 [refl]: https://github.com/rust-lang/rfcs/blob/master/text/0379-remove-reflection.md
8467 [panic]: https://github.com/rust-lang/rfcs/blob/master/text/0221-panic.md
8468 [structvars]: https://github.com/rust-lang/rfcs/blob/master/text/0418-struct-variants.md
8469 [hrtb]: https://github.com/rust-lang/rfcs/blob/master/text/0387-higher-ranked-trait-bounds.md
8470 [unicode]: https://github.com/rust-lang/rfcs/blob/master/text/0446-es6-unicode-escapes.md
8471 [oibit]: https://github.com/rust-lang/rfcs/blob/master/text/0019-opt-in-builtin-traits.md
8472 [macros]: https://github.com/rust-lang/rfcs/blob/master/text/0378-expr-macros.md
8473 [range]: https://github.com/rust-lang/rfcs/blob/master/text/0439-cmp-ops-reform.md#indexing-and-slicing
8474 [arrays]: https://github.com/rust-lang/rfcs/blob/master/text/0520-new-array-repeat-syntax.md
8475 [show]: https://github.com/rust-lang/rfcs/blob/master/text/0504-show-stabilization.md
8476 [derive]: https://github.com/rust-lang/rfcs/blob/master/text/0534-deriving2derive.md
8477 [self]: https://github.com/rust-lang/rfcs/blob/master/text/0532-self-in-use.md
8478 [fb]: https://github.com/rust-lang/rfcs/blob/master/text/0212-restore-int-fallback.md
8479 [objsafe]: https://github.com/rust-lang/rfcs/blob/master/text/0255-object-safety.md
8480 [assoc]: https://github.com/rust-lang/rfcs/blob/master/text/0195-associated-items.md
8481 [ints]: https://github.com/rust-lang/rfcs/pull/544#issuecomment-68760871
8482 [trpl]: https://doc.rust-lang.org/book/index.html
8483 [rbe]: http://rustbyexample.com/
8484
8485
8486 Version 0.12.0 (2014-10-09)
8487 =============================
8488
8489   * ~1900 changes, numerous bugfixes
8490
8491   * Highlights
8492
8493     * The introductory documentation (now called The Rust Guide) has
8494       been completely rewritten, as have a number of supplementary
8495       guides.
8496     * Rust's package manager, Cargo, continues to improve and is
8497       sometimes considered to be quite awesome.
8498     * Many API's in `std` have been reviewed and updated for
8499       consistency with the in-development Rust coding
8500       guidelines. The standard library documentation tracks
8501       stabilization progress.
8502     * Minor libraries have been moved out-of-tree to the rust-lang org
8503       on GitHub: uuid, semver, glob, num, hexfloat, fourcc. They can
8504       be installed with Cargo.
8505     * Lifetime elision allows lifetime annotations to be left off of
8506       function declarations in many common scenarios.
8507     * Rust now works on 64-bit Windows.
8508
8509   * Language
8510     * Indexing can be overloaded with the `Index` and `IndexMut`
8511       traits.
8512     * The `if let` construct takes a branch only if the `let` pattern
8513       matches, currently behind the 'if_let' feature gate.
8514     * 'where clauses', a more flexible syntax for specifying trait
8515       bounds that is more aesthetic, have been added for traits and
8516       free functions. Where clauses will in the future make it
8517       possible to constrain associated types, which would be
8518       impossible with the existing syntax.
8519     * A new slicing syntax (e.g. `[0..4]`) has been introduced behind
8520       the 'slicing_syntax' feature gate, and can be overloaded with
8521       the `Slice` or `SliceMut` traits.
8522     * The syntax for matching of sub-slices has been changed to use a
8523       postfix `..` instead of prefix (.e.g. `[a, b, c..]`), for
8524       consistency with other uses of `..` and to future-proof
8525       potential additional uses of the syntax.
8526     * The syntax for matching inclusive ranges in patterns has changed
8527       from `0..3` to `0...4` to be consistent with the exclusive range
8528       syntax for slicing.
8529     * Matching of sub-slices in non-tail positions (e.g.  `[a.., b,
8530       c]`) has been put behind the 'advanced_slice_patterns' feature
8531       gate and may be removed in the future.
8532     * Components of tuples and tuple structs can be extracted using
8533       the `value.0` syntax, currently behind the `tuple_indexing`
8534       feature gate.
8535     * The `#[crate_id]` attribute is no longer supported; versioning
8536       is handled by the package manager.
8537     * Renaming crate imports are now written `extern crate foo as bar`
8538       instead of `extern crate bar = foo`.
8539     * Renaming use statements are now written `use foo as bar` instead
8540       of `use bar = foo`.
8541     * `let` and `match` bindings and argument names in macros are now
8542       hygienic.
8543     * The new, more efficient, closure types ('unboxed closures') have
8544       been added under a feature gate, 'unboxed_closures'. These will
8545       soon replace the existing closure types, once higher-ranked
8546       trait lifetimes are added to the language.
8547     * `move` has been added as a keyword, for indicating closures
8548       that capture by value.
8549     * Mutation and assignment is no longer allowed in pattern guards.
8550     * Generic structs and enums can now have trait bounds.
8551     * The `Share` trait is now called `Sync` to free up the term
8552       'shared' to refer to 'shared reference' (the default reference
8553       type.
8554     * Dynamically-sized types have been mostly implemented,
8555       unifying the behavior of fat-pointer types with the rest of the
8556       type system.
8557     * As part of dynamically-sized types, the `Sized` trait has been
8558       introduced, which qualifying types implement by default, and
8559       which type parameters expect by default. To specify that a type
8560       parameter does not need to be sized, write `<Sized? T>`. Most
8561       types are `Sized`, notable exceptions being unsized arrays
8562       (`[T]`) and trait types.
8563     * Closures can return `!`, as in `|| -> !` or `proc() -> !`.
8564     * Lifetime bounds can now be applied to type parameters and object
8565       types.
8566     * The old, reference counted GC type, `Gc<T>` which was once
8567       denoted by the `@` sigil, has finally been removed. GC will be
8568       revisited in the future.
8569
8570   * Libraries
8571     * Library documentation has been improved for a number of modules.
8572     * Bit-vectors, collections::bitv has been modernized.
8573     * The url crate is deprecated in favor of
8574       http://github.com/servo/rust-url, which can be installed with
8575       Cargo.
8576     * Most I/O stream types can be cloned and subsequently closed from
8577       a different thread.
8578     * A `std::time::Duration` type has been added for use in I/O
8579       methods that rely on timers, as well as in the 'time' crate's
8580       `Timespec` arithmetic.
8581     * The runtime I/O abstraction layer that enabled the green thread
8582       scheduler to do non-thread-blocking I/O has been removed, along
8583       with the libuv-based implementation employed by the green thread
8584       scheduler. This will greatly simplify the future I/O work.
8585     * `collections::btree` has been rewritten to have a more
8586       idiomatic and efficient design.
8587
8588   * Tooling
8589     * rustdoc output now indicates the stability levels of API's.
8590     * The `--crate-name` flag can specify the name of the crate
8591       being compiled, like `#[crate_name]`.
8592     * The `-C metadata` specifies additional metadata to hash into
8593       symbol names, and `-C extra-filename` specifies additional
8594       information to put into the output filename, for use by the
8595       package manager for versioning.
8596     * debug info generation has continued to improve and should be
8597       more reliable under both gdb and lldb.
8598     * rustc has experimental support for compiling in parallel
8599       using the `-C codegen-units` flag.
8600     * rustc no longer encodes rpath information into binaries by
8601       default.
8602
8603   * Misc
8604     * Stack usage has been optimized with LLVM lifetime annotations.
8605     * Official Rust binaries on Linux are more compatible with older
8606       kernels and distributions, built on CentOS 5.10.
8607
8608
8609 Version 0.11.0 (2014-07-02)
8610 ==========================
8611
8612   * ~1700 changes, numerous bugfixes
8613
8614   * Language
8615     * ~[T] has been removed from the language. This type is superseded by
8616       the Vec<T> type.
8617     * ~str has been removed from the language. This type is superseded by
8618       the String type.
8619     * ~T has been removed from the language. This type is superseded by the
8620       Box<T> type.
8621     * @T has been removed from the language. This type is superseded by the
8622       standard library's std::gc::Gc<T> type.
8623     * Struct fields are now all private by default.
8624     * Vector indices and shift amounts are both required to be a `uint`
8625       instead of any integral type.
8626     * Byte character, byte string, and raw byte string literals are now all
8627       supported by prefixing the normal literal with a `b`.
8628     * Multiple ABIs are no longer allowed in an ABI string
8629     * The syntax for lifetimes on closures/procedures has been tweaked
8630       slightly: `<'a>|A, B|: 'b + K -> T`
8631     * Floating point modulus has been removed from the language; however it
8632       is still provided by a library implementation.
8633     * Private enum variants are now disallowed.
8634     * The `priv` keyword has been removed from the language.
8635     * A closure can no longer be invoked through a &-pointer.
8636     * The `use foo, bar, baz;` syntax has been removed from the language.
8637     * The transmute intrinsic no longer works on type parameters.
8638     * Statics now allow blocks/items in their definition.
8639     * Trait bounds are separated from objects with + instead of : now.
8640     * Objects can no longer be read while they are mutably borrowed.
8641     * The address of a static is now marked as insignificant unless the
8642       #[inline(never)] attribute is placed it.
8643     * The #[unsafe_destructor] attribute is now behind a feature gate.
8644     * Struct literals are no longer allowed in ambiguous positions such as
8645       if, while, match, and for..in.
8646     * Declaration of lang items and intrinsics are now feature-gated by
8647       default.
8648     * Integral literals no longer default to `int`, and floating point
8649       literals no longer default to `f64`. Literals must be suffixed with an
8650       appropriate type if inference cannot determine the type of the
8651       literal.
8652     * The Box<T> type is no longer implicitly borrowed to &mut T.
8653     * Procedures are now required to not capture borrowed references.
8654
8655   * Libraries
8656     * The standard library is now a "facade" over a number of underlying
8657       libraries. This means that development on the standard library should
8658       be speedier due to smaller crates, as well as a clearer line between
8659       all dependencies.
8660     * A new library, libcore, lives under the standard library's facade
8661       which is Rust's "0-assumption" library, suitable for embedded and
8662       kernel development for example.
8663     * A regex crate has been added to the standard distribution. This crate
8664       includes statically compiled regular expressions.
8665     * The unwrap/unwrap_err methods on Result require a Show bound for
8666       better error messages.
8667     * The return types of the std::comm primitives have been centralized
8668       around the Result type.
8669     * A number of I/O primitives have gained the ability to time out their
8670       operations.
8671     * A number of I/O primitives have gained the ability to close their
8672       reading/writing halves to cancel pending operations.
8673     * Reverse iterator methods have been removed in favor of `rev()` on
8674       their forward-iteration counterparts.
8675     * A bitflags! macro has been added to enable easy interop with C and
8676       management of bit flags.
8677     * A debug_assert! macro is now provided which is disabled when
8678       `--cfg ndebug` is passed to the compiler.
8679     * A graphviz crate has been added for creating .dot files.
8680     * The std::cast module has been migrated into std::mem.
8681     * The std::local_data api has been migrated from freestanding functions
8682       to being based on methods.
8683     * The Pod trait has been renamed to Copy.
8684     * jemalloc has been added as the default allocator for types.
8685     * The API for allocating memory has been changed to use proper alignment
8686       and sized deallocation
8687     * Connecting a TcpStream or binding a TcpListener is now based on a
8688       string address and a u16 port. This allows connecting to a hostname as
8689       opposed to an IP.
8690     * The Reader trait now contains a core method, read_at_least(), which
8691       correctly handles many repeated 0-length reads.
8692     * The process-spawning API is now centered around a builder-style
8693       Command struct.
8694     * The :? printing qualifier has been moved from the standard library to
8695       an external libdebug crate.
8696     * Eq/Ord have been renamed to PartialEq/PartialOrd. TotalEq/TotalOrd
8697       have been renamed to Eq/Ord.
8698     * The select/plural methods have been removed from format!. The escapes
8699       for { and } have also changed from \{ and \} to {{ and }},
8700       respectively.
8701     * The TaskBuilder API has been re-worked to be a true builder, and
8702       extension traits for spawning native/green tasks have been added.
8703
8704   * Tooling
8705     * All breaking changes to the language or libraries now have their
8706       commit message annotated with `[breaking-change]` to allow for easy
8707       discovery of breaking changes.
8708     * The compiler will now try to suggest how to annotate lifetimes if a
8709       lifetime-related error occurs.
8710     * Debug info continues to be improved greatly with general bug fixes and
8711       better support for situations like link time optimization (LTO).
8712     * Usage of syntax extensions when cross-compiling has been fixed.
8713     * Functionality equivalent to GCC & Clang's -ffunction-sections,
8714       -fdata-sections and --gc-sections has been enabled by default
8715     * The compiler is now stricter about where it will load module files
8716       from when a module is declared via `mod foo;`.
8717     * The #[phase(syntax)] attribute has been renamed to #[phase(plugin)].
8718       Syntax extensions are now discovered via a "plugin registrar" type
8719       which will be extended in the future to other various plugins.
8720     * Lints have been restructured to allow for dynamically loadable lints.
8721     * A number of rustdoc improvements:
8722       * The HTML output has been visually redesigned.
8723       * Markdown is now powered by hoedown instead of sundown.
8724       * Searching heuristics have been greatly improved.
8725       * The search index has been reduced in size by a great amount.
8726       * Cross-crate documentation via `pub use` has been greatly improved.
8727       * Primitive types are now hyperlinked and documented.
8728     * Documentation has been moved from static.rust-lang.org/doc to
8729       doc.rust-lang.org
8730     * A new sandbox, play.rust-lang.org, is available for running and
8731       sharing rust code examples on-line.
8732     * Unused attributes are now more robustly warned about.
8733     * The dead_code lint now warns about unused struct fields.
8734     * Cross-compiling to iOS is now supported.
8735     * Cross-compiling to mipsel is now supported.
8736     * Stability attributes are now inherited by default and no longer apply
8737       to intra-crate usage, only inter-crate usage.
8738     * Error message related to non-exhaustive match expressions have been
8739       greatly improved.
8740
8741
8742 Version 0.10 (2014-04-03)
8743 =========================
8744
8745   * ~1500 changes, numerous bugfixes
8746
8747   * Language
8748     * A new RFC process is now in place for modifying the language.
8749     * Patterns with `@`-pointers have been removed from the language.
8750     * Patterns with unique vectors (`~[T]`) have been removed from the
8751       language.
8752     * Patterns with unique strings (`~str`) have been removed from the
8753       language.
8754     * `@str` has been removed from the language.
8755     * `@[T]` has been removed from the language.
8756     * `@self` has been removed from the language.
8757     * `@Trait` has been removed from the language.
8758     * Headers on `~` allocations which contain `@` boxes inside the type for
8759       reference counting have been removed.
8760     * The semantics around the lifetimes of temporary expressions have changed,
8761       see #3511 and #11585 for more information.
8762     * Cross-crate syntax extensions are now possible, but feature gated. See
8763       #11151 for more information. This includes both `macro_rules!` macros as
8764       well as syntax extensions such as `format!`.
8765     * New lint modes have been added, and older ones have been turned on to be
8766       warn-by-default.
8767       * Unnecessary parentheses
8768       * Uppercase statics
8769       * Camel Case types
8770       * Uppercase variables
8771       * Publicly visible private types
8772       * `#[deriving]` with raw pointers
8773     * Unsafe functions can no longer be coerced to closures.
8774     * Various obscure macros such as `log_syntax!` are now behind feature gates.
8775     * The `#[simd]` attribute is now behind a feature gate.
8776     * Visibility is no longer allowed on `extern crate` statements, and
8777       unnecessary visibility (`priv`) is no longer allowed on `use` statements.
8778     * Trailing commas are now allowed in argument lists and tuple patterns.
8779     * The `do` keyword has been removed, it is now a reserved keyword.
8780     * Default type parameters have been implemented, but are feature gated.
8781     * Borrowed variables through captures in closures are now considered soundly.
8782     * `extern mod` is now `extern crate`
8783     * The `Freeze` trait has been removed.
8784     * The `Share` trait has been added for types that can be shared among
8785       threads.
8786     * Labels in macros are now hygienic.
8787     * Expression/statement macro invocations can be delimited with `{}` now.
8788     * Treatment of types allowed in `static mut` locations has been tweaked.
8789     * The `*` and `.` operators are now overloadable through the `Deref` and
8790       `DerefMut` traits.
8791     * `~Trait` and `proc` no longer have `Send` bounds by default.
8792     * Partial type hints are now supported with the `_` type marker.
8793     * An `Unsafe` type was introduced for interior mutability. It is now
8794       considered undefined to transmute from `&T` to `&mut T` without using the
8795       `Unsafe` type.
8796     * The #[linkage] attribute was implemented for extern statics/functions.
8797     * The inner attribute syntax has changed from `#[foo];` to `#![foo]`.
8798     * `Pod` was renamed to `Copy`.
8799
8800   * Libraries
8801     * The `libextra` library has been removed. It has now been decomposed into
8802       component libraries with smaller and more focused nuggets of
8803       functionality. The full list of libraries can be found on the
8804       documentation index page.
8805     * std: `std::condition` has been removed. All I/O errors are now propagated
8806       through the `Result` type. In order to assist with error handling, a
8807       `try!` macro for unwrapping errors with an early return and a lint for
8808       unused results has been added. See #12039 for more information.
8809     * std: The `vec` module has been renamed to `slice`.
8810     * std: A new vector type, `Vec<T>`, has been added in preparation for DST.
8811       This will become the only growable vector in the future.
8812     * std: `std::io` now has more public re-exports. Types such as `BufferedReader`
8813       are now found at `std::io::BufferedReader` instead of
8814       `std::io::buffered::BufferedReader`.
8815     * std: `print` and `println` are no longer in the prelude, the `print!` and
8816       `println!` macros are intended to be used instead.
8817     * std: `Rc` now has a `Weak` pointer for breaking cycles, and it no longer
8818       attempts to statically prevent cycles.
8819     * std: The standard distribution is adopting the policy of pushing failure
8820       to the user rather than failing in libraries. Many functions (such as
8821       `slice::last()`) now return `Option<T>` instead of `T` + failing.
8822     * std: `fmt::Default` has been renamed to `fmt::Show`, and it now has a new
8823       deriving mode: `#[deriving(Show)]`.
8824     * std: `ToStr` is now implemented for all types implementing `Show`.
8825     * std: The formatting trait methods now take `&self` instead of `&T`
8826     * std: The `invert()` method on iterators has been renamed to `rev()`
8827     * std: `std::num` has seen a reduction in the genericity of its traits,
8828       consolidating functionality into a few core traits.
8829     * std: Backtraces are now printed on task failure if the environment
8830       variable `RUST_BACKTRACE` is present.
8831     * std: Naming conventions for iterators have been standardized. More details
8832       can be found on the wiki's style guide.
8833     * std: `eof()` has been removed from the `Reader` trait. Specific types may
8834       still implement the function.
8835     * std: Networking types are now cloneable to allow simultaneous reads/writes.
8836     * std: `assert_approx_eq!` has been removed
8837     * std: The `e` and `E` formatting specifiers for floats have been added to
8838       print them in exponential notation.
8839     * std: The `Times` trait has been removed
8840     * std: Indications of variance and opting out of builtin bounds is done
8841       through marker types in `std::kinds::marker` now
8842     * std: `hash` has been rewritten, `IterBytes` has been removed, and
8843       `#[deriving(Hash)]` is now possible.
8844     * std: `SharedChan` has been removed, `Sender` is now cloneable.
8845     * std: `Chan` and `Port` were renamed to `Sender` and `Receiver`.
8846     * std: `Chan::new` is now `channel()`.
8847     * std: A new synchronous channel type has been implemented.
8848     * std: A `select!` macro is now provided for selecting over `Receiver`s.
8849     * std: `hashmap` and `trie` have been moved to `libcollections`
8850     * std: `run` has been rolled into `io::process`
8851     * std: `assert_eq!` now uses `{}` instead of `{:?}`
8852     * std: The equality and comparison traits have seen some reorganization.
8853     * std: `rand` has moved to `librand`.
8854     * std: `to_{lower,upper}case` has been implemented for `char`.
8855     * std: Logging has been moved to `liblog`.
8856     * collections: `HashMap` has been rewritten for higher performance and less
8857       memory usage.
8858     * native: The default runtime is now `libnative`. If `libgreen` is desired,
8859       it can be booted manually. The runtime guide has more information and
8860       examples.
8861     * native: All I/O functionality except signals has been implemented.
8862     * green: Task spawning with `libgreen` has been optimized with stack caching
8863       and various trimming of code.
8864     * green: Tasks spawned by `libgreen` now have an unmapped guard page.
8865     * sync: The `extra::sync` module has been updated to modern rust (and moved
8866       to the `sync` library), tweaking and improving various interfaces while
8867       dropping redundant functionality.
8868     * sync: A new `Barrier` type has been added to the `sync` library.
8869     * sync: An efficient mutex for native and green tasks has been implemented.
8870     * serialize: The `base64` module has seen some improvement. It treats
8871       newlines better, has non-string error values, and has seen general
8872       cleanup.
8873     * fourcc: A `fourcc!` macro was introduced
8874     * hexfloat: A `hexfloat!` macro was implemented for specifying floats via a
8875       hexadecimal literal.
8876
8877   * Tooling
8878     * `rustpkg` has been deprecated and removed from the main repository. Its
8879       replacement, `cargo`, is under development.
8880     * Nightly builds of rust are now available
8881     * The memory usage of rustc has been improved many times throughout this
8882       release cycle.
8883     * The build process supports disabling rpath support for the rustc binary
8884       itself.
8885     * Code generation has improved in some cases, giving more information to the
8886       LLVM optimization passes to enable more extensive optimizations.
8887     * Debuginfo compatibility with lldb on OSX has been restored.
8888     * The master branch is now gated on an android bot, making building for
8889       android much more reliable.
8890     * Output flags have been centralized into one `--emit` flag.
8891     * Crate type flags have been centralized into one `--crate-type` flag.
8892     * Codegen flags have been consolidated behind a `-C` flag.
8893     * Linking against outdated crates now has improved error messages.
8894     * Error messages with lifetimes will often suggest how to annotate the
8895       function to fix the error.
8896     * Many more types are documented in the standard library, and new guides
8897       were written.
8898     * Many `rustdoc` improvements:
8899       * code blocks are syntax highlighted.
8900       * render standalone markdown files.
8901       * the --test flag tests all code blocks by default.
8902       * exported macros are displayed.
8903       * re-exported types have their documentation inlined at the location of the
8904         first re-export.
8905       * search works across crates that have been rendered to the same output
8906         directory.
8907
8908
8909 Version 0.9 (2014-01-09)
8910 ==========================
8911
8912    * ~1800 changes, numerous bugfixes
8913
8914    * Language
8915       * The `float` type has been removed. Use `f32` or `f64` instead.
8916       * A new facility for enabling experimental features (feature gating) has
8917         been added, using the crate-level `#[feature(foo)]` attribute.
8918       * Managed boxes (@) are now behind a feature gate
8919         (`#[feature(managed_boxes)]`) in preparation for future removal. Use the
8920         standard library's `Gc` or `Rc` types instead.
8921       * `@mut` has been removed. Use `std::cell::{Cell, RefCell}` instead.
8922       * Jumping back to the top of a loop is now done with `continue` instead of
8923         `loop`.
8924       * Strings can no longer be mutated through index assignment.
8925       * Raw strings can be created via the basic `r"foo"` syntax or with matched
8926         hash delimiters, as in `r###"foo"###`.
8927       * `~fn` is now written `proc (args) -> retval { ... }` and may only be
8928         called once.
8929       * The `&fn` type is now written `|args| -> ret` to match the literal form.
8930       * `@fn`s have been removed.
8931       * `do` only works with procs in order to make it obvious what the cost
8932         of `do` is.
8933       * Single-element tuple-like structs can no longer be dereferenced to
8934         obtain the inner value. A more comprehensive solution for overloading
8935         the dereference operator will be provided in the future.
8936       * The `#[link(...)]` attribute has been replaced with
8937         `#[crate_id = "name#vers"]`.
8938       * Empty `impl`s must be terminated with empty braces and may not be
8939         terminated with a semicolon.
8940       * Keywords are no longer allowed as lifetime names; the `self` lifetime
8941         no longer has any special meaning.
8942       * The old `fmt!` string formatting macro has been removed.
8943       * `printf!` and `printfln!` (old-style formatting) removed in favor of
8944         `print!` and `println!`.
8945       * `mut` works in patterns now, as in `let (mut x, y) = (1, 2);`.
8946       * The `extern mod foo (name = "bar")` syntax has been removed. Use
8947         `extern mod foo = "bar"` instead.
8948       * New reserved keywords: `alignof`, `offsetof`, `sizeof`.
8949       * Macros can have attributes.
8950       * Macros can expand to items with attributes.
8951       * Macros can expand to multiple items.
8952       * The `asm!` macro is feature-gated (`#[feature(asm)]`).
8953       * Comments may be nested.
8954       * Values automatically coerce to trait objects they implement, without
8955         an explicit `as`.
8956       * Enum discriminants are no longer an entire word but as small as needed to
8957         contain all the variants. The `repr` attribute can be used to override
8958         the discriminant size, as in `#[repr(int)]` for integer-sized, and
8959         `#[repr(C)]` to match C enums.
8960       * Non-string literals are not allowed in attributes (they never worked).
8961       * The FFI now supports variadic functions.
8962       * Octal numeric literals, as in `0o7777`.
8963       * The `concat!` syntax extension performs compile-time string concatenation.
8964       * The `#[fixed_stack_segment]` and `#[rust_stack]` attributes have been
8965         removed as Rust no longer uses segmented stacks.
8966       * Non-ascii identifiers are feature-gated (`#[feature(non_ascii_idents)]`).
8967       * Ignoring all fields of an enum variant or tuple-struct is done with `..`,
8968         not `*`; ignoring remaining fields of a struct is also done with `..`,
8969         not `_`; ignoring a slice of a vector is done with `..`, not `.._`.
8970       * `rustc` supports the "win64" calling convention via `extern "win64"`.
8971       * `rustc` supports the "system" calling convention, which defaults to the
8972         preferred convention for the target platform, "stdcall" on 32-bit Windows,
8973         "C" elsewhere.
8974       * The `type_overflow` lint (default: warn) checks literals for overflow.
8975       * The `unsafe_block` lint (default: allow) checks for usage of `unsafe`.
8976       * The `attribute_usage` lint (default: warn) warns about unknown
8977         attributes.
8978       * The `unknown_features` lint (default: warn) warns about unknown
8979         feature gates.
8980       * The `dead_code` lint (default: warn) checks for dead code.
8981       * Rust libraries can be linked statically to one another
8982       * `#[link_args]` is behind the `link_args` feature gate.
8983       * Native libraries are now linked with `#[link(name = "foo")]`
8984       * Native libraries can be statically linked to a rust crate
8985         (`#[link(name = "foo", kind = "static")]`).
8986       * Native OS X frameworks are now officially supported
8987         (`#[link(name = "foo", kind = "framework")]`).
8988       * The `#[thread_local]` attribute creates thread-local (not task-local)
8989         variables. Currently behind the `thread_local` feature gate.
8990       * The `return` keyword may be used in closures.
8991       * Types that can be copied via a memcpy implement the `Pod` kind.
8992       * The `cfg` attribute can now be used on struct fields and enum variants.
8993
8994    * Libraries
8995       * std: The `option` and `result` API's have been overhauled to make them
8996         simpler, more consistent, and more composable.
8997       * std: The entire `std::io` module has been replaced with one that is
8998         more comprehensive and that properly interfaces with the underlying
8999         scheduler. File, TCP, UDP, Unix sockets, pipes, and timers are all
9000         implemented.
9001       * std: `io::util` contains a number of useful implementations of
9002         `Reader` and `Writer`, including `NullReader`, `NullWriter`,
9003         `ZeroReader`, `TeeReader`.
9004       * std: The reference counted pointer type `extra::rc` moved into std.
9005       * std: The `Gc` type in the `gc` module will replace `@` (it is currently
9006         just a wrapper around it).
9007       * std: The `Either` type has been removed.
9008       * std: `fmt::Default` can be implemented for any type to provide default
9009         formatting to the `format!` macro, as in `format!("{}", myfoo)`.
9010       * std: The `rand` API continues to be tweaked.
9011       * std: The `rust_begin_unwind` function, useful for inserting breakpoints
9012         on failure in gdb, is now named `rust_fail`.
9013       * std: The `each_key` and `each_value` methods on `HashMap` have been
9014         replaced by the `keys` and `values` iterators.
9015       * std: Functions dealing with type size and alignment have moved from the
9016         `sys` module to the `mem` module.
9017       * std: The `path` module was written and API changed.
9018       * std: `str::from_utf8` has been changed to cast instead of allocate.
9019       * std: `starts_with` and `ends_with` methods added to vectors via the
9020         `ImmutableEqVector` trait, which is in the prelude.
9021       * std: Vectors can be indexed with the `get_opt` method, which returns `None`
9022         if the index is out of bounds.
9023       * std: Task failure no longer propagates between tasks, as the model was
9024         complex, expensive, and incompatible with thread-based tasks.
9025       * std: The `Any` type can be used for dynamic typing.
9026       * std: `~Any` can be passed to the `fail!` macro and retrieved via
9027         `task::try`.
9028       * std: Methods that produce iterators generally do not have an `_iter`
9029         suffix now.
9030       * std: `cell::Cell` and `cell::RefCell` can be used to introduce mutability
9031         roots (mutable fields, etc.). Use instead of e.g. `@mut`.
9032       * std: `util::ignore` renamed to `prelude::drop`.
9033       * std: Slices have `sort` and `sort_by` methods via the `MutableVector`
9034         trait.
9035       * std: `vec::raw` has seen a lot of cleanup and API changes.
9036       * std: The standard library no longer includes any C++ code, and very
9037         minimal C, eliminating the dependency on libstdc++.
9038       * std: Runtime scheduling and I/O functionality has been factored out into
9039         extensible interfaces and is now implemented by two different crates:
9040         libnative, for native threading and I/O; and libgreen, for green threading
9041         and I/O. This paves the way for using the standard library in more limited
9042         embedded environments.
9043       * std: The `comm` module has been rewritten to be much faster, have a
9044         simpler, more consistent API, and to work for both native and green
9045         threading.
9046       * std: All libuv dependencies have been moved into the rustuv crate.
9047       * native: New implementations of runtime scheduling on top of OS threads.
9048       * native: New native implementations of TCP, UDP, file I/O, process spawning,
9049         and other I/O.
9050       * green: The green thread scheduler and message passing types are almost
9051         entirely lock-free.
9052       * extra: The `flatpipes` module had bitrotted and was removed.
9053       * extra: All crypto functions have been removed and Rust now has a policy of
9054         not reimplementing crypto in the standard library. In the future crypto
9055         will be provided by external crates with bindings to established libraries.
9056       * extra: `c_vec` has been modernized.
9057       * extra: The `sort` module has been removed. Use the `sort` method on
9058         mutable slices.
9059
9060    * Tooling
9061       * The `rust` and `rusti` commands have been removed, due to lack of
9062         maintenance.
9063       * `rustdoc` was completely rewritten.
9064       * `rustdoc` can test code examples in documentation.
9065       * `rustpkg` can test packages with the argument, 'test'.
9066       * `rustpkg` supports arbitrary dependencies, including C libraries.
9067       * `rustc`'s support for generating debug info is improved again.
9068       * `rustc` has better error reporting for unbalanced delimiters.
9069       * `rustc`'s JIT support was removed due to bitrot.
9070       * Executables and static libraries can be built with LTO (-Z lto)
9071       * `rustc` adds a `--dep-info` flag for communicating dependencies to
9072         build tools.
9073
9074
9075 Version 0.8 (2013-09-26)
9076 ============================
9077
9078    * ~2200 changes, numerous bugfixes
9079
9080    * Language
9081       * The `for` loop syntax has changed to work with the `Iterator` trait.
9082       * At long last, unwinding works on Windows.
9083       * Default methods are ready for use.
9084       * Many trait inheritance bugs fixed.
9085       * Owned and borrowed trait objects work more reliably.
9086       * `copy` is no longer a keyword. It has been replaced by the `Clone` trait.
9087       * rustc can omit emission of code for the `debug!` macro if it is passed
9088         `--cfg ndebug`
9089       * mod.rs is now "blessed". When loading `mod foo;`, rustc will now look
9090         for foo.rs, then foo/mod.rs, and will generate an error when both are
9091         present.
9092       * Strings no longer contain trailing nulls. The new `std::c_str` module
9093         provides new mechanisms for converting to C strings.
9094       * The type of foreign functions is now `extern "C" fn` instead of `*u8'.
9095       * The FFI has been overhauled such that foreign functions are called directly,
9096         instead of through a stack-switching wrapper.
9097       * Calling a foreign function must be done through a Rust function with the
9098         `#[fixed_stack_segment]` attribute.
9099       * The `externfn!` macro can be used to declare both a foreign function and
9100         a `#[fixed_stack_segment]` wrapper at once.
9101       * `pub` and `priv` modifiers on `extern` blocks are no longer parsed.
9102       * `unsafe` is no longer allowed on extern fns - they are all unsafe.
9103       * `priv` is disallowed everywhere except for struct fields and enum variants.
9104       * `&T` (besides `&'static T`) is no longer allowed in `@T`.
9105       * `ref` bindings in irrefutable patterns work correctly now.
9106       * `char` is now prevented from containing invalid code points.
9107       * Casting to `bool` is no longer allowed.
9108       * `\0` is now accepted as an escape in chars and strings.
9109       * `yield` is a reserved keyword.
9110       * `typeof` is a reserved keyword.
9111       * Crates may be imported by URL with `extern mod foo = "url";`.
9112       * Explicit enum discriminants may be given as uints as in `enum E { V = 0u }`
9113       * Static vectors can be initialized with repeating elements,
9114         e.g. `static foo: [u8, .. 100]: [0, .. 100];`.
9115       * Static structs can be initialized with functional record update,
9116         e.g. `static foo: Foo = Foo { a: 5, .. bar };`.
9117       * `cfg!` can be used to conditionally execute code based on the crate
9118         configuration, similarly to `#[cfg(...)]`.
9119       * The `unnecessary_qualification` lint detects unneeded module
9120         prefixes (default: allow).
9121       * Arithmetic operations have been implemented on the SIMD types in
9122         `std::unstable::simd`.
9123       * Exchange allocation headers were removed, reducing memory usage.
9124       * `format!` implements a completely new, extensible, and higher-performance
9125         string formatting system. It will replace `fmt!`.
9126       * `print!` and `println!` write formatted strings (using the `format!`
9127         extension) to stdout.
9128       * `write!` and `writeln!` write formatted strings (using the `format!`
9129         extension) to the new Writers in `std::rt::io`.
9130       * The library section in which a function or static is placed may
9131         be specified with `#[link_section = "..."]`.
9132       * The `proto!` syntax extension for defining bounded message protocols
9133         was removed.
9134       * `macro_rules!` is hygienic for `let` declarations.
9135       * The `#[export_name]` attribute specifies the name of a symbol.
9136       * `unreachable!` can be used to indicate unreachable code, and fails
9137         if executed.
9138
9139    * Libraries
9140       * std: Transitioned to the new runtime, written in Rust.
9141       * std: Added an experimental I/O library, `rt::io`, based on the new
9142         runtime.
9143       * std: A new generic `range` function was added to the prelude, replacing
9144         `uint::range` and friends.
9145       * std: `range_rev` no longer exists. Since range is an iterator it can be
9146         reversed with `range(lo, hi).invert()`.
9147       * std: The `chain` method on option renamed to `and_then`; `unwrap_or_default`
9148         renamed to `unwrap_or`.
9149       * std: The `iterator` module was renamed to `iter`.
9150       * std: Integral types now support the `checked_add`, `checked_sub`, and
9151         `checked_mul` operations for detecting overflow.
9152       * std: Many methods in `str`, `vec`, `option, `result` were renamed for
9153         consistency.
9154       * std: Methods are standardizing on conventions for casting methods:
9155         `to_foo` for copying, `into_foo` for moving, `as_foo` for temporary
9156         and cheap casts.
9157       * std: The `CString` type in `c_str` provides new ways to convert to and
9158         from C strings.
9159       * std: `DoubleEndedIterator` can yield elements in two directions.
9160       * std: The `mut_split` method on vectors partitions an `&mut [T]` into
9161         two splices.
9162       * std: `str::from_bytes` renamed to `str::from_utf8`.
9163       * std: `pop_opt` and `shift_opt` methods added to vectors.
9164       * std: The task-local data interface no longer uses @, and keys are
9165         no longer function pointers.
9166       * std: The `swap_unwrap` method of `Option` renamed to `take_unwrap`.
9167       * std: Added `SharedPort` to `comm`.
9168       * std: `Eq` has a default method for `ne`; only `eq` is required
9169         in implementations.
9170       * std: `Ord` has default methods for `le`, `gt` and `ge`; only `lt`
9171         is required in implementations.
9172       * std: `is_utf8` performance is improved, impacting many string functions.
9173       * std: `os::MemoryMap` provides cross-platform mmap.
9174       * std: `ptr::offset` is now unsafe, but also more optimized. Offsets that
9175         are not 'in-bounds' are considered undefined.
9176       * std: Many freestanding functions in `vec` removed in favor of methods.
9177       * std: Many freestanding functions on scalar types removed in favor of
9178         methods.
9179       * std: Many options to task builders were removed since they don't make
9180         sense in the new scheduler design.
9181       * std: More containers implement `FromIterator` so can be created by the
9182         `collect` method.
9183       * std: More complete atomic types in `unstable::atomics`.
9184       * std: `comm::PortSet` removed.
9185       * std: Mutating methods in the `Set` and `Map` traits have been moved into
9186         the `MutableSet` and `MutableMap` traits. `Container::is_empty`,
9187         `Map::contains_key`, `MutableMap::insert`, and `MutableMap::remove` have
9188         default implementations.
9189       * std: Various `from_str` functions were removed in favor of a generic
9190         `from_str` which is available in the prelude.
9191       * std: `util::unreachable` removed in favor of the `unreachable!` macro.
9192       * extra: `dlist`, the doubly-linked list was modernized.
9193       * extra: Added a `hex` module with `ToHex` and `FromHex` traits.
9194       * extra: Added `glob` module, replacing `std::os::glob`.
9195       * extra: `rope` was removed.
9196       * extra: `deque` was renamed to `ringbuf`. `RingBuf` implements `Deque`.
9197       * extra: `net`, and `timer` were removed. The experimental replacements
9198         are `std::rt::io::net` and `std::rt::io::timer`.
9199       * extra: Iterators implemented for `SmallIntMap`.
9200       * extra: Iterators implemented for `Bitv` and `BitvSet`.
9201       * extra: `SmallIntSet` removed. Use `BitvSet`.
9202       * extra: Performance of JSON parsing greatly improved.
9203       * extra: `semver` updated to SemVer 2.0.0.
9204       * extra: `term` handles more terminals correctly.
9205       * extra: `dbg` module removed.
9206       * extra: `par` module removed.
9207       * extra: `future` was cleaned up, with some method renames.
9208       * extra: Most free functions in `getopts` were converted to methods.
9209
9210    * Other
9211       * rustc's debug info generation (`-Z debug-info`) is greatly improved.
9212       * rustc accepts `--target-cpu` to compile to a specific CPU architecture,
9213         similarly to gcc's `--march` flag.
9214       * rustc's performance compiling small crates is much better.
9215       * rustpkg has received many improvements.
9216       * rustpkg supports git tags as package IDs.
9217       * rustpkg builds into target-specific directories so it can be used for
9218         cross-compiling.
9219       * The number of concurrent test tasks is controlled by the environment
9220         variable RUST_TEST_TASKS.
9221       * The test harness can now report metrics for benchmarks.
9222       * All tools have man pages.
9223       * Programs compiled with `--test` now support the `-h` and `--help` flags.
9224       * The runtime uses jemalloc for allocations.
9225       * Segmented stacks are temporarily disabled as part of the transition to
9226         the new runtime. Stack overflows are possible!
9227       * A new documentation backend, rustdoc_ng, is available for use. It is
9228         still invoked through the normal `rustdoc` command.
9229
9230
9231 Version 0.7 (2013-07-03)
9232 =======================
9233
9234    * ~2000 changes, numerous bugfixes
9235
9236    * Language
9237       * `impl`s no longer accept a visibility qualifier. Put them on methods
9238         instead.
9239       * The borrow checker has been rewritten with flow-sensitivity, fixing
9240         many bugs and inconveniences.
9241       * The `self` parameter no longer implicitly means `&'self self`,
9242         and can be explicitly marked with a lifetime.
9243       * Overloadable compound operators (`+=`, etc.) have been temporarily
9244         removed due to bugs.
9245       * The `for` loop protocol now requires `for`-iterators to return `bool`
9246         so they compose better.
9247       * The `Durable` trait is replaced with the `'static` bounds.
9248       * Trait default methods work more often.
9249       * Structs with the `#[packed]` attribute have byte alignment and
9250         no padding between fields.
9251       * Type parameters bound by `Copy` must now be copied explicitly with
9252         the `copy` keyword.
9253       * It is now illegal to move out of a dereferenced unsafe pointer.
9254       * `Option<~T>` is now represented as a nullable pointer.
9255       * `@mut` does dynamic borrow checks correctly.
9256       * The `main` function is only detected at the topmost level of the crate.
9257         The `#[main]` attribute is still valid anywhere.
9258       * Struct fields may no longer be mutable. Use inherited mutability.
9259       * The `#[no_send]` attribute makes a type that would otherwise be
9260         `Send`, not.
9261       * The `#[no_freeze]` attribute makes a type that would otherwise be
9262         `Freeze`, not.
9263       * Unbounded recursion will abort the process after reaching the limit
9264         specified by the `RUST_MAX_STACK` environment variable (default: 1GB).
9265       * The `vecs_implicitly_copyable` lint mode has been removed. Vectors
9266         are never implicitly copyable.
9267       * `#[static_assert]` makes compile-time assertions about static bools.
9268       * At long last, 'argument modes' no longer exist.
9269       * The rarely used `use mod` statement no longer exists.
9270
9271    * Syntax extensions
9272       * `fail!` and `assert!` accept `~str`, `&'static str` or `fmt!`-style
9273         argument list.
9274       * `Encodable`, `Decodable`, `Ord`, `TotalOrd`, `TotalEq`, `DeepClone`,
9275         `Rand`, `Zero` and `ToStr` can all be automatically derived with
9276         `#[deriving(...)]`.
9277       * The `bytes!` macro returns a vector of bytes for string, u8, char,
9278         and unsuffixed integer literals.
9279
9280    * Libraries
9281       * The `core` crate was renamed to `std`.
9282       * The `std` crate was renamed to `extra`.
9283       * More and improved documentation.
9284       * std: `iterator` module for external iterator objects.
9285       * Many old-style (internal, higher-order function) iterators replaced by
9286         implementations of `Iterator`.
9287       * std: Many old internal vector and string iterators,
9288         incl. `any`, `all`. removed.
9289       * std: The `finalize` method of `Drop` renamed to `drop`.
9290       * std: The `drop` method now takes `&mut self` instead of `&self`.
9291       * std: The prelude no longer re-exports any modules, only types and traits.
9292       * std: Prelude additions: `print`, `println`, `FromStr`, `ApproxEq`, `Equiv`,
9293         `Iterator`, `IteratorUtil`, many numeric traits, many tuple traits.
9294       * std: New numeric traits: `Fractional`, `Real`, `RealExt`, `Integer`, `Ratio`,
9295         `Algebraic`, `Trigonometric`, `Exponential`, `Primitive`.
9296       * std: Tuple traits and accessors defined for up to 12-tuples, e.g.
9297         `(0, 1, 2).n2()` or `(0, 1, 2).n2_ref()`.
9298       * std: Many types implement `Clone`.
9299       * std: `path` type renamed to `Path`.
9300       * std: `mut` module and `Mut` type removed.
9301       * std: Many standalone functions removed in favor of methods and iterators
9302         in `vec`, `str`. In the future methods will also work as functions.
9303       * std: `reinterpret_cast` removed. Use `transmute`.
9304       * std: ascii string handling in `std::ascii`.
9305       * std: `Rand` is implemented for ~/@.
9306       * std: `run` module for spawning processes overhauled.
9307       * std: Various atomic types added to `unstable::atomic`.
9308       * std: Various types implement `Zero`.
9309       * std: `LinearMap` and `LinearSet` renamed to `HashMap` and `HashSet`.
9310       * std: Borrowed pointer functions moved from `ptr` to `borrow`.
9311       * std: Added `os::mkdir_recursive`.
9312       * std: Added `os::glob` function performs filesystems globs.
9313       * std: `FuzzyEq` renamed to `ApproxEq`.
9314       * std: `Map` now defines `pop` and `swap` methods.
9315       * std: `Cell` constructors converted to static methods.
9316       * extra: `rc` module adds the reference counted pointers, `Rc` and `RcMut`.
9317       * extra: `flate` module moved from `std` to `extra`.
9318       * extra: `fileinput` module for iterating over a series of files.
9319       * extra: `Complex` number type and `complex` module.
9320       * extra: `Rational` number type and `rational` module.
9321       * extra: `BigInt`, `BigUint` implement numeric and comparison traits.
9322       * extra: `term` uses terminfo now, is more correct.
9323       * extra: `arc` functions converted to methods.
9324       * extra: Implementation of fixed output size variations of SHA-2.
9325
9326    * Tooling
9327       * `unused_variables` lint mode for unused variables (default: warn).
9328       * `unused_unsafe` lint mode for detecting unnecessary `unsafe` blocks
9329         (default: warn).
9330       * `unused_mut` lint mode for identifying unused `mut` qualifiers
9331         (default: warn).
9332       * `dead_assignment` lint mode for unread variables (default: warn).
9333       * `unnecessary_allocation` lint mode detects some heap allocations that are
9334         immediately borrowed so could be written without allocating (default: warn).
9335       * `missing_doc` lint mode (default: allow).
9336       * `unreachable_code` lint mode (default: warn).
9337       * The `rusti` command has been rewritten and a number of bugs addressed.
9338       * rustc outputs in color on more terminals.
9339       * rustc accepts a `--link-args` flag to pass arguments to the linker.
9340       * rustc accepts a `-Z print-link-args` flag for debugging linkage.
9341       * Compiling with `-g` will make the binary record information about
9342         dynamic borrowcheck failures for debugging.
9343       * rustdoc has a nicer stylesheet.
9344       * Various improvements to rustdoc.
9345       * Improvements to rustpkg (see the detailed release notes).
9346
9347
9348 Version 0.6 (2013-04-03)
9349 ========================
9350
9351    * ~2100 changes, numerous bugfixes
9352
9353    * Syntax changes
9354       * The self type parameter in traits is now spelled `Self`
9355       * The `self` parameter in trait and impl methods must now be explicitly
9356         named (for example: `fn f(&self) { }`). Implicit self is deprecated.
9357       * Static methods no longer require the `static` keyword and instead
9358         are distinguished by the lack of a `self` parameter
9359       * Replaced the `Durable` trait with the `'static` lifetime
9360       * The old closure type syntax with the trailing sigil has been
9361         removed in favor of the more consistent leading sigil
9362       * `super` is a keyword, and may be prefixed to paths
9363       * Trait bounds are separated with `+` instead of whitespace
9364       * Traits are implemented with `impl Trait for Type`
9365         instead of `impl Type: Trait`
9366       * Lifetime syntax is now `&'l foo` instead of `&l/foo`
9367       * The `export` keyword has finally been removed
9368       * The `move` keyword has been removed (see "Semantic changes")
9369       * The interior mutability qualifier on vectors, `[mut T]`, has been
9370         removed. Use `&mut [T]`, etc.
9371       * `mut` is no longer valid in `~mut T`. Use inherited mutability
9372       * `fail` is no longer a keyword. Use `fail!()`
9373       * `assert` is no longer a keyword. Use `assert!()`
9374       * `log` is no longer a keyword. use `debug!`, etc.
9375       * 1-tuples may be represented as `(T,)`
9376       * Struct fields may no longer be `mut`. Use inherited mutability,
9377         `@mut T`, `core::mut` or `core::cell`
9378       * `extern mod { ... }` is no longer valid syntax for foreign
9379         function modules. Use extern blocks: `extern { ... }`
9380       * Newtype enums removed. Use tuple-structs.
9381       * Trait implementations no longer support visibility modifiers
9382       * Pattern matching over vectors improved and expanded
9383       * `const` renamed to `static` to correspond to lifetime name,
9384         and make room for future `static mut` unsafe mutable globals.
9385       * Replaced `#[deriving_eq]` with `#[deriving(Eq)]`, etc.
9386       * `Clone` implementations can be automatically generated with
9387         `#[deriving(Clone)]`
9388       * Casts to traits must use a pointer sigil, e.g. `@foo as @Bar`
9389         instead of `foo as Bar`.
9390       * Fixed length vector types are now written as `[int, .. 3]`
9391         instead of `[int * 3]`.
9392       * Fixed length vector types can express the length as a constant
9393         expression. (ex: `[int, .. GL_BUFFER_SIZE - 2]`)
9394
9395    * Semantic changes
9396       * Types with owned pointers or custom destructors move by default,
9397         eliminating the `move` keyword
9398       * All foreign functions are considered unsafe
9399       * &mut is now unaliasable
9400       * Writes to borrowed @mut pointers are prevented dynamically
9401       * () has size 0
9402       * The name of the main function can be customized using #[main]
9403       * The default type of an inferred closure is &fn instead of @fn
9404       * `use` statements may no longer be "chained" - they cannot import
9405         identifiers imported by previous `use` statements
9406       * `use` statements are crate relative, importing from the "top"
9407         of the crate by default. Paths may be prefixed with `super::`
9408         or `self::` to change the search behavior.
9409       * Method visibility is inherited from the implementation declaration
9410       * Structural records have been removed
9411       * Many more types can be used in static items, including enums
9412         'static-lifetime pointers and vectors
9413       * Pattern matching over vectors improved and expanded
9414       * Typechecking of closure types has been overhauled to
9415         improve inference and eliminate unsoundness
9416       * Macros leave scope at the end of modules, unless that module is
9417         tagged with #[macro_escape]
9418
9419    * Libraries
9420       * Added big integers to `std::bigint`
9421       * Removed `core::oldcomm` module
9422       * Added pipe-based `core::comm` module
9423       * Numeric traits have been reorganized under `core::num`
9424       * `vec::slice` finally returns a slice
9425       * `debug!` and friends don't require a format string, e.g. `debug!(Foo)`
9426       * Containers reorganized around traits in `core::container`
9427       * `core::dvec` removed, `~[T]` is a drop-in replacement
9428       * `core::send_map` renamed to `core::hashmap`
9429       * `std::map` removed; replaced with `core::hashmap`
9430       * `std::treemap` reimplemented as an owned balanced tree
9431       * `std::deque` and `std::smallintmap` reimplemented as owned containers
9432       * `core::trie` added as a fast ordered map for integer keys
9433       * Set types added to `core::hashmap`, `core::trie` and `std::treemap`
9434       * `Ord` split into `Ord` and `TotalOrd`. `Ord` is still used to
9435         overload the comparison operators, whereas `TotalOrd` is used
9436         by certain container types
9437
9438    * Other
9439       * Replaced the 'cargo' package manager with 'rustpkg'
9440       * Added all-purpose 'rust' tool
9441       * `rustc --test` now supports benchmarks with the `#[bench]` attribute
9442       * rustc now *attempts* to offer spelling suggestions
9443       * Improved support for ARM and Android
9444       * Preliminary MIPS backend
9445       * Improved foreign function ABI implementation for x86, x86_64
9446       * Various memory usage improvements
9447       * Rust code may be embedded in foreign code under limited circumstances
9448       * Inline assembler supported by new asm!() syntax extension.
9449
9450
9451 Version 0.5 (2012-12-21)
9452 ===========================
9453
9454    * ~900 changes, numerous bugfixes
9455
9456    * Syntax changes
9457       * Removed `<-` move operator
9458       * Completed the transition from the `#fmt` extension syntax to `fmt!`
9459       * Removed old fixed length vector syntax - `[T]/N`
9460       * New token-based quasi-quoters, `quote_tokens!`, `quote_expr!`, etc.
9461       * Macros may now expand to items and statements
9462       * `a.b()` is always parsed as a method call, never as a field projection
9463       * `Eq` and `IterBytes` implementations can be automatically generated
9464         with `#[deriving_eq]` and `#[deriving_iter_bytes]` respectively
9465       * Removed the special crate language for `.rc` files
9466       * Function arguments may consist of any irrefutable pattern
9467
9468    * Semantic changes
9469       * `&` and `~` pointers may point to objects
9470       * Tuple structs - `struct Foo(Bar, Baz)`. Will replace newtype enums.
9471       * Enum variants may be structs
9472       * Destructors can be added to all nominal types with the Drop trait
9473       * Structs and nullary enum variants may be constants
9474       * Values that cannot be implicitly copied are now automatically moved
9475         without writing `move` explicitly
9476       * `&T` may now be coerced to `*T`
9477       * Coercions happen in `let` statements as well as function calls
9478       * `use` statements now take crate-relative paths
9479       * The module and type namespaces have been merged so that static
9480         method names can be resolved under the trait in which they are
9481         declared
9482
9483    * Improved support for language features
9484       * Trait inheritance works in many scenarios
9485       * More support for explicit self arguments in methods - `self`, `&self`
9486         `@self`, and `~self` all generally work as expected
9487       * Static methods work in more situations
9488       * Experimental: Traits may declare default methods for the implementations
9489         to use
9490
9491    * Libraries
9492       * New condition handling system in `core::condition`
9493       * Timsort added to `std::sort`
9494       * New priority queue, `std::priority_queue`
9495       * Pipes for serializable types, `std::flatpipes'
9496       * Serialization overhauled to be trait-based
9497       * Expanded `getopts` definitions
9498       * Moved futures to `std`
9499       * More functions are pure now
9500       * `core::comm` renamed to `oldcomm`. Still deprecated
9501       * `rustdoc` and `cargo` are libraries now
9502
9503    * Misc
9504       * Added a preliminary REPL, `rusti`
9505       * License changed from MIT to dual MIT/APL2
9506
9507
9508 Version 0.4 (2012-10-15)
9509 ==========================
9510
9511    * ~2000 changes, numerous bugfixes
9512
9513    * Syntax
9514       * All keywords are now strict and may not be used as identifiers anywhere
9515       * Keyword removal: 'again', 'import', 'check', 'new', 'owned', 'send',
9516         'of', 'with', 'to', 'class'.
9517       * Classes are replaced with simpler structs
9518       * Explicit method self types
9519       * `ret` became `return` and `alt` became `match`
9520       * `import` is now `use`; `use is now `extern mod`
9521       * `extern mod { ... }` is now `extern { ... }`
9522       * `use mod` is the recommended way to import modules
9523       * `pub` and `priv` replace deprecated export lists
9524       * The syntax of `match` pattern arms now uses fat arrow (=>)
9525       * `main` no longer accepts an args vector; use `os::args` instead
9526
9527    * Semantics
9528       * Trait implementations are now coherent, ala Haskell typeclasses
9529       * Trait methods may be static
9530       * Argument modes are deprecated
9531       * Borrowed pointers are much more mature and recommended for use
9532       * Strings and vectors in the static region are stored in constant memory
9533       * Typestate was removed
9534       * Resolution rewritten to be more reliable
9535       * Support for 'dual-mode' data structures (freezing and thawing)
9536
9537    * Libraries
9538       * Most binary operators can now be overloaded via the traits in
9539         `core::ops'
9540       * `std::net::url` for representing URLs
9541       * Sendable hash maps in `core::send_map`
9542       * `core::task' gained a (currently unsafe) task-local storage API
9543
9544    * Concurrency
9545       * An efficient new intertask communication primitive called the pipe,
9546         along with a number of higher-level channel types, in `core::pipes`
9547       * `std::arc`, an atomically reference counted, immutable, shared memory
9548         type
9549       * `std::sync`, various exotic synchronization tools based on arcs and pipes
9550       * Futures are now based on pipes and sendable
9551       * More robust linked task failure
9552       * Improved task builder API
9553
9554    * Other
9555       * Improved error reporting
9556       * Preliminary JIT support
9557       * Preliminary work on precise GC
9558       * Extensive architectural improvements to rustc
9559       * Begun a transition away from buggy C++-based reflection (shape) code to
9560         Rust-based (visitor) code
9561       * All hash functions and tables converted to secure, randomized SipHash
9562
9563
9564 Version 0.3  (2012-07-12)
9565 ========================
9566
9567    * ~1900 changes, numerous bugfixes
9568
9569    * New coding conveniences
9570       * Integer-literal suffix inference
9571       * Per-item control over warnings, errors
9572       * #[cfg(windows)] and #[cfg(unix)] attributes
9573       * Documentation comments
9574       * More compact closure syntax
9575       * 'do' expressions for treating higher-order functions as
9576         control structures
9577       * *-patterns (wildcard extended to all constructor fields)
9578
9579    * Semantic cleanup
9580       * Name resolution pass and exhaustiveness checker rewritten
9581       * Region pointers and borrow checking supersede alias
9582         analysis
9583       * Init-ness checking is now provided by a region-based liveness
9584         pass instead of the typestate pass; same for last-use analysis
9585       * Extensive work on region pointers
9586
9587    * Experimental new language features
9588       * Slices and fixed-size, interior-allocated vectors
9589       * #!-comments for lang versioning, shell execution
9590       * Destructors and iface implementation for classes;
9591         type-parameterized classes and class methods
9592       * 'const' type kind for types that can be used to implement
9593         shared-memory concurrency patterns
9594
9595    * Type reflection
9596
9597    * Removal of various obsolete features
9598       * Keywords: 'be', 'prove', 'syntax', 'note', 'mutable', 'bind',
9599                  'crust', 'native' (now 'extern'), 'cont' (now 'again')
9600
9601       * Constructs: do-while loops ('do' repurposed), fn binding,
9602                     resources (replaced by destructors)
9603
9604    * Compiler reorganization
9605       * Syntax-layer of compiler split into separate crate
9606       * Clang (from LLVM project) integrated into build
9607       * Typechecker split into sub-modules
9608
9609    * New library code
9610       * New time functions
9611       * Extension methods for many built-in types
9612       * Arc: atomic-refcount read-only / exclusive-use shared cells
9613       * Par: parallel map and search routines
9614       * Extensive work on libuv interface
9615       * Much vector code moved to libraries
9616       * Syntax extensions: #line, #col, #file, #mod, #stringify,
9617         #include, #include_str, #include_bin
9618
9619    * Tool improvements
9620       * Cargo automatically resolves dependencies
9621
9622
9623 Version 0.2  (2012-03-29)
9624 =========================
9625
9626    * >1500 changes, numerous bugfixes
9627
9628    * New docs and doc tooling
9629
9630    * New port: FreeBSD x86_64
9631
9632    * Compilation model enhancements
9633       * Generics now specialized, multiply instantiated
9634       * Functions now inlined across separate crates
9635
9636    * Scheduling, stack and threading fixes
9637       * Noticeably improved message-passing performance
9638       * Explicit schedulers
9639       * Callbacks from C
9640       * Helgrind clean
9641
9642    * Experimental new language features
9643       * Operator overloading
9644       * Region pointers
9645       * Classes
9646
9647    * Various language extensions
9648       * C-callback function types: 'crust fn ...'
9649       * Infinite-loop construct: 'loop { ... }'
9650       * Shorten 'mutable' to 'mut'
9651       * Required mutable-local qualifier: 'let mut ...'
9652       * Basic glob-exporting: 'export foo::*;'
9653       * Alt now exhaustive, 'alt check' for runtime-checked
9654       * Block-function form of 'for' loop, with 'break' and 'ret'.
9655
9656    * New library code
9657       * AST quasi-quote syntax extension
9658       * Revived libuv interface
9659       * New modules: core::{future, iter}, std::arena
9660       * Merged per-platform std::{os*, fs*} to core::{libc, os}
9661       * Extensive cleanup, regularization in libstd, libcore
9662
9663
9664 Version 0.1  (2012-01-20)
9665 ===============================
9666
9667    * Most language features work, including:
9668       * Unique pointers, unique closures, move semantics
9669       * Interface-constrained generics
9670       * Static interface dispatch
9671       * Stack growth
9672       * Multithread task scheduling
9673       * Typestate predicates
9674       * Failure unwinding, destructors
9675       * Pattern matching and destructuring assignment
9676       * Lightweight block-lambda syntax
9677       * Preliminary macro-by-example
9678
9679    * Compiler works with the following configurations:
9680       * Linux: x86 and x86_64 hosts and targets
9681       * macOS: x86 and x86_64 hosts and targets
9682       * Windows: x86 hosts and targets
9683
9684    * Cross compilation / multi-target configuration supported.
9685
9686    * Preliminary API-documentation and package-management tools included.
9687
9688 Known issues:
9689
9690    * Documentation is incomplete.
9691
9692    * Performance is below intended target.
9693
9694    * Standard library APIs are subject to extensive change, reorganization.
9695
9696    * Language-level versioning is not yet operational - future code will
9697      break unexpectedly.