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refactor: vec_deque ignore-tidy-filelength

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commit c547d5fabcd756515afa7263ee5304965bb4c497
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 11:22:23 2020 +0000

    test: updating ui/hygiene/panic-location.rs expected

commit 2af03769c4ffdbbbad75197a1ad0df8c599186be
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 10:43:30 2020 +0000

    fix: documentation unresolved link

commit c4b0df361ce27d7392d8016229f2e0265af32086
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 02:58:31 2020 +0000

    style: compiling with Rust's style guidelines

commit bdd2de5f3c09b49a18e3293f2457fcab25557c96
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 02:56:31 2020 +0000

    refactor: removing ignore-tidy-filelength

commit fcc4b3bc41f57244c65ebb8e4efe4cbc9460b5a9
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 02:51:35 2020 +0000

    refactor: moving trait RingSlices to ring_slices.rs

commit 2f0cc539c06d8841baf7f675168f68ca7c21e68e
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 02:46:09 2020 +0000

    refactor: moving struct PairSlices to pair_slices.rs

commit a55d3ef1dab4c3d85962b3a601ff8d1f7497faf2
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 02:31:45 2020 +0000

    refactor: moving struct Iter to iter.rs

commit 76ab33a12442a03726f36f606b4e0fe70f8f246b
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 02:24:32 2020 +0000

    refactor: moving struct IntoIter into into_iter.rs

commit abe0d9eea2933881858c3b1bc09df67cedc5ada5
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 02:19:07 2020 +0000

    refactor: moving struct IterMut into iter_mut.rs

commit 70ebd6420335e1895e2afa2763a0148897963e24
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 01:49:15 2020 +0000

    refactor: moved macros into macros.rs

commit b08dd2add994b04ae851aa065800bd8bd6326134
Author: C <DeveloperC@protonmail.com>
Date:   Sat Oct 31 01:05:36 2020 +0000

    refactor: moving vec_deque.rs to vec_deque/mod.rs
This commit is contained in:
C 2020-11-13 17:56:39 +00:00
parent a1f7ca788d
commit 75dfc711da
8 changed files with 515 additions and 473 deletions
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57
library/alloc/src/collections/vec_deque/into_iter.rs Normal file
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@ -0,0 +1,57 @@
use core::fmt;
use core::iter::FusedIterator;
use super::VecDeque;
/// An owning iterator over the elements of a `VecDeque`.
///
/// This `struct` is created by the [`into_iter`] method on [`VecDeque`]
/// (provided by the `IntoIterator` trait). See its documentation for more.
///
/// [`into_iter`]: VecDeque::into_iter
#[derive(Clone)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct IntoIter<T> {
pub(crate) inner: VecDeque<T>,
}
#[stable(feature = "collection_debug", since = "1.17.0")]
impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_tuple("IntoIter").field(&self.inner).finish()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> Iterator for IntoIter<T> {
type Item = T;
#[inline]
fn next(&mut self) -> Option<T> {
self.inner.pop_front()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let len = self.inner.len();
(len, Some(len))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> DoubleEndedIterator for IntoIter<T> {
#[inline]
fn next_back(&mut self) -> Option<T> {
self.inner.pop_back()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ExactSizeIterator for IntoIter<T> {
fn is_empty(&self) -> bool {
self.inner.is_empty()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<T> FusedIterator for IntoIter<T> {}

159
library/alloc/src/collections/vec_deque/iter.rs Normal file
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@ -0,0 +1,159 @@
use core::fmt;
use core::iter::FusedIterator;
use core::ops::Try;
use super::{count, wrap_index, RingSlices};
/// An iterator over the elements of a `VecDeque`.
///
/// This `struct` is created by the [`iter`] method on [`super::VecDeque`]. See its
/// documentation for more.
///
/// [`iter`]: super::VecDeque::iter
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Iter<'a, T: 'a> {
pub(crate) ring: &'a [T],
pub(crate) tail: usize,
pub(crate) head: usize,
}
#[stable(feature = "collection_debug", since = "1.17.0")]
impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
f.debug_tuple("Iter").field(&front).field(&back).finish()
}
}
// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> Clone for Iter<'_, T> {
fn clone(&self) -> Self {
Iter { ring: self.ring, tail: self.tail, head: self.head }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> Iterator for Iter<'a, T> {
type Item = &'a T;
#[inline]
fn next(&mut self) -> Option<&'a T> {
if self.tail == self.head {
return None;
}
let tail = self.tail;
self.tail = wrap_index(self.tail.wrapping_add(1), self.ring.len());
unsafe { Some(self.ring.get_unchecked(tail)) }
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let len = count(self.tail, self.head, self.ring.len());
(len, Some(len))
}
fn fold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
accum = front.iter().fold(accum, &mut f);
back.iter().fold(accum, &mut f)
}
fn try_fold<B, F, R>(&mut self, init: B, mut f: F) -> R
where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
{
let (mut iter, final_res);
if self.tail <= self.head {
// single slice self.ring[self.tail..self.head]
iter = self.ring[self.tail..self.head].iter();
final_res = iter.try_fold(init, &mut f);
} else {
// two slices: self.ring[self.tail..], self.ring[..self.head]
let (front, back) = self.ring.split_at(self.tail);
let mut back_iter = back.iter();
let res = back_iter.try_fold(init, &mut f);
let len = self.ring.len();
self.tail = (self.ring.len() - back_iter.len()) & (len - 1);
iter = front[..self.head].iter();
final_res = iter.try_fold(res?, &mut f);
}
self.tail = self.head - iter.len();
final_res
}
fn nth(&mut self, n: usize) -> Option<Self::Item> {
if n >= count(self.tail, self.head, self.ring.len()) {
self.tail = self.head;
None
} else {
self.tail = wrap_index(self.tail.wrapping_add(n), self.ring.len());
self.next()
}
}
#[inline]
fn last(mut self) -> Option<&'a T> {
self.next_back()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
#[inline]
fn next_back(&mut self) -> Option<&'a T> {
if self.tail == self.head {
return None;
}
self.head = wrap_index(self.head.wrapping_sub(1), self.ring.len());
unsafe { Some(self.ring.get_unchecked(self.head)) }
}
fn rfold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
accum = back.iter().rfold(accum, &mut f);
front.iter().rfold(accum, &mut f)
}
fn try_rfold<B, F, R>(&mut self, init: B, mut f: F) -> R
where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
{
let (mut iter, final_res);
if self.tail <= self.head {
// single slice self.ring[self.tail..self.head]
iter = self.ring[self.tail..self.head].iter();
final_res = iter.try_rfold(init, &mut f);
} else {
// two slices: self.ring[self.tail..], self.ring[..self.head]
let (front, back) = self.ring.split_at(self.tail);
let mut front_iter = front[..self.head].iter();
let res = front_iter.try_rfold(init, &mut f);
self.head = front_iter.len();
iter = back.iter();
final_res = iter.try_rfold(res?, &mut f);
}
self.head = self.tail + iter.len();
final_res
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ExactSizeIterator for Iter<'_, T> {
fn is_empty(&self) -> bool {
self.head == self.tail
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<T> FusedIterator for Iter<'_, T> {}

128
library/alloc/src/collections/vec_deque/iter_mut.rs Normal file
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@ -0,0 +1,128 @@
use core::fmt;
use core::iter::FusedIterator;
use core::marker::PhantomData;
use super::{count, wrap_index, RingSlices};
/// A mutable iterator over the elements of a `VecDeque`.
///
/// This `struct` is created by the [`iter_mut`] method on [`super::VecDeque`]. See its
/// documentation for more.
///
/// [`iter_mut`]: super::VecDeque::iter_mut
#[stable(feature = "rust1", since = "1.0.0")]
pub struct IterMut<'a, T: 'a> {
// Internal safety invariant: the entire slice is dereferencable.
pub(crate) ring: *mut [T],
pub(crate) tail: usize,
pub(crate) head: usize,
pub(crate) phantom: PhantomData<&'a mut [T]>,
}
// SAFETY: we do nothing thread-local and there is no interior mutability,
// so the usual structural `Send`/`Sync` apply.
#[stable(feature = "rust1", since = "1.0.0")]
unsafe impl<T: Send> Send for IterMut<'_, T> {}
#[stable(feature = "rust1", since = "1.0.0")]
unsafe impl<T: Sync> Sync for IterMut<'_, T> {}
#[stable(feature = "collection_debug", since = "1.17.0")]
impl<T: fmt::Debug> fmt::Debug for IterMut<'_, T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
// SAFETY: these are the elements we have not handed out yet, so aliasing is fine.
// The `IterMut` invariant also ensures everything is dereferencable.
let (front, back) = unsafe { (&*front, &*back) };
f.debug_tuple("IterMut").field(&front).field(&back).finish()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> Iterator for IterMut<'a, T> {
type Item = &'a mut T;
#[inline]
fn next(&mut self) -> Option<&'a mut T> {
if self.tail == self.head {
return None;
}
let tail = self.tail;
self.tail = wrap_index(self.tail.wrapping_add(1), self.ring.len());
unsafe {
let elem = self.ring.get_unchecked_mut(tail);
Some(&mut *elem)
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let len = count(self.tail, self.head, self.ring.len());
(len, Some(len))
}
fn fold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
// SAFETY: these are the elements we have not handed out yet, so aliasing is fine.
// The `IterMut` invariant also ensures everything is dereferencable.
let (front, back) = unsafe { (&mut *front, &mut *back) };
accum = front.iter_mut().fold(accum, &mut f);
back.iter_mut().fold(accum, &mut f)
}
fn nth(&mut self, n: usize) -> Option<Self::Item> {
if n >= count(self.tail, self.head, self.ring.len()) {
self.tail = self.head;
None
} else {
self.tail = wrap_index(self.tail.wrapping_add(n), self.ring.len());
self.next()
}
}
#[inline]
fn last(mut self) -> Option<&'a mut T> {
self.next_back()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> DoubleEndedIterator for IterMut<'a, T> {
#[inline]
fn next_back(&mut self) -> Option<&'a mut T> {
if self.tail == self.head {
return None;
}
self.head = wrap_index(self.head.wrapping_sub(1), self.ring.len());
unsafe {
let elem = self.ring.get_unchecked_mut(self.head);
Some(&mut *elem)
}
}
fn rfold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
// SAFETY: these are the elements we have not handed out yet, so aliasing is fine.
// The `IterMut` invariant also ensures everything is dereferencable.
let (front, back) = unsafe { (&mut *front, &mut *back) };
accum = back.iter_mut().rfold(accum, &mut f);
front.iter_mut().rfold(accum, &mut f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ExactSizeIterator for IterMut<'_, T> {
fn is_empty(&self) -> bool {
self.head == self.tail
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<T> FusedIterator for IterMut<'_, T> {}

19
library/alloc/src/collections/vec_deque/macros.rs Normal file
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@ -0,0 +1,19 @@
macro_rules! __impl_slice_eq1 {
([$($vars:tt)*] $lhs:ty, $rhs:ty, $($constraints:tt)*) => {
#[stable(feature = "vec_deque_partial_eq_slice", since = "1.17.0")]
impl<A, B, $($vars)*> PartialEq<$rhs> for $lhs
where
A: PartialEq<B>,
$($constraints)*
{
fn eq(&self, other: &$rhs) -> bool {
if self.len() != other.len() {
return false;
}
let (sa, sb) = self.as_slices();
let (oa, ob) = other[..].split_at(sa.len());
sa == oa && sb == ob
}
}
}
}

501
library/alloc/src/collections/vec_deque.rs → library/alloc/src/collections/vec_deque/mod.rs
View File

@ -7,16 +7,13 @@
#![stable(feature = "rust1", since = "1.0.0")]
// ignore-tidy-filelength
use core::array;
use core::cmp::{self, Ordering};
use core::fmt;
use core::hash::{Hash, Hasher};
use core::iter::{repeat_with, FromIterator, FusedIterator};
use core::iter::{repeat_with, FromIterator};
use core::marker::PhantomData;
use core::mem::{self, replace, ManuallyDrop};
use core::ops::{Index, IndexMut, Range, RangeBounds, Try};
use core::mem::{self, ManuallyDrop};
use core::ops::{Index, IndexMut, Range, RangeBounds};
use core::ptr::{self, NonNull};
use core::slice;
@ -24,11 +21,37 @@ use crate::collections::TryReserveError;
use crate::raw_vec::RawVec;
use crate::vec::Vec;
#[macro_use]
mod macros;
#[stable(feature = "drain", since = "1.6.0")]
pub use self::drain::Drain;
mod drain;
#[stable(feature = "rust1", since = "1.0.0")]
pub use self::iter_mut::IterMut;
mod iter_mut;
#[stable(feature = "rust1", since = "1.0.0")]
pub use self::into_iter::IntoIter;
mod into_iter;
#[stable(feature = "rust1", since = "1.0.0")]
pub use self::iter::Iter;
mod iter;
use self::pair_slices::PairSlices;
mod pair_slices;
use self::ring_slices::RingSlices;
mod ring_slices;
#[cfg(test)]
mod tests;
@ -68,67 +91,6 @@ pub struct VecDeque<T> {
buf: RawVec<T>,
}
/// PairSlices pairs up equal length slice parts of two deques
///
/// For example, given deques "A" and "B" with the following division into slices:
///
/// A: [0 1 2] [3 4 5]
/// B: [a b] [c d e]
///
/// It produces the following sequence of matching slices:
///
/// ([0 1], [a b])
/// (\[2\], \[c\])
/// ([3 4], [d e])
///
/// and the uneven remainder of either A or B is skipped.
struct PairSlices<'a, 'b, T> {
a0: &'a mut [T],
a1: &'a mut [T],
b0: &'b [T],
b1: &'b [T],
}
impl<'a, 'b, T> PairSlices<'a, 'b, T> {
fn from(to: &'a mut VecDeque<T>, from: &'b VecDeque<T>) -> Self {
let (a0, a1) = to.as_mut_slices();
let (b0, b1) = from.as_slices();
PairSlices { a0, a1, b0, b1 }
}
fn has_remainder(&self) -> bool {
!self.b0.is_empty()
}
fn remainder(self) -> impl Iterator<Item = &'b [T]> {
array::IntoIter::new([self.b0, self.b1])
}
}
impl<'a, 'b, T> Iterator for PairSlices<'a, 'b, T> {
type Item = (&'a mut [T], &'b [T]);
fn next(&mut self) -> Option<Self::Item> {
// Get next part length
let part = cmp::min(self.a0.len(), self.b0.len());
if part == 0 {
return None;
}
let (p0, p1) = replace(&mut self.a0, &mut []).split_at_mut(part);
let (q0, q1) = self.b0.split_at(part);
// Move a1 into a0, if it's empty (and b1, b0 the same way).
self.a0 = p1;
self.b0 = q1;
if self.a0.is_empty() {
self.a0 = replace(&mut self.a1, &mut []);
}
if self.b0.is_empty() {
self.b0 = replace(&mut self.b1, &[]);
}
Some((p0, q0))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: Clone> Clone for VecDeque<T> {
fn clone(&self) -> VecDeque<T> {
@ -2605,61 +2567,6 @@ fn wrap_index(index: usize, size: usize) -> usize {
index & (size - 1)
}
/// Returns the two slices that cover the `VecDeque`'s valid range
trait RingSlices: Sized {
fn slice(self, from: usize, to: usize) -> Self;
fn split_at(self, i: usize) -> (Self, Self);
fn ring_slices(buf: Self, head: usize, tail: usize) -> (Self, Self) {
let contiguous = tail <= head;
if contiguous {
let (empty, buf) = buf.split_at(0);
(buf.slice(tail, head), empty)
} else {
let (mid, right) = buf.split_at(tail);
let (left, _) = mid.split_at(head);
(right, left)
}
}
}
impl<T> RingSlices for &[T] {
fn slice(self, from: usize, to: usize) -> Self {
&self[from..to]
}
fn split_at(self, i: usize) -> (Self, Self) {
(*self).split_at(i)
}
}
impl<T> RingSlices for &mut [T] {
fn slice(self, from: usize, to: usize) -> Self {
&mut self[from..to]
}
fn split_at(self, i: usize) -> (Self, Self) {
(*self).split_at_mut(i)
}
}
impl<T> RingSlices for *mut [T] {
fn slice(self, from: usize, to: usize) -> Self {
assert!(from <= to && to < self.len());
// Not using `get_unchecked_mut` to keep this a safe operation.
let len = to - from;
ptr::slice_from_raw_parts_mut(self.as_mut_ptr().wrapping_add(from), len)
}
fn split_at(self, mid: usize) -> (Self, Self) {
let len = self.len();
let ptr = self.as_mut_ptr();
assert!(mid <= len);
(
ptr::slice_from_raw_parts_mut(ptr, mid),
ptr::slice_from_raw_parts_mut(ptr.wrapping_add(mid), len - mid),
)
}
}
/// Calculate the number of elements left to be read in the buffer
#[inline]
fn count(tail: usize, head: usize, size: usize) -> usize {
@ -2667,336 +2574,6 @@ fn count(tail: usize, head: usize, size: usize) -> usize {
(head.wrapping_sub(tail)) & (size - 1)
}
/// An iterator over the elements of a `VecDeque`.
///
/// This `struct` is created by the [`iter`] method on [`VecDeque`]. See its
/// documentation for more.
///
/// [`iter`]: VecDeque::iter
#[stable(feature = "rust1", since = "1.0.0")]
pub struct Iter<'a, T: 'a> {
ring: &'a [T],
tail: usize,
head: usize,
}
#[stable(feature = "collection_debug", since = "1.17.0")]
impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
f.debug_tuple("Iter").field(&front).field(&back).finish()
}
}
// FIXME(#26925) Remove in favor of `#[derive(Clone)]`
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> Clone for Iter<'_, T> {
fn clone(&self) -> Self {
Iter { ring: self.ring, tail: self.tail, head: self.head }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> Iterator for Iter<'a, T> {
type Item = &'a T;
#[inline]
fn next(&mut self) -> Option<&'a T> {
if self.tail == self.head {
return None;
}
let tail = self.tail;
self.tail = wrap_index(self.tail.wrapping_add(1), self.ring.len());
unsafe { Some(self.ring.get_unchecked(tail)) }
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let len = count(self.tail, self.head, self.ring.len());
(len, Some(len))
}
fn fold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
accum = front.iter().fold(accum, &mut f);
back.iter().fold(accum, &mut f)
}
fn try_fold<B, F, R>(&mut self, init: B, mut f: F) -> R
where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
{
let (mut iter, final_res);
if self.tail <= self.head {
// single slice self.ring[self.tail..self.head]
iter = self.ring[self.tail..self.head].iter();
final_res = iter.try_fold(init, &mut f);
} else {
// two slices: self.ring[self.tail..], self.ring[..self.head]
let (front, back) = self.ring.split_at(self.tail);
let mut back_iter = back.iter();
let res = back_iter.try_fold(init, &mut f);
let len = self.ring.len();
self.tail = (self.ring.len() - back_iter.len()) & (len - 1);
iter = front[..self.head].iter();
final_res = iter.try_fold(res?, &mut f);
}
self.tail = self.head - iter.len();
final_res
}
fn nth(&mut self, n: usize) -> Option<Self::Item> {
if n >= count(self.tail, self.head, self.ring.len()) {
self.tail = self.head;
None
} else {
self.tail = wrap_index(self.tail.wrapping_add(n), self.ring.len());
self.next()
}
}
#[inline]
fn last(mut self) -> Option<&'a T> {
self.next_back()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
#[inline]
fn next_back(&mut self) -> Option<&'a T> {
if self.tail == self.head {
return None;
}
self.head = wrap_index(self.head.wrapping_sub(1), self.ring.len());
unsafe { Some(self.ring.get_unchecked(self.head)) }
}
fn rfold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
accum = back.iter().rfold(accum, &mut f);
front.iter().rfold(accum, &mut f)
}
fn try_rfold<B, F, R>(&mut self, init: B, mut f: F) -> R
where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Ok = B>,
{
let (mut iter, final_res);
if self.tail <= self.head {
// single slice self.ring[self.tail..self.head]
iter = self.ring[self.tail..self.head].iter();
final_res = iter.try_rfold(init, &mut f);
} else {
// two slices: self.ring[self.tail..], self.ring[..self.head]
let (front, back) = self.ring.split_at(self.tail);
let mut front_iter = front[..self.head].iter();
let res = front_iter.try_rfold(init, &mut f);
self.head = front_iter.len();
iter = back.iter();
final_res = iter.try_rfold(res?, &mut f);
}
self.head = self.tail + iter.len();
final_res
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ExactSizeIterator for Iter<'_, T> {
fn is_empty(&self) -> bool {
self.head == self.tail
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<T> FusedIterator for Iter<'_, T> {}
/// A mutable iterator over the elements of a `VecDeque`.
///
/// This `struct` is created by the [`iter_mut`] method on [`VecDeque`]. See its
/// documentation for more.
///
/// [`iter_mut`]: VecDeque::iter_mut
#[stable(feature = "rust1", since = "1.0.0")]
pub struct IterMut<'a, T: 'a> {
// Internal safety invariant: the entire slice is dereferencable.
ring: *mut [T],
tail: usize,
head: usize,
phantom: PhantomData<&'a mut [T]>,
}
// SAFETY: we do nothing thread-local and there is no interior mutability,
// so the usual structural `Send`/`Sync` apply.
#[stable(feature = "rust1", since = "1.0.0")]
unsafe impl<T: Send> Send for IterMut<'_, T> {}
#[stable(feature = "rust1", since = "1.0.0")]
unsafe impl<T: Sync> Sync for IterMut<'_, T> {}
#[stable(feature = "collection_debug", since = "1.17.0")]
impl<T: fmt::Debug> fmt::Debug for IterMut<'_, T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
// SAFETY: these are the elements we have not handed out yet, so aliasing is fine.
// The `IterMut` invariant also ensures everything is dereferencable.
let (front, back) = unsafe { (&*front, &*back) };
f.debug_tuple("IterMut").field(&front).field(&back).finish()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> Iterator for IterMut<'a, T> {
type Item = &'a mut T;
#[inline]
fn next(&mut self) -> Option<&'a mut T> {
if self.tail == self.head {
return None;
}
let tail = self.tail;
self.tail = wrap_index(self.tail.wrapping_add(1), self.ring.len());
unsafe {
let elem = self.ring.get_unchecked_mut(tail);
Some(&mut *elem)
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let len = count(self.tail, self.head, self.ring.len());
(len, Some(len))
}
fn fold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
// SAFETY: these are the elements we have not handed out yet, so aliasing is fine.
// The `IterMut` invariant also ensures everything is dereferencable.
let (front, back) = unsafe { (&mut *front, &mut *back) };
accum = front.iter_mut().fold(accum, &mut f);
back.iter_mut().fold(accum, &mut f)
}
fn nth(&mut self, n: usize) -> Option<Self::Item> {
if n >= count(self.tail, self.head, self.ring.len()) {
self.tail = self.head;
None
} else {
self.tail = wrap_index(self.tail.wrapping_add(n), self.ring.len());
self.next()
}
}
#[inline]
fn last(mut self) -> Option<&'a mut T> {
self.next_back()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, T> DoubleEndedIterator for IterMut<'a, T> {
#[inline]
fn next_back(&mut self) -> Option<&'a mut T> {
if self.tail == self.head {
return None;
}
self.head = wrap_index(self.head.wrapping_sub(1), self.ring.len());
unsafe {
let elem = self.ring.get_unchecked_mut(self.head);
Some(&mut *elem)
}
}
fn rfold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
// SAFETY: these are the elements we have not handed out yet, so aliasing is fine.
// The `IterMut` invariant also ensures everything is dereferencable.
let (front, back) = unsafe { (&mut *front, &mut *back) };
accum = back.iter_mut().rfold(accum, &mut f);
front.iter_mut().rfold(accum, &mut f)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ExactSizeIterator for IterMut<'_, T> {
fn is_empty(&self) -> bool {
self.head == self.tail
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<T> FusedIterator for IterMut<'_, T> {}
/// An owning iterator over the elements of a `VecDeque`.
///
/// This `struct` is created by the [`into_iter`] method on [`VecDeque`]
/// (provided by the `IntoIterator` trait). See its documentation for more.
///
/// [`into_iter`]: VecDeque::into_iter
#[derive(Clone)]
#[stable(feature = "rust1", since = "1.0.0")]
pub struct IntoIter<T> {
inner: VecDeque<T>,
}
#[stable(feature = "collection_debug", since = "1.17.0")]
impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_tuple("IntoIter").field(&self.inner).finish()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> Iterator for IntoIter<T> {
type Item = T;
#[inline]
fn next(&mut self) -> Option<T> {
self.inner.pop_front()
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
let len = self.inner.len();
(len, Some(len))
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> DoubleEndedIterator for IntoIter<T> {
#[inline]
fn next_back(&mut self) -> Option<T> {
self.inner.pop_back()
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> ExactSizeIterator for IntoIter<T> {
fn is_empty(&self) -> bool {
self.inner.is_empty()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<T> FusedIterator for IntoIter<T> {}
#[stable(feature = "rust1", since = "1.0.0")]
impl<A: PartialEq> PartialEq for VecDeque<A> {
fn eq(&self, other: &VecDeque<A>) -> bool {
@ -3039,26 +2616,6 @@ impl<A: PartialEq> PartialEq for VecDeque<A> {
#[stable(feature = "rust1", since = "1.0.0")]
impl<A: Eq> Eq for VecDeque<A> {}
macro_rules! __impl_slice_eq1 {
([$($vars:tt)*] $lhs:ty, $rhs:ty, $($constraints:tt)*) => {
#[stable(feature = "vec_deque_partial_eq_slice", since = "1.17.0")]
impl<A, B, $($vars)*> PartialEq<$rhs> for $lhs
where
A: PartialEq<B>,
$($constraints)*
{
fn eq(&self, other: &$rhs) -> bool {
if self.len() != other.len() {
return false;
}
let (sa, sb) = self.as_slices();
let (oa, ob) = other[..].split_at(sa.len());
sa == oa && sb == ob
}
}
}
}
__impl_slice_eq1! { [] VecDeque<A>, Vec<B>, }
__impl_slice_eq1! { [] VecDeque<A>, &[B], }
__impl_slice_eq1! { [] VecDeque<A>, &mut [B], }

66
library/alloc/src/collections/vec_deque/pair_slices.rs Normal file
View File

@ -0,0 +1,66 @@
use core::array;
use core::cmp::{self};
use core::mem::replace;
use super::VecDeque;
/// PairSlices pairs up equal length slice parts of two deques
///
/// For example, given deques "A" and "B" with the following division into slices:
///
/// A: [0 1 2] [3 4 5]
/// B: [a b] [c d e]
///
/// It produces the following sequence of matching slices:
///
/// ([0 1], [a b])
/// (\[2\], \[c\])
/// ([3 4], [d e])
///
/// and the uneven remainder of either A or B is skipped.
pub struct PairSlices<'a, 'b, T> {
pub(crate) a0: &'a mut [T],
pub(crate) a1: &'a mut [T],
pub(crate) b0: &'b [T],
pub(crate) b1: &'b [T],
}
impl<'a, 'b, T> PairSlices<'a, 'b, T> {
pub fn from(to: &'a mut VecDeque<T>, from: &'b VecDeque<T>) -> Self {
let (a0, a1) = to.as_mut_slices();
let (b0, b1) = from.as_slices();
PairSlices { a0, a1, b0, b1 }
}
pub fn has_remainder(&self) -> bool {
!self.b0.is_empty()
}
pub fn remainder(self) -> impl Iterator<Item = &'b [T]> {
array::IntoIter::new([self.b0, self.b1])
}
}
impl<'a, 'b, T> Iterator for PairSlices<'a, 'b, T> {
type Item = (&'a mut [T], &'b [T]);
fn next(&mut self) -> Option<Self::Item> {
// Get next part length
let part = cmp::min(self.a0.len(), self.b0.len());
if part == 0 {
return None;
}
let (p0, p1) = replace(&mut self.a0, &mut []).split_at_mut(part);
let (q0, q1) = self.b0.split_at(part);
// Move a1 into a0, if it's empty (and b1, b0 the same way).
self.a0 = p1;
self.b0 = q1;
if self.a0.is_empty() {
self.a0 = replace(&mut self.a1, &mut []);
}
if self.b0.is_empty() {
self.b0 = replace(&mut self.b1, &[]);
}
Some((p0, q0))
}
}

56
library/alloc/src/collections/vec_deque/ring_slices.rs Normal file
View File

@ -0,0 +1,56 @@
use core::ptr::{self};
/// Returns the two slices that cover the `VecDeque`'s valid range
pub trait RingSlices: Sized {
fn slice(self, from: usize, to: usize) -> Self;
fn split_at(self, i: usize) -> (Self, Self);
fn ring_slices(buf: Self, head: usize, tail: usize) -> (Self, Self) {
let contiguous = tail <= head;
if contiguous {
let (empty, buf) = buf.split_at(0);
(buf.slice(tail, head), empty)
} else {
let (mid, right) = buf.split_at(tail);
let (left, _) = mid.split_at(head);
(right, left)
}
}
}
impl<T> RingSlices for &[T] {
fn slice(self, from: usize, to: usize) -> Self {
&self[from..to]
}
fn split_at(self, i: usize) -> (Self, Self) {
(*self).split_at(i)
}
}
impl<T> RingSlices for &mut [T] {
fn slice(self, from: usize, to: usize) -> Self {
&mut self[from..to]
}
fn split_at(self, i: usize) -> (Self, Self) {
(*self).split_at_mut(i)
}
}
impl<T> RingSlices for *mut [T] {
fn slice(self, from: usize, to: usize) -> Self {
assert!(from <= to && to < self.len());
// Not using `get_unchecked_mut` to keep this a safe operation.
let len = to - from;
ptr::slice_from_raw_parts_mut(self.as_mut_ptr().wrapping_add(from), len)
}
fn split_at(self, mid: usize) -> (Self, Self) {
let len = self.len();
let ptr = self.as_mut_ptr();
assert!(mid <= len);
(
ptr::slice_from_raw_parts_mut(ptr, mid),
ptr::slice_from_raw_parts_mut(ptr.wrapping_add(mid), len - mid),
)
}
}

2
src/test/ui/hygiene/panic-location.run.stderr
View File

@ -1,2 +1,2 @@
thread 'main' panicked at 'capacity overflow', $SRC_DIR/alloc/src/collections/vec_deque.rs:LL:COL
thread 'main' panicked at 'capacity overflow', $SRC_DIR/alloc/src/collections/vec_deque/mod.rs:LL:COL
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace