src/librustc_index/vec.rs

   1 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
   2
   3 use std::fmt;
   4 use std::fmt::Debug;
   5 use std::hash::Hash;
   6 use std::iter::{self, FromIterator};
   7 use std::marker::PhantomData;
   8 use std::ops::{Index, IndexMut, Range, RangeBounds};
   9 use std::slice;
  10 use std::vec;
  11
  12 /// Represents some newtyped `usize` wrapper.
  13 ///
  14 /// Purpose: avoid mixing indexes for different bitvector domains.
  15 pub trait Idx: Copy + 'static + Ord + Debug + Hash {
  16     fn new(idx: usize) -> Self;
  17
  18     fn index(self) -> usize;
  19
  20     fn increment_by(&mut self, amount: usize) {
  21         *self = self.plus(amount);
  22     }
  23
  24     fn plus(self, amount: usize) -> Self {
  25         Self::new(self.index() + amount)
  26     }
  27 }
  28
  29 impl Idx for usize {
  30     #[inline]
  31     fn new(idx: usize) -> Self {
  32         idx
  33     }
  34     #[inline]
  35     fn index(self) -> usize {
  36         self
  37     }
  38 }
  39
  40 impl Idx for u32 {
  41     #[inline]
  42     fn new(idx: usize) -> Self {
  43         assert!(idx <= u32::MAX as usize);
  44         idx as u32
  45     }
  46     #[inline]
  47     fn index(self) -> usize {
  48         self as usize
  49     }
  50 }
  51
  52 /// Creates a struct type `S` that can be used as an index with
  53 /// `IndexVec` and so on.
  54 ///
  55 /// There are two ways of interacting with these indices:
  56 ///
  57 /// - The `From` impls are the preferred way. So you can do
  58 ///   `S::from(v)` with a `usize` or `u32`. And you can convert back
  59 ///   to an integer with `u32::from(s)`.
  60 ///
  61 /// - Alternatively, you can use the methods `S::new(v)` and `s.index()`
  62 ///   to create/return a value.
  63 ///
  64 /// Internally, the index uses a u32, so the index must not exceed
  65 /// `u32::MAX`. You can also customize things like the `Debug` impl,
  66 /// what traits are derived, and so forth via the macro.
  67 #[macro_export]
  68 #[allow_internal_unstable(step_trait, rustc_attrs)]
  69 macro_rules! newtype_index {
  70     // ---- public rules ----
  71
  72     // Use default constants
  73     ($(#[$attrs:meta])* $v:vis struct $name:ident { .. }) => (
  74         $crate::newtype_index!(
  75             // Leave out derives marker so we can use its absence to ensure it comes first
  76             @attrs        [$(#[$attrs])*]
  77             @type         [$name]
  78             // shave off 256 indices at the end to allow space for packing these indices into enums
  79             @max          [0xFFFF_FF00]
  80             @vis          [$v]
  81             @debug_format ["{}"]);
  82     );
  83
  84     // Define any constants
  85     ($(#[$attrs:meta])* $v:vis struct $name:ident { $($tokens:tt)+ }) => (
  86         $crate::newtype_index!(
  87             // Leave out derives marker so we can use its absence to ensure it comes first
  88             @attrs        [$(#[$attrs])*]
  89             @type         [$name]
  90             // shave off 256 indices at the end to allow space for packing these indices into enums
  91             @max          [0xFFFF_FF00]
  92             @vis          [$v]
  93             @debug_format ["{}"]
  94                           $($tokens)+);
  95     );
  96
  97     // ---- private rules ----
  98
  99     // Base case, user-defined constants (if any) have already been defined
 100     (@derives      [$($derives:ident,)*]
 101      @attrs        [$(#[$attrs:meta])*]
 102      @type         [$type:ident]
 103      @max          [$max:expr]
 104      @vis          [$v:vis]
 105      @debug_format [$debug_format:tt]) => (
 106         $(#[$attrs])*
 107         #[derive(Copy, PartialEq, Eq, Hash, PartialOrd, Ord, $($derives),*)]
 108         #[rustc_layout_scalar_valid_range_end($max)]
 109         $v struct $type {
 110             private: u32
 111         }
 112
 113         impl Clone for $type {
 114             fn clone(&self) -> Self {
 115                 *self
 116             }
 117         }
 118
 119         impl $type {
 120             $v const MAX_AS_U32: u32 = $max;
 121
 122             $v const MAX: Self = Self::from_u32($max);
 123
 124             #[inline]
 125             $v const fn from_usize(value: usize) -> Self {
 126                 assert!(value <= ($max as usize));
 127                 unsafe {
 128                     Self::from_u32_unchecked(value as u32)
 129                 }
 130             }
 131
 132             #[inline]
 133             $v const fn from_u32(value: u32) -> Self {
 134                 assert!(value <= $max);
 135                 unsafe {
 136                     Self::from_u32_unchecked(value)
 137                 }
 138             }
 139
 140             #[inline]
 141             $v const unsafe fn from_u32_unchecked(value: u32) -> Self {
 142                 Self { private: value }
 143             }
 144
 145             /// Extracts the value of this index as an integer.
 146             #[inline]
 147             $v const fn index(self) -> usize {
 148                 self.as_usize()
 149             }
 150
 151             /// Extracts the value of this index as a `u32`.
 152             #[inline]
 153             $v const fn as_u32(self) -> u32 {
 154                 self.private
 155             }
 156
 157             /// Extracts the value of this index as a `usize`.
 158             #[inline]
 159             $v const fn as_usize(self) -> usize {
 160                 self.as_u32() as usize
 161             }
 162         }
 163
 164         impl std::ops::Add<usize> for $type {
 165             type Output = Self;
 166
 167             fn add(self, other: usize) -> Self {
 168                 Self::from_usize(self.index() + other)
 169             }
 170         }
 171
 172         impl $crate::vec::Idx for $type {
 173             #[inline]
 174             fn new(value: usize) -> Self {
 175                 Self::from_usize(value)
 176             }
 177
 178             #[inline]
 179             fn index(self) -> usize {
 180                 self.as_usize()
 181             }
 182         }
 183
 184         impl ::std::iter::Step for $type {
 185             #[inline]
 186             fn steps_between(start: &Self, end: &Self) -> Option<usize> {
 187                 <usize as ::std::iter::Step>::steps_between(
 188                     &Self::index(*start),
 189                     &Self::index(*end),
 190                 )
 191             }
 192
 193             #[inline]
 194             fn replace_one(&mut self) -> Self {
 195                 ::std::mem::replace(self, Self::from_u32(1))
 196             }
 197
 198             #[inline]
 199             fn replace_zero(&mut self) -> Self {
 200                 ::std::mem::replace(self, Self::from_u32(0))
 201             }
 202
 203             #[inline]
 204             fn add_one(&self) -> Self {
 205                 Self::from_usize(Self::index(*self) + 1)
 206             }
 207
 208             #[inline]
 209             fn sub_one(&self) -> Self {
 210                 Self::from_usize(Self::index(*self) - 1)
 211             }
 212
 213             #[inline]
 214             fn add_usize(&self, u: usize) -> Option<Self> {
 215                 Self::index(*self).checked_add(u).map(Self::from_usize)
 216             }
 217
 218             #[inline]
 219             fn sub_usize(&self, u: usize) -> Option<Self> {
 220                 Self::index(*self).checked_sub(u).map(Self::from_usize)
 221             }
 222         }
 223
 224         impl From<$type> for u32 {
 225             #[inline]
 226             fn from(v: $type) -> u32 {
 227                 v.as_u32()
 228             }
 229         }
 230
 231         impl From<$type> for usize {
 232             #[inline]
 233             fn from(v: $type) -> usize {
 234                 v.as_usize()
 235             }
 236         }
 237
 238         impl From<usize> for $type {
 239             #[inline]
 240             fn from(value: usize) -> Self {
 241                 Self::from_usize(value)
 242             }
 243         }
 244
 245         impl From<u32> for $type {
 246             #[inline]
 247             fn from(value: u32) -> Self {
 248                 Self::from_u32(value)
 249             }
 250         }
 251
 252         $crate::newtype_index!(
 253             @handle_debug
 254             @derives      [$($derives,)*]
 255             @type         [$type]
 256             @debug_format [$debug_format]);
 257     );
 258
 259     // base case for handle_debug where format is custom. No Debug implementation is emitted.
 260     (@handle_debug
 261      @derives      [$($_derives:ident,)*]
 262      @type         [$type:ident]
 263      @debug_format [custom]) => ();
 264
 265     // base case for handle_debug, no debug overrides found, so use default
 266     (@handle_debug
 267      @derives      []
 268      @type         [$type:ident]
 269      @debug_format [$debug_format:tt]) => (
 270         impl ::std::fmt::Debug for $type {
 271             fn fmt(&self, fmt: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
 272                 write!(fmt, $debug_format, self.as_u32())
 273             }
 274         }
 275     );
 276
 277     // Debug is requested for derive, don't generate any Debug implementation.
 278     (@handle_debug
 279      @derives      [Debug, $($derives:ident,)*]
 280      @type         [$type:ident]
 281      @debug_format [$debug_format:tt]) => ();
 282
 283     // It's not Debug, so just pop it off the front of the derives stack and check the rest.
 284     (@handle_debug
 285      @derives      [$_derive:ident, $($derives:ident,)*]
 286      @type         [$type:ident]
 287      @debug_format [$debug_format:tt]) => (
 288         $crate::newtype_index!(
 289             @handle_debug
 290             @derives      [$($derives,)*]
 291             @type         [$type]
 292             @debug_format [$debug_format]);
 293     );
 294
 295     // Append comma to end of derives list if it's missing
 296     (@attrs        [$(#[$attrs:meta])*]
 297      @type         [$type:ident]
 298      @max          [$max:expr]
 299      @vis          [$v:vis]
 300      @debug_format [$debug_format:tt]
 301                    derive [$($derives:ident),*]
 302                    $($tokens:tt)*) => (
 303         $crate::newtype_index!(
 304             @attrs        [$(#[$attrs])*]
 305             @type         [$type]
 306             @max          [$max]
 307             @vis          [$v]
 308             @debug_format [$debug_format]
 309                           derive [$($derives,)*]
 310                           $($tokens)*);
 311     );
 312
 313     // By not including the @derives marker in this list nor in the default args, we can force it
 314     // to come first if it exists. When encodable is custom, just use the derives list as-is.
 315     (@attrs        [$(#[$attrs:meta])*]
 316      @type         [$type:ident]
 317      @max          [$max:expr]
 318      @vis          [$v:vis]
 319      @debug_format [$debug_format:tt]
 320                    derive [$($derives:ident,)+]
 321                    ENCODABLE = custom
 322                    $($tokens:tt)*) => (
 323         $crate::newtype_index!(
 324             @attrs        [$(#[$attrs])*]
 325             @derives      [$($derives,)+]
 326             @type         [$type]
 327             @max          [$max]
 328             @vis          [$v]
 329             @debug_format [$debug_format]
 330                           $($tokens)*);
 331     );
 332
 333     // By not including the @derives marker in this list nor in the default args, we can force it
 334     // to come first if it exists. When encodable isn't custom, add serialization traits by default.
 335     (@attrs        [$(#[$attrs:meta])*]
 336      @type         [$type:ident]
 337      @max          [$max:expr]
 338      @vis          [$v:vis]
 339      @debug_format [$debug_format:tt]
 340                    derive [$($derives:ident,)+]
 341                    $($tokens:tt)*) => (
 342         $crate::newtype_index!(
 343             @derives      [$($derives,)+ RustcEncodable,]
 344             @attrs        [$(#[$attrs])*]
 345             @type         [$type]
 346             @max          [$max]
 347             @vis          [$v]
 348             @debug_format [$debug_format]
 349                           $($tokens)*);
 350         $crate::newtype_index!(@decodable $type);
 351     );
 352
 353     // The case where no derives are added, but encodable is overridden. Don't
 354     // derive serialization traits
 355     (@attrs        [$(#[$attrs:meta])*]
 356      @type         [$type:ident]
 357      @max          [$max:expr]
 358      @vis          [$v:vis]
 359      @debug_format [$debug_format:tt]
 360                    ENCODABLE = custom
 361                    $($tokens:tt)*) => (
 362         $crate::newtype_index!(
 363             @derives      []
 364             @attrs        [$(#[$attrs])*]
 365             @type         [$type]
 366             @max          [$max]
 367             @vis          [$v]
 368             @debug_format [$debug_format]
 369                           $($tokens)*);
 370     );
 371
 372     // The case where no derives are added, add serialization derives by default
 373     (@attrs        [$(#[$attrs:meta])*]
 374      @type         [$type:ident]
 375      @max          [$max:expr]
 376      @vis          [$v:vis]
 377      @debug_format [$debug_format:tt]
 378                    $($tokens:tt)*) => (
 379         $crate::newtype_index!(
 380             @derives      [RustcEncodable,]
 381             @attrs        [$(#[$attrs])*]
 382             @type         [$type]
 383             @max          [$max]
 384             @vis          [$v]
 385             @debug_format [$debug_format]
 386                           $($tokens)*);
 387         $crate::newtype_index!(@decodable $type);
 388     );
 389
 390     (@decodable $type:ident) => (
 391         impl ::rustc_serialize::Decodable for $type {
 392             fn decode<D: ::rustc_serialize::Decoder>(d: &mut D) -> Result<Self, D::Error> {
 393                 d.read_u32().map(Self::from_u32)
 394             }
 395         }
 396     );
 397
 398     // Rewrite final without comma to one that includes comma
 399     (@derives      [$($derives:ident,)*]
 400      @attrs        [$(#[$attrs:meta])*]
 401      @type         [$type:ident]
 402      @max          [$max:expr]
 403      @vis          [$v:vis]
 404      @debug_format [$debug_format:tt]
 405                    $name:ident = $constant:expr) => (
 406         $crate::newtype_index!(
 407             @derives      [$($derives,)*]
 408             @attrs        [$(#[$attrs])*]
 409             @type         [$type]
 410             @max          [$max]
 411             @vis          [$v]
 412             @debug_format [$debug_format]
 413                           $name = $constant,);
 414     );
 415
 416     // Rewrite final const without comma to one that includes comma
 417     (@derives      [$($derives:ident,)*]
 418      @attrs        [$(#[$attrs:meta])*]
 419      @type         [$type:ident]
 420      @max          [$max:expr]
 421      @vis          [$v:vis]
 422      @debug_format [$debug_format:tt]
 423                    $(#[doc = $doc:expr])*
 424                    const $name:ident = $constant:expr) => (
 425         $crate::newtype_index!(
 426             @derives      [$($derives,)*]
 427             @attrs        [$(#[$attrs])*]
 428             @type         [$type]
 429             @max          [$max]
 430             @vis          [$v]
 431             @debug_format [$debug_format]
 432                           $(#[doc = $doc])* const $name = $constant,);
 433     );
 434
 435     // Replace existing default for max
 436     (@derives      [$($derives:ident,)*]
 437      @attrs        [$(#[$attrs:meta])*]
 438      @type         [$type:ident]
 439      @max          [$_max:expr]
 440      @vis          [$v:vis]
 441      @debug_format [$debug_format:tt]
 442                    MAX = $max:expr,
 443                    $($tokens:tt)*) => (
 444         $crate::newtype_index!(
 445             @derives      [$($derives,)*]
 446             @attrs        [$(#[$attrs])*]
 447             @type         [$type]
 448             @max          [$max]
 449             @vis          [$v]
 450             @debug_format [$debug_format]
 451                           $($tokens)*);
 452     );
 453
 454     // Replace existing default for debug_format
 455     (@derives      [$($derives:ident,)*]
 456      @attrs        [$(#[$attrs:meta])*]
 457      @type         [$type:ident]
 458      @max          [$max:expr]
 459      @vis          [$v:vis]
 460      @debug_format [$_debug_format:tt]
 461                    DEBUG_FORMAT = $debug_format:tt,
 462                    $($tokens:tt)*) => (
 463         $crate::newtype_index!(
 464             @derives      [$($derives,)*]
 465             @attrs        [$(#[$attrs])*]
 466             @type         [$type]
 467             @max          [$max]
 468             @vis          [$v]
 469             @debug_format [$debug_format]
 470                           $($tokens)*);
 471     );
 472
 473     // Assign a user-defined constant
 474     (@derives      [$($derives:ident,)*]
 475      @attrs        [$(#[$attrs:meta])*]
 476      @type         [$type:ident]
 477      @max          [$max:expr]
 478      @vis          [$v:vis]
 479      @debug_format [$debug_format:tt]
 480                    $(#[doc = $doc:expr])*
 481                    const $name:ident = $constant:expr,
 482                    $($tokens:tt)*) => (
 483         $(#[doc = $doc])*
 484         $v const $name: $type = $type::from_u32($constant);
 485         $crate::newtype_index!(
 486             @derives      [$($derives,)*]
 487             @attrs        [$(#[$attrs])*]
 488             @type         [$type]
 489             @max          [$max]
 490             @vis          [$v]
 491             @debug_format [$debug_format]
 492                           $($tokens)*);
 493     );
 494 }
 495
 496 #[derive(Clone, PartialEq, Eq, Hash)]
 497 pub struct IndexVec<I: Idx, T> {
 498     pub raw: Vec<T>,
 499     _marker: PhantomData<fn(&I)>,
 500 }
 501
 502 // Whether `IndexVec` is `Send` depends only on the data,
 503 // not the phantom data.
 504 unsafe impl<I: Idx, T> Send for IndexVec<I, T> where T: Send {}
 505
 506 impl<I: Idx, T: Encodable> Encodable for IndexVec<I, T> {
 507     fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
 508         Encodable::encode(&self.raw, s)
 509     }
 510 }
 511
 512 impl<I: Idx, T: Decodable> Decodable for IndexVec<I, T> {
 513     fn decode<D: Decoder>(d: &mut D) -> Result<Self, D::Error> {
 514         Decodable::decode(d).map(|v| IndexVec { raw: v, _marker: PhantomData })
 515     }
 516 }
 517
 518 impl<I: Idx, T: fmt::Debug> fmt::Debug for IndexVec<I, T> {
 519     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
 520         fmt::Debug::fmt(&self.raw, fmt)
 521     }
 522 }
 523
 524 pub type Enumerated<I, J> = iter::Map<iter::Enumerate<J>, IntoIdx<I>>;
 525
 526 impl<I: Idx, T> IndexVec<I, T> {
 527     #[inline]
 528     pub fn new() -> Self {
 529         IndexVec { raw: Vec::new(), _marker: PhantomData }
 530     }
 531
 532     #[inline]
 533     pub fn from_raw(raw: Vec<T>) -> Self {
 534         IndexVec { raw, _marker: PhantomData }
 535     }
 536
 537     #[inline]
 538     pub fn with_capacity(capacity: usize) -> Self {
 539         IndexVec { raw: Vec::with_capacity(capacity), _marker: PhantomData }
 540     }
 541
 542     #[inline]
 543     pub fn from_elem<S>(elem: T, universe: &IndexVec<I, S>) -> Self
 544     where
 545         T: Clone,
 546     {
 547         IndexVec { raw: vec![elem; universe.len()], _marker: PhantomData }
 548     }
 549
 550     #[inline]
 551     pub fn from_elem_n(elem: T, n: usize) -> Self
 552     where
 553         T: Clone,
 554     {
 555         IndexVec { raw: vec![elem; n], _marker: PhantomData }
 556     }
 557
 558     /// Create an `IndexVec` with `n` elements, where the value of each
 559     /// element is the result of `func(i)`
 560     #[inline]
 561     pub fn from_fn_n(func: impl FnMut(I) -> T, n: usize) -> Self {
 562         let indices = (0..n).map(I::new);
 563         Self::from_raw(indices.map(func).collect())
 564     }
 565
 566     #[inline]
 567     pub fn push(&mut self, d: T) -> I {
 568         let idx = I::new(self.len());
 569         self.raw.push(d);
 570         idx
 571     }
 572
 573     #[inline]
 574     pub fn pop(&mut self) -> Option<T> {
 575         self.raw.pop()
 576     }
 577
 578     #[inline]
 579     pub fn len(&self) -> usize {
 580         self.raw.len()
 581     }
 582
 583     /// Gives the next index that will be assigned when `push` is
 584     /// called.
 585     #[inline]
 586     pub fn next_index(&self) -> I {
 587         I::new(self.len())
 588     }
 589
 590     #[inline]
 591     pub fn is_empty(&self) -> bool {
 592         self.raw.is_empty()
 593     }
 594
 595     #[inline]
 596     pub fn into_iter(self) -> vec::IntoIter<T> {
 597         self.raw.into_iter()
 598     }
 599
 600     #[inline]
 601     pub fn into_iter_enumerated(self) -> Enumerated<I, vec::IntoIter<T>> {
 602         self.raw.into_iter().enumerate().map(IntoIdx { _marker: PhantomData })
 603     }
 604
 605     #[inline]
 606     pub fn iter(&self) -> slice::Iter<'_, T> {
 607         self.raw.iter()
 608     }
 609
 610     #[inline]
 611     pub fn iter_enumerated(&self) -> Enumerated<I, slice::Iter<'_, T>> {
 612         self.raw.iter().enumerate().map(IntoIdx { _marker: PhantomData })
 613     }
 614
 615     #[inline]
 616     pub fn indices(&self) -> iter::Map<Range<usize>, IntoIdx<I>> {
 617         (0..self.len()).map(IntoIdx { _marker: PhantomData })
 618     }
 619
 620     #[inline]
 621     pub fn iter_mut(&mut self) -> slice::IterMut<'_, T> {
 622         self.raw.iter_mut()
 623     }
 624
 625     #[inline]
 626     pub fn iter_enumerated_mut(&mut self) -> Enumerated<I, slice::IterMut<'_, T>> {
 627         self.raw.iter_mut().enumerate().map(IntoIdx { _marker: PhantomData })
 628     }
 629
 630     #[inline]
 631     pub fn drain<'a, R: RangeBounds<usize>>(
 632         &'a mut self,
 633         range: R,
 634     ) -> impl Iterator<Item = T> + 'a {
 635         self.raw.drain(range)
 636     }
 637
 638     #[inline]
 639     pub fn drain_enumerated<'a, R: RangeBounds<usize>>(
 640         &'a mut self,
 641         range: R,
 642     ) -> impl Iterator<Item = (I, T)> + 'a {
 643         self.raw.drain(range).enumerate().map(IntoIdx { _marker: PhantomData })
 644     }
 645
 646     #[inline]
 647     pub fn last(&self) -> Option<I> {
 648         self.len().checked_sub(1).map(I::new)
 649     }
 650
 651     #[inline]
 652     pub fn shrink_to_fit(&mut self) {
 653         self.raw.shrink_to_fit()
 654     }
 655
 656     #[inline]
 657     pub fn swap(&mut self, a: I, b: I) {
 658         self.raw.swap(a.index(), b.index())
 659     }
 660
 661     #[inline]
 662     pub fn truncate(&mut self, a: usize) {
 663         self.raw.truncate(a)
 664     }
 665
 666     #[inline]
 667     pub fn get(&self, index: I) -> Option<&T> {
 668         self.raw.get(index.index())
 669     }
 670
 671     #[inline]
 672     pub fn get_mut(&mut self, index: I) -> Option<&mut T> {
 673         self.raw.get_mut(index.index())
 674     }
 675
 676     /// Returns mutable references to two distinct elements, a and b. Panics if a == b.
 677     #[inline]
 678     pub fn pick2_mut(&mut self, a: I, b: I) -> (&mut T, &mut T) {
 679         let (ai, bi) = (a.index(), b.index());
 680         assert!(ai != bi);
 681
 682         if ai < bi {
 683             let (c1, c2) = self.raw.split_at_mut(bi);
 684             (&mut c1[ai], &mut c2[0])
 685         } else {
 686             let (c2, c1) = self.pick2_mut(b, a);
 687             (c1, c2)
 688         }
 689     }
 690
 691     pub fn convert_index_type<Ix: Idx>(self) -> IndexVec<Ix, T> {
 692         IndexVec { raw: self.raw, _marker: PhantomData }
 693     }
 694 }
 695
 696 impl<I: Idx, T: Clone> IndexVec<I, T> {
 697     /// Grows the index vector so that it contains an entry for
 698     /// `elem`; if that is already true, then has no
 699     /// effect. Otherwise, inserts new values as needed by invoking
 700     /// `fill_value`.
 701     #[inline]
 702     pub fn ensure_contains_elem(&mut self, elem: I, fill_value: impl FnMut() -> T) {
 703         let min_new_len = elem.index() + 1;
 704         if self.len() < min_new_len {
 705             self.raw.resize_with(min_new_len, fill_value);
 706         }
 707     }
 708
 709     #[inline]
 710     pub fn resize(&mut self, new_len: usize, value: T) {
 711         self.raw.resize(new_len, value)
 712     }
 713
 714     #[inline]
 715     pub fn resize_to_elem(&mut self, elem: I, fill_value: impl FnMut() -> T) {
 716         let min_new_len = elem.index() + 1;
 717         self.raw.resize_with(min_new_len, fill_value);
 718     }
 719 }
 720
 721 impl<I: Idx, T: Ord> IndexVec<I, T> {
 722     #[inline]
 723     pub fn binary_search(&self, value: &T) -> Result<I, I> {
 724         match self.raw.binary_search(value) {
 725             Ok(i) => Ok(Idx::new(i)),
 726             Err(i) => Err(Idx::new(i)),
 727         }
 728     }
 729 }
 730
 731 impl<I: Idx, T> Index<I> for IndexVec<I, T> {
 732     type Output = T;
 733
 734     #[inline]
 735     fn index(&self, index: I) -> &T {
 736         &self.raw[index.index()]
 737     }
 738 }
 739
 740 impl<I: Idx, T> IndexMut<I> for IndexVec<I, T> {
 741     #[inline]
 742     fn index_mut(&mut self, index: I) -> &mut T {
 743         &mut self.raw[index.index()]
 744     }
 745 }
 746
 747 impl<I: Idx, T> Default for IndexVec<I, T> {
 748     #[inline]
 749     fn default() -> Self {
 750         Self::new()
 751     }
 752 }
 753
 754 impl<I: Idx, T> Extend<T> for IndexVec<I, T> {
 755     #[inline]
 756     fn extend<J: IntoIterator<Item = T>>(&mut self, iter: J) {
 757         self.raw.extend(iter);
 758     }
 759 }
 760
 761 impl<I: Idx, T> FromIterator<T> for IndexVec<I, T> {
 762     #[inline]
 763     fn from_iter<J>(iter: J) -> Self
 764     where
 765         J: IntoIterator<Item = T>,
 766     {
 767         IndexVec { raw: FromIterator::from_iter(iter), _marker: PhantomData }
 768     }
 769 }
 770
 771 impl<I: Idx, T> IntoIterator for IndexVec<I, T> {
 772     type Item = T;
 773     type IntoIter = vec::IntoIter<T>;
 774
 775     #[inline]
 776     fn into_iter(self) -> vec::IntoIter<T> {
 777         self.raw.into_iter()
 778     }
 779 }
 780
 781 impl<'a, I: Idx, T> IntoIterator for &'a IndexVec<I, T> {
 782     type Item = &'a T;
 783     type IntoIter = slice::Iter<'a, T>;
 784
 785     #[inline]
 786     fn into_iter(self) -> slice::Iter<'a, T> {
 787         self.raw.iter()
 788     }
 789 }
 790
 791 impl<'a, I: Idx, T> IntoIterator for &'a mut IndexVec<I, T> {
 792     type Item = &'a mut T;
 793     type IntoIter = slice::IterMut<'a, T>;
 794
 795     #[inline]
 796     fn into_iter(self) -> slice::IterMut<'a, T> {
 797         self.raw.iter_mut()
 798     }
 799 }
 800
 801 pub struct IntoIdx<I: Idx> {
 802     _marker: PhantomData<fn(&I)>,
 803 }
 804 impl<I: Idx, T> FnOnce<((usize, T),)> for IntoIdx<I> {
 805     type Output = (I, T);
 806
 807     extern "rust-call" fn call_once(self, ((n, t),): ((usize, T),)) -> Self::Output {
 808         (I::new(n), t)
 809     }
 810 }
 811
 812 impl<I: Idx, T> FnMut<((usize, T),)> for IntoIdx<I> {
 813     extern "rust-call" fn call_mut(&mut self, ((n, t),): ((usize, T),)) -> Self::Output {
 814         (I::new(n), t)
 815     }
 816 }
 817
 818 impl<I: Idx> FnOnce<(usize,)> for IntoIdx<I> {
 819     type Output = I;
 820
 821     extern "rust-call" fn call_once(self, (n,): (usize,)) -> Self::Output {
 822         I::new(n)
 823     }
 824 }
 825
 826 impl<I: Idx> FnMut<(usize,)> for IntoIdx<I> {
 827     extern "rust-call" fn call_mut(&mut self, (n,): (usize,)) -> Self::Output {
 828         I::new(n)
 829     }
 830 }
 831
 832 #[cfg(test)]
 833 mod tests;