2194 lines
67 KiB
Rust
2194 lines
67 KiB
Rust
// Copyright 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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//! A contiguous growable array type with heap-allocated contents, written
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//! `Vec<T>` but pronounced 'vector.'
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//!
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//! Vectors have `O(1)` indexing, amortized `O(1)` push (to the end) and
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//! `O(1)` pop (from the end).
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//!
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//! # Examples
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//!
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//! You can explicitly create a [`Vec<T>`] with [`new()`]:
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//!
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//! ```
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//! let v: Vec<i32> = Vec::new();
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//! ```
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//!
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//! ...or by using the [`vec!`] macro:
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//!
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//! ```
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//! let v: Vec<i32> = vec![];
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//!
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//! let v = vec![1, 2, 3, 4, 5];
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//!
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//! let v = vec![0; 10]; // ten zeroes
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//! ```
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//!
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//! You can [`push`] values onto the end of a vector (which will grow the vector
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//! as needed):
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//!
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//! ```
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//! let mut v = vec![1, 2];
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//!
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//! v.push(3);
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//! ```
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//!
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//! Popping values works in much the same way:
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//!
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//! ```
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//! let mut v = vec![1, 2];
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//!
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//! let two = v.pop();
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//! ```
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//!
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//! Vectors also support indexing (through the [`Index`] and [`IndexMut`] traits):
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//!
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//! ```
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//! let mut v = vec![1, 2, 3];
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//! let three = v[2];
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//! v[1] = v[1] + 5;
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//! ```
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//!
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//! [`Vec<T>`]: ../../std/vec/struct.Vec.html
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//! [`new()`]: ../../std/vec/struct.Vec.html#method.new
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//! [`push`]: ../../std/vec/struct.Vec.html#method.push
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//! [`Index`]: ../../std/ops/trait.Index.html
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//! [`IndexMut`]: ../../std/ops/trait.IndexMut.html
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//! [`vec!`]: ../../std/macro.vec.html
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#![stable(feature = "rust1", since = "1.0.0")]
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use alloc::boxed::Box;
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use alloc::heap::EMPTY;
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use alloc::raw_vec::RawVec;
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use borrow::ToOwned;
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use borrow::Cow;
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use core::cmp::Ordering;
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use core::fmt;
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use core::hash::{self, Hash};
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use core::intrinsics::{arith_offset, assume};
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use core::iter::{FromIterator, FusedIterator, TrustedLen};
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use core::mem;
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use core::ops::{InPlace, Index, IndexMut, Place, Placer};
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use core::ops;
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use core::ptr;
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use core::ptr::Shared;
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use core::slice;
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use super::range::RangeArgument;
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/// A contiguous growable array type, written `Vec<T>` but pronounced 'vector'.
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///
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/// # Examples
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///
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/// ```
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/// let mut vec = Vec::new();
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/// vec.push(1);
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/// vec.push(2);
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///
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/// assert_eq!(vec.len(), 2);
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/// assert_eq!(vec[0], 1);
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///
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/// assert_eq!(vec.pop(), Some(2));
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/// assert_eq!(vec.len(), 1);
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///
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/// vec[0] = 7;
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/// assert_eq!(vec[0], 7);
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///
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/// vec.extend([1, 2, 3].iter().cloned());
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///
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/// for x in &vec {
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/// println!("{}", x);
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/// }
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/// assert_eq!(vec, [7, 1, 2, 3]);
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/// ```
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///
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/// The [`vec!`] macro is provided to make initialization more convenient:
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///
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/// ```
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/// let mut vec = vec![1, 2, 3];
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/// vec.push(4);
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/// assert_eq!(vec, [1, 2, 3, 4]);
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/// ```
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///
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/// It can also initialize each element of a `Vec<T>` with a given value:
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///
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/// ```
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/// let vec = vec![0; 5];
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/// assert_eq!(vec, [0, 0, 0, 0, 0]);
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/// ```
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///
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/// Use a `Vec<T>` as an efficient stack:
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///
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/// ```
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/// let mut stack = Vec::new();
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///
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/// stack.push(1);
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/// stack.push(2);
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/// stack.push(3);
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///
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/// while let Some(top) = stack.pop() {
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/// // Prints 3, 2, 1
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/// println!("{}", top);
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/// }
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/// ```
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///
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/// # Indexing
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///
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/// The `Vec` type allows to access values by index, because it implements the
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/// [`Index`] trait. An example will be more explicit:
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///
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/// ```
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/// let v = vec![0, 2, 4, 6];
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/// println!("{}", v[1]); // it will display '2'
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/// ```
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///
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/// However be careful: if you try to access an index which isn't in the `Vec`,
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/// your software will panic! You cannot do this:
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///
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/// ```ignore
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/// let v = vec![0, 2, 4, 6];
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/// println!("{}", v[6]); // it will panic!
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/// ```
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///
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/// In conclusion: always check if the index you want to get really exists
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/// before doing it.
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///
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/// # Slicing
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///
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/// A `Vec` can be mutable. Slices, on the other hand, are read-only objects.
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/// To get a slice, use `&`. Example:
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///
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/// ```
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/// fn read_slice(slice: &[usize]) {
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/// // ...
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/// }
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///
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/// let v = vec![0, 1];
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/// read_slice(&v);
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///
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/// // ... and that's all!
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/// // you can also do it like this:
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/// let x : &[usize] = &v;
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/// ```
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///
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/// In Rust, it's more common to pass slices as arguments rather than vectors
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/// when you just want to provide a read access. The same goes for [`String`] and
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/// [`&str`].
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///
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/// # Capacity and reallocation
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///
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/// The capacity of a vector is the amount of space allocated for any future
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/// elements that will be added onto the vector. This is not to be confused with
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/// the *length* of a vector, which specifies the number of actual elements
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/// within the vector. If a vector's length exceeds its capacity, its capacity
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/// will automatically be increased, but its elements will have to be
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/// reallocated.
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///
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/// For example, a vector with capacity 10 and length 0 would be an empty vector
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/// with space for 10 more elements. Pushing 10 or fewer elements onto the
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/// vector will not change its capacity or cause reallocation to occur. However,
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/// if the vector's length is increased to 11, it will have to reallocate, which
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/// can be slow. For this reason, it is recommended to use [`Vec::with_capacity`]
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/// whenever possible to specify how big the vector is expected to get.
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///
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/// # Guarantees
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///
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/// Due to its incredibly fundamental nature, `Vec` makes a lot of guarantees
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/// about its design. This ensures that it's as low-overhead as possible in
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/// the general case, and can be correctly manipulated in primitive ways
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/// by unsafe code. Note that these guarantees refer to an unqualified `Vec<T>`.
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/// If additional type parameters are added (e.g. to support custom allocators),
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/// overriding their defaults may change the behavior.
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///
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/// Most fundamentally, `Vec` is and always will be a (pointer, capacity, length)
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/// triplet. No more, no less. The order of these fields is completely
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/// unspecified, and you should use the appropriate methods to modify these.
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/// The pointer will never be null, so this type is null-pointer-optimized.
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///
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/// However, the pointer may not actually point to allocated memory. In particular,
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/// if you construct a `Vec` with capacity 0 via [`Vec::new()`], [`vec![]`][`vec!`],
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/// [`Vec::with_capacity(0)`][`Vec::with_capacity`], or by calling [`shrink_to_fit()`]
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/// on an empty Vec, it will not allocate memory. Similarly, if you store zero-sized
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/// types inside a `Vec`, it will not allocate space for them. *Note that in this case
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/// the `Vec` may not report a [`capacity()`] of 0*. `Vec` will allocate if and only
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/// if [`mem::size_of::<T>()`]` * capacity() > 0`. In general, `Vec`'s allocation
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/// details are subtle enough that it is strongly recommended that you only
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/// free memory allocated by a `Vec` by creating a new `Vec` and dropping it.
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///
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/// If a `Vec` *has* allocated memory, then the memory it points to is on the heap
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/// (as defined by the allocator Rust is configured to use by default), and its
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/// pointer points to [`len()`] initialized elements in order (what you would see
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/// if you coerced it to a slice), followed by [`capacity()`]` - `[`len()`]
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/// logically uninitialized elements.
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///
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/// `Vec` will never perform a "small optimization" where elements are actually
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/// stored on the stack for two reasons:
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///
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/// * It would make it more difficult for unsafe code to correctly manipulate
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/// a `Vec`. The contents of a `Vec` wouldn't have a stable address if it were
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/// only moved, and it would be more difficult to determine if a `Vec` had
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/// actually allocated memory.
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///
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/// * It would penalize the general case, incurring an additional branch
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/// on every access.
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///
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/// `Vec` will never automatically shrink itself, even if completely empty. This
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/// ensures no unnecessary allocations or deallocations occur. Emptying a `Vec`
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/// and then filling it back up to the same [`len()`] should incur no calls to
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/// the allocator. If you wish to free up unused memory, use
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/// [`shrink_to_fit`][`shrink_to_fit()`].
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///
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/// [`push`] and [`insert`] will never (re)allocate if the reported capacity is
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/// sufficient. [`push`] and [`insert`] *will* (re)allocate if
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/// [`len()`]` == `[`capacity()`]. That is, the reported capacity is completely
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/// accurate, and can be relied on. It can even be used to manually free the memory
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/// allocated by a `Vec` if desired. Bulk insertion methods *may* reallocate, even
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/// when not necessary.
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///
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/// `Vec` does not guarantee any particular growth strategy when reallocating
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/// when full, nor when [`reserve`] is called. The current strategy is basic
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/// and it may prove desirable to use a non-constant growth factor. Whatever
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/// strategy is used will of course guarantee `O(1)` amortized [`push`].
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///
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/// `vec![x; n]`, `vec![a, b, c, d]`, and
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/// [`Vec::with_capacity(n)`][`Vec::with_capacity`], will all produce a `Vec`
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/// with exactly the requested capacity. If [`len()`]` == `[`capacity()`],
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/// (as is the case for the [`vec!`] macro), then a `Vec<T>` can be converted to
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/// and from a [`Box<[T]>`][owned slice] without reallocating or moving the elements.
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///
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/// `Vec` will not specifically overwrite any data that is removed from it,
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/// but also won't specifically preserve it. Its uninitialized memory is
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/// scratch space that it may use however it wants. It will generally just do
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/// whatever is most efficient or otherwise easy to implement. Do not rely on
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/// removed data to be erased for security purposes. Even if you drop a `Vec`, its
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/// buffer may simply be reused by another `Vec`. Even if you zero a `Vec`'s memory
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/// first, that may not actually happen because the optimizer does not consider
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/// this a side-effect that must be preserved.
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///
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/// `Vec` does not currently guarantee the order in which elements are dropped
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/// (the order has changed in the past, and may change again).
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///
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/// [`vec!`]: ../../std/macro.vec.html
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/// [`Index`]: ../../std/ops/trait.Index.html
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/// [`String`]: ../../std/string/struct.String.html
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/// [`&str`]: ../../std/primitive.str.html
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/// [`Vec::with_capacity`]: ../../std/vec/struct.Vec.html#method.with_capacity
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/// [`Vec::new()`]: ../../std/vec/struct.Vec.html#method.new
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/// [`shrink_to_fit()`]: ../../std/vec/struct.Vec.html#method.shrink_to_fit
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/// [`capacity()`]: ../../std/vec/struct.Vec.html#method.capacity
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/// [`mem::size_of::<T>()`]: ../../std/mem/fn.size_of.html
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/// [`len()`]: ../../std/vec/struct.Vec.html#method.len
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/// [`push`]: ../../std/vec/struct.Vec.html#method.push
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/// [`insert`]: ../../std/vec/struct.Vec.html#method.insert
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/// [`reserve`]: ../../std/vec/struct.Vec.html#method.reserve
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/// [owned slice]: ../../std/boxed/struct.Box.html
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#[stable(feature = "rust1", since = "1.0.0")]
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pub struct Vec<T> {
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buf: RawVec<T>,
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len: usize,
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}
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////////////////////////////////////////////////////////////////////////////////
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// Inherent methods
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////////////////////////////////////////////////////////////////////////////////
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impl<T> Vec<T> {
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/// Constructs a new, empty `Vec<T>`.
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///
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/// The vector will not allocate until elements are pushed onto it.
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///
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/// # Examples
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///
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/// ```
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/// # #![allow(unused_mut)]
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/// let mut vec: Vec<i32> = Vec::new();
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn new() -> Vec<T> {
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Vec {
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buf: RawVec::new(),
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len: 0,
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}
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}
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/// Constructs a new, empty `Vec<T>` with the specified capacity.
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///
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/// The vector will be able to hold exactly `capacity` elements without
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/// reallocating. If `capacity` is 0, the vector will not allocate.
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///
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/// It is important to note that this function does not specify the *length*
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/// of the returned vector, but only the *capacity*. For an explanation of
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/// the difference between length and capacity, see *[Capacity and reallocation]*.
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///
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/// [Capacity and reallocation]: #capacity-and-reallocation
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///
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/// # Examples
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///
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/// ```
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/// let mut vec = Vec::with_capacity(10);
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///
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/// // The vector contains no items, even though it has capacity for more
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/// assert_eq!(vec.len(), 0);
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///
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/// // These are all done without reallocating...
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/// for i in 0..10 {
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/// vec.push(i);
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/// }
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///
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/// // ...but this may make the vector reallocate
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/// vec.push(11);
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn with_capacity(capacity: usize) -> Vec<T> {
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Vec {
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buf: RawVec::with_capacity(capacity),
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len: 0,
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}
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}
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/// Creates a `Vec<T>` directly from the raw components of another vector.
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///
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/// # Safety
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///
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/// This is highly unsafe, due to the number of invariants that aren't
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/// checked:
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///
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/// * `ptr` needs to have been previously allocated via [`String`]/`Vec<T>`
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/// (at least, it's highly likely to be incorrect if it wasn't).
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/// * `length` needs to be less than or equal to `capacity`.
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/// * `capacity` needs to be the capacity that the pointer was allocated with.
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///
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/// Violating these may cause problems like corrupting the allocator's
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/// internal datastructures.
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///
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/// The ownership of `ptr` is effectively transferred to the
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/// `Vec<T>` which may then deallocate, reallocate or change the
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/// contents of memory pointed to by the pointer at will. Ensure
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/// that nothing else uses the pointer after calling this
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/// function.
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///
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/// [`String`]: ../../std/string/struct.String.html
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///
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/// # Examples
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///
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/// ```
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/// use std::ptr;
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/// use std::mem;
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///
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/// fn main() {
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/// let mut v = vec![1, 2, 3];
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///
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/// // Pull out the various important pieces of information about `v`
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/// let p = v.as_mut_ptr();
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/// let len = v.len();
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/// let cap = v.capacity();
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///
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/// unsafe {
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/// // Cast `v` into the void: no destructor run, so we are in
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/// // complete control of the allocation to which `p` points.
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/// mem::forget(v);
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///
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/// // Overwrite memory with 4, 5, 6
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/// for i in 0..len as isize {
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/// ptr::write(p.offset(i), 4 + i);
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/// }
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///
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/// // Put everything back together into a Vec
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/// let rebuilt = Vec::from_raw_parts(p, len, cap);
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/// assert_eq!(rebuilt, [4, 5, 6]);
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/// }
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/// }
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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pub unsafe fn from_raw_parts(ptr: *mut T, length: usize, capacity: usize) -> Vec<T> {
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Vec {
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buf: RawVec::from_raw_parts(ptr, capacity),
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len: length,
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}
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}
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/// Returns the number of elements the vector can hold without
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/// reallocating.
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///
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/// # Examples
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///
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/// ```
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/// let vec: Vec<i32> = Vec::with_capacity(10);
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/// assert_eq!(vec.capacity(), 10);
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/// ```
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#[inline]
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn capacity(&self) -> usize {
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self.buf.cap()
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}
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/// Reserves capacity for at least `additional` more elements to be inserted
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/// in the given `Vec<T>`. The collection may reserve more space to avoid
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/// frequent reallocations.
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///
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/// # Panics
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///
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/// Panics if the new capacity overflows `usize`.
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///
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/// # Examples
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///
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/// ```
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/// let mut vec = vec![1];
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/// vec.reserve(10);
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/// assert!(vec.capacity() >= 11);
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn reserve(&mut self, additional: usize) {
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self.buf.reserve(self.len, additional);
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}
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/// Reserves the minimum capacity for exactly `additional` more elements to
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/// be inserted in the given `Vec<T>`. Does nothing if the capacity is already
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/// sufficient.
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///
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/// Note that the allocator may give the collection more space than it
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/// requests. Therefore capacity can not be relied upon to be precisely
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/// minimal. Prefer `reserve` if future insertions are expected.
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///
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/// # Panics
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///
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/// Panics if the new capacity overflows `usize`.
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///
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/// # Examples
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///
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/// ```
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/// let mut vec = vec![1];
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/// vec.reserve_exact(10);
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/// assert!(vec.capacity() >= 11);
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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pub fn reserve_exact(&mut self, additional: usize) {
|
|
self.buf.reserve_exact(self.len, additional);
|
|
}
|
|
|
|
/// Shrinks the capacity of the vector as much as possible.
|
|
///
|
|
/// It will drop down as close as possible to the length but the allocator
|
|
/// may still inform the vector that there is space for a few more elements.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = Vec::with_capacity(10);
|
|
/// vec.extend([1, 2, 3].iter().cloned());
|
|
/// assert_eq!(vec.capacity(), 10);
|
|
/// vec.shrink_to_fit();
|
|
/// assert!(vec.capacity() >= 3);
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn shrink_to_fit(&mut self) {
|
|
self.buf.shrink_to_fit(self.len);
|
|
}
|
|
|
|
/// Converts the vector into [`Box<[T]>`][owned slice].
|
|
///
|
|
/// Note that this will drop any excess capacity. Calling this and
|
|
/// converting back to a vector with [`into_vec()`] is equivalent to calling
|
|
/// [`shrink_to_fit()`].
|
|
///
|
|
/// [owned slice]: ../../std/boxed/struct.Box.html
|
|
/// [`into_vec()`]: ../../std/primitive.slice.html#method.into_vec
|
|
/// [`shrink_to_fit()`]: #method.shrink_to_fit
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let v = vec![1, 2, 3];
|
|
///
|
|
/// let slice = v.into_boxed_slice();
|
|
/// ```
|
|
///
|
|
/// Any excess capacity is removed:
|
|
///
|
|
/// ```
|
|
/// let mut vec = Vec::with_capacity(10);
|
|
/// vec.extend([1, 2, 3].iter().cloned());
|
|
///
|
|
/// assert_eq!(vec.capacity(), 10);
|
|
/// let slice = vec.into_boxed_slice();
|
|
/// assert_eq!(slice.into_vec().capacity(), 3);
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn into_boxed_slice(mut self) -> Box<[T]> {
|
|
unsafe {
|
|
self.shrink_to_fit();
|
|
let buf = ptr::read(&self.buf);
|
|
mem::forget(self);
|
|
buf.into_box()
|
|
}
|
|
}
|
|
|
|
/// Shortens the vector, keeping the first `len` elements and dropping
|
|
/// the rest.
|
|
///
|
|
/// If `len` is greater than the vector's current length, this has no
|
|
/// effect.
|
|
///
|
|
/// The [`drain`] method can emulate `truncate`, but causes the excess
|
|
/// elements to be returned instead of dropped.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// Truncating a five element vector to two elements:
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2, 3, 4, 5];
|
|
/// vec.truncate(2);
|
|
/// assert_eq!(vec, [1, 2]);
|
|
/// ```
|
|
///
|
|
/// No truncation occurs when `len` is greater than the vector's current
|
|
/// length:
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2, 3];
|
|
/// vec.truncate(8);
|
|
/// assert_eq!(vec, [1, 2, 3]);
|
|
/// ```
|
|
///
|
|
/// Truncating when `len == 0` is equivalent to calling the [`clear`]
|
|
/// method.
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2, 3];
|
|
/// vec.truncate(0);
|
|
/// assert_eq!(vec, []);
|
|
/// ```
|
|
///
|
|
/// [`clear`]: #method.clear
|
|
/// [`drain`]: #method.drain
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn truncate(&mut self, len: usize) {
|
|
unsafe {
|
|
// drop any extra elements
|
|
while len < self.len {
|
|
// decrement len before the drop_in_place(), so a panic on Drop
|
|
// doesn't re-drop the just-failed value.
|
|
self.len -= 1;
|
|
let len = self.len;
|
|
ptr::drop_in_place(self.get_unchecked_mut(len));
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Extracts a slice containing the entire vector.
|
|
///
|
|
/// Equivalent to `&s[..]`.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use std::io::{self, Write};
|
|
/// let buffer = vec![1, 2, 3, 5, 8];
|
|
/// io::sink().write(buffer.as_slice()).unwrap();
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "vec_as_slice", since = "1.7.0")]
|
|
pub fn as_slice(&self) -> &[T] {
|
|
self
|
|
}
|
|
|
|
/// Extracts a mutable slice of the entire vector.
|
|
///
|
|
/// Equivalent to `&mut s[..]`.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use std::io::{self, Read};
|
|
/// let mut buffer = vec![0; 3];
|
|
/// io::repeat(0b101).read_exact(buffer.as_mut_slice()).unwrap();
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "vec_as_slice", since = "1.7.0")]
|
|
pub fn as_mut_slice(&mut self) -> &mut [T] {
|
|
self
|
|
}
|
|
|
|
/// Sets the length of a vector.
|
|
///
|
|
/// This will explicitly set the size of the vector, without actually
|
|
/// modifying its buffers, so it is up to the caller to ensure that the
|
|
/// vector is actually the specified size.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// use std::ptr;
|
|
///
|
|
/// let mut vec = vec!['r', 'u', 's', 't'];
|
|
///
|
|
/// unsafe {
|
|
/// ptr::drop_in_place(&mut vec[3]);
|
|
/// vec.set_len(3);
|
|
/// }
|
|
/// assert_eq!(vec, ['r', 'u', 's']);
|
|
/// ```
|
|
///
|
|
/// In this example, there is a memory leak since the memory locations
|
|
/// owned by the inner vectors were not freed prior to the `set_len` call:
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![vec![1, 0, 0],
|
|
/// vec![0, 1, 0],
|
|
/// vec![0, 0, 1]];
|
|
/// unsafe {
|
|
/// vec.set_len(0);
|
|
/// }
|
|
/// ```
|
|
///
|
|
/// In this example, the vector gets expanded from zero to four items
|
|
/// without any memory allocations occurring, resulting in vector
|
|
/// values of unallocated memory:
|
|
///
|
|
/// ```
|
|
/// let mut vec: Vec<char> = Vec::new();
|
|
///
|
|
/// unsafe {
|
|
/// vec.set_len(4);
|
|
/// }
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub unsafe fn set_len(&mut self, len: usize) {
|
|
self.len = len;
|
|
}
|
|
|
|
/// Removes an element from anywhere in the vector and return it, replacing
|
|
/// it with the last element.
|
|
///
|
|
/// This does not preserve ordering, but is O(1).
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if `index` is out of bounds.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut v = vec!["foo", "bar", "baz", "qux"];
|
|
///
|
|
/// assert_eq!(v.swap_remove(1), "bar");
|
|
/// assert_eq!(v, ["foo", "qux", "baz"]);
|
|
///
|
|
/// assert_eq!(v.swap_remove(0), "foo");
|
|
/// assert_eq!(v, ["baz", "qux"]);
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn swap_remove(&mut self, index: usize) -> T {
|
|
let length = self.len();
|
|
self.swap(index, length - 1);
|
|
self.pop().unwrap()
|
|
}
|
|
|
|
/// Inserts an element at position `index` within the vector, shifting all
|
|
/// elements after it to the right.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if `index` is out of bounds.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2, 3];
|
|
/// vec.insert(1, 4);
|
|
/// assert_eq!(vec, [1, 4, 2, 3]);
|
|
/// vec.insert(4, 5);
|
|
/// assert_eq!(vec, [1, 4, 2, 3, 5]);
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn insert(&mut self, index: usize, element: T) {
|
|
let len = self.len();
|
|
assert!(index <= len);
|
|
|
|
// space for the new element
|
|
if len == self.buf.cap() {
|
|
self.buf.double();
|
|
}
|
|
|
|
unsafe {
|
|
// infallible
|
|
// The spot to put the new value
|
|
{
|
|
let p = self.as_mut_ptr().offset(index as isize);
|
|
// Shift everything over to make space. (Duplicating the
|
|
// `index`th element into two consecutive places.)
|
|
ptr::copy(p, p.offset(1), len - index);
|
|
// Write it in, overwriting the first copy of the `index`th
|
|
// element.
|
|
ptr::write(p, element);
|
|
}
|
|
self.set_len(len + 1);
|
|
}
|
|
}
|
|
|
|
/// Removes and returns the element at position `index` within the vector,
|
|
/// shifting all elements after it to the left.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if `index` is out of bounds.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut v = vec![1, 2, 3];
|
|
/// assert_eq!(v.remove(1), 2);
|
|
/// assert_eq!(v, [1, 3]);
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn remove(&mut self, index: usize) -> T {
|
|
let len = self.len();
|
|
assert!(index < len);
|
|
unsafe {
|
|
// infallible
|
|
let ret;
|
|
{
|
|
// the place we are taking from.
|
|
let ptr = self.as_mut_ptr().offset(index as isize);
|
|
// copy it out, unsafely having a copy of the value on
|
|
// the stack and in the vector at the same time.
|
|
ret = ptr::read(ptr);
|
|
|
|
// Shift everything down to fill in that spot.
|
|
ptr::copy(ptr.offset(1), ptr, len - index - 1);
|
|
}
|
|
self.set_len(len - 1);
|
|
ret
|
|
}
|
|
}
|
|
|
|
/// Retains only the elements specified by the predicate.
|
|
///
|
|
/// In other words, remove all elements `e` such that `f(&e)` returns `false`.
|
|
/// This method operates in place and preserves the order of the retained
|
|
/// elements.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2, 3, 4];
|
|
/// vec.retain(|&x| x%2 == 0);
|
|
/// assert_eq!(vec, [2, 4]);
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn retain<F>(&mut self, mut f: F)
|
|
where F: FnMut(&T) -> bool
|
|
{
|
|
let len = self.len();
|
|
let mut del = 0;
|
|
{
|
|
let v = &mut **self;
|
|
|
|
for i in 0..len {
|
|
if !f(&v[i]) {
|
|
del += 1;
|
|
} else if del > 0 {
|
|
v.swap(i - del, i);
|
|
}
|
|
}
|
|
}
|
|
if del > 0 {
|
|
self.truncate(len - del);
|
|
}
|
|
}
|
|
|
|
/// Removes consecutive elements in the vector that resolve to the same key.
|
|
///
|
|
/// If the vector is sorted, this removes all duplicates.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// #![feature(dedup_by)]
|
|
///
|
|
/// let mut vec = vec![10, 20, 21, 30, 20];
|
|
///
|
|
/// vec.dedup_by_key(|i| *i / 10);
|
|
///
|
|
/// assert_eq!(vec, [10, 20, 30, 20]);
|
|
/// ```
|
|
#[unstable(feature = "dedup_by", reason = "recently added", issue = "37087")]
|
|
#[inline]
|
|
pub fn dedup_by_key<F, K>(&mut self, mut key: F) where F: FnMut(&mut T) -> K, K: PartialEq {
|
|
self.dedup_by(|a, b| key(a) == key(b))
|
|
}
|
|
|
|
/// Removes consecutive elements in the vector that resolve to the same key.
|
|
///
|
|
/// If the vector is sorted, this removes all duplicates.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// #![feature(dedup_by)]
|
|
/// use std::ascii::AsciiExt;
|
|
///
|
|
/// let mut vec = vec!["foo", "bar", "Bar", "baz", "bar"];
|
|
///
|
|
/// vec.dedup_by(|a, b| a.eq_ignore_ascii_case(b));
|
|
///
|
|
/// assert_eq!(vec, ["foo", "bar", "baz", "bar"]);
|
|
/// ```
|
|
#[unstable(feature = "dedup_by", reason = "recently added", issue = "37087")]
|
|
pub fn dedup_by<F>(&mut self, mut same_bucket: F) where F: FnMut(&mut T, &mut T) -> bool {
|
|
unsafe {
|
|
// Although we have a mutable reference to `self`, we cannot make
|
|
// *arbitrary* changes. The `same_bucket` calls could panic, so we
|
|
// must ensure that the vector is in a valid state at all time.
|
|
//
|
|
// The way that we handle this is by using swaps; we iterate
|
|
// over all the elements, swapping as we go so that at the end
|
|
// the elements we wish to keep are in the front, and those we
|
|
// wish to reject are at the back. We can then truncate the
|
|
// vector. This operation is still O(n).
|
|
//
|
|
// Example: We start in this state, where `r` represents "next
|
|
// read" and `w` represents "next_write`.
|
|
//
|
|
// r
|
|
// +---+---+---+---+---+---+
|
|
// | 0 | 1 | 1 | 2 | 3 | 3 |
|
|
// +---+---+---+---+---+---+
|
|
// w
|
|
//
|
|
// Comparing self[r] against self[w-1], this is not a duplicate, so
|
|
// we swap self[r] and self[w] (no effect as r==w) and then increment both
|
|
// r and w, leaving us with:
|
|
//
|
|
// r
|
|
// +---+---+---+---+---+---+
|
|
// | 0 | 1 | 1 | 2 | 3 | 3 |
|
|
// +---+---+---+---+---+---+
|
|
// w
|
|
//
|
|
// Comparing self[r] against self[w-1], this value is a duplicate,
|
|
// so we increment `r` but leave everything else unchanged:
|
|
//
|
|
// r
|
|
// +---+---+---+---+---+---+
|
|
// | 0 | 1 | 1 | 2 | 3 | 3 |
|
|
// +---+---+---+---+---+---+
|
|
// w
|
|
//
|
|
// Comparing self[r] against self[w-1], this is not a duplicate,
|
|
// so swap self[r] and self[w] and advance r and w:
|
|
//
|
|
// r
|
|
// +---+---+---+---+---+---+
|
|
// | 0 | 1 | 2 | 1 | 3 | 3 |
|
|
// +---+---+---+---+---+---+
|
|
// w
|
|
//
|
|
// Not a duplicate, repeat:
|
|
//
|
|
// r
|
|
// +---+---+---+---+---+---+
|
|
// | 0 | 1 | 2 | 3 | 1 | 3 |
|
|
// +---+---+---+---+---+---+
|
|
// w
|
|
//
|
|
// Duplicate, advance r. End of vec. Truncate to w.
|
|
|
|
let ln = self.len();
|
|
if ln <= 1 {
|
|
return;
|
|
}
|
|
|
|
// Avoid bounds checks by using raw pointers.
|
|
let p = self.as_mut_ptr();
|
|
let mut r: usize = 1;
|
|
let mut w: usize = 1;
|
|
|
|
while r < ln {
|
|
let p_r = p.offset(r as isize);
|
|
let p_wm1 = p.offset((w - 1) as isize);
|
|
if !same_bucket(&mut *p_r, &mut *p_wm1) {
|
|
if r != w {
|
|
let p_w = p_wm1.offset(1);
|
|
mem::swap(&mut *p_r, &mut *p_w);
|
|
}
|
|
w += 1;
|
|
}
|
|
r += 1;
|
|
}
|
|
|
|
self.truncate(w);
|
|
}
|
|
}
|
|
|
|
/// Appends an element to the back of a collection.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if the number of elements in the vector overflows a `usize`.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2];
|
|
/// vec.push(3);
|
|
/// assert_eq!(vec, [1, 2, 3]);
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn push(&mut self, value: T) {
|
|
// This will panic or abort if we would allocate > isize::MAX bytes
|
|
// or if the length increment would overflow for zero-sized types.
|
|
if self.len == self.buf.cap() {
|
|
self.buf.double();
|
|
}
|
|
unsafe {
|
|
let end = self.as_mut_ptr().offset(self.len as isize);
|
|
ptr::write(end, value);
|
|
self.len += 1;
|
|
}
|
|
}
|
|
|
|
/// Removes the last element from a vector and returns it, or [`None`] if it
|
|
/// is empty.
|
|
///
|
|
/// [`None`]: ../../std/option/enum.Option.html#variant.None
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2, 3];
|
|
/// assert_eq!(vec.pop(), Some(3));
|
|
/// assert_eq!(vec, [1, 2]);
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn pop(&mut self) -> Option<T> {
|
|
if self.len == 0 {
|
|
None
|
|
} else {
|
|
unsafe {
|
|
self.len -= 1;
|
|
Some(ptr::read(self.get_unchecked(self.len())))
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Moves all the elements of `other` into `Self`, leaving `other` empty.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if the number of elements in the vector overflows a `usize`.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2, 3];
|
|
/// let mut vec2 = vec![4, 5, 6];
|
|
/// vec.append(&mut vec2);
|
|
/// assert_eq!(vec, [1, 2, 3, 4, 5, 6]);
|
|
/// assert_eq!(vec2, []);
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "append", since = "1.4.0")]
|
|
pub fn append(&mut self, other: &mut Self) {
|
|
self.reserve(other.len());
|
|
let len = self.len();
|
|
unsafe {
|
|
ptr::copy_nonoverlapping(other.as_ptr(), self.get_unchecked_mut(len), other.len());
|
|
}
|
|
|
|
self.len += other.len();
|
|
unsafe {
|
|
other.set_len(0);
|
|
}
|
|
}
|
|
|
|
/// Create a draining iterator that removes the specified range in the vector
|
|
/// and yields the removed items.
|
|
///
|
|
/// Note 1: The element range is removed even if the iterator is not
|
|
/// consumed until the end.
|
|
///
|
|
/// Note 2: It is unspecified how many elements are removed from the vector,
|
|
/// if the `Drain` value is leaked.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if the starting point is greater than the end point or if
|
|
/// the end point is greater than the length of the vector.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut v = vec![1, 2, 3];
|
|
/// let u: Vec<_> = v.drain(1..).collect();
|
|
/// assert_eq!(v, &[1]);
|
|
/// assert_eq!(u, &[2, 3]);
|
|
///
|
|
/// // A full range clears the vector
|
|
/// v.drain(..);
|
|
/// assert_eq!(v, &[]);
|
|
/// ```
|
|
#[stable(feature = "drain", since = "1.6.0")]
|
|
pub fn drain<R>(&mut self, range: R) -> Drain<T>
|
|
where R: RangeArgument<usize>
|
|
{
|
|
// Memory safety
|
|
//
|
|
// When the Drain is first created, it shortens the length of
|
|
// the source vector to make sure no uninitalized or moved-from elements
|
|
// are accessible at all if the Drain's destructor never gets to run.
|
|
//
|
|
// Drain will ptr::read out the values to remove.
|
|
// When finished, remaining tail of the vec is copied back to cover
|
|
// the hole, and the vector length is restored to the new length.
|
|
//
|
|
let len = self.len();
|
|
let start = *range.start().unwrap_or(&0);
|
|
let end = *range.end().unwrap_or(&len);
|
|
assert!(start <= end);
|
|
assert!(end <= len);
|
|
|
|
unsafe {
|
|
// set self.vec length's to start, to be safe in case Drain is leaked
|
|
self.set_len(start);
|
|
// Use the borrow in the IterMut to indicate borrowing behavior of the
|
|
// whole Drain iterator (like &mut T).
|
|
let range_slice = slice::from_raw_parts_mut(self.as_mut_ptr().offset(start as isize),
|
|
end - start);
|
|
Drain {
|
|
tail_start: end,
|
|
tail_len: len - end,
|
|
iter: range_slice.iter(),
|
|
vec: Shared::new(self as *mut _),
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Clears the vector, removing all values.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut v = vec![1, 2, 3];
|
|
///
|
|
/// v.clear();
|
|
///
|
|
/// assert!(v.is_empty());
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn clear(&mut self) {
|
|
self.truncate(0)
|
|
}
|
|
|
|
/// Returns the number of elements in the vector.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let a = vec![1, 2, 3];
|
|
/// assert_eq!(a.len(), 3);
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn len(&self) -> usize {
|
|
self.len
|
|
}
|
|
|
|
/// Returns `true` if the vector contains no elements.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut v = Vec::new();
|
|
/// assert!(v.is_empty());
|
|
///
|
|
/// v.push(1);
|
|
/// assert!(!v.is_empty());
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn is_empty(&self) -> bool {
|
|
self.len() == 0
|
|
}
|
|
|
|
/// Splits the collection into two at the given index.
|
|
///
|
|
/// Returns a newly allocated `Self`. `self` contains elements `[0, at)`,
|
|
/// and the returned `Self` contains elements `[at, len)`.
|
|
///
|
|
/// Note that the capacity of `self` does not change.
|
|
///
|
|
/// # Panics
|
|
///
|
|
/// Panics if `at > len`.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1,2,3];
|
|
/// let vec2 = vec.split_off(1);
|
|
/// assert_eq!(vec, [1]);
|
|
/// assert_eq!(vec2, [2, 3]);
|
|
/// ```
|
|
#[inline]
|
|
#[stable(feature = "split_off", since = "1.4.0")]
|
|
pub fn split_off(&mut self, at: usize) -> Self {
|
|
assert!(at <= self.len(), "`at` out of bounds");
|
|
|
|
let other_len = self.len - at;
|
|
let mut other = Vec::with_capacity(other_len);
|
|
|
|
// Unsafely `set_len` and copy items to `other`.
|
|
unsafe {
|
|
self.set_len(at);
|
|
other.set_len(other_len);
|
|
|
|
ptr::copy_nonoverlapping(self.as_ptr().offset(at as isize),
|
|
other.as_mut_ptr(),
|
|
other.len());
|
|
}
|
|
other
|
|
}
|
|
}
|
|
|
|
impl<T: Clone> Vec<T> {
|
|
/// Resizes the `Vec` in-place so that `len()` is equal to `new_len`.
|
|
///
|
|
/// If `new_len` is greater than `len()`, the `Vec` is extended by the
|
|
/// difference, with each additional slot filled with `value`.
|
|
/// If `new_len` is less than `len()`, the `Vec` is simply truncated.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec!["hello"];
|
|
/// vec.resize(3, "world");
|
|
/// assert_eq!(vec, ["hello", "world", "world"]);
|
|
///
|
|
/// let mut vec = vec![1, 2, 3, 4];
|
|
/// vec.resize(2, 0);
|
|
/// assert_eq!(vec, [1, 2]);
|
|
/// ```
|
|
#[stable(feature = "vec_resize", since = "1.5.0")]
|
|
pub fn resize(&mut self, new_len: usize, value: T) {
|
|
let len = self.len();
|
|
|
|
if new_len > len {
|
|
self.extend_with_element(new_len - len, value);
|
|
} else {
|
|
self.truncate(new_len);
|
|
}
|
|
}
|
|
|
|
/// Extend the vector by `n` additional clones of `value`.
|
|
fn extend_with_element(&mut self, n: usize, value: T) {
|
|
self.reserve(n);
|
|
|
|
unsafe {
|
|
let mut ptr = self.as_mut_ptr().offset(self.len() as isize);
|
|
// Use SetLenOnDrop to work around bug where compiler
|
|
// may not realize the store through `ptr` trough self.set_len()
|
|
// don't alias.
|
|
let mut local_len = SetLenOnDrop::new(&mut self.len);
|
|
|
|
// Write all elements except the last one
|
|
for _ in 1..n {
|
|
ptr::write(ptr, value.clone());
|
|
ptr = ptr.offset(1);
|
|
// Increment the length in every step in case clone() panics
|
|
local_len.increment_len(1);
|
|
}
|
|
|
|
if n > 0 {
|
|
// We can write the last element directly without cloning needlessly
|
|
ptr::write(ptr, value);
|
|
local_len.increment_len(1);
|
|
}
|
|
|
|
// len set by scope guard
|
|
}
|
|
}
|
|
|
|
/// Clones and appends all elements in a slice to the `Vec`.
|
|
///
|
|
/// Iterates over the slice `other`, clones each element, and then appends
|
|
/// it to this `Vec`. The `other` vector is traversed in-order.
|
|
///
|
|
/// Note that this function is same as `extend` except that it is
|
|
/// specialized to work with slices instead. If and when Rust gets
|
|
/// specialization this function will likely be deprecated (but still
|
|
/// available).
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1];
|
|
/// vec.extend_from_slice(&[2, 3, 4]);
|
|
/// assert_eq!(vec, [1, 2, 3, 4]);
|
|
/// ```
|
|
#[stable(feature = "vec_extend_from_slice", since = "1.6.0")]
|
|
pub fn extend_from_slice(&mut self, other: &[T]) {
|
|
self.spec_extend(other.iter())
|
|
}
|
|
|
|
/// Returns a place for insertion at the back of the `Vec`.
|
|
///
|
|
/// Using this method with placement syntax is equivalent to [`push`](#method.push),
|
|
/// but may be more efficient.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// #![feature(collection_placement)]
|
|
/// #![feature(placement_in_syntax)]
|
|
///
|
|
/// let mut vec = vec![1, 2];
|
|
/// vec.place_back() <- 3;
|
|
/// vec.place_back() <- 4;
|
|
/// assert_eq!(&vec, &[1, 2, 3, 4]);
|
|
/// ```
|
|
#[unstable(feature = "collection_placement",
|
|
reason = "placement protocol is subject to change",
|
|
issue = "30172")]
|
|
pub fn place_back(&mut self) -> PlaceBack<T> {
|
|
PlaceBack { vec: self }
|
|
}
|
|
}
|
|
|
|
// Set the length of the vec when the `SetLenOnDrop` value goes out of scope.
|
|
//
|
|
// The idea is: The length field in SetLenOnDrop is a local variable
|
|
// that the optimizer will see does not alias with any stores through the Vec's data
|
|
// pointer. This is a workaround for alias analysis issue #32155
|
|
struct SetLenOnDrop<'a> {
|
|
len: &'a mut usize,
|
|
local_len: usize,
|
|
}
|
|
|
|
impl<'a> SetLenOnDrop<'a> {
|
|
#[inline]
|
|
fn new(len: &'a mut usize) -> Self {
|
|
SetLenOnDrop { local_len: *len, len: len }
|
|
}
|
|
|
|
#[inline]
|
|
fn increment_len(&mut self, increment: usize) {
|
|
self.local_len += increment;
|
|
}
|
|
}
|
|
|
|
impl<'a> Drop for SetLenOnDrop<'a> {
|
|
#[inline]
|
|
fn drop(&mut self) {
|
|
*self.len = self.local_len;
|
|
}
|
|
}
|
|
|
|
impl<T: PartialEq> Vec<T> {
|
|
/// Removes consecutive repeated elements in the vector.
|
|
///
|
|
/// If the vector is sorted, this removes all duplicates.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let mut vec = vec![1, 2, 2, 3, 2];
|
|
///
|
|
/// vec.dedup();
|
|
///
|
|
/// assert_eq!(vec, [1, 2, 3, 2]);
|
|
/// ```
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
#[inline]
|
|
pub fn dedup(&mut self) {
|
|
self.dedup_by(|a, b| a == b)
|
|
}
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// Internal methods and functions
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#[doc(hidden)]
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub fn from_elem<T: Clone>(elem: T, n: usize) -> Vec<T> {
|
|
let mut v = Vec::with_capacity(n);
|
|
v.extend_with_element(n, elem);
|
|
v
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// Common trait implementations for Vec
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: Clone> Clone for Vec<T> {
|
|
#[cfg(not(test))]
|
|
fn clone(&self) -> Vec<T> {
|
|
<[T]>::to_vec(&**self)
|
|
}
|
|
|
|
// HACK(japaric): with cfg(test) the inherent `[T]::to_vec` method, which is
|
|
// required for this method definition, is not available. Instead use the
|
|
// `slice::to_vec` function which is only available with cfg(test)
|
|
// NB see the slice::hack module in slice.rs for more information
|
|
#[cfg(test)]
|
|
fn clone(&self) -> Vec<T> {
|
|
::slice::to_vec(&**self)
|
|
}
|
|
|
|
fn clone_from(&mut self, other: &Vec<T>) {
|
|
// drop anything in self that will not be overwritten
|
|
self.truncate(other.len());
|
|
let len = self.len();
|
|
|
|
// reuse the contained values' allocations/resources.
|
|
self.clone_from_slice(&other[..len]);
|
|
|
|
// self.len <= other.len due to the truncate above, so the
|
|
// slice here is always in-bounds.
|
|
self.extend_from_slice(&other[len..]);
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: Hash> Hash for Vec<T> {
|
|
#[inline]
|
|
fn hash<H: hash::Hasher>(&self, state: &mut H) {
|
|
Hash::hash(&**self, state)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> Index<usize> for Vec<T> {
|
|
type Output = T;
|
|
|
|
#[inline]
|
|
fn index(&self, index: usize) -> &T {
|
|
// NB built-in indexing via `&[T]`
|
|
&(**self)[index]
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> IndexMut<usize> for Vec<T> {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: usize) -> &mut T {
|
|
// NB built-in indexing via `&mut [T]`
|
|
&mut (**self)[index]
|
|
}
|
|
}
|
|
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::Index<ops::Range<usize>> for Vec<T> {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::Range<usize>) -> &[T] {
|
|
Index::index(&**self, index)
|
|
}
|
|
}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::Index<ops::RangeTo<usize>> for Vec<T> {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::RangeTo<usize>) -> &[T] {
|
|
Index::index(&**self, index)
|
|
}
|
|
}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::Index<ops::RangeFrom<usize>> for Vec<T> {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::RangeFrom<usize>) -> &[T] {
|
|
Index::index(&**self, index)
|
|
}
|
|
}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::Index<ops::RangeFull> for Vec<T> {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, _index: ops::RangeFull) -> &[T] {
|
|
self
|
|
}
|
|
}
|
|
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
|
|
impl<T> ops::Index<ops::RangeInclusive<usize>> for Vec<T> {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::RangeInclusive<usize>) -> &[T] {
|
|
Index::index(&**self, index)
|
|
}
|
|
}
|
|
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
|
|
impl<T> ops::Index<ops::RangeToInclusive<usize>> for Vec<T> {
|
|
type Output = [T];
|
|
|
|
#[inline]
|
|
fn index(&self, index: ops::RangeToInclusive<usize>) -> &[T] {
|
|
Index::index(&**self, index)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::IndexMut<ops::Range<usize>> for Vec<T> {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::Range<usize>) -> &mut [T] {
|
|
IndexMut::index_mut(&mut **self, index)
|
|
}
|
|
}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::IndexMut<ops::RangeTo<usize>> for Vec<T> {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::RangeTo<usize>) -> &mut [T] {
|
|
IndexMut::index_mut(&mut **self, index)
|
|
}
|
|
}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::IndexMut<ops::RangeFrom<usize>> for Vec<T> {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::RangeFrom<usize>) -> &mut [T] {
|
|
IndexMut::index_mut(&mut **self, index)
|
|
}
|
|
}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::IndexMut<ops::RangeFull> for Vec<T> {
|
|
#[inline]
|
|
fn index_mut(&mut self, _index: ops::RangeFull) -> &mut [T] {
|
|
self
|
|
}
|
|
}
|
|
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
|
|
impl<T> ops::IndexMut<ops::RangeInclusive<usize>> for Vec<T> {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::RangeInclusive<usize>) -> &mut [T] {
|
|
IndexMut::index_mut(&mut **self, index)
|
|
}
|
|
}
|
|
#[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
|
|
impl<T> ops::IndexMut<ops::RangeToInclusive<usize>> for Vec<T> {
|
|
#[inline]
|
|
fn index_mut(&mut self, index: ops::RangeToInclusive<usize>) -> &mut [T] {
|
|
IndexMut::index_mut(&mut **self, index)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::Deref for Vec<T> {
|
|
type Target = [T];
|
|
|
|
fn deref(&self) -> &[T] {
|
|
unsafe {
|
|
let p = self.buf.ptr();
|
|
assume(!p.is_null());
|
|
slice::from_raw_parts(p, self.len)
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ops::DerefMut for Vec<T> {
|
|
fn deref_mut(&mut self) -> &mut [T] {
|
|
unsafe {
|
|
let ptr = self.buf.ptr();
|
|
assume(!ptr.is_null());
|
|
slice::from_raw_parts_mut(ptr, self.len)
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> FromIterator<T> for Vec<T> {
|
|
#[inline]
|
|
fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Vec<T> {
|
|
<Self as SpecExtend<_, _>>::from_iter(iter.into_iter())
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> IntoIterator for Vec<T> {
|
|
type Item = T;
|
|
type IntoIter = IntoIter<T>;
|
|
|
|
/// Creates a consuming iterator, that is, one that moves each value out of
|
|
/// the vector (from start to end). The vector cannot be used after calling
|
|
/// this.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let v = vec!["a".to_string(), "b".to_string()];
|
|
/// for s in v.into_iter() {
|
|
/// // s has type String, not &String
|
|
/// println!("{}", s);
|
|
/// }
|
|
/// ```
|
|
#[inline]
|
|
fn into_iter(mut self) -> IntoIter<T> {
|
|
unsafe {
|
|
let begin = self.as_mut_ptr();
|
|
assume(!begin.is_null());
|
|
let end = if mem::size_of::<T>() == 0 {
|
|
arith_offset(begin as *const i8, self.len() as isize) as *const T
|
|
} else {
|
|
begin.offset(self.len() as isize) as *const T
|
|
};
|
|
let cap = self.buf.cap();
|
|
mem::forget(self);
|
|
IntoIter {
|
|
buf: Shared::new(begin),
|
|
cap: cap,
|
|
ptr: begin,
|
|
end: end,
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> IntoIterator for &'a Vec<T> {
|
|
type Item = &'a T;
|
|
type IntoIter = slice::Iter<'a, T>;
|
|
|
|
fn into_iter(self) -> slice::Iter<'a, T> {
|
|
self.iter()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> IntoIterator for &'a mut Vec<T> {
|
|
type Item = &'a mut T;
|
|
type IntoIter = slice::IterMut<'a, T>;
|
|
|
|
fn into_iter(mut self) -> slice::IterMut<'a, T> {
|
|
self.iter_mut()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> Extend<T> for Vec<T> {
|
|
#[inline]
|
|
fn extend<I: IntoIterator<Item = T>>(&mut self, iter: I) {
|
|
self.spec_extend(iter.into_iter())
|
|
}
|
|
}
|
|
|
|
// Specialization trait used for Vec::from_iter and Vec::extend
|
|
trait SpecExtend<T, I> {
|
|
fn from_iter(iter: I) -> Self;
|
|
fn spec_extend(&mut self, iter: I);
|
|
}
|
|
|
|
impl<T, I> SpecExtend<T, I> for Vec<T>
|
|
where I: Iterator<Item=T>,
|
|
{
|
|
default fn from_iter(mut iterator: I) -> Self {
|
|
// Unroll the first iteration, as the vector is going to be
|
|
// expanded on this iteration in every case when the iterable is not
|
|
// empty, but the loop in extend_desugared() is not going to see the
|
|
// vector being full in the few subsequent loop iterations.
|
|
// So we get better branch prediction.
|
|
let mut vector = match iterator.next() {
|
|
None => return Vec::new(),
|
|
Some(element) => {
|
|
let (lower, _) = iterator.size_hint();
|
|
let mut vector = Vec::with_capacity(lower.saturating_add(1));
|
|
unsafe {
|
|
ptr::write(vector.get_unchecked_mut(0), element);
|
|
vector.set_len(1);
|
|
}
|
|
vector
|
|
}
|
|
};
|
|
vector.spec_extend(iterator);
|
|
vector
|
|
}
|
|
|
|
default fn spec_extend(&mut self, iter: I) {
|
|
self.extend_desugared(iter)
|
|
}
|
|
}
|
|
|
|
impl<T, I> SpecExtend<T, I> for Vec<T>
|
|
where I: TrustedLen<Item=T>,
|
|
{
|
|
fn from_iter(iterator: I) -> Self {
|
|
let mut vector = Vec::new();
|
|
vector.spec_extend(iterator);
|
|
vector
|
|
}
|
|
|
|
fn spec_extend(&mut self, iterator: I) {
|
|
// This is the case for a TrustedLen iterator.
|
|
let (low, high) = iterator.size_hint();
|
|
if let Some(high_value) = high {
|
|
debug_assert_eq!(low, high_value,
|
|
"TrustedLen iterator's size hint is not exact: {:?}",
|
|
(low, high));
|
|
}
|
|
if let Some(additional) = high {
|
|
self.reserve(additional);
|
|
unsafe {
|
|
let mut ptr = self.as_mut_ptr().offset(self.len() as isize);
|
|
let mut local_len = SetLenOnDrop::new(&mut self.len);
|
|
for element in iterator {
|
|
ptr::write(ptr, element);
|
|
ptr = ptr.offset(1);
|
|
// NB can't overflow since we would have had to alloc the address space
|
|
local_len.increment_len(1);
|
|
}
|
|
}
|
|
} else {
|
|
self.extend_desugared(iterator)
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a, T: 'a, I> SpecExtend<&'a T, I> for Vec<T>
|
|
where I: Iterator<Item=&'a T>,
|
|
T: Clone,
|
|
{
|
|
default fn from_iter(iterator: I) -> Self {
|
|
SpecExtend::from_iter(iterator.cloned())
|
|
}
|
|
|
|
default fn spec_extend(&mut self, iterator: I) {
|
|
self.spec_extend(iterator.cloned())
|
|
}
|
|
}
|
|
|
|
impl<'a, T: 'a> SpecExtend<&'a T, slice::Iter<'a, T>> for Vec<T>
|
|
where T: Copy,
|
|
{
|
|
fn spec_extend(&mut self, iterator: slice::Iter<'a, T>) {
|
|
let slice = iterator.as_slice();
|
|
self.reserve(slice.len());
|
|
unsafe {
|
|
let len = self.len();
|
|
self.set_len(len + slice.len());
|
|
self.get_unchecked_mut(len..).copy_from_slice(slice);
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<T> Vec<T> {
|
|
fn extend_desugared<I: Iterator<Item = T>>(&mut self, mut iterator: I) {
|
|
// This is the case for a general iterator.
|
|
//
|
|
// This function should be the moral equivalent of:
|
|
//
|
|
// for item in iterator {
|
|
// self.push(item);
|
|
// }
|
|
while let Some(element) = iterator.next() {
|
|
let len = self.len();
|
|
if len == self.capacity() {
|
|
let (lower, _) = iterator.size_hint();
|
|
self.reserve(lower.saturating_add(1));
|
|
}
|
|
unsafe {
|
|
ptr::write(self.get_unchecked_mut(len), element);
|
|
// NB can't overflow since we would have had to alloc the address space
|
|
self.set_len(len + 1);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "extend_ref", since = "1.2.0")]
|
|
impl<'a, T: 'a + Copy> Extend<&'a T> for Vec<T> {
|
|
fn extend<I: IntoIterator<Item = &'a T>>(&mut self, iter: I) {
|
|
self.spec_extend(iter.into_iter())
|
|
}
|
|
}
|
|
|
|
macro_rules! __impl_slice_eq1 {
|
|
($Lhs: ty, $Rhs: ty) => {
|
|
__impl_slice_eq1! { $Lhs, $Rhs, Sized }
|
|
};
|
|
($Lhs: ty, $Rhs: ty, $Bound: ident) => {
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, 'b, A: $Bound, B> PartialEq<$Rhs> for $Lhs where A: PartialEq<B> {
|
|
#[inline]
|
|
fn eq(&self, other: &$Rhs) -> bool { self[..] == other[..] }
|
|
#[inline]
|
|
fn ne(&self, other: &$Rhs) -> bool { self[..] != other[..] }
|
|
}
|
|
}
|
|
}
|
|
|
|
__impl_slice_eq1! { Vec<A>, Vec<B> }
|
|
__impl_slice_eq1! { Vec<A>, &'b [B] }
|
|
__impl_slice_eq1! { Vec<A>, &'b mut [B] }
|
|
__impl_slice_eq1! { Cow<'a, [A]>, &'b [B], Clone }
|
|
__impl_slice_eq1! { Cow<'a, [A]>, &'b mut [B], Clone }
|
|
__impl_slice_eq1! { Cow<'a, [A]>, Vec<B>, Clone }
|
|
|
|
macro_rules! array_impls {
|
|
($($N: expr)+) => {
|
|
$(
|
|
// NOTE: some less important impls are omitted to reduce code bloat
|
|
__impl_slice_eq1! { Vec<A>, [B; $N] }
|
|
__impl_slice_eq1! { Vec<A>, &'b [B; $N] }
|
|
// __impl_slice_eq1! { Vec<A>, &'b mut [B; $N] }
|
|
// __impl_slice_eq1! { Cow<'a, [A]>, [B; $N], Clone }
|
|
// __impl_slice_eq1! { Cow<'a, [A]>, &'b [B; $N], Clone }
|
|
// __impl_slice_eq1! { Cow<'a, [A]>, &'b mut [B; $N], Clone }
|
|
)+
|
|
}
|
|
}
|
|
|
|
array_impls! {
|
|
0 1 2 3 4 5 6 7 8 9
|
|
10 11 12 13 14 15 16 17 18 19
|
|
20 21 22 23 24 25 26 27 28 29
|
|
30 31 32
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: PartialOrd> PartialOrd for Vec<T> {
|
|
#[inline]
|
|
fn partial_cmp(&self, other: &Vec<T>) -> Option<Ordering> {
|
|
PartialOrd::partial_cmp(&**self, &**other)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: Eq> Eq for Vec<T> {}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: Ord> Ord for Vec<T> {
|
|
#[inline]
|
|
fn cmp(&self, other: &Vec<T>) -> Ordering {
|
|
Ord::cmp(&**self, &**other)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> Drop for Vec<T> {
|
|
#[unsafe_destructor_blind_to_params]
|
|
fn drop(&mut self) {
|
|
unsafe {
|
|
// use drop for [T]
|
|
ptr::drop_in_place(&mut self[..]);
|
|
}
|
|
// RawVec handles deallocation
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> Default for Vec<T> {
|
|
/// Creates an empty `Vec<T>`.
|
|
fn default() -> Vec<T> {
|
|
Vec::new()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T: fmt::Debug> fmt::Debug for Vec<T> {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
fmt::Debug::fmt(&**self, f)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> AsRef<Vec<T>> for Vec<T> {
|
|
fn as_ref(&self) -> &Vec<T> {
|
|
self
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "vec_as_mut", since = "1.5.0")]
|
|
impl<T> AsMut<Vec<T>> for Vec<T> {
|
|
fn as_mut(&mut self) -> &mut Vec<T> {
|
|
self
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> AsRef<[T]> for Vec<T> {
|
|
fn as_ref(&self) -> &[T] {
|
|
self
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "vec_as_mut", since = "1.5.0")]
|
|
impl<T> AsMut<[T]> for Vec<T> {
|
|
fn as_mut(&mut self) -> &mut [T] {
|
|
self
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T: Clone> From<&'a [T]> for Vec<T> {
|
|
#[cfg(not(test))]
|
|
fn from(s: &'a [T]) -> Vec<T> {
|
|
s.to_vec()
|
|
}
|
|
#[cfg(test)]
|
|
fn from(s: &'a [T]) -> Vec<T> {
|
|
::slice::to_vec(s)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "vec_from_cow_slice", since = "1.14.0")]
|
|
impl<'a, T> From<Cow<'a, [T]>> for Vec<T> where [T]: ToOwned<Owned=Vec<T>> {
|
|
fn from(s: Cow<'a, [T]>) -> Vec<T> {
|
|
s.into_owned()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a> From<&'a str> for Vec<u8> {
|
|
fn from(s: &'a str) -> Vec<u8> {
|
|
From::from(s.as_bytes())
|
|
}
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// Clone-on-write
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#[stable(feature = "cow_from_vec", since = "1.7.0")]
|
|
impl<'a, T: Clone> From<&'a [T]> for Cow<'a, [T]> {
|
|
fn from(s: &'a [T]) -> Cow<'a, [T]> {
|
|
Cow::Borrowed(s)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "cow_from_vec", since = "1.7.0")]
|
|
impl<'a, T: Clone> From<Vec<T>> for Cow<'a, [T]> {
|
|
fn from(v: Vec<T>) -> Cow<'a, [T]> {
|
|
Cow::Owned(v)
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<'a, T> FromIterator<T> for Cow<'a, [T]> where T: Clone {
|
|
fn from_iter<I: IntoIterator<Item = T>>(it: I) -> Cow<'a, [T]> {
|
|
Cow::Owned(FromIterator::from_iter(it))
|
|
}
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// Iterators
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
|
|
/// An iterator that moves out of a vector.
|
|
///
|
|
/// This `struct` is created by the `into_iter` method on [`Vec`][`Vec`] (provided
|
|
/// by the [`IntoIterator`] trait).
|
|
///
|
|
/// [`Vec`]: struct.Vec.html
|
|
/// [`IntoIterator`]: ../../std/iter/trait.IntoIterator.html
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
pub struct IntoIter<T> {
|
|
buf: Shared<T>,
|
|
cap: usize,
|
|
ptr: *const T,
|
|
end: *const T,
|
|
}
|
|
|
|
#[stable(feature = "vec_intoiter_debug", since = "1.13.0")]
|
|
impl<T: fmt::Debug> fmt::Debug for IntoIter<T> {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
f.debug_tuple("IntoIter")
|
|
.field(&self.as_slice())
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
impl<T> IntoIter<T> {
|
|
/// Returns the remaining items of this iterator as a slice.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let vec = vec!['a', 'b', 'c'];
|
|
/// let mut into_iter = vec.into_iter();
|
|
/// assert_eq!(into_iter.as_slice(), &['a', 'b', 'c']);
|
|
/// let _ = into_iter.next().unwrap();
|
|
/// assert_eq!(into_iter.as_slice(), &['b', 'c']);
|
|
/// ```
|
|
#[stable(feature = "vec_into_iter_as_slice", since = "1.15.0")]
|
|
pub fn as_slice(&self) -> &[T] {
|
|
unsafe {
|
|
slice::from_raw_parts(self.ptr, self.len())
|
|
}
|
|
}
|
|
|
|
/// Returns the remaining items of this iterator as a mutable slice.
|
|
///
|
|
/// # Examples
|
|
///
|
|
/// ```
|
|
/// let vec = vec!['a', 'b', 'c'];
|
|
/// let mut into_iter = vec.into_iter();
|
|
/// assert_eq!(into_iter.as_slice(), &['a', 'b', 'c']);
|
|
/// into_iter.as_mut_slice()[2] = 'z';
|
|
/// assert_eq!(into_iter.next().unwrap(), 'a');
|
|
/// assert_eq!(into_iter.next().unwrap(), 'b');
|
|
/// assert_eq!(into_iter.next().unwrap(), 'z');
|
|
/// ```
|
|
#[stable(feature = "vec_into_iter_as_slice", since = "1.15.0")]
|
|
pub fn as_mut_slice(&self) -> &mut [T] {
|
|
unsafe {
|
|
slice::from_raw_parts_mut(self.ptr as *mut T, self.len())
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
unsafe impl<T: Send> Send for IntoIter<T> {}
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
unsafe impl<T: Sync> Sync for IntoIter<T> {}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> Iterator for IntoIter<T> {
|
|
type Item = T;
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<T> {
|
|
unsafe {
|
|
if self.ptr as *const _ == self.end {
|
|
None
|
|
} else {
|
|
if mem::size_of::<T>() == 0 {
|
|
// purposefully don't use 'ptr.offset' because for
|
|
// vectors with 0-size elements this would return the
|
|
// same pointer.
|
|
self.ptr = arith_offset(self.ptr as *const i8, 1) as *mut T;
|
|
|
|
// Use a non-null pointer value
|
|
Some(ptr::read(EMPTY as *mut T))
|
|
} else {
|
|
let old = self.ptr;
|
|
self.ptr = self.ptr.offset(1);
|
|
|
|
Some(ptr::read(old))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[inline]
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
let diff = (self.end as usize) - (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()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> DoubleEndedIterator for IntoIter<T> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<T> {
|
|
unsafe {
|
|
if self.end == self.ptr {
|
|
None
|
|
} else {
|
|
if mem::size_of::<T>() == 0 {
|
|
// See above for why 'ptr.offset' isn't used
|
|
self.end = arith_offset(self.end as *const i8, -1) as *mut T;
|
|
|
|
// Use a non-null pointer value
|
|
Some(ptr::read(EMPTY as *mut T))
|
|
} else {
|
|
self.end = self.end.offset(-1);
|
|
|
|
Some(ptr::read(self.end))
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> ExactSizeIterator for IntoIter<T> {
|
|
fn is_empty(&self) -> bool {
|
|
self.ptr == self.end
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<T> FusedIterator for IntoIter<T> {}
|
|
|
|
#[unstable(feature = "trusted_len", issue = "37572")]
|
|
unsafe impl<T> TrustedLen for IntoIter<T> {}
|
|
|
|
#[stable(feature = "vec_into_iter_clone", since = "1.8.0")]
|
|
impl<T: Clone> Clone for IntoIter<T> {
|
|
fn clone(&self) -> IntoIter<T> {
|
|
self.as_slice().to_owned().into_iter()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "rust1", since = "1.0.0")]
|
|
impl<T> Drop for IntoIter<T> {
|
|
#[unsafe_destructor_blind_to_params]
|
|
fn drop(&mut self) {
|
|
// destroy the remaining elements
|
|
for _x in self.by_ref() {}
|
|
|
|
// RawVec handles deallocation
|
|
let _ = unsafe { RawVec::from_raw_parts(*self.buf, self.cap) };
|
|
}
|
|
}
|
|
|
|
/// A draining iterator for `Vec<T>`.
|
|
///
|
|
/// This `struct` is created by the [`drain`] method on [`Vec`].
|
|
///
|
|
/// [`drain`]: struct.Vec.html#method.drain
|
|
/// [`Vec`]: struct.Vec.html
|
|
#[stable(feature = "drain", since = "1.6.0")]
|
|
pub struct Drain<'a, T: 'a> {
|
|
/// Index of tail to preserve
|
|
tail_start: usize,
|
|
/// Length of tail
|
|
tail_len: usize,
|
|
/// Current remaining range to remove
|
|
iter: slice::Iter<'a, T>,
|
|
vec: Shared<Vec<T>>,
|
|
}
|
|
|
|
#[stable(feature = "drain", since = "1.6.0")]
|
|
unsafe impl<'a, T: Sync> Sync for Drain<'a, T> {}
|
|
#[stable(feature = "drain", since = "1.6.0")]
|
|
unsafe impl<'a, T: Send> Send for Drain<'a, T> {}
|
|
|
|
#[stable(feature = "drain", since = "1.6.0")]
|
|
impl<'a, T> Iterator for Drain<'a, T> {
|
|
type Item = T;
|
|
|
|
#[inline]
|
|
fn next(&mut self) -> Option<T> {
|
|
self.iter.next().map(|elt| unsafe { ptr::read(elt as *const _) })
|
|
}
|
|
|
|
fn size_hint(&self) -> (usize, Option<usize>) {
|
|
self.iter.size_hint()
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "drain", since = "1.6.0")]
|
|
impl<'a, T> DoubleEndedIterator for Drain<'a, T> {
|
|
#[inline]
|
|
fn next_back(&mut self) -> Option<T> {
|
|
self.iter.next_back().map(|elt| unsafe { ptr::read(elt as *const _) })
|
|
}
|
|
}
|
|
|
|
#[stable(feature = "drain", since = "1.6.0")]
|
|
impl<'a, T> Drop for Drain<'a, T> {
|
|
fn drop(&mut self) {
|
|
// exhaust self first
|
|
while let Some(_) = self.next() {}
|
|
|
|
if self.tail_len > 0 {
|
|
unsafe {
|
|
let source_vec = &mut **self.vec;
|
|
// memmove back untouched tail, update to new length
|
|
let start = source_vec.len();
|
|
let tail = self.tail_start;
|
|
let src = source_vec.as_ptr().offset(tail as isize);
|
|
let dst = source_vec.as_mut_ptr().offset(start as isize);
|
|
ptr::copy(src, dst, self.tail_len);
|
|
source_vec.set_len(start + self.tail_len);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
#[stable(feature = "drain", since = "1.6.0")]
|
|
impl<'a, T> ExactSizeIterator for Drain<'a, T> {
|
|
fn is_empty(&self) -> bool {
|
|
self.iter.is_empty()
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "fused", issue = "35602")]
|
|
impl<'a, T> FusedIterator for Drain<'a, T> {}
|
|
|
|
/// A place for insertion at the back of a `Vec`.
|
|
///
|
|
/// See [`Vec::place_back`](struct.Vec.html#method.place_back) for details.
|
|
#[must_use = "places do nothing unless written to with `<-` syntax"]
|
|
#[unstable(feature = "collection_placement",
|
|
reason = "struct name and placement protocol are subject to change",
|
|
issue = "30172")]
|
|
pub struct PlaceBack<'a, T: 'a> {
|
|
vec: &'a mut Vec<T>,
|
|
}
|
|
|
|
#[unstable(feature = "collection_placement",
|
|
reason = "placement protocol is subject to change",
|
|
issue = "30172")]
|
|
impl<'a, T> Placer<T> for PlaceBack<'a, T> {
|
|
type Place = PlaceBack<'a, T>;
|
|
|
|
fn make_place(self) -> Self {
|
|
// This will panic or abort if we would allocate > isize::MAX bytes
|
|
// or if the length increment would overflow for zero-sized types.
|
|
if self.vec.len == self.vec.buf.cap() {
|
|
self.vec.buf.double();
|
|
}
|
|
self
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "collection_placement",
|
|
reason = "placement protocol is subject to change",
|
|
issue = "30172")]
|
|
impl<'a, T> Place<T> for PlaceBack<'a, T> {
|
|
fn pointer(&mut self) -> *mut T {
|
|
unsafe { self.vec.as_mut_ptr().offset(self.vec.len as isize) }
|
|
}
|
|
}
|
|
|
|
#[unstable(feature = "collection_placement",
|
|
reason = "placement protocol is subject to change",
|
|
issue = "30172")]
|
|
impl<'a, T> InPlace<T> for PlaceBack<'a, T> {
|
|
type Owner = &'a mut T;
|
|
|
|
unsafe fn finalize(mut self) -> &'a mut T {
|
|
let ptr = self.pointer();
|
|
self.vec.len += 1;
|
|
&mut *ptr
|
|
}
|
|
}
|