1979 lines
58 KiB
Rust
1979 lines
58 KiB
Rust
// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Slice management and manipulation
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//!
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//! For more details `std::slice`.
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#![stable(feature = "rust1", since = "1.0.0")]
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// How this module is organized.
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//
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// The library infrastructure for slices is fairly messy. There's
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// a lot of stuff defined here. Let's keep it clean.
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//
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// Since slices don't support inherent methods; all operations
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// on them are defined on traits, which are then reexported from
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// the prelude for convenience. So there are a lot of traits here.
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//
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// The layout of this file is thus:
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//
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// * Slice-specific 'extension' traits and their implementations. This
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// is where most of the slice API resides.
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// * Implementations of a few common traits with important slice ops.
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// * Definitions of a bunch of iterators.
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// * Free functions.
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// * The `raw` and `bytes` submodules.
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// * Boilerplate trait implementations.
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use cmp::Ordering::{self, Less, Equal, Greater};
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use cmp;
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use fmt;
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use intrinsics::assume;
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use iter::*;
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use ops::{self, RangeFull};
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use ptr;
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use mem;
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use marker;
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use iter_private::TrustedRandomAccess;
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#[repr(C)]
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struct Repr<T> {
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pub data: *const T,
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pub len: usize,
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}
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//
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// Extension traits
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//
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/// Extension methods for slices.
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#[unstable(feature = "core_slice_ext",
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reason = "stable interface provided by `impl [T]` in later crates",
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issue = "32110")]
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#[allow(missing_docs)] // documented elsewhere
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pub trait SliceExt {
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type Item;
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#[stable(feature = "core", since = "1.6.0")]
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fn split_at(&self, mid: usize) -> (&[Self::Item], &[Self::Item]);
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#[stable(feature = "core", since = "1.6.0")]
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fn iter(&self) -> Iter<Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn split<P>(&self, pred: P) -> Split<Self::Item, P>
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where P: FnMut(&Self::Item) -> bool;
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#[stable(feature = "core", since = "1.6.0")]
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fn splitn<P>(&self, n: usize, pred: P) -> SplitN<Self::Item, P>
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where P: FnMut(&Self::Item) -> bool;
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#[stable(feature = "core", since = "1.6.0")]
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fn rsplitn<P>(&self, n: usize, pred: P) -> RSplitN<Self::Item, P>
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where P: FnMut(&Self::Item) -> bool;
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#[stable(feature = "core", since = "1.6.0")]
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fn windows(&self, size: usize) -> Windows<Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn chunks(&self, size: usize) -> Chunks<Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn get(&self, index: usize) -> Option<&Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn first(&self) -> Option<&Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn split_first(&self) -> Option<(&Self::Item, &[Self::Item])>;
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#[stable(feature = "core", since = "1.6.0")]
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fn split_last(&self) -> Option<(&Self::Item, &[Self::Item])>;
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#[stable(feature = "core", since = "1.6.0")]
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fn last(&self) -> Option<&Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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unsafe fn get_unchecked(&self, index: usize) -> &Self::Item;
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#[stable(feature = "core", since = "1.6.0")]
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fn as_ptr(&self) -> *const Self::Item;
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#[stable(feature = "core", since = "1.6.0")]
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fn binary_search(&self, x: &Self::Item) -> Result<usize, usize>
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where Self::Item: Ord;
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#[stable(feature = "core", since = "1.6.0")]
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fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize>
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where F: FnMut(&'a Self::Item) -> Ordering;
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#[stable(feature = "slice_binary_search_by_key", since = "1.10.0")]
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fn binary_search_by_key<'a, B, F>(&'a self, b: &B, f: F) -> Result<usize, usize>
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where F: FnMut(&'a Self::Item) -> B,
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B: Ord;
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#[stable(feature = "core", since = "1.6.0")]
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fn len(&self) -> usize;
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#[stable(feature = "core", since = "1.6.0")]
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fn is_empty(&self) -> bool { self.len() == 0 }
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#[stable(feature = "core", since = "1.6.0")]
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fn get_mut(&mut self, index: usize) -> Option<&mut Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn iter_mut(&mut self) -> IterMut<Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn first_mut(&mut self) -> Option<&mut Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn split_first_mut(&mut self) -> Option<(&mut Self::Item, &mut [Self::Item])>;
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#[stable(feature = "core", since = "1.6.0")]
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fn split_last_mut(&mut self) -> Option<(&mut Self::Item, &mut [Self::Item])>;
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#[stable(feature = "core", since = "1.6.0")]
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fn last_mut(&mut self) -> Option<&mut Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn split_mut<P>(&mut self, pred: P) -> SplitMut<Self::Item, P>
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where P: FnMut(&Self::Item) -> bool;
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#[stable(feature = "core", since = "1.6.0")]
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fn splitn_mut<P>(&mut self, n: usize, pred: P) -> SplitNMut<Self::Item, P>
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where P: FnMut(&Self::Item) -> bool;
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#[stable(feature = "core", since = "1.6.0")]
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fn rsplitn_mut<P>(&mut self, n: usize, pred: P) -> RSplitNMut<Self::Item, P>
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where P: FnMut(&Self::Item) -> bool;
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#[stable(feature = "core", since = "1.6.0")]
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fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<Self::Item>;
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#[stable(feature = "core", since = "1.6.0")]
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fn swap(&mut self, a: usize, b: usize);
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#[stable(feature = "core", since = "1.6.0")]
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fn split_at_mut(&mut self, mid: usize) -> (&mut [Self::Item], &mut [Self::Item]);
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#[stable(feature = "core", since = "1.6.0")]
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fn reverse(&mut self);
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#[stable(feature = "core", since = "1.6.0")]
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unsafe fn get_unchecked_mut(&mut self, index: usize) -> &mut Self::Item;
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#[stable(feature = "core", since = "1.6.0")]
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fn as_mut_ptr(&mut self) -> *mut Self::Item;
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#[stable(feature = "core", since = "1.6.0")]
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fn contains(&self, x: &Self::Item) -> bool where Self::Item: PartialEq;
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#[stable(feature = "core", since = "1.6.0")]
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fn starts_with(&self, needle: &[Self::Item]) -> bool where Self::Item: PartialEq;
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#[stable(feature = "core", since = "1.6.0")]
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fn ends_with(&self, needle: &[Self::Item]) -> bool where Self::Item: PartialEq;
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#[stable(feature = "clone_from_slice", since = "1.7.0")]
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fn clone_from_slice(&mut self, src: &[Self::Item]) where Self::Item: Clone;
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#[stable(feature = "copy_from_slice", since = "1.9.0")]
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fn copy_from_slice(&mut self, src: &[Self::Item]) where Self::Item: Copy;
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}
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// Use macros to be generic over const/mut
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macro_rules! slice_offset {
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($ptr:expr, $by:expr) => {{
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let ptr = $ptr;
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if size_from_ptr(ptr) == 0 {
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::intrinsics::arith_offset(ptr as *mut i8, $by) as *mut _
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} else {
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ptr.offset($by)
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}
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}};
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}
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macro_rules! slice_ref {
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($ptr:expr) => {{
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let ptr = $ptr;
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if size_from_ptr(ptr) == 0 {
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// Use a non-null pointer value
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&mut *(1 as *mut _)
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} else {
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mem::transmute(ptr)
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}
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}};
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}
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#[unstable(feature = "core_slice_ext",
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reason = "stable interface provided by `impl [T]` in later crates",
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issue = "32110")]
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impl<T> SliceExt for [T] {
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type Item = T;
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#[inline]
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fn split_at(&self, mid: usize) -> (&[T], &[T]) {
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(&self[..mid], &self[mid..])
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}
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#[inline]
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fn iter(&self) -> Iter<T> {
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unsafe {
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let p = if mem::size_of::<T>() == 0 {
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1 as *const _
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} else {
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let p = self.as_ptr();
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assume(!p.is_null());
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p
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};
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Iter {
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ptr: p,
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end: slice_offset!(p, self.len() as isize),
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_marker: marker::PhantomData
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}
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}
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}
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#[inline]
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fn split<P>(&self, pred: P) -> Split<T, P> where P: FnMut(&T) -> bool {
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Split {
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v: self,
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pred: pred,
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finished: false
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}
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}
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#[inline]
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fn splitn<P>(&self, n: usize, pred: P) -> SplitN<T, P> where
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P: FnMut(&T) -> bool,
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{
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SplitN {
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inner: GenericSplitN {
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iter: self.split(pred),
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count: n,
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invert: false
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}
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}
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}
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#[inline]
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fn rsplitn<P>(&self, n: usize, pred: P) -> RSplitN<T, P> where
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P: FnMut(&T) -> bool,
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{
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RSplitN {
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inner: GenericSplitN {
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iter: self.split(pred),
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count: n,
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invert: true
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}
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}
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}
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#[inline]
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fn windows(&self, size: usize) -> Windows<T> {
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assert!(size != 0);
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Windows { v: self, size: size }
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}
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#[inline]
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fn chunks(&self, size: usize) -> Chunks<T> {
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assert!(size != 0);
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Chunks { v: self, size: size }
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}
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#[inline]
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fn get(&self, index: usize) -> Option<&T> {
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if index < self.len() { Some(&self[index]) } else { None }
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}
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#[inline]
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fn first(&self) -> Option<&T> {
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if self.is_empty() { None } else { Some(&self[0]) }
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}
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#[inline]
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fn split_first(&self) -> Option<(&T, &[T])> {
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if self.is_empty() { None } else { Some((&self[0], &self[1..])) }
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}
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#[inline]
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fn split_last(&self) -> Option<(&T, &[T])> {
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let len = self.len();
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if len == 0 { None } else { Some((&self[len - 1], &self[..(len - 1)])) }
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}
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#[inline]
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fn last(&self) -> Option<&T> {
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if self.is_empty() { None } else { Some(&self[self.len() - 1]) }
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}
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#[inline]
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unsafe fn get_unchecked(&self, index: usize) -> &T {
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&*(self.as_ptr().offset(index as isize))
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}
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#[inline]
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fn as_ptr(&self) -> *const T {
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self as *const [T] as *const T
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}
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fn binary_search_by<'a, F>(&'a self, mut f: F) -> Result<usize, usize>
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where F: FnMut(&'a T) -> Ordering
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{
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let mut base = 0usize;
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let mut s = self;
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loop {
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let (head, tail) = s.split_at(s.len() >> 1);
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if tail.is_empty() {
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return Err(base)
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}
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match f(&tail[0]) {
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Less => {
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base += head.len() + 1;
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s = &tail[1..];
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}
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Greater => s = head,
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Equal => return Ok(base + head.len()),
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}
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}
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}
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#[inline]
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fn len(&self) -> usize {
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unsafe {
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mem::transmute::<&[T], Repr<T>>(self).len
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}
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}
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#[inline]
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fn get_mut(&mut self, index: usize) -> Option<&mut T> {
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if index < self.len() { Some(&mut self[index]) } else { None }
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}
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#[inline]
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fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T]) {
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let len = self.len();
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let ptr = self.as_mut_ptr();
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unsafe {
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assert!(mid <= len);
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(from_raw_parts_mut(ptr, mid),
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from_raw_parts_mut(ptr.offset(mid as isize), len - mid))
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}
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}
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#[inline]
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fn iter_mut(&mut self) -> IterMut<T> {
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unsafe {
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let p = if mem::size_of::<T>() == 0 {
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1 as *mut _
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} else {
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let p = self.as_mut_ptr();
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assume(!p.is_null());
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p
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};
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IterMut {
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ptr: p,
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end: slice_offset!(p, self.len() as isize),
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_marker: marker::PhantomData
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}
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}
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}
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#[inline]
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fn last_mut(&mut self) -> Option<&mut T> {
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let len = self.len();
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if len == 0 { return None; }
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Some(&mut self[len - 1])
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}
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#[inline]
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fn first_mut(&mut self) -> Option<&mut T> {
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if self.is_empty() { None } else { Some(&mut self[0]) }
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}
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#[inline]
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fn split_first_mut(&mut self) -> Option<(&mut T, &mut [T])> {
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if self.is_empty() { None } else {
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let split = self.split_at_mut(1);
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Some((&mut split.0[0], split.1))
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}
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}
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#[inline]
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fn split_last_mut(&mut self) -> Option<(&mut T, &mut [T])> {
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let len = self.len();
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if len == 0 { None } else {
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let split = self.split_at_mut(len - 1);
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Some((&mut split.1[0], split.0))
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}
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}
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#[inline]
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fn split_mut<P>(&mut self, pred: P) -> SplitMut<T, P> where P: FnMut(&T) -> bool {
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SplitMut { v: self, pred: pred, finished: false }
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}
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#[inline]
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fn splitn_mut<P>(&mut self, n: usize, pred: P) -> SplitNMut<T, P> where
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P: FnMut(&T) -> bool
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{
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SplitNMut {
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inner: GenericSplitN {
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iter: self.split_mut(pred),
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count: n,
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invert: false
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}
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}
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}
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#[inline]
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fn rsplitn_mut<P>(&mut self, n: usize, pred: P) -> RSplitNMut<T, P> where
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P: FnMut(&T) -> bool,
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{
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RSplitNMut {
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inner: GenericSplitN {
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iter: self.split_mut(pred),
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count: n,
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invert: true
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}
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}
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}
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#[inline]
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fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<T> {
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assert!(chunk_size > 0);
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ChunksMut { v: self, chunk_size: chunk_size }
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}
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#[inline]
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fn swap(&mut self, a: usize, b: usize) {
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unsafe {
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// Can't take two mutable loans from one vector, so instead just cast
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// them to their raw pointers to do the swap
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let pa: *mut T = &mut self[a];
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let pb: *mut T = &mut self[b];
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ptr::swap(pa, pb);
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}
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}
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fn reverse(&mut self) {
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let mut i: usize = 0;
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let ln = self.len();
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while i < ln / 2 {
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// Unsafe swap to avoid the bounds check in safe swap.
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unsafe {
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let pa: *mut T = self.get_unchecked_mut(i);
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let pb: *mut T = self.get_unchecked_mut(ln - i - 1);
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ptr::swap(pa, pb);
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}
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i += 1;
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}
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}
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#[inline]
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unsafe fn get_unchecked_mut(&mut self, index: usize) -> &mut T {
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&mut *self.as_mut_ptr().offset(index as isize)
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}
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#[inline]
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fn as_mut_ptr(&mut self) -> *mut T {
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self as *mut [T] as *mut T
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}
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#[inline]
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fn contains(&self, x: &T) -> bool where T: PartialEq {
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self.iter().any(|elt| *x == *elt)
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}
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#[inline]
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fn starts_with(&self, needle: &[T]) -> bool where T: PartialEq {
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let n = needle.len();
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self.len() >= n && needle == &self[..n]
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}
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#[inline]
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fn ends_with(&self, needle: &[T]) -> bool where T: PartialEq {
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let (m, n) = (self.len(), needle.len());
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m >= n && needle == &self[m-n..]
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}
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fn binary_search(&self, x: &T) -> Result<usize, usize> where T: Ord {
|
|
self.binary_search_by(|p| p.cmp(x))
|
|
}
|
|
|
|
#[inline]
|
|
fn clone_from_slice(&mut self, src: &[T]) where T: Clone {
|
|
assert!(self.len() == src.len(),
|
|
"destination and source slices have different lengths");
|
|
// NOTE: We need to explicitly slice them to the same length
|
|
// for bounds checking to be elided, and the optimizer will
|
|
// generate memcpy for simple cases (for example T = u8).
|
|
let len = self.len();
|
|
let src = &src[..len];
|
|
for i in 0..len {
|
|
self[i].clone_from(&src[i]);
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn copy_from_slice(&mut self, src: &[T]) where T: Copy {
|
|
assert!(self.len() == src.len(),
|
|
"destination and source slices have different lengths");
|
|
unsafe {
|
|
ptr::copy_nonoverlapping(
|
|
src.as_ptr(), self.as_mut_ptr(), self.len());
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn binary_search_by_key<'a, B, F>(&'a self, b: &B, mut f: F) -> Result<usize, usize>
|
|
where F: FnMut(&'a Self::Item) -> B,
|
|
B: Ord
|
|
{
|
|
self.binary_search_by(|k| f(k).cmp(b))
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::Index<usize> for [T] {
|
|
type Output = T;
|
|
|
|
fn index(&self, index: usize) -> &T {
|
|
assert!(index < self.len());
|
|
unsafe { self.get_unchecked(index) }
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::IndexMut<usize> for [T] {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: usize) -> &mut T {
|
|
assert!(index < self.len());
|
|
unsafe { self.get_unchecked_mut(index) }
|
|
}
|
|
}
|
|
|
|
#[inline(never)]
|
|
#[cold]
|
|
fn slice_index_len_fail(index: usize, len: usize) -> ! {
|
|
panic!("index {} out of range for slice of length {}", index, len);
|
|
}
|
|
|
|
#[inline(never)]
|
|
#[cold]
|
|
fn slice_index_order_fail(index: usize, end: usize) -> ! {
|
|
panic!("slice index starts at {} but ends at {}", index, end);
|
|
}
|
|
|
|
|
|
/// Implements slicing with syntax `&self[begin .. end]`.
|
|
///
|
|
/// Returns a slice of self for the index range [`begin`..`end`).
|
|
///
|
|
/// This operation is `O(1)`.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Requires that `begin <= end` and `end <= self.len()`,
|
|
/// otherwise slicing will panic.
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::Index<ops::Range<usize>> for [T] {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::Range<usize>) -> &[T] {
|
|
if index.start > index.end {
|
|
slice_index_order_fail(index.start, index.end);
|
|
} else if index.end > self.len() {
|
|
slice_index_len_fail(index.end, self.len());
|
|
}
|
|
unsafe {
|
|
from_raw_parts (
|
|
self.as_ptr().offset(index.start as isize),
|
|
index.end - index.start
|
|
)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Implements slicing with syntax `&self[.. end]`.
|
|
///
|
|
/// Returns a slice of self from the beginning until but not including
|
|
/// the index `end`.
|
|
///
|
|
/// Equivalent to `&self[0 .. end]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::Index<ops::RangeTo<usize>> for [T] {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::RangeTo<usize>) -> &[T] {
|
|
self.index(0 .. index.end)
|
|
}
|
|
}
|
|
|
|
/// Implements slicing with syntax `&self[begin ..]`.
|
|
///
|
|
/// Returns a slice of self from and including the index `begin` until the end.
|
|
///
|
|
/// Equivalent to `&self[begin .. self.len()]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::Index<ops::RangeFrom<usize>> for [T] {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::RangeFrom<usize>) -> &[T] {
|
|
self.index(index.start .. self.len())
|
|
}
|
|
}
|
|
|
|
/// Implements slicing with syntax `&self[..]`.
|
|
///
|
|
/// Returns a slice of the whole slice. This operation cannot panic.
|
|
///
|
|
/// Equivalent to `&self[0 .. self.len()]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::Index<RangeFull> for [T] {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, _index: RangeFull) -> &[T] {
|
|
self
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::Index<ops::RangeInclusive<usize>> for [T] {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::RangeInclusive<usize>) -> &[T] {
|
|
match index {
|
|
ops::RangeInclusive::Empty { .. } => &[],
|
|
ops::RangeInclusive::NonEmpty { end, .. } if end == usize::max_value() =>
|
|
panic!("attempted to index slice up to maximum usize"),
|
|
ops::RangeInclusive::NonEmpty { start, end } =>
|
|
self.index(start .. end+1)
|
|
}
|
|
}
|
|
}
|
|
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::Index<ops::RangeToInclusive<usize>> for [T] {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::RangeToInclusive<usize>) -> &[T] {
|
|
self.index(0...index.end)
|
|
}
|
|
}
|
|
|
|
/// Implements mutable slicing with syntax `&mut self[begin .. end]`.
|
|
///
|
|
/// Returns a slice of self for the index range [`begin`..`end`).
|
|
///
|
|
/// This operation is `O(1)`.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Requires that `begin <= end` and `end <= self.len()`,
|
|
/// otherwise slicing will panic.
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::IndexMut<ops::Range<usize>> for [T] {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::Range<usize>) -> &mut [T] {
|
|
if index.start > index.end {
|
|
slice_index_order_fail(index.start, index.end);
|
|
} else if index.end > self.len() {
|
|
slice_index_len_fail(index.end, self.len());
|
|
}
|
|
unsafe {
|
|
from_raw_parts_mut(
|
|
self.as_mut_ptr().offset(index.start as isize),
|
|
index.end - index.start
|
|
)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Implements mutable slicing with syntax `&mut self[.. end]`.
|
|
///
|
|
/// Returns a slice of self from the beginning until but not including
|
|
/// the index `end`.
|
|
///
|
|
/// Equivalent to `&mut self[0 .. end]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::IndexMut<ops::RangeTo<usize>> for [T] {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::RangeTo<usize>) -> &mut [T] {
|
|
self.index_mut(0 .. index.end)
|
|
}
|
|
}
|
|
|
|
/// Implements mutable slicing with syntax `&mut self[begin ..]`.
|
|
///
|
|
/// Returns a slice of self from and including the index `begin` until the end.
|
|
///
|
|
/// Equivalent to `&mut self[begin .. self.len()]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::IndexMut<ops::RangeFrom<usize>> for [T] {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::RangeFrom<usize>) -> &mut [T] {
|
|
let len = self.len();
|
|
self.index_mut(index.start .. len)
|
|
}
|
|
}
|
|
|
|
/// Implements mutable slicing with syntax `&mut self[..]`.
|
|
///
|
|
/// Returns a slice of the whole slice. This operation can not panic.
|
|
///
|
|
/// Equivalent to `&mut self[0 .. self.len()]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::IndexMut<RangeFull> for [T] {
|
|
#[inline]
|
|
fn index_mut(&mut self, _index: RangeFull) -> &mut [T] {
|
|
self
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::IndexMut<ops::RangeInclusive<usize>> for [T] {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::RangeInclusive<usize>) -> &mut [T] {
|
|
match index {
|
|
ops::RangeInclusive::Empty { .. } => &mut [],
|
|
ops::RangeInclusive::NonEmpty { end, .. } if end == usize::max_value() =>
|
|
panic!("attempted to index slice up to maximum usize"),
|
|
ops::RangeInclusive::NonEmpty { start, end } =>
|
|
self.index_mut(start .. end+1)
|
|
}
|
|
}
|
|
}
|
|
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
|
|
#[rustc_on_unimplemented = "slice indices are of type `usize`"]
|
|
impl<T> ops::IndexMut<ops::RangeToInclusive<usize>> for [T] {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::RangeToInclusive<usize>) -> &mut [T] {
|
|
self.index_mut(0...index.end)
|
|
}
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// Common traits
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> Default for &'a [T] {
|
|
/// Creates an empty slice.
|
|
fn default() -> &'a [T] { &[] }
|
|
}
|
|
|
|
#[stable(feature = "mut_slice_default", since = "1.5.0")]
|
|
impl<'a, T> Default for &'a mut [T] {
|
|
/// Creates a mutable empty slice.
|
|
fn default() -> &'a mut [T] { &mut [] }
|
|
}
|
|
|
|
//
|
|
// Iterators
|
|
//
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> IntoIterator for &'a [T] {
|
|
type Item = &'a T;
|
|
type IntoIter = Iter<'a, T>;
|
|
|
|
fn into_iter(self) -> Iter<'a, T> {
|
|
self.iter()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> IntoIterator for &'a mut [T] {
|
|
type Item = &'a mut T;
|
|
type IntoIter = IterMut<'a, T>;
|
|
|
|
fn into_iter(self) -> IterMut<'a, T> {
|
|
self.iter_mut()
|
|
}
|
|
}
|
|
|
|
#[inline(always)]
|
|
fn size_from_ptr<T>(_: *const T) -> usize {
|
|
mem::size_of::<T>()
|
|
}
|
|
|
|
// The shared definition of the `Iter` and `IterMut` iterators
|
|
macro_rules! iterator {
|
|
(struct $name:ident -> $ptr:ty, $elem:ty) => {
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> Iterator for $name<'a, T> {
|
|
type Item = $elem;
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<$elem> {
|
|
// could be implemented with slices, but this avoids bounds checks
|
|
unsafe {
|
|
if mem::size_of::<T>() != 0 {
|
|
assume(!self.ptr.is_null());
|
|
assume(!self.end.is_null());
|
|
}
|
|
if self.ptr == self.end {
|
|
None
|
|
} else {
|
|
let old = self.ptr;
|
|
self.ptr = slice_offset!(self.ptr, 1);
|
|
Some(slice_ref!(old))
|
|
}
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
let diff = (self.end as usize).wrapping_sub(self.ptr as usize);
|
|
let size = mem::size_of::<T>();
|
|
let exact = diff / (if size == 0 {1} else {size});
|
|
(exact, Some(exact))
|
|
}
|
|
|
|
#[inline]
|
|
fn count(self) -> usize {
|
|
self.len()
|
|
}
|
|
|
|
#[inline]
|
|
fn nth(&mut self, n: usize) -> Option<$elem> {
|
|
// Call helper method. Can't put the definition here because mut versus const.
|
|
self.iter_nth(n)
|
|
}
|
|
|
|
#[inline]
|
|
fn last(mut self) -> Option<$elem> {
|
|
self.next_back()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> DoubleEndedIterator for $name<'a, T> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<$elem> {
|
|
// could be implemented with slices, but this avoids bounds checks
|
|
unsafe {
|
|
if mem::size_of::<T>() != 0 {
|
|
assume(!self.ptr.is_null());
|
|
assume(!self.end.is_null());
|
|
}
|
|
if self.end == self.ptr {
|
|
None
|
|
} else {
|
|
self.end = slice_offset!(self.end, -1);
|
|
Some(slice_ref!(self.end))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
macro_rules! make_slice {
|
|
($start: expr, $end: expr) => {{
|
|
let start = $start;
|
|
let diff = ($end as usize).wrapping_sub(start as usize);
|
|
if size_from_ptr(start) == 0 {
|
|
// use a non-null pointer value
|
|
unsafe { from_raw_parts(1 as *const _, diff) }
|
|
} else {
|
|
let len = diff / size_from_ptr(start);
|
|
unsafe { from_raw_parts(start, len) }
|
|
}
|
|
}}
|
|
}
|
|
|
|
macro_rules! make_mut_slice {
|
|
($start: expr, $end: expr) => {{
|
|
let start = $start;
|
|
let diff = ($end as usize).wrapping_sub(start as usize);
|
|
if size_from_ptr(start) == 0 {
|
|
// use a non-null pointer value
|
|
unsafe { from_raw_parts_mut(1 as *mut _, diff) }
|
|
} else {
|
|
let len = diff / size_from_ptr(start);
|
|
unsafe { from_raw_parts_mut(start, len) }
|
|
}
|
|
}}
|
|
}
|
|
|
|
/// Immutable slice iterator
|
|
///
|
|
/// This struct is created by the [`iter`] method on [slices].
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// Basic usage:
|
|
///
|
|
/// ```
|
|
/// // First, we declare a type which has `iter` method to get the `Iter` struct (&[usize here]):
|
|
/// let slice = &[1, 2, 3];
|
|
///
|
|
/// // Then, we iterate over it:
|
|
/// for element in slice.iter() {
|
|
/// println!("{}", element);
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// [`iter`]: ../../std/primitive.slice.html#method.iter
|
|
/// [slices]: ../../std/primitive.slice.html
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct Iter<'a, T: 'a> {
|
|
ptr: *const T,
|
|
end: *const T,
|
|
_marker: marker::PhantomData<&'a T>,
|
|
}
|
|
|
|
#[stable(feature = "core_impl_debug", since = "1.9.0")]
|
|
impl<'a, T: 'a + fmt::Debug> fmt::Debug for Iter<'a, T> {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_tuple("Iter")
|
|
.field(&self.as_slice())
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
unsafe impl<'a, T: Sync> Sync for Iter<'a, T> {}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
unsafe impl<'a, T: Sync> Send for Iter<'a, T> {}
|
|
|
|
impl<'a, T> Iter<'a, T> {
|
|
/// View the underlying data as a subslice of the original data.
|
|
///
|
|
/// This has the same lifetime as the original slice, and so the
|
|
/// iterator can continue to be used while this exists.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// Basic usage:
|
|
///
|
|
/// ```
|
|
/// // First, we declare a type which has the `iter` method to get the `Iter`
|
|
/// // struct (&[usize here]):
|
|
/// let slice = &[1, 2, 3];
|
|
///
|
|
/// // Then, we get the iterator:
|
|
/// let mut iter = slice.iter();
|
|
/// // So if we print what `as_slice` method returns here, we have "[1, 2, 3]":
|
|
/// println!("{:?}", iter.as_slice());
|
|
///
|
|
/// // Next, we move to the second element of the slice:
|
|
/// iter.next();
|
|
/// // Now `as_slice` returns "[2, 3]":
|
|
/// println!("{:?}", iter.as_slice());
|
|
/// ```
|
|
#[stable(feature = "iter_to_slice", since = "1.4.0")]
|
|
pub fn as_slice(&self) -> &'a [T] {
|
|
make_slice!(self.ptr, self.end)
|
|
}
|
|
|
|
// Helper function for Iter::nth
|
|
fn iter_nth(&mut self, n: usize) -> Option<&'a T> {
|
|
match self.as_slice().get(n) {
|
|
Some(elem_ref) => unsafe {
|
|
self.ptr = slice_offset!(self.ptr, (n as isize).wrapping_add(1));
|
|
Some(elem_ref)
|
|
},
|
|
None => {
|
|
self.ptr = self.end;
|
|
None
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
iterator!{struct Iter -> *const T, &'a T}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> ExactSizeIterator for Iter<'a, T> {}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, T> FusedIterator for Iter<'a, T> {}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> Clone for Iter<'a, T> {
|
|
fn clone(&self) -> Iter<'a, T> { Iter { ptr: self.ptr, end: self.end, _marker: self._marker } }
|
|
}
|
|
|
|
#[stable(feature = "slice_iter_as_ref", since = "1.12.0")]
|
|
impl<'a, T> AsRef<[T]> for Iter<'a, T> {
|
|
fn as_ref(&self) -> &[T] {
|
|
self.as_slice()
|
|
}
|
|
}
|
|
|
|
/// Mutable slice iterator.
|
|
///
|
|
/// This struct is created by the [`iter_mut`] method on [slices].
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// Basic usage:
|
|
///
|
|
/// ```
|
|
/// // First, we declare a type which has `iter_mut` method to get the `IterMut`
|
|
/// // struct (&[usize here]):
|
|
/// let mut slice = &mut [1, 2, 3];
|
|
///
|
|
/// // Then, we iterate over it and increment each element value:
|
|
/// for element in slice.iter_mut() {
|
|
/// *element += 1;
|
|
/// }
|
|
///
|
|
/// // We now have "[2, 3, 4]":
|
|
/// println!("{:?}", slice);
|
|
/// ```
|
|
///
|
|
/// [`iter_mut`]: ../../std/primitive.slice.html#method.iter_mut
|
|
/// [slices]: ../../std/primitive.slice.html
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct IterMut<'a, T: 'a> {
|
|
ptr: *mut T,
|
|
end: *mut T,
|
|
_marker: marker::PhantomData<&'a mut T>,
|
|
}
|
|
|
|
#[stable(feature = "core_impl_debug", since = "1.9.0")]
|
|
impl<'a, T: 'a + fmt::Debug> fmt::Debug for IterMut<'a, T> {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_tuple("IterMut")
|
|
.field(&make_slice!(self.ptr, self.end))
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
unsafe impl<'a, T: Sync> Sync for IterMut<'a, T> {}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
unsafe impl<'a, T: Send> Send for IterMut<'a, T> {}
|
|
|
|
impl<'a, T> IterMut<'a, T> {
|
|
/// View the underlying data as a subslice of the original data.
|
|
///
|
|
/// To avoid creating `&mut` references that alias, this is forced
|
|
/// to consume the iterator. Consider using the `Slice` and
|
|
/// `SliceMut` implementations for obtaining slices with more
|
|
/// restricted lifetimes that do not consume the iterator.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// Basic usage:
|
|
///
|
|
/// ```
|
|
/// // First, we declare a type which has `iter_mut` method to get the `IterMut`
|
|
/// // struct (&[usize here]):
|
|
/// let mut slice = &mut [1, 2, 3];
|
|
///
|
|
/// {
|
|
/// // Then, we get the iterator:
|
|
/// let mut iter = slice.iter_mut();
|
|
/// // We move to next element:
|
|
/// iter.next();
|
|
/// // So if we print what `into_slice` method returns here, we have "[2, 3]":
|
|
/// println!("{:?}", iter.into_slice());
|
|
/// }
|
|
///
|
|
/// // Now let's modify a value of the slice:
|
|
/// {
|
|
/// // First we get back the iterator:
|
|
/// let mut iter = slice.iter_mut();
|
|
/// // We change the value of the first element of the slice returned by the `next` method:
|
|
/// *iter.next().unwrap() += 1;
|
|
/// }
|
|
/// // Now slice is "[2, 2, 3]":
|
|
/// println!("{:?}", slice);
|
|
/// ```
|
|
#[stable(feature = "iter_to_slice", since = "1.4.0")]
|
|
pub fn into_slice(self) -> &'a mut [T] {
|
|
make_mut_slice!(self.ptr, self.end)
|
|
}
|
|
|
|
// Helper function for IterMut::nth
|
|
fn iter_nth(&mut self, n: usize) -> Option<&'a mut T> {
|
|
match make_mut_slice!(self.ptr, self.end).get_mut(n) {
|
|
Some(elem_ref) => unsafe {
|
|
self.ptr = slice_offset!(self.ptr, (n as isize).wrapping_add(1));
|
|
Some(elem_ref)
|
|
},
|
|
None => {
|
|
self.ptr = self.end;
|
|
None
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
iterator!{struct IterMut -> *mut T, &'a mut T}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> ExactSizeIterator for IterMut<'a, T> {}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, T> FusedIterator for IterMut<'a, T> {}
|
|
|
|
/// An internal abstraction over the splitting iterators, so that
|
|
/// splitn, splitn_mut etc can be implemented once.
|
|
#[doc(hidden)]
|
|
trait SplitIter: DoubleEndedIterator {
|
|
/// Mark the underlying iterator as complete, extracting the remaining
|
|
/// portion of the slice.
|
|
fn finish(&mut self) -> Option<Self::Item>;
|
|
}
|
|
|
|
/// An iterator over subslices separated by elements that match a predicate
|
|
/// function.
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct Split<'a, T:'a, P> where P: FnMut(&T) -> bool {
|
|
v: &'a [T],
|
|
pred: P,
|
|
finished: bool
|
|
}
|
|
|
|
#[stable(feature = "core_impl_debug", since = "1.9.0")]
|
|
impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for Split<'a, T, P> where P: FnMut(&T) -> bool {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_struct("Split")
|
|
.field("v", &self.v)
|
|
.field("finished", &self.finished)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T, P> Clone for Split<'a, T, P> where P: Clone + FnMut(&T) -> bool {
|
|
fn clone(&self) -> Split<'a, T, P> {
|
|
Split {
|
|
v: self.v,
|
|
pred: self.pred.clone(),
|
|
finished: self.finished,
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T, P> Iterator for Split<'a, T, P> where P: FnMut(&T) -> bool {
|
|
type Item = &'a [T];
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<&'a [T]> {
|
|
if self.finished { return None; }
|
|
|
|
match self.v.iter().position(|x| (self.pred)(x)) {
|
|
None => self.finish(),
|
|
Some(idx) => {
|
|
let ret = Some(&self.v[..idx]);
|
|
self.v = &self.v[idx + 1..];
|
|
ret
|
|
}
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
if self.finished {
|
|
(0, Some(0))
|
|
} else {
|
|
(1, Some(self.v.len() + 1))
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T, P> DoubleEndedIterator for Split<'a, T, P> where P: FnMut(&T) -> bool {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<&'a [T]> {
|
|
if self.finished { return None; }
|
|
|
|
match self.v.iter().rposition(|x| (self.pred)(x)) {
|
|
None => self.finish(),
|
|
Some(idx) => {
|
|
let ret = Some(&self.v[idx + 1..]);
|
|
self.v = &self.v[..idx];
|
|
ret
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, T, P> SplitIter for Split<'a, T, P> where P: FnMut(&T) -> bool {
|
|
#[inline]
|
|
fn finish(&mut self) -> Option<&'a [T]> {
|
|
if self.finished { None } else { self.finished = true; Some(self.v) }
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, T, P> FusedIterator for Split<'a, T, P> where P: FnMut(&T) -> bool {}
|
|
|
|
/// An iterator over the subslices of the vector which are separated
|
|
/// by elements that match `pred`.
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct SplitMut<'a, T:'a, P> where P: FnMut(&T) -> bool {
|
|
v: &'a mut [T],
|
|
pred: P,
|
|
finished: bool
|
|
}
|
|
|
|
#[stable(feature = "core_impl_debug", since = "1.9.0")]
|
|
impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for SplitMut<'a, T, P> where P: FnMut(&T) -> bool {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_struct("SplitMut")
|
|
.field("v", &self.v)
|
|
.field("finished", &self.finished)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
impl<'a, T, P> SplitIter for SplitMut<'a, T, P> where P: FnMut(&T) -> bool {
|
|
#[inline]
|
|
fn finish(&mut self) -> Option<&'a mut [T]> {
|
|
if self.finished {
|
|
None
|
|
} else {
|
|
self.finished = true;
|
|
Some(mem::replace(&mut self.v, &mut []))
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T, P> Iterator for SplitMut<'a, T, P> where P: FnMut(&T) -> bool {
|
|
type Item = &'a mut [T];
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<&'a mut [T]> {
|
|
if self.finished { return None; }
|
|
|
|
let idx_opt = { // work around borrowck limitations
|
|
let pred = &mut self.pred;
|
|
self.v.iter().position(|x| (*pred)(x))
|
|
};
|
|
match idx_opt {
|
|
None => self.finish(),
|
|
Some(idx) => {
|
|
let tmp = mem::replace(&mut self.v, &mut []);
|
|
let (head, tail) = tmp.split_at_mut(idx);
|
|
self.v = &mut tail[1..];
|
|
Some(head)
|
|
}
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
if self.finished {
|
|
(0, Some(0))
|
|
} else {
|
|
// if the predicate doesn't match anything, we yield one slice
|
|
// if it matches every element, we yield len+1 empty slices.
|
|
(1, Some(self.v.len() + 1))
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T, P> DoubleEndedIterator for SplitMut<'a, T, P> where
|
|
P: FnMut(&T) -> bool,
|
|
{
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<&'a mut [T]> {
|
|
if self.finished { return None; }
|
|
|
|
let idx_opt = { // work around borrowck limitations
|
|
let pred = &mut self.pred;
|
|
self.v.iter().rposition(|x| (*pred)(x))
|
|
};
|
|
match idx_opt {
|
|
None => self.finish(),
|
|
Some(idx) => {
|
|
let tmp = mem::replace(&mut self.v, &mut []);
|
|
let (head, tail) = tmp.split_at_mut(idx);
|
|
self.v = head;
|
|
Some(&mut tail[1..])
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, T, P> FusedIterator for SplitMut<'a, T, P> where P: FnMut(&T) -> bool {}
|
|
|
|
/// An private iterator over subslices separated by elements that
|
|
/// match a predicate function, splitting at most a fixed number of
|
|
/// times.
|
|
#[derive(Debug)]
|
|
struct GenericSplitN<I> {
|
|
iter: I,
|
|
count: usize,
|
|
invert: bool
|
|
}
|
|
|
|
impl<T, I: SplitIter<Item=T>> Iterator for GenericSplitN<I> {
|
|
type Item = T;
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<T> {
|
|
match self.count {
|
|
0 => None,
|
|
1 => { self.count -= 1; self.iter.finish() }
|
|
_ => {
|
|
self.count -= 1;
|
|
if self.invert {self.iter.next_back()} else {self.iter.next()}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
let (lower, upper_opt) = self.iter.size_hint();
|
|
(lower, upper_opt.map(|upper| cmp::min(self.count, upper)))
|
|
}
|
|
}
|
|
|
|
/// An iterator over subslices separated by elements that match a predicate
|
|
/// function, limited to a given number of splits.
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct SplitN<'a, T: 'a, P> where P: FnMut(&T) -> bool {
|
|
inner: GenericSplitN<Split<'a, T, P>>
|
|
}
|
|
|
|
#[stable(feature = "core_impl_debug", since = "1.9.0")]
|
|
impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for SplitN<'a, T, P> where P: FnMut(&T) -> bool {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_struct("SplitN")
|
|
.field("inner", &self.inner)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
/// An iterator over subslices separated by elements that match a
|
|
/// predicate function, limited to a given number of splits, starting
|
|
/// from the end of the slice.
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct RSplitN<'a, T: 'a, P> where P: FnMut(&T) -> bool {
|
|
inner: GenericSplitN<Split<'a, T, P>>
|
|
}
|
|
|
|
#[stable(feature = "core_impl_debug", since = "1.9.0")]
|
|
impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for RSplitN<'a, T, P> where P: FnMut(&T) -> bool {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_struct("RSplitN")
|
|
.field("inner", &self.inner)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
/// An iterator over subslices separated by elements that match a predicate
|
|
/// function, limited to a given number of splits.
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct SplitNMut<'a, T: 'a, P> where P: FnMut(&T) -> bool {
|
|
inner: GenericSplitN<SplitMut<'a, T, P>>
|
|
}
|
|
|
|
#[stable(feature = "core_impl_debug", since = "1.9.0")]
|
|
impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for SplitNMut<'a, T, P> where P: FnMut(&T) -> bool {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_struct("SplitNMut")
|
|
.field("inner", &self.inner)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
/// An iterator over subslices separated by elements that match a
|
|
/// predicate function, limited to a given number of splits, starting
|
|
/// from the end of the slice.
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct RSplitNMut<'a, T: 'a, P> where P: FnMut(&T) -> bool {
|
|
inner: GenericSplitN<SplitMut<'a, T, P>>
|
|
}
|
|
|
|
#[stable(feature = "core_impl_debug", since = "1.9.0")]
|
|
impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for RSplitNMut<'a, T, P> where P: FnMut(&T) -> bool {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_struct("RSplitNMut")
|
|
.field("inner", &self.inner)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
macro_rules! forward_iterator {
|
|
($name:ident: $elem:ident, $iter_of:ty) => {
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, $elem, P> Iterator for $name<'a, $elem, P> where
|
|
P: FnMut(&T) -> bool
|
|
{
|
|
type Item = $iter_of;
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<$iter_of> {
|
|
self.inner.next()
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
self.inner.size_hint()
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, $elem, P> FusedIterator for $name<'a, $elem, P>
|
|
where P: FnMut(&T) -> bool {}
|
|
}
|
|
}
|
|
|
|
forward_iterator! { SplitN: T, &'a [T] }
|
|
forward_iterator! { RSplitN: T, &'a [T] }
|
|
forward_iterator! { SplitNMut: T, &'a mut [T] }
|
|
forward_iterator! { RSplitNMut: T, &'a mut [T] }
|
|
|
|
/// An iterator over overlapping subslices of length `size`.
|
|
#[derive(Debug)]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct Windows<'a, T:'a> {
|
|
v: &'a [T],
|
|
size: usize
|
|
}
|
|
|
|
// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> Clone for Windows<'a, T> {
|
|
fn clone(&self) -> Windows<'a, T> {
|
|
Windows {
|
|
v: self.v,
|
|
size: self.size,
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> Iterator for Windows<'a, T> {
|
|
type Item = &'a [T];
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<&'a [T]> {
|
|
if self.size > self.v.len() {
|
|
None
|
|
} else {
|
|
let ret = Some(&self.v[..self.size]);
|
|
self.v = &self.v[1..];
|
|
ret
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
if self.size > self.v.len() {
|
|
(0, Some(0))
|
|
} else {
|
|
let size = self.v.len() - self.size + 1;
|
|
(size, Some(size))
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn count(self) -> usize {
|
|
self.len()
|
|
}
|
|
|
|
#[inline]
|
|
fn nth(&mut self, n: usize) -> Option<Self::Item> {
|
|
let (end, overflow) = self.size.overflowing_add(n);
|
|
if end > self.v.len() || overflow {
|
|
self.v = &[];
|
|
None
|
|
} else {
|
|
let nth = &self.v[n..end];
|
|
self.v = &self.v[n+1..];
|
|
Some(nth)
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn last(self) -> Option<Self::Item> {
|
|
if self.size > self.v.len() {
|
|
None
|
|
} else {
|
|
let start = self.v.len() - self.size;
|
|
Some(&self.v[start..])
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> DoubleEndedIterator for Windows<'a, T> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<&'a [T]> {
|
|
if self.size > self.v.len() {
|
|
None
|
|
} else {
|
|
let ret = Some(&self.v[self.v.len()-self.size..]);
|
|
self.v = &self.v[..self.v.len()-1];
|
|
ret
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> ExactSizeIterator for Windows<'a, T> {}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, T> FusedIterator for Windows<'a, T> {}
|
|
|
|
/// An iterator over a slice in (non-overlapping) chunks (`size` elements at a
|
|
/// time).
|
|
///
|
|
/// When the slice len is not evenly divided by the chunk size, the last slice
|
|
/// of the iteration will be the remainder.
|
|
#[derive(Debug)]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct Chunks<'a, T:'a> {
|
|
v: &'a [T],
|
|
size: usize
|
|
}
|
|
|
|
// FIXME(#19839) Remove in favor of `#[derive(Clone)]`
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> Clone for Chunks<'a, T> {
|
|
fn clone(&self) -> Chunks<'a, T> {
|
|
Chunks {
|
|
v: self.v,
|
|
size: self.size,
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> Iterator for Chunks<'a, T> {
|
|
type Item = &'a [T];
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<&'a [T]> {
|
|
if self.v.is_empty() {
|
|
None
|
|
} else {
|
|
let chunksz = cmp::min(self.v.len(), self.size);
|
|
let (fst, snd) = self.v.split_at(chunksz);
|
|
self.v = snd;
|
|
Some(fst)
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
if self.v.is_empty() {
|
|
(0, Some(0))
|
|
} else {
|
|
let n = self.v.len() / self.size;
|
|
let rem = self.v.len() % self.size;
|
|
let n = if rem > 0 { n+1 } else { n };
|
|
(n, Some(n))
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn count(self) -> usize {
|
|
self.len()
|
|
}
|
|
|
|
#[inline]
|
|
fn nth(&mut self, n: usize) -> Option<Self::Item> {
|
|
let (start, overflow) = n.overflowing_mul(self.size);
|
|
if start >= self.v.len() || overflow {
|
|
self.v = &[];
|
|
None
|
|
} else {
|
|
let end = match start.checked_add(self.size) {
|
|
Some(sum) => cmp::min(self.v.len(), sum),
|
|
None => self.v.len(),
|
|
};
|
|
let nth = &self.v[start..end];
|
|
self.v = &self.v[end..];
|
|
Some(nth)
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn last(self) -> Option<Self::Item> {
|
|
if self.v.is_empty() {
|
|
None
|
|
} else {
|
|
let start = (self.v.len() - 1) / self.size * self.size;
|
|
Some(&self.v[start..])
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> DoubleEndedIterator for Chunks<'a, T> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<&'a [T]> {
|
|
if self.v.is_empty() {
|
|
None
|
|
} else {
|
|
let remainder = self.v.len() % self.size;
|
|
let chunksz = if remainder != 0 { remainder } else { self.size };
|
|
let (fst, snd) = self.v.split_at(self.v.len() - chunksz);
|
|
self.v = fst;
|
|
Some(snd)
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> ExactSizeIterator for Chunks<'a, T> {}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, T> FusedIterator for Chunks<'a, T> {}
|
|
|
|
/// An iterator over a slice in (non-overlapping) mutable chunks (`size`
|
|
/// elements at a time). When the slice len is not evenly divided by the chunk
|
|
/// size, the last slice of the iteration will be the remainder.
|
|
#[derive(Debug)]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct ChunksMut<'a, T:'a> {
|
|
v: &'a mut [T],
|
|
chunk_size: usize
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> Iterator for ChunksMut<'a, T> {
|
|
type Item = &'a mut [T];
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<&'a mut [T]> {
|
|
if self.v.is_empty() {
|
|
None
|
|
} else {
|
|
let sz = cmp::min(self.v.len(), self.chunk_size);
|
|
let tmp = mem::replace(&mut self.v, &mut []);
|
|
let (head, tail) = tmp.split_at_mut(sz);
|
|
self.v = tail;
|
|
Some(head)
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
if self.v.is_empty() {
|
|
(0, Some(0))
|
|
} else {
|
|
let n = self.v.len() / self.chunk_size;
|
|
let rem = self.v.len() % self.chunk_size;
|
|
let n = if rem > 0 { n + 1 } else { n };
|
|
(n, Some(n))
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn count(self) -> usize {
|
|
self.len()
|
|
}
|
|
|
|
#[inline]
|
|
fn nth(&mut self, n: usize) -> Option<&'a mut [T]> {
|
|
let (start, overflow) = n.overflowing_mul(self.chunk_size);
|
|
if start >= self.v.len() || overflow {
|
|
self.v = &mut [];
|
|
None
|
|
} else {
|
|
let end = match start.checked_add(self.chunk_size) {
|
|
Some(sum) => cmp::min(self.v.len(), sum),
|
|
None => self.v.len(),
|
|
};
|
|
let tmp = mem::replace(&mut self.v, &mut []);
|
|
let (head, tail) = tmp.split_at_mut(end);
|
|
let (_, nth) = head.split_at_mut(start);
|
|
self.v = tail;
|
|
Some(nth)
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn last(self) -> Option<Self::Item> {
|
|
if self.v.is_empty() {
|
|
None
|
|
} else {
|
|
let start = (self.v.len() - 1) / self.chunk_size * self.chunk_size;
|
|
Some(&mut self.v[start..])
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> DoubleEndedIterator for ChunksMut<'a, T> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<&'a mut [T]> {
|
|
if self.v.is_empty() {
|
|
None
|
|
} else {
|
|
let remainder = self.v.len() % self.chunk_size;
|
|
let sz = if remainder != 0 { remainder } else { self.chunk_size };
|
|
let tmp = mem::replace(&mut self.v, &mut []);
|
|
let tmp_len = tmp.len();
|
|
let (head, tail) = tmp.split_at_mut(tmp_len - sz);
|
|
self.v = head;
|
|
Some(tail)
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> ExactSizeIterator for ChunksMut<'a, T> {}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, T> FusedIterator for ChunksMut<'a, T> {}
|
|
|
|
//
|
|
// Free functions
|
|
//
|
|
|
|
/// Forms a slice from a pointer and a length.
|
|
///
|
|
/// The `len` argument is the number of **elements**, not the number of bytes.
|
|
///
|
|
/// # Safety
|
|
///
|
|
/// This function is unsafe as there is no guarantee that the given pointer is
|
|
/// valid for `len` elements, nor whether the lifetime inferred is a suitable
|
|
/// lifetime for the returned slice.
|
|
///
|
|
/// `p` must be non-null, even for zero-length slices.
|
|
///
|
|
/// # Caveat
|
|
///
|
|
/// The lifetime for the returned slice is inferred from its usage. To
|
|
/// prevent accidental misuse, it's suggested to tie the lifetime to whichever
|
|
/// source lifetime is safe in the context, such as by providing a helper
|
|
/// function taking the lifetime of a host value for the slice, or by explicit
|
|
/// annotation.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use std::slice;
|
|
///
|
|
/// // manifest a slice out of thin air!
|
|
/// let ptr = 0x1234 as *const usize;
|
|
/// let amt = 10;
|
|
/// unsafe {
|
|
/// let slice = slice::from_raw_parts(ptr, amt);
|
|
/// }
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub unsafe fn from_raw_parts<'a, T>(p: *const T, len: usize) -> &'a [T] {
|
|
mem::transmute(Repr { data: p, len: len })
|
|
}
|
|
|
|
/// Performs the same functionality as `from_raw_parts`, except that a mutable
|
|
/// slice is returned.
|
|
///
|
|
/// This function is unsafe for the same reasons as `from_raw_parts`, as well
|
|
/// as not being able to provide a non-aliasing guarantee of the returned
|
|
/// mutable slice.
|
|
#[inline]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub unsafe fn from_raw_parts_mut<'a, T>(p: *mut T, len: usize) -> &'a mut [T] {
|
|
mem::transmute(Repr { data: p, len: len })
|
|
}
|
|
|
|
//
|
|
// Comparison traits
|
|
//
|
|
|
|
extern {
|
|
/// Call implementation provided memcmp
|
|
///
|
|
/// Interprets the data as u8.
|
|
///
|
|
/// Return 0 for equal, < 0 for less than and > 0 for greater
|
|
/// than.
|
|
// FIXME(#32610): Return type should be c_int
|
|
fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32;
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<A, B> PartialEq<[B]> for [A] where A: PartialEq<B> {
|
|
fn eq(&self, other: &[B]) -> bool {
|
|
SlicePartialEq::equal(self, other)
|
|
}
|
|
|
|
fn ne(&self, other: &[B]) -> bool {
|
|
SlicePartialEq::not_equal(self, other)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: Eq> Eq for [T] {}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: Ord> Ord for [T] {
|
|
fn cmp(&self, other: &[T]) -> Ordering {
|
|
SliceOrd::compare(self, other)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: PartialOrd> PartialOrd for [T] {
|
|
fn partial_cmp(&self, other: &[T]) -> Option<Ordering> {
|
|
SlicePartialOrd::partial_compare(self, other)
|
|
}
|
|
}
|
|
|
|
#[doc(hidden)]
|
|
// intermediate trait for specialization of slice's PartialEq
|
|
trait SlicePartialEq<B> {
|
|
fn equal(&self, other: &[B]) -> bool;
|
|
|
|
fn not_equal(&self, other: &[B]) -> bool { !self.equal(other) }
|
|
}
|
|
|
|
// Generic slice equality
|
|
impl<A, B> SlicePartialEq<B> for [A]
|
|
where A: PartialEq<B>
|
|
{
|
|
default fn equal(&self, other: &[B]) -> bool {
|
|
if self.len() != other.len() {
|
|
return false;
|
|
}
|
|
|
|
for i in 0..self.len() {
|
|
if !self[i].eq(&other[i]) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
true
|
|
}
|
|
}
|
|
|
|
// Use memcmp for bytewise equality when the types allow
|
|
impl<A> SlicePartialEq<A> for [A]
|
|
where A: PartialEq<A> + BytewiseEquality
|
|
{
|
|
fn equal(&self, other: &[A]) -> bool {
|
|
if self.len() != other.len() {
|
|
return false;
|
|
}
|
|
if self.as_ptr() == other.as_ptr() {
|
|
return true;
|
|
}
|
|
unsafe {
|
|
let size = mem::size_of_val(self);
|
|
memcmp(self.as_ptr() as *const u8,
|
|
other.as_ptr() as *const u8, size) == 0
|
|
}
|
|
}
|
|
}
|
|
|
|
#[doc(hidden)]
|
|
// intermediate trait for specialization of slice's PartialOrd
|
|
trait SlicePartialOrd<B> {
|
|
fn partial_compare(&self, other: &[B]) -> Option<Ordering>;
|
|
}
|
|
|
|
impl<A> SlicePartialOrd<A> for [A]
|
|
where A: PartialOrd
|
|
{
|
|
default fn partial_compare(&self, other: &[A]) -> Option<Ordering> {
|
|
let l = cmp::min(self.len(), other.len());
|
|
|
|
// Slice to the loop iteration range to enable bound check
|
|
// elimination in the compiler
|
|
let lhs = &self[..l];
|
|
let rhs = &other[..l];
|
|
|
|
for i in 0..l {
|
|
match lhs[i].partial_cmp(&rhs[i]) {
|
|
Some(Ordering::Equal) => (),
|
|
non_eq => return non_eq,
|
|
}
|
|
}
|
|
|
|
self.len().partial_cmp(&other.len())
|
|
}
|
|
}
|
|
|
|
impl SlicePartialOrd<u8> for [u8] {
|
|
#[inline]
|
|
fn partial_compare(&self, other: &[u8]) -> Option<Ordering> {
|
|
Some(SliceOrd::compare(self, other))
|
|
}
|
|
}
|
|
|
|
#[doc(hidden)]
|
|
// intermediate trait for specialization of slice's Ord
|
|
trait SliceOrd<B> {
|
|
fn compare(&self, other: &[B]) -> Ordering;
|
|
}
|
|
|
|
impl<A> SliceOrd<A> for [A]
|
|
where A: Ord
|
|
{
|
|
default fn compare(&self, other: &[A]) -> Ordering {
|
|
let l = cmp::min(self.len(), other.len());
|
|
|
|
// Slice to the loop iteration range to enable bound check
|
|
// elimination in the compiler
|
|
let lhs = &self[..l];
|
|
let rhs = &other[..l];
|
|
|
|
for i in 0..l {
|
|
match lhs[i].cmp(&rhs[i]) {
|
|
Ordering::Equal => (),
|
|
non_eq => return non_eq,
|
|
}
|
|
}
|
|
|
|
self.len().cmp(&other.len())
|
|
}
|
|
}
|
|
|
|
// memcmp compares a sequence of unsigned bytes lexicographically.
|
|
// this matches the order we want for [u8], but no others (not even [i8]).
|
|
impl SliceOrd<u8> for [u8] {
|
|
#[inline]
|
|
fn compare(&self, other: &[u8]) -> Ordering {
|
|
let order = unsafe {
|
|
memcmp(self.as_ptr(), other.as_ptr(),
|
|
cmp::min(self.len(), other.len()))
|
|
};
|
|
if order == 0 {
|
|
self.len().cmp(&other.len())
|
|
} else if order < 0 {
|
|
Less
|
|
} else {
|
|
Greater
|
|
}
|
|
}
|
|
}
|
|
|
|
#[doc(hidden)]
|
|
/// Trait implemented for types that can be compared for equality using
|
|
/// their bytewise representation
|
|
trait BytewiseEquality { }
|
|
|
|
macro_rules! impl_marker_for {
|
|
($traitname:ident, $($ty:ty)*) => {
|
|
$(
|
|
impl $traitname for $ty { }
|
|
)*
|
|
}
|
|
}
|
|
|
|
impl_marker_for!(BytewiseEquality,
|
|
u8 i8 u16 i16 u32 i32 u64 i64 usize isize char bool);
|
|
|
|
#[doc(hidden)]
|
|
unsafe impl<'a, T> TrustedRandomAccess for Iter<'a, T> {
|
|
unsafe fn get_unchecked(&mut self, i: usize) -> &'a T {
|
|
&*self.ptr.offset(i as isize)
|
|
}
|
|
}
|
|
|
|
#[doc(hidden)]
|
|
unsafe impl<'a, T> TrustedRandomAccess for IterMut<'a, T> {
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unsafe fn get_unchecked(&mut self, i: usize) -> &'a mut T {
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&mut *self.ptr.offset(i as isize)
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}
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}
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