1 //! List of the active feature gates.
3 use super::{to_nonzero, Feature, State}
;
5 use rustc_span
::edition
::Edition
;
6 use rustc_span
::symbol
::{sym, Symbol}
;
11 fn f(features
: &mut Features
, _
: Span
) {
12 features
.$field
= true;
14 f
as fn(&mut Features
, Span
)
18 macro_rules
! declare_features
{
19 (__status_to_bool active
) => {
22 (__status_to_bool incomplete
) => {
26 $
(#[doc = $doc:tt])* ($status:ident, $feature:ident, $ver:expr, $issue:expr, $edition:expr),
28 /// Represents active features that are currently being implemented or
29 /// currently being considered for addition/removal.
30 pub const ACTIVE_FEATURES
:
33 // (sym::$feature, $ver, $issue, $edition, set!($feature))
35 state
: State
::Active { set: set!($feature) }
,
38 issue
: to_nonzero($issue
),
40 description
: concat
!($
($doc
,)*),
44 /// A set of features to be used by later passes.
45 #[derive(Clone, Default, Debug)]
47 /// `#![feature]` attrs for language features, for error reporting.
48 pub declared_lang_features
: Vec
<(Symbol
, Span
, Option
<Symbol
>)>,
49 /// `#![feature]` attrs for non-language (library) features.
50 pub declared_lib_features
: Vec
<(Symbol
, Span
)>,
58 pub fn walk_feature_fields(&self, mut f
: impl FnMut(&str, bool
)) {
59 $
(f(stringify
!($feature
), self.$feature
);)+
62 /// Is the given feature enabled?
64 /// Panics if the symbol doesn't correspond to a declared feature.
65 pub fn enabled(&self, feature
: Symbol
) -> bool
{
67 $
( sym
::$feature
=> self.$feature
, )*
69 _
=> panic
!("`{}` was not listed in `declare_features`", feature
),
73 pub fn unordered_const_ty_params(&self) -> bool
{
74 self.const_generics_defaults
|| self.generic_const_exprs
|| self.adt_const_params
77 /// Some features are known to be incomplete and using them is likely to have
78 /// unanticipated results, such as compiler crashes. We warn the user about these
80 pub fn incomplete(&self, feature
: Symbol
) -> bool
{
83 sym
::$feature
=> declare_features
!(__status_to_bool $status
),
85 // accepted and removed features aren't in this file but are never incomplete
86 _
if self.declared_lang_features
.iter().any(|f
| f
.0 == feature
) => false,
87 _
if self.declared_lib_features
.iter().any(|f
| f
.0 == feature
) => false,
88 _
=> panic
!("`{}` was not listed in `declare_features`", feature
),
96 /// Sets this feature in `Features`. Panics if called on a non-active feature.
97 pub fn set(&self, features
: &mut Features
, span
: Span
) {
99 State
::Active { set }
=> set(features
, span
),
100 _
=> panic
!("called `set` on feature `{}` which is not `active`", self.name
),
105 // If you change this, please modify `src/doc/unstable-book` as well.
107 // Don't ever remove anything from this list; move them to `removed.rs`.
109 // The version numbers here correspond to the version in which the current status
110 // was set. This is most important for knowing when a particular feature became
113 // Note that the features are grouped into internal/user-facing and then
114 // sorted by version inside those groups. This is enforced with tidy.
116 // N.B., `tools/tidy/src/features.rs` parses this information directly out of the
117 // source, so take care when modifying it.
121 // -------------------------------------------------------------------------
122 // feature-group-start: internal feature gates
123 // -------------------------------------------------------------------------
125 // no-tracking-issue-start
127 /// Allows using `rustc_*` attributes (RFC 572).
128 (active
, rustc_attrs
, "1.0.0", None
, None
),
130 /// Allows using compiler's own crates.
131 (active
, rustc_private
, "1.0.0", Some(27812), None
),
133 /// Allows using the `rust-intrinsic`'s "ABI".
134 (active
, intrinsics
, "1.0.0", None
, None
),
136 /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic.
137 (active
, lang_items
, "1.0.0", None
, None
),
139 /// Allows using the `#[stable]` and `#[unstable]` attributes.
140 (active
, staged_api
, "1.0.0", None
, None
),
142 /// Allows using `#[allow_internal_unstable]`. This is an
143 /// attribute on `macro_rules!` and can't use the attribute handling
144 /// below (it has to be checked before expansion possibly makes
145 /// macros disappear).
146 (active
, allow_internal_unstable
, "1.0.0", None
, None
),
148 /// Allows using `#[allow_internal_unsafe]`. This is an
149 /// attribute on `macro_rules!` and can't use the attribute handling
150 /// below (it has to be checked before expansion possibly makes
151 /// macros disappear).
152 (active
, allow_internal_unsafe
, "1.0.0", None
, None
),
154 /// no-tracking-issue-end
156 /// Allows using `#[link_name="llvm.*"]`.
157 (active
, link_llvm_intrinsics
, "1.0.0", Some(29602), None
),
159 /// Allows using the `box $expr` syntax.
160 (active
, box_syntax
, "1.0.0", Some(49733), None
),
162 /// Allows using `#[start]` on a function indicating that it is the program entrypoint.
163 (active
, start
, "1.0.0", Some(29633), None
),
165 /// Allows using the `#[fundamental]` attribute.
166 (active
, fundamental
, "1.0.0", Some(29635), None
),
168 /// Allows using the `rust-call` ABI.
169 (active
, unboxed_closures
, "1.0.0", Some(29625), None
),
171 /// Allows using the `#[linkage = ".."]` attribute.
172 (active
, linkage
, "1.0.0", Some(29603), None
),
174 /// Allows using `box` in patterns (RFC 469).
175 (active
, box_patterns
, "1.0.0", Some(29641), None
),
177 // no-tracking-issue-start
179 /// Allows using `#[prelude_import]` on glob `use` items.
180 (active
, prelude_import
, "1.2.0", None
, None
),
182 // no-tracking-issue-end
184 // no-tracking-issue-start
186 /// Allows using `#[omit_gdb_pretty_printer_section]`.
187 (active
, omit_gdb_pretty_printer_section
, "1.5.0", None
, None
),
189 /// Allows using the `vectorcall` ABI.
190 (active
, abi_vectorcall
, "1.7.0", None
, None
),
192 // no-tracking-issue-end
194 /// Allows using `#[structural_match]` which indicates that a type is structurally matchable.
195 /// FIXME: Subsumed by trait `StructuralPartialEq`, cannot move to removed until a library
196 /// feature with the same name exists.
197 (active
, structural_match
, "1.8.0", Some(31434), None
),
199 /// Allows using the `may_dangle` attribute (RFC 1327).
200 (active
, dropck_eyepatch
, "1.10.0", Some(34761), None
),
202 /// Allows using the `#![panic_runtime]` attribute.
203 (active
, panic_runtime
, "1.10.0", Some(32837), None
),
205 /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed.
206 (active
, needs_panic_runtime
, "1.10.0", Some(32837), None
),
208 // no-tracking-issue-start
210 /// Allows identifying the `compiler_builtins` crate.
211 (active
, compiler_builtins
, "1.13.0", None
, None
),
213 /// Allows using the `unadjusted` ABI; perma-unstable.
214 (active
, abi_unadjusted
, "1.16.0", None
, None
),
216 /// Used to identify crates that contain the profiler runtime.
217 (active
, profiler_runtime
, "1.18.0", None
, None
),
219 /// Allows using the `thiscall` ABI.
220 (active
, abi_thiscall
, "1.19.0", None
, None
),
222 /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`.
223 (active
, allocator_internals
, "1.20.0", None
, None
),
225 /// Added for testing E0705; perma-unstable.
226 (active
, test_2018_feature
, "1.31.0", None
, Some(Edition
::Edition2018
)),
228 /// Allows `#[repr(no_niche)]` (an implementation detail of `rustc`,
229 /// it is not on path for eventual stabilization).
230 (active
, no_niche
, "1.42.0", None
, None
),
232 /// Allows using `#[rustc_allow_const_fn_unstable]`.
233 /// This is an attribute on `const fn` for the same
234 /// purpose as `#[allow_internal_unstable]`.
235 (active
, rustc_allow_const_fn_unstable
, "1.49.0", Some(69399), None
),
237 /// Allows features specific to auto traits.
238 /// Renamed from `optin_builtin_traits`.
239 (active
, auto_traits
, "1.50.0", Some(13231), None
),
241 /// Allows `#[doc(notable_trait)]`.
242 /// Renamed from `doc_spotlight`.
243 (active
, doc_notable_trait
, "1.52.0", Some(45040), None
),
245 // no-tracking-issue-end
247 // -------------------------------------------------------------------------
248 // feature-group-end: internal feature gates
249 // -------------------------------------------------------------------------
251 // -------------------------------------------------------------------------
252 // feature-group-start: actual feature gates (target features)
253 // -------------------------------------------------------------------------
255 // FIXME: Document these and merge with the list below.
257 // Unstable `#[target_feature]` directives.
258 (active
, arm_target_feature
, "1.27.0", Some(44839), None
),
259 (active
, aarch64_target_feature
, "1.27.0", Some(44839), None
),
260 (active
, hexagon_target_feature
, "1.27.0", Some(44839), None
),
261 (active
, powerpc_target_feature
, "1.27.0", Some(44839), None
),
262 (active
, mips_target_feature
, "1.27.0", Some(44839), None
),
263 (active
, avx512_target_feature
, "1.27.0", Some(44839), None
),
264 (active
, sse4a_target_feature
, "1.27.0", Some(44839), None
),
265 (active
, tbm_target_feature
, "1.27.0", Some(44839), None
),
266 (active
, wasm_target_feature
, "1.30.0", Some(44839), None
),
267 (active
, adx_target_feature
, "1.32.0", Some(44839), None
),
268 (active
, cmpxchg16b_target_feature
, "1.32.0", Some(44839), None
),
269 (active
, movbe_target_feature
, "1.34.0", Some(44839), None
),
270 (active
, rtm_target_feature
, "1.35.0", Some(44839), None
),
271 (active
, f16c_target_feature
, "1.36.0", Some(44839), None
),
272 (active
, riscv_target_feature
, "1.45.0", Some(44839), None
),
273 (active
, ermsb_target_feature
, "1.49.0", Some(44839), None
),
274 (active
, bpf_target_feature
, "1.54.0", Some(44839), None
),
276 // -------------------------------------------------------------------------
277 // feature-group-end: actual feature gates (target features)
278 // -------------------------------------------------------------------------
280 // -------------------------------------------------------------------------
281 // feature-group-start: actual feature gates
282 // -------------------------------------------------------------------------
284 /// Allows using `#![plugin(myplugin)]`.
285 (active
, plugin
, "1.0.0", Some(29597), None
),
287 /// Allows using `#[thread_local]` on `static` items.
288 (active
, thread_local
, "1.0.0", Some(29594), None
),
290 /// Allows the use of SIMD types in functions declared in `extern` blocks.
291 (active
, simd_ffi
, "1.0.0", Some(27731), None
),
293 /// Allows using non lexical lifetimes (RFC 2094).
294 (active
, nll
, "1.0.0", Some(43234), None
),
296 /// Allows associated type defaults.
297 (active
, associated_type_defaults
, "1.2.0", Some(29661), None
),
299 /// Allows `#![no_core]`.
300 (active
, no_core
, "1.3.0", Some(29639), None
),
302 /// Allows default type parameters to influence type inference.
303 (active
, default_type_parameter_fallback
, "1.3.0", Some(27336), None
),
305 /// Allows `repr(simd)` and importing the various simd intrinsics.
306 (active
, repr_simd
, "1.4.0", Some(27731), None
),
308 /// Allows `extern "platform-intrinsic" { ... }`.
309 (active
, platform_intrinsics
, "1.4.0", Some(27731), None
),
311 /// Allows attributes on expressions and non-item statements.
312 (active
, stmt_expr_attributes
, "1.6.0", Some(15701), None
),
314 /// Allows the use of type ascription in expressions.
315 (active
, type_ascription
, "1.6.0", Some(23416), None
),
317 /// Allows `cfg(target_thread_local)`.
318 (active
, cfg_target_thread_local
, "1.7.0", Some(29594), None
),
320 /// Allows specialization of implementations (RFC 1210).
321 (incomplete
, specialization
, "1.7.0", Some(31844), None
),
323 /// A minimal, sound subset of specialization intended to be used by the
324 /// standard library until the soundness issues with specialization
326 (active
, min_specialization
, "1.7.0", Some(31844), None
),
328 /// Allows using `#[naked]` on functions.
329 (active
, naked_functions
, "1.9.0", Some(32408), None
),
331 /// Allows `cfg(target_has_atomic = "...")`.
332 (active
, cfg_target_has_atomic
, "1.9.0", Some(32976), None
),
334 /// Allows `X..Y` patterns.
335 (active
, exclusive_range_pattern
, "1.11.0", Some(37854), None
),
337 /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more.
338 (active
, never_type
, "1.13.0", Some(35121), None
),
340 /// Allows exhaustive pattern matching on types that contain uninhabited types.
341 (active
, exhaustive_patterns
, "1.13.0", Some(51085), None
),
343 /// Allows `union`s to implement `Drop`. Moreover, `union`s may now include fields
344 /// that don't implement `Copy` as long as they don't have any drop glue.
345 /// This is checked recursively. On encountering type variable where no progress can be made,
346 /// `T: Copy` is used as a substitute for "no drop glue".
348 /// NOTE: A limited form of `union U { ... }` was accepted in 1.19.0.
349 (active
, untagged_unions
, "1.13.0", Some(55149), None
),
351 /// Allows `#[link(..., cfg(..))]`.
352 (active
, link_cfg
, "1.14.0", Some(37406), None
),
354 /// Allows `extern "ptx-*" fn()`.
355 (active
, abi_ptx
, "1.15.0", Some(38788), None
),
357 /// Allows the `#[repr(i128)]` attribute for enums.
358 (incomplete
, repr128
, "1.16.0", Some(56071), None
),
360 /// Allows `#[link(kind="static-nobundle"...)]`.
361 (active
, static_nobundle
, "1.16.0", Some(37403), None
),
363 /// Allows `extern "msp430-interrupt" fn()`.
364 (active
, abi_msp430_interrupt
, "1.16.0", Some(38487), None
),
366 /// Allows declarative macros 2.0 (`macro`).
367 (active
, decl_macro
, "1.17.0", Some(39412), None
),
369 /// Allows `extern "x86-interrupt" fn()`.
370 (active
, abi_x86_interrupt
, "1.17.0", Some(40180), None
),
372 /// Allows a test to fail without failing the whole suite.
373 (active
, allow_fail
, "1.19.0", Some(46488), None
),
375 /// Allows unsized tuple coercion.
376 (active
, unsized_tuple_coercion
, "1.20.0", Some(42877), None
),
378 /// Allows defining generators.
379 (active
, generators
, "1.21.0", Some(43122), None
),
381 /// Allows `#[doc(cfg(...))]`.
382 (active
, doc_cfg
, "1.21.0", Some(43781), None
),
384 /// Allows `#[doc(masked)]`.
385 (active
, doc_masked
, "1.21.0", Some(44027), None
),
387 /// Allows using `crate` as visibility modifier, synonymous with `pub(crate)`.
388 (active
, crate_visibility_modifier
, "1.23.0", Some(53120), None
),
390 /// Allows defining `extern type`s.
391 (active
, extern_types
, "1.23.0", Some(43467), None
),
393 /// Allows trait methods with arbitrary self types.
394 (active
, arbitrary_self_types
, "1.23.0", Some(44874), None
),
396 /// Allows in-band quantification of lifetime bindings (e.g., `fn foo(x: &'a u8) -> &'a u8`).
397 (active
, in_band_lifetimes
, "1.23.0", Some(44524), None
),
399 /// Allows associated types to be generic, e.g., `type Foo<T>;` (RFC 1598).
400 (active
, generic_associated_types
, "1.23.0", Some(44265), None
),
402 /// Allows defining `trait X = A + B;` alias items.
403 (active
, trait_alias
, "1.24.0", Some(41517), None
),
405 /// Allows inferring `'static` outlives requirements (RFC 2093).
406 (active
, infer_static_outlives_requirements
, "1.26.0", Some(54185), None
),
408 /// Allows dereferencing raw pointers during const eval.
409 (active
, const_raw_ptr_deref
, "1.27.0", Some(51911), None
),
411 /// Allows inconsistent bounds in where clauses.
412 (active
, trivial_bounds
, "1.28.0", Some(48214), None
),
414 /// Allows `'a: { break 'a; }`.
415 (active
, label_break_value
, "1.28.0", Some(48594), None
),
417 /// Allows using `#[doc(keyword = "...")]`.
418 (active
, doc_keyword
, "1.28.0", Some(51315), None
),
420 /// Allows using `try {...}` expressions.
421 (active
, try_blocks
, "1.29.0", Some(31436), None
),
423 /// Allows defining an `#[alloc_error_handler]`.
424 (active
, alloc_error_handler
, "1.29.0", Some(51540), None
),
426 /// Allows using the `amdgpu-kernel` ABI.
427 (active
, abi_amdgpu_kernel
, "1.29.0", Some(51575), None
),
429 /// Allows panicking during const eval (producing compile-time errors).
430 (active
, const_panic
, "1.30.0", Some(51999), None
),
432 /// Allows `#[marker]` on certain traits allowing overlapping implementations.
433 (active
, marker_trait_attr
, "1.30.0", Some(29864), None
),
435 /// Allows macro attributes on expressions, statements and non-inline modules.
436 (active
, proc_macro_hygiene
, "1.30.0", Some(54727), None
),
438 /// Allows unsized rvalues at arguments and parameters.
439 (incomplete
, unsized_locals
, "1.30.0", Some(48055), None
),
441 /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`.
442 (active
, custom_test_frameworks
, "1.30.0", Some(50297), None
),
444 /// Allows non-builtin attributes in inner attribute position.
445 (active
, custom_inner_attributes
, "1.30.0", Some(54726), None
),
447 /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check.
448 (active
, lint_reasons
, "1.31.0", Some(54503), None
),
450 /// Allows exhaustive integer pattern matching on `usize` and `isize`.
451 (active
, precise_pointer_size_matching
, "1.32.0", Some(56354), None
),
453 /// Allows using `#[ffi_returns_twice]` on foreign functions.
454 (active
, ffi_returns_twice
, "1.34.0", Some(58314), None
),
456 /// Allows using `#[optimize(X)]`.
457 (active
, optimize_attribute
, "1.34.0", Some(54882), None
),
459 /// Allows using C-variadics.
460 (active
, c_variadic
, "1.34.0", Some(44930), None
),
462 /// Allows the user of associated type bounds.
463 (active
, associated_type_bounds
, "1.34.0", Some(52662), None
),
465 /// Allows `if/while p && let q = r && ...` chains.
466 (incomplete
, let_chains
, "1.37.0", Some(53667), None
),
468 /// Allows #[repr(transparent)] on unions (RFC 2645).
469 (active
, transparent_unions
, "1.37.0", Some(60405), None
),
471 /// Allows explicit discriminants on non-unit enum variants.
472 (active
, arbitrary_enum_discriminant
, "1.37.0", Some(60553), None
),
474 /// Allows `async || body` closures.
475 (active
, async_closure
, "1.37.0", Some(62290), None
),
477 /// Allows `impl Trait` to be used inside type aliases (RFC 2515).
478 (active
, type_alias_impl_trait
, "1.38.0", Some(63063), None
),
480 /// Allows the definition of `const extern fn` and `const unsafe extern fn`.
481 (active
, const_extern_fn
, "1.40.0", Some(64926), None
),
483 /// Allows the use of raw-dylibs (RFC 2627).
484 (incomplete
, raw_dylib
, "1.40.0", Some(58713), None
),
486 /// Allows making `dyn Trait` well-formed even if `Trait` is not object safe.
487 /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and
488 /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
489 (active
, object_safe_for_dispatch
, "1.40.0", Some(43561), None
),
491 /// Allows using the `efiapi` ABI.
492 (active
, abi_efiapi
, "1.40.0", Some(65815), None
),
494 /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions.
495 (active
, raw_ref_op
, "1.41.0", Some(64490), None
),
497 /// Allows diverging expressions to fall back to `!` rather than `()`.
498 (active
, never_type_fallback
, "1.41.0", Some(65992), None
),
500 /// Allows using the `#[register_attr]` attribute.
501 (active
, register_attr
, "1.41.0", Some(66080), None
),
503 /// Allows using the `#[register_tool]` attribute.
504 (active
, register_tool
, "1.41.0", Some(66079), None
),
506 /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used.
507 (active
, cfg_sanitize
, "1.41.0", Some(39699), None
),
509 /// Allows using `..X`, `..=X`, `...X`, and `X..` as a pattern.
510 (active
, half_open_range_patterns
, "1.41.0", Some(67264), None
),
512 /// Allows using `&mut` in constant functions.
513 (active
, const_mut_refs
, "1.41.0", Some(57349), None
),
515 /// Allows `impl const Trait for T` syntax.
516 (active
, const_trait_impl
, "1.42.0", Some(67792), None
),
518 /// Allows the use of `no_sanitize` attribute.
519 (active
, no_sanitize
, "1.42.0", Some(39699), None
),
521 // Allows limiting the evaluation steps of const expressions
522 (active
, const_eval_limit
, "1.43.0", Some(67217), None
),
524 /// Allow negative trait implementations.
525 (active
, negative_impls
, "1.44.0", Some(68318), None
),
527 /// Allows the use of `#[target_feature]` on safe functions.
528 (active
, target_feature_11
, "1.45.0", Some(69098), None
),
530 /// Allow conditional compilation depending on rust version
531 (active
, cfg_version
, "1.45.0", Some(64796), None
),
533 /// Allows the use of `#[ffi_pure]` on foreign functions.
534 (active
, ffi_pure
, "1.45.0", Some(58329), None
),
536 /// Allows the use of `#[ffi_const]` on foreign functions.
537 (active
, ffi_const
, "1.45.0", Some(58328), None
),
539 /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`.
540 (active
, abi_avr_interrupt
, "1.45.0", Some(69664), None
),
542 /// Be more precise when looking for live drops in a const context.
543 (active
, const_precise_live_drops
, "1.46.0", Some(73255), None
),
545 /// Allows capturing variables in scope using format_args!
546 (active
, format_args_capture
, "1.46.0", Some(67984), None
),
548 /// Allows `if let` guard in match arms.
549 (active
, if_let_guard
, "1.47.0", Some(51114), None
),
551 /// Allows basic arithmetic on floating point types in a `const fn`.
552 (active
, const_fn_floating_point_arithmetic
, "1.48.0", Some(57241), None
),
554 /// Allows using and casting function pointers in a `const fn`.
555 (active
, const_fn_fn_ptr_basics
, "1.48.0", Some(57563), None
),
557 /// Allows to use the `#[cmse_nonsecure_entry]` attribute.
558 (active
, cmse_nonsecure_entry
, "1.48.0", Some(75835), None
),
560 /// Allows rustc to inject a default alloc_error_handler
561 (active
, default_alloc_error_handler
, "1.48.0", Some(66741), None
),
563 /// Allows argument and return position `impl Trait` in a `const fn`.
564 (active
, const_impl_trait
, "1.48.0", Some(77463), None
),
566 /// Allows `#[instruction_set(_)]` attribute
567 (active
, isa_attribute
, "1.48.0", Some(74727), None
),
569 /// Allow anonymous constants from an inline `const` block
570 (incomplete
, inline_const
, "1.49.0", Some(76001), None
),
572 /// Allows unsized fn parameters.
573 (active
, unsized_fn_params
, "1.49.0", Some(48055), None
),
575 /// Allows the use of destructuring assignments.
576 (active
, destructuring_assignment
, "1.49.0", Some(71126), None
),
578 /// Enables `#[cfg(panic = "...")]` config key.
579 (active
, cfg_panic
, "1.49.0", Some(77443), None
),
581 /// Allows capturing disjoint fields in a closure/generator (RFC 2229).
582 (incomplete
, capture_disjoint_fields
, "1.49.0", Some(53488), None
),
584 /// Allows const generics to have default values (e.g. `struct Foo<const N: usize = 3>(...);`).
585 (active
, const_generics_defaults
, "1.51.0", Some(44580), None
),
587 /// Allows references to types with interior mutability within constants
588 (active
, const_refs_to_cell
, "1.51.0", Some(80384), None
),
590 /// Allows using `pointer` and `reference` in intra-doc links
591 (active
, intra_doc_pointers
, "1.51.0", Some(80896), None
),
593 /// Allows `extern "C-cmse-nonsecure-call" fn()`.
594 (active
, abi_c_cmse_nonsecure_call
, "1.51.0", Some(81391), None
),
596 /// Lessens the requirements for structs to implement `Unsize`.
597 (active
, relaxed_struct_unsize
, "1.51.0", Some(81793), None
),
599 /// Allows macro attributes to observe output of `#[derive]`.
600 (active
, macro_attributes_in_derive_output
, "1.51.0", Some(81119), None
),
602 /// Allows associated types in inherent impls.
603 (incomplete
, inherent_associated_types
, "1.52.0", Some(8995), None
),
605 // Allows setting the threshold for the `large_assignments` lint.
606 (active
, large_assignments
, "1.52.0", Some(83518), None
),
608 /// Allows `extern "C-unwind" fn` to enable unwinding across ABI boundaries.
609 (active
, c_unwind
, "1.52.0", Some(74990), None
),
611 /// Allows using `#[repr(align(...))]` on function items
612 (active
, fn_align
, "1.53.0", Some(82232), None
),
614 /// Allows `extern "wasm" fn`
615 (active
, wasm_abi
, "1.53.0", Some(83788), None
),
617 /// Allows function attribute `#[no_coverage]`, to bypass coverage
618 /// instrumentation of that function.
619 (active
, no_coverage
, "1.53.0", Some(84605), None
),
621 /// Allows trait bounds in `const fn`.
622 (active
, const_fn_trait_bound
, "1.53.0", Some(57563), None
),
624 /// Allows `async {}` expressions in const contexts.
625 (active
, const_async_blocks
, "1.53.0", Some(85368), None
),
627 /// Allows using imported `main` function
628 (active
, imported_main
, "1.53.0", Some(28937), None
),
630 /// Allows specifying modifiers in the link attribute: `#[link(modifiers = "...")]`
631 (active
, native_link_modifiers
, "1.53.0", Some(81490), None
),
633 /// Allows specifying the bundle link modifier
634 (active
, native_link_modifiers_bundle
, "1.53.0", Some(81490), None
),
636 /// Allows specifying the verbatim link modifier
637 (active
, native_link_modifiers_verbatim
, "1.53.0", Some(81490), None
),
639 /// Allows specifying the whole-archive link modifier
640 (active
, native_link_modifiers_whole_archive
, "1.53.0", Some(81490), None
),
642 /// Allows specifying the as-needed link modifier
643 (active
, native_link_modifiers_as_needed
, "1.53.0", Some(81490), None
),
645 /// Allows qualified paths in struct expressions, struct patterns and tuple struct patterns.
646 (active
, more_qualified_paths
, "1.54.0", Some(86935), None
),
648 /// Allows `cfg(target_abi = "...")`.
649 (active
, cfg_target_abi
, "1.55.0", Some(80970), None
),
651 /// Infer generic args for both consts and types.
652 (active
, generic_arg_infer
, "1.55.0", Some(85077), None
),
654 /// Allows `#[derive(Default)]` and `#[default]` on enums.
655 (active
, derive_default_enum
, "1.56.0", Some(86985), None
),
657 /// Allows `for _ in _` loops in const contexts.
658 (active
, const_for
, "1.56.0", Some(87575), None
),
660 /// Allows the `?` operator in const contexts.
661 (active
, const_try
, "1.56.0", Some(74935), None
),
663 /// Allows upcasting trait objects via supertraits.
664 /// Trait upcasting is casting, e.g., `dyn Foo -> dyn Bar` where `Foo: Bar`.
665 (incomplete
, trait_upcasting
, "1.56.0", Some(65991), None
),
667 /// Allows explicit generic arguments specification with `impl Trait` present.
668 (active
, explicit_generic_args_with_impl_trait
, "1.56.0", Some(83701), None
),
670 /// Allows using doc(primitive) without a future-incompat warning
671 (active
, doc_primitive
, "1.56.0", Some(88070), None
),
673 /// Allows non-trivial generic constants which have to have wfness manually propagated to callers
674 (incomplete
, generic_const_exprs
, "1.56.0", Some(76560), None
),
676 /// Allows additional const parameter types, such as `&'static str` or user defined types
677 (incomplete
, adt_const_params
, "1.56.0", Some(44580), None
),
679 /// Allows `let...else` statements.
680 (active
, let_else
, "1.56.0", Some(87335), None
),
682 // -------------------------------------------------------------------------
683 // feature-group-end: actual feature gates
684 // -------------------------------------------------------------------------
687 /// Some features are not allowed to be used together at the same time, if
688 /// the two are present, produce an error.
690 /// Currently empty, but we will probably need this again in the future,
691 /// so let's keep it in for now.
692 pub const INCOMPATIBLE_FEATURES
: &[(Symbol
, Symbol
)] = &[];