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rust/src/libcollections/slice.rs

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// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Utilities for slice manipulation
//!
//! The `slice` module contains useful code to help work with slice values.
//! Slices are a view into a block of memory represented as a pointer and a length.
//!
//! ```rust
//! // slicing a Vec
//! let vec = vec!(1, 2, 3);
//! let int_slice = vec.as_slice();
//! // coercing an array to a slice
//! let str_slice: &[&str] = &["one", "two", "three"];
//! ```
//!
//! Slices are either mutable or shared. The shared slice type is `&[T]`,
//! while the mutable slice type is `&mut[T]`. For example, you can mutate the
//! block of memory that a mutable slice points to:
//!
//! ```rust
//! let x: &mut[i32] = &mut [1, 2, 3];
//! x[1] = 7;
//! assert_eq!(x[0], 1);
//! assert_eq!(x[1], 7);
//! assert_eq!(x[2], 3);
//! ```
//!
//! Here are some of the things this module contains:
//!
//! ## Structs
//!
//! There are several structs that are useful for slices, such as `Iter`, which
//! represents iteration over a slice.
//!
//! ## Traits
//!
//! A number of traits add methods that allow you to accomplish tasks
//! with slices, the most important being `SliceExt`. Other traits
//! apply only to slices of elements satisfying certain bounds (like
//! `Ord`).
//!
//! An example is the `slice` method which enables slicing syntax `[a..b]` that
//! returns an immutable "view" into a `Vec` or another slice from the index
//! interval `[a, b)`:
//!
//! ```rust
//! fn main() {
//! let numbers = [0, 1, 2];
//! let last_numbers = &numbers[1..3];
//! // last_numbers is now &[1, 2]
//! }
//! ```
//!
//! ## Implementations of other traits
//!
//! There are several implementations of common traits for slices. Some examples
//! include:
//!
//! * `Clone`
//! * `Eq`, `Ord` - for immutable slices whose element type are `Eq` or `Ord`.
//! * `Hash` - for slices whose element type is `Hash`
//!
//! ## Iteration
//!
//! The method `iter()` returns an iteration value for a slice. The iterator
//! yields references to the slice's elements, so if the element
//! type of the slice is `isize`, the element type of the iterator is `&isize`.
//!
//! ```rust
//! let numbers = [0, 1, 2];
//! for &x in numbers.iter() {
//! println!("{} is a number!", x);
//! }
//! ```
//!
//! * `.iter_mut()` returns an iterator that allows modifying each value.
//! * Further iterators exist that split, chunk or permute the slice.
#![doc(primitive = "slice")]
#![stable(feature = "rust1", since = "1.0.0")]
use alloc::boxed::Box;
use core::clone::Clone;
use core::cmp::Ordering::{self, Greater, Less};
use core::cmp::{self, Ord, PartialEq};
use core::iter::{Iterator, IteratorExt};
use core::iter::{range_step, MultiplicativeIterator};
use core::marker::Sized;
use core::mem::size_of;
use core::mem;
use core::num::wrapping::WrappingOps;
use core::ops::FnMut;
use core::option::Option::{self, Some, None};
use core::ptr::PtrExt;
use core::ptr;
use core::result::Result;
use core::slice as core_slice;
use self::Direction::*;
use borrow::{Borrow, BorrowMut, ToOwned};
use vec::Vec;
pub use core::slice::{Chunks, AsSlice, Windows};
pub use core::slice::{Iter, IterMut};
pub use core::slice::{IntSliceExt, SplitMut, ChunksMut, Split};
pub use core::slice::{SplitN, RSplitN, SplitNMut, RSplitNMut};
pub use core::slice::{bytes, mut_ref_slice, ref_slice};
pub use core::slice::{from_raw_parts, from_raw_parts_mut};
pub use core::slice::{from_raw_buf, from_raw_mut_buf};
////////////////////////////////////////////////////////////////////////////////
// Basic slice extension methods
////////////////////////////////////////////////////////////////////////////////
/// Allocating extension methods for slices.
#[stable(feature = "rust1", since = "1.0.0")]
pub trait SliceExt {
#[stable(feature = "rust1", since = "1.0.0")]
type Item;
/// Sorts the slice, in place, using `compare` to compare
/// elements.
///
/// This sort is `O(n log n)` worst-case and stable, but allocates
/// approximately `2 * n`, where `n` is the length of `self`.
///
/// # Examples
///
/// ```rust
/// let mut v = [5, 4, 1, 3, 2];
/// v.sort_by(|a, b| a.cmp(b));
/// assert!(v == [1, 2, 3, 4, 5]);
///
/// // reverse sorting
/// v.sort_by(|a, b| b.cmp(a));
/// assert!(v == [5, 4, 3, 2, 1]);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn sort_by<F>(&mut self, compare: F) where F: FnMut(&Self::Item, &Self::Item) -> Ordering;
/// Consumes `src` and moves as many elements as it can into `self`
/// from the range [start,end).
///
/// Returns the number of elements copied (the shorter of `self.len()`
/// and `end - start`).
///
/// # Arguments
///
/// * src - A mutable vector of `T`
/// * start - The index into `src` to start copying from
/// * end - The index into `src` to stop copying from
///
/// # Examples
///
/// ```rust
/// let mut a = [1, 2, 3, 4, 5];
/// let b = vec![6, 7, 8];
/// let num_moved = a.move_from(b, 0, 3);
/// assert_eq!(num_moved, 3);
/// assert!(a == [6, 7, 8, 4, 5]);
/// ```
#[unstable(feature = "collections",
reason = "uncertain about this API approach")]
fn move_from(&mut self, src: Vec<Self::Item>, start: usize, end: usize) -> usize;
/// Deprecated: use `&s[start .. end]` notation instead.
#[unstable(feature = "collections",
reason = "will be replaced by slice syntax")]
#[deprecated(since = "1.0.0", reason = "use &s[start .. end] instead")]
fn slice(&self, start: usize, end: usize) -> &[Self::Item];
/// Deprecated: use `&s[start..]` notation instead.
#[unstable(feature = "collections",
reason = "will be replaced by slice syntax")]
#[deprecated(since = "1.0.0", reason = "use &s[start..] instead")]
fn slice_from(&self, start: usize) -> &[Self::Item];
/// Deprecated: use `&s[..end]` notation instead.
#[unstable(feature = "collections",
reason = "will be replaced by slice syntax")]
#[deprecated(since = "1.0.0", reason = "use &s[..end] instead")]
fn slice_to(&self, end: usize) -> &[Self::Item];
/// Divides one slice into two at an index.
///
/// The first will contain all indices from `[0, mid)` (excluding
/// the index `mid` itself) and the second will contain all
/// indices from `[mid, len)` (excluding the index `len` itself).
///
/// Panics if `mid > len`.
///
/// # Examples
///
/// ```
/// let v = [10, 40, 30, 20, 50];
/// let (v1, v2) = v.split_at(2);
/// assert_eq!([10, 40], v1);
/// assert_eq!([30, 20, 50], v2);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn split_at(&self, mid: usize) -> (&[Self::Item], &[Self::Item]);
/// Returns an iterator over the slice.
#[stable(feature = "rust1", since = "1.0.0")]
fn iter(&self) -> Iter<Self::Item>;
/// Returns an iterator over subslices separated by elements that match
/// `pred`. The matched element is not contained in the subslices.
///
/// # Examples
///
/// Print the slice split by numbers divisible by 3 (i.e. `[10, 40]`,
/// `[20]`, `[50]`):
///
/// ```
/// let v = [10, 40, 30, 20, 60, 50];
/// for group in v.split(|num| *num % 3 == 0) {
/// println!("{:?}", group);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn split<F>(&self, pred: F) -> Split<Self::Item, F>
where F: FnMut(&Self::Item) -> bool;
/// Returns an iterator over subslices separated by elements that match
/// `pred`, limited to splitting at most `n` times. The matched element is
/// not contained in the subslices.
///
/// # Examples
///
/// Print the slice split once by numbers divisible by 3 (i.e. `[10, 40]`,
/// `[20, 60, 50]`):
///
/// ```
/// let v = [10, 40, 30, 20, 60, 50];
/// for group in v.splitn(1, |num| *num % 3 == 0) {
/// println!("{:?}", group);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn splitn<F>(&self, n: usize, pred: F) -> SplitN<Self::Item, F>
where F: FnMut(&Self::Item) -> bool;
/// Returns an iterator over subslices separated by elements that match
/// `pred` limited to splitting at most `n` times. This starts at the end of
/// the slice and works backwards. The matched element is not contained in
/// the subslices.
///
/// # Examples
///
/// Print the slice split once, starting from the end, by numbers divisible
/// by 3 (i.e. `[50]`, `[10, 40, 30, 20]`):
///
/// ```
/// let v = [10, 40, 30, 20, 60, 50];
/// for group in v.rsplitn(1, |num| *num % 3 == 0) {
/// println!("{:?}", group);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<Self::Item, F>
where F: FnMut(&Self::Item) -> bool;
/// Returns an iterator over all contiguous windows of length
/// `size`. The windows overlap. If the slice is shorter than
/// `size`, the iterator returns no values.
///
/// # Panics
///
/// Panics if `size` is 0.
///
/// # Examples
///
/// Print the adjacent pairs of a slice (i.e. `[1,2]`, `[2,3]`,
/// `[3,4]`):
///
/// ```rust
/// let v = &[1, 2, 3, 4];
/// for win in v.windows(2) {
/// println!("{:?}", win);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn windows(&self, size: usize) -> Windows<Self::Item>;
/// Returns an iterator over `size` elements of the slice at a
/// time. The chunks do not overlap. If `size` does not divide the
/// length of the slice, then the last chunk will not have length
/// `size`.
///
/// # Panics
///
/// Panics if `size` is 0.
///
/// # Examples
///
/// Print the slice two elements at a time (i.e. `[1,2]`,
/// `[3,4]`, `[5]`):
///
/// ```rust
/// let v = &[1, 2, 3, 4, 5];
/// for win in v.chunks(2) {
/// println!("{:?}", win);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn chunks(&self, size: usize) -> Chunks<Self::Item>;
/// Returns the element of a slice at the given index, or `None` if the
/// index is out of bounds.
///
/// # Examples
///
/// ```
/// let v = [10, 40, 30];
/// assert_eq!(Some(&40), v.get(1));
/// assert_eq!(None, v.get(3));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn get(&self, index: usize) -> Option<&Self::Item>;
/// Returns the first element of a slice, or `None` if it is empty.
///
/// # Examples
///
/// ```
/// let v = [10, 40, 30];
/// assert_eq!(Some(&10), v.first());
///
/// let w: &[i32] = &[];
/// assert_eq!(None, w.first());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn first(&self) -> Option<&Self::Item>;
/// Returns all but the first element of a slice.
#[unstable(feature = "collections", reason = "likely to be renamed")]
fn tail(&self) -> &[Self::Item];
/// Returns all but the last element of a slice.
#[unstable(feature = "collections", reason = "likely to be renamed")]
fn init(&self) -> &[Self::Item];
/// Returns the last element of a slice, or `None` if it is empty.
///
/// # Examples
///
/// ```
/// let v = [10, 40, 30];
/// assert_eq!(Some(&30), v.last());
///
/// let w: &[i32] = &[];
/// assert_eq!(None, w.last());
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn last(&self) -> Option<&Self::Item>;
/// Returns a pointer to the element at the given index, without doing
/// bounds checking.
#[stable(feature = "rust1", since = "1.0.0")]
unsafe fn get_unchecked(&self, index: usize) -> &Self::Item;
/// Returns an unsafe pointer to the slice's buffer
///
/// The caller must ensure that the slice outlives the pointer this
/// function returns, or else it will end up pointing to garbage.
///
/// Modifying the slice may cause its buffer to be reallocated, which
/// would also make any pointers to it invalid.
#[stable(feature = "rust1", since = "1.0.0")]
fn as_ptr(&self) -> *const Self::Item;
/// Binary search a sorted slice with a comparator function.
///
/// The comparator function should implement an order consistent
/// with the sort order of the underlying slice, returning an
/// order code that indicates whether its argument is `Less`,
/// `Equal` or `Greater` the desired target.
///
/// If a matching value is found then returns `Ok`, containing
/// the index for the matched element; if no match is found then
/// `Err` is returned, containing the index where a matching
/// element could be inserted while maintaining sorted order.
///
/// # Examples
///
/// Looks up a series of four elements. The first is found, with a
/// uniquely determined position; the second and third are not
/// found; the fourth could match any position in `[1,4]`.
///
/// ```rust
/// let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];
/// let s = s.as_slice();
///
/// let seek = 13;
/// assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9));
/// let seek = 4;
/// assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7));
/// let seek = 100;
/// assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13));
/// let seek = 1;
/// let r = s.binary_search_by(|probe| probe.cmp(&seek));
/// assert!(match r { Ok(1...4) => true, _ => false, });
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn binary_search_by<F>(&self, f: F) -> Result<usize, usize> where
F: FnMut(&Self::Item) -> Ordering;
/// Return the number of elements in the slice
///
/// # Examples
///
/// ```
/// let a = [1, 2, 3];
/// assert_eq!(a.len(), 3);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn len(&self) -> usize;
/// Returns true if the slice has a length of 0
///
/// # Examples
///
/// ```
/// let a = [1, 2, 3];
/// assert!(!a.is_empty());
/// ```
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
fn is_empty(&self) -> bool { self.len() == 0 }
/// Returns a mutable reference to the element at the given index,
/// or `None` if the index is out of bounds
#[stable(feature = "rust1", since = "1.0.0")]
fn get_mut(&mut self, index: usize) -> Option<&mut Self::Item>;
/// Work with `self` as a mut slice.
/// Primarily intended for getting a &mut [T] from a [T; N].
#[stable(feature = "rust1", since = "1.0.0")]
fn as_mut_slice(&mut self) -> &mut [Self::Item];
/// Deprecated: use `&mut s[start .. end]` instead.
#[unstable(feature = "collections",
reason = "will be replaced by slice syntax")]
#[deprecated(since = "1.0.0", reason = "use &mut s[start .. end] instead")]
fn slice_mut(&mut self, start: usize, end: usize) -> &mut [Self::Item];
/// Deprecated: use `&mut s[start ..]` instead.
#[unstable(feature = "collections",
reason = "will be replaced by slice syntax")]
#[deprecated(since = "1.0.0", reason = "use &mut s[start ..] instead")]
fn slice_from_mut(&mut self, start: usize) -> &mut [Self::Item];
/// Deprecated: use `&mut s[.. end]` instead.
#[unstable(feature = "collections",
reason = "will be replaced by slice syntax")]
#[deprecated(since = "1.0.0", reason = "use &mut s[.. end] instead")]
fn slice_to_mut(&mut self, end: usize) -> &mut [Self::Item];
/// Returns an iterator that allows modifying each value
#[stable(feature = "rust1", since = "1.0.0")]
fn iter_mut(&mut self) -> IterMut<Self::Item>;
/// Returns a mutable pointer to the first element of a slice, or `None` if it is empty
#[stable(feature = "rust1", since = "1.0.0")]
fn first_mut(&mut self) -> Option<&mut Self::Item>;
/// Returns all but the first element of a mutable slice
#[unstable(feature = "collections",
reason = "likely to be renamed or removed")]
fn tail_mut(&mut self) -> &mut [Self::Item];
/// Returns all but the last element of a mutable slice
#[unstable(feature = "collections",
reason = "likely to be renamed or removed")]
fn init_mut(&mut self) -> &mut [Self::Item];
/// Returns a mutable pointer to the last item in the slice.
#[stable(feature = "rust1", since = "1.0.0")]
fn last_mut(&mut self) -> Option<&mut Self::Item>;
/// Returns an iterator over mutable subslices separated by elements that
/// match `pred`. The matched element is not contained in the subslices.
#[stable(feature = "rust1", since = "1.0.0")]
fn split_mut<F>(&mut self, pred: F) -> SplitMut<Self::Item, F>
where F: FnMut(&Self::Item) -> bool;
/// Returns an iterator over subslices separated by elements that match
/// `pred`, limited to splitting at most `n` times. The matched element is
/// not contained in the subslices.
#[stable(feature = "rust1", since = "1.0.0")]
fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<Self::Item, F>
where F: FnMut(&Self::Item) -> bool;
/// Returns an iterator over subslices separated by elements that match
/// `pred` limited to splitting at most `n` times. This starts at the end of
/// the slice and works backwards. The matched element is not contained in
/// the subslices.
#[stable(feature = "rust1", since = "1.0.0")]
fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<Self::Item, F>
where F: FnMut(&Self::Item) -> bool;
/// Returns an iterator over `chunk_size` elements of the slice at a time.
/// The chunks are mutable and do not overlap. If `chunk_size` does
/// not divide the length of the slice, then the last chunk will not
/// have length `chunk_size`.
///
/// # Panics
///
/// Panics if `chunk_size` is 0.
#[stable(feature = "rust1", since = "1.0.0")]
fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<Self::Item>;
/// Swaps two elements in a slice.
///
/// # Arguments
///
/// * a - The index of the first element
/// * b - The index of the second element
///
/// # Panics
///
/// Panics if `a` or `b` are out of bounds.
///
/// # Examples
///
/// ```rust
/// let mut v = ["a", "b", "c", "d"];
/// v.swap(1, 3);
/// assert!(v == ["a", "d", "c", "b"]);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn swap(&mut self, a: usize, b: usize);
/// Divides one `&mut` into two at an index.
///
/// The first will contain all indices from `[0, mid)` (excluding
/// the index `mid` itself) and the second will contain all
/// indices from `[mid, len)` (excluding the index `len` itself).
///
/// # Panics
///
/// Panics if `mid > len`.
///
/// # Examples
///
/// ```rust
/// let mut v = [1, 2, 3, 4, 5, 6];
///
/// // scoped to restrict the lifetime of the borrows
/// {
/// let (left, right) = v.split_at_mut(0);
/// assert!(left == []);
/// assert!(right == [1, 2, 3, 4, 5, 6]);
/// }
///
/// {
/// let (left, right) = v.split_at_mut(2);
/// assert!(left == [1, 2]);
/// assert!(right == [3, 4, 5, 6]);
/// }
///
/// {
/// let (left, right) = v.split_at_mut(6);
/// assert!(left == [1, 2, 3, 4, 5, 6]);
/// assert!(right == []);
/// }
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn split_at_mut(&mut self, mid: usize) -> (&mut [Self::Item], &mut [Self::Item]);
/// Reverse the order of elements in a slice, in place.
///
/// # Examples
///
/// ```rust
/// let mut v = [1, 2, 3];
/// v.reverse();
/// assert!(v == [3, 2, 1]);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn reverse(&mut self);
/// Returns an unsafe mutable pointer to the element in index
#[stable(feature = "rust1", since = "1.0.0")]
unsafe fn get_unchecked_mut(&mut self, index: usize) -> &mut Self::Item;
/// Return an unsafe mutable pointer to the slice's buffer.
///
/// The caller must ensure that the slice outlives the pointer this
/// function returns, or else it will end up pointing to garbage.
///
/// Modifying the slice may cause its buffer to be reallocated, which
/// would also make any pointers to it invalid.
#[inline]
#[stable(feature = "rust1", since = "1.0.0")]
fn as_mut_ptr(&mut self) -> *mut Self::Item;
/// Copies `self` into a new `Vec`.
#[stable(feature = "rust1", since = "1.0.0")]
fn to_vec(&self) -> Vec<Self::Item> where Self::Item: Clone;
/// Creates an iterator that yields every possible permutation of the
/// vector in succession.
///
/// # Examples
///
/// ```rust
/// let v = [1, 2, 3];
/// let mut perms = v.permutations();
///
/// for p in perms {
/// println!("{:?}", p);
/// }
/// ```
///
/// Iterating through permutations one by one.
///
/// ```rust
/// let v = [1, 2, 3];
/// let mut perms = v.permutations();
///
/// assert_eq!(Some(vec![1, 2, 3]), perms.next());
/// assert_eq!(Some(vec![1, 3, 2]), perms.next());
/// assert_eq!(Some(vec![3, 1, 2]), perms.next());
/// ```
#[unstable(feature = "collections")]
fn permutations(&self) -> Permutations<Self::Item> where Self::Item: Clone;
/// Copies as many elements from `src` as it can into `self` (the
/// shorter of `self.len()` and `src.len()`). Returns the number
/// of elements copied.
///
/// # Examples
///
/// ```rust
/// let mut dst = [0, 0, 0];
/// let src = [1, 2];
///
/// assert!(dst.clone_from_slice(&src) == 2);
/// assert!(dst == [1, 2, 0]);
///
/// let src2 = [3, 4, 5, 6];
/// assert!(dst.clone_from_slice(&src2) == 3);
/// assert!(dst == [3, 4, 5]);
/// ```
#[unstable(feature = "collections")]
fn clone_from_slice(&mut self, &[Self::Item]) -> usize where Self::Item: Clone;
/// Sorts the slice, in place.
///
/// This is equivalent to `self.sort_by(|a, b| a.cmp(b))`.
///
/// # Examples
///
/// ```rust
/// let mut v = [-5, 4, 1, -3, 2];
///
/// v.sort();
/// assert!(v == [-5, -3, 1, 2, 4]);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn sort(&mut self) where Self::Item: Ord;
/// Binary search a sorted slice for a given element.
///
/// If the value is found then `Ok` is returned, containing the
/// index of the matching element; if the value is not found then
/// `Err` is returned, containing the index where a matching
/// element could be inserted while maintaining sorted order.
///
/// # Examples
///
/// Looks up a series of four elements. The first is found, with a
/// uniquely determined position; the second and third are not
/// found; the fourth could match any position in `[1,4]`.
///
/// ```rust
/// let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];
/// let s = s.as_slice();
///
/// assert_eq!(s.binary_search(&13), Ok(9));
/// assert_eq!(s.binary_search(&4), Err(7));
/// assert_eq!(s.binary_search(&100), Err(13));
/// let r = s.binary_search(&1);
/// assert!(match r { Ok(1...4) => true, _ => false, });
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn binary_search(&self, x: &Self::Item) -> Result<usize, usize> where Self::Item: Ord;
/// Deprecated: use `binary_search` instead.
#[unstable(feature = "collections")]
#[deprecated(since = "1.0.0", reason = "use binary_search instead")]
fn binary_search_elem(&self, x: &Self::Item) -> Result<usize, usize> where Self::Item: Ord {
self.binary_search(x)
}
/// Mutates the slice to the next lexicographic permutation.
///
/// Returns `true` if successful and `false` if the slice is at the
/// last-ordered permutation.
///
/// # Examples
///
/// ```rust
/// let v: &mut [_] = &mut [0, 1, 2];
/// v.next_permutation();
/// let b: &mut [_] = &mut [0, 2, 1];
/// assert!(v == b);
/// v.next_permutation();
/// let b: &mut [_] = &mut [1, 0, 2];
/// assert!(v == b);
/// ```
#[unstable(feature = "collections",
reason = "uncertain if this merits inclusion in std")]
fn next_permutation(&mut self) -> bool where Self::Item: Ord;
/// Mutates the slice to the previous lexicographic permutation.
///
/// Returns `true` if successful and `false` if the slice is at the
/// first-ordered permutation.
///
/// # Examples
///
/// ```rust
/// let v: &mut [_] = &mut [1, 0, 2];
/// v.prev_permutation();
/// let b: &mut [_] = &mut [0, 2, 1];
/// assert!(v == b);
/// v.prev_permutation();
/// let b: &mut [_] = &mut [0, 1, 2];
/// assert!(v == b);
/// ```
#[unstable(feature = "collections",
reason = "uncertain if this merits inclusion in std")]
fn prev_permutation(&mut self) -> bool where Self::Item: Ord;
/// Find the first index containing a matching value.
#[unstable(feature = "collections")]
fn position_elem(&self, t: &Self::Item) -> Option<usize> where Self::Item: PartialEq;
/// Find the last index containing a matching value.
#[unstable(feature = "collections")]
fn rposition_elem(&self, t: &Self::Item) -> Option<usize> where Self::Item: PartialEq;
/// Returns true if the slice contains an element with the given value.
///
/// # Examples
///
/// ```
/// let v = [10, 40, 30];
/// assert!(v.contains(&30));
/// assert!(!v.contains(&50));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn contains(&self, x: &Self::Item) -> bool where Self::Item: PartialEq;
/// Returns true if `needle` is a prefix of the slice.
///
/// # Examples
///
/// ```
/// let v = [10, 40, 30];
/// assert!(v.starts_with(&[10]));
/// assert!(v.starts_with(&[10, 40]));
/// assert!(!v.starts_with(&[50]));
/// assert!(!v.starts_with(&[10, 50]));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn starts_with(&self, needle: &[Self::Item]) -> bool where Self::Item: PartialEq;
/// Returns true if `needle` is a suffix of the slice.
///
/// # Examples
///
/// ```
/// let v = [10, 40, 30];
/// assert!(v.ends_with(&[30]));
/// assert!(v.ends_with(&[40, 30]));
/// assert!(!v.ends_with(&[50]));
/// assert!(!v.ends_with(&[50, 30]));
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn ends_with(&self, needle: &[Self::Item]) -> bool where Self::Item: PartialEq;
/// Convert `self` into a vector without clones or allocation.
#[stable(feature = "rust1", since = "1.0.0")]
fn into_vec(self: Box<Self>) -> Vec<Self::Item>;
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> SliceExt for [T] {
type Item = T;
#[inline]
fn sort_by<F>(&mut self, compare: F) where F: FnMut(&T, &T) -> Ordering {
merge_sort(self, compare)
}
#[inline]
fn move_from(&mut self, mut src: Vec<T>, start: usize, end: usize) -> usize {
for (a, b) in self.iter_mut().zip(src[start .. end].iter_mut()) {
mem::swap(a, b);
}
cmp::min(self.len(), end-start)
}
#[inline]
fn slice(&self, start: usize, end: usize) -> &[T] {
&self[start .. end]
}
#[inline]
fn slice_from(&self, start: usize) -> &[T] {
&self[start ..]
}
#[inline]
fn slice_to(&self, end: usize) -> &[T] {
&self[.. end]
}
#[inline]
fn split_at(&self, mid: usize) -> (&[T], &[T]) {
core_slice::SliceExt::split_at(self, mid)
}
#[inline]
fn iter(&self) -> Iter<T> {
core_slice::SliceExt::iter(self)
}
#[inline]
fn split<F>(&self, pred: F) -> Split<T, F>
where F: FnMut(&T) -> bool {
core_slice::SliceExt::split(self, pred)
}
#[inline]
fn splitn<F>(&self, n: usize, pred: F) -> SplitN<T, F>
where F: FnMut(&T) -> bool {
core_slice::SliceExt::splitn(self, n, pred)
}
#[inline]
fn rsplitn<F>(&self, n: usize, pred: F) -> RSplitN<T, F>
where F: FnMut(&T) -> bool {
core_slice::SliceExt::rsplitn(self, n, pred)
}
#[inline]
fn windows(&self, size: usize) -> Windows<T> {
core_slice::SliceExt::windows(self, size)
}
#[inline]
fn chunks(&self, size: usize) -> Chunks<T> {
core_slice::SliceExt::chunks(self, size)
}
#[inline]
fn get(&self, index: usize) -> Option<&T> {
core_slice::SliceExt::get(self, index)
}
#[inline]
fn first(&self) -> Option<&T> {
core_slice::SliceExt::first(self)
}
#[inline]
fn tail(&self) -> &[T] {
core_slice::SliceExt::tail(self)
}
#[inline]
fn init(&self) -> &[T] {
core_slice::SliceExt::init(self)
}
#[inline]
fn last(&self) -> Option<&T> {
core_slice::SliceExt::last(self)
}
#[inline]
unsafe fn get_unchecked(&self, index: usize) -> &T {
core_slice::SliceExt::get_unchecked(self, index)
}
#[inline]
fn as_ptr(&self) -> *const T {
core_slice::SliceExt::as_ptr(self)
}
#[inline]
fn binary_search_by<F>(&self, f: F) -> Result<usize, usize>
where F: FnMut(&T) -> Ordering {
core_slice::SliceExt::binary_search_by(self, f)
}
#[inline]
fn len(&self) -> usize {
core_slice::SliceExt::len(self)
}
#[inline]
fn is_empty(&self) -> bool {
core_slice::SliceExt::is_empty(self)
}
#[inline]
fn get_mut(&mut self, index: usize) -> Option<&mut T> {
core_slice::SliceExt::get_mut(self, index)
}
#[inline]
fn as_mut_slice(&mut self) -> &mut [T] {
core_slice::SliceExt::as_mut_slice(self)
}
#[inline]
fn slice_mut(&mut self, start: usize, end: usize) -> &mut [T] {
&mut self[start .. end]
}
#[inline]
fn slice_from_mut(&mut self, start: usize) -> &mut [T] {
&mut self[start ..]
}
#[inline]
fn slice_to_mut(&mut self, end: usize) -> &mut [T] {
&mut self[.. end]
}
#[inline]
fn iter_mut(&mut self) -> IterMut<T> {
core_slice::SliceExt::iter_mut(self)
}
#[inline]
fn first_mut(&mut self) -> Option<&mut T> {
core_slice::SliceExt::first_mut(self)
}
#[inline]
fn tail_mut(&mut self) -> &mut [T] {
core_slice::SliceExt::tail_mut(self)
}
#[inline]
fn init_mut(&mut self) -> &mut [T] {
core_slice::SliceExt::init_mut(self)
}
#[inline]
fn last_mut(&mut self) -> Option<&mut T> {
core_slice::SliceExt::last_mut(self)
}
#[inline]
fn split_mut<F>(&mut self, pred: F) -> SplitMut<T, F>
where F: FnMut(&T) -> bool {
core_slice::SliceExt::split_mut(self, pred)
}
#[inline]
fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<T, F>
where F: FnMut(&T) -> bool {
core_slice::SliceExt::splitn_mut(self, n, pred)
}
#[inline]
fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<T, F>
where F: FnMut(&T) -> bool {
core_slice::SliceExt::rsplitn_mut(self, n, pred)
}
#[inline]
fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<T> {
core_slice::SliceExt::chunks_mut(self, chunk_size)
}
#[inline]
fn swap(&mut self, a: usize, b: usize) {
core_slice::SliceExt::swap(self, a, b)
}
#[inline]
fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T]) {
core_slice::SliceExt::split_at_mut(self, mid)
}
#[inline]
fn reverse(&mut self) {
core_slice::SliceExt::reverse(self)
}
#[inline]
unsafe fn get_unchecked_mut(&mut self, index: usize) -> &mut T {
core_slice::SliceExt::get_unchecked_mut(self, index)
}
#[inline]
fn as_mut_ptr(&mut self) -> *mut T {
core_slice::SliceExt::as_mut_ptr(self)
}
/// Returns a copy of `v`.
#[inline]
fn to_vec(&self) -> Vec<T> where T: Clone {
let mut vector = Vec::with_capacity(self.len());
vector.push_all(self);
vector
}
/// Returns an iterator over all permutations of a vector.
fn permutations(&self) -> Permutations<T> where T: Clone {
Permutations{
swaps: ElementSwaps::new(self.len()),
v: self.to_vec(),
}
}
fn clone_from_slice(&mut self, src: &[T]) -> usize where T: Clone {
core_slice::SliceExt::clone_from_slice(self, src)
}
#[inline]
fn sort(&mut self) where T: Ord {
self.sort_by(|a, b| a.cmp(b))
}
fn binary_search(&self, x: &T) -> Result<usize, usize> where T: Ord {
core_slice::SliceExt::binary_search(self, x)
}
fn next_permutation(&mut self) -> bool where T: Ord {
core_slice::SliceExt::next_permutation(self)
}
fn prev_permutation(&mut self) -> bool where T: Ord {
core_slice::SliceExt::prev_permutation(self)
}
fn position_elem(&self, t: &T) -> Option<usize> where T: PartialEq {
core_slice::SliceExt::position_elem(self, t)
}
fn rposition_elem(&self, t: &T) -> Option<usize> where T: PartialEq {
core_slice::SliceExt::rposition_elem(self, t)
}
fn contains(&self, x: &T) -> bool where T: PartialEq {
core_slice::SliceExt::contains(self, x)
}
fn starts_with(&self, needle: &[T]) -> bool where T: PartialEq {
core_slice::SliceExt::starts_with(self, needle)
}
fn ends_with(&self, needle: &[T]) -> bool where T: PartialEq {
core_slice::SliceExt::ends_with(self, needle)
}
fn into_vec(mut self: Box<Self>) -> Vec<T> {
unsafe {
let xs = Vec::from_raw_parts(self.as_mut_ptr(), self.len(), self.len());
mem::forget(self);
xs
}
}
}
////////////////////////////////////////////////////////////////////////////////
// Extension traits for slices over specific kinds of data
////////////////////////////////////////////////////////////////////////////////
#[unstable(feature = "collections", reason = "U should be an associated type")]
/// An extension trait for concatenating slices
pub trait SliceConcatExt<T: ?Sized, U> {
/// Flattens a slice of `T` into a single value `U`.
///
/// # Examples
///
/// ```
/// let v = vec!["hello", "world"];
///
/// let s: String = v.concat();
///
/// println!("{}", s); // prints "helloworld"
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn concat(&self) -> U;
/// Flattens a slice of `T` into a single value `U`, placing a given separator between each.
///
/// # Examples
///
/// ```
/// let v = vec!["hello", "world"];
///
/// let s: String = v.connect(" ");
///
/// println!("{}", s); // prints "hello world"
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn connect(&self, sep: &T) -> U;
}
impl<T: Clone, V: AsSlice<T>> SliceConcatExt<T, Vec<T>> for [V] {
fn concat(&self) -> Vec<T> {
let size = self.iter().fold(0, |acc, v| acc + v.as_slice().len());
let mut result = Vec::with_capacity(size);
for v in self {
result.push_all(v.as_slice())
}
result
}
fn connect(&self, sep: &T) -> Vec<T> {
let size = self.iter().fold(0, |acc, v| acc + v.as_slice().len());
let mut result = Vec::with_capacity(size + self.len());
let mut first = true;
for v in self {
if first { first = false } else { result.push(sep.clone()) }
result.push_all(v.as_slice())
}
result
}
}
/// An iterator that yields the element swaps needed to produce
/// a sequence of all possible permutations for an indexed sequence of
/// elements. Each permutation is only a single swap apart.
///
/// The Steinhaus-Johnson-Trotter algorithm is used.
///
/// Generates even and odd permutations alternately.
///
/// The last generated swap is always (0, 1), and it returns the
/// sequence to its initial order.
#[unstable(feature = "collections")]
#[derive(Clone)]
pub struct ElementSwaps {
sdir: Vec<SizeDirection>,
/// If `true`, emit the last swap that returns the sequence to initial
/// state.
emit_reset: bool,
swaps_made : usize,
}
impl ElementSwaps {
/// Creates an `ElementSwaps` iterator for a sequence of `length` elements.
#[unstable(feature = "collections")]
pub fn new(length: usize) -> ElementSwaps {
// Initialize `sdir` with a direction that position should move in
// (all negative at the beginning) and the `size` of the
// element (equal to the original index).
ElementSwaps{
emit_reset: true,
sdir: (0..length).map(|i| SizeDirection{ size: i, dir: Neg }).collect(),
swaps_made: 0
}
}
}
////////////////////////////////////////////////////////////////////////////////
// Standard trait implementations for slices
////////////////////////////////////////////////////////////////////////////////
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> Borrow<[T]> for Vec<T> {
fn borrow(&self) -> &[T] { &self[..] }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T> BorrowMut<[T]> for Vec<T> {
fn borrow_mut(&mut self) -> &mut [T] { &mut self[..] }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<T: Clone> ToOwned for [T] {
type Owned = Vec<T>;
fn to_owned(&self) -> Vec<T> { self.to_vec() }
}
////////////////////////////////////////////////////////////////////////////////
// Iterators
////////////////////////////////////////////////////////////////////////////////
#[derive(Copy, Clone)]
enum Direction { Pos, Neg }
/// An `Index` and `Direction` together.
#[derive(Copy, Clone)]
struct SizeDirection {
size: usize,
dir: Direction,
}
#[stable(feature = "rust1", since = "1.0.0")]
impl Iterator for ElementSwaps {
type Item = (usize, usize);
// #[inline]
fn next(&mut self) -> Option<(usize, usize)> {
fn new_pos_wrapping(i: usize, s: Direction) -> usize {
i.wrapping_add(match s { Pos => 1, Neg => -1 })
}
fn new_pos(i: usize, s: Direction) -> usize {
match s { Pos => i + 1, Neg => i - 1 }
}
// Find the index of the largest mobile element:
// The direction should point into the vector, and the
// swap should be with a smaller `size` element.
let max = self.sdir.iter().cloned().enumerate()
.filter(|&(i, sd)|
new_pos_wrapping(i, sd.dir) < self.sdir.len() &&
self.sdir[new_pos(i, sd.dir)].size < sd.size)
.max_by(|&(_, sd)| sd.size);
match max {
Some((i, sd)) => {
let j = new_pos(i, sd.dir);
self.sdir.swap(i, j);
// Swap the direction of each larger SizeDirection
for x in &mut self.sdir {
if x.size > sd.size {
x.dir = match x.dir { Pos => Neg, Neg => Pos };
}
}
self.swaps_made += 1;
Some((i, j))
},
None => if self.emit_reset {
self.emit_reset = false;
if self.sdir.len() > 1 {
// The last swap
self.swaps_made += 1;
Some((0, 1))
} else {
// Vector is of the form [] or [x], and the only permutation is itself
self.swaps_made += 1;
Some((0,0))
}
} else { None }
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
// For a vector of size n, there are exactly n! permutations.
let n = (2..self.sdir.len() + 1).product();
(n - self.swaps_made, Some(n - self.swaps_made))
}
}
/// An iterator that uses `ElementSwaps` to iterate through
/// all possible permutations of a vector.
///
/// The first iteration yields a clone of the vector as it is,
/// then each successive element is the vector with one
/// swap applied.
///
/// Generates even and odd permutations alternately.
#[unstable(feature = "collections")]
pub struct Permutations<T> {
swaps: ElementSwaps,
v: Vec<T>,
}
#[unstable(feature = "collections", reason = "trait is unstable")]
impl<T: Clone> Iterator for Permutations<T> {
type Item = Vec<T>;
#[inline]
fn next(&mut self) -> Option<Vec<T>> {
match self.swaps.next() {
None => None,
Some((0,0)) => Some(self.v.clone()),
Some((a, b)) => {
let elt = self.v.clone();
self.v.swap(a, b);
Some(elt)
}
}
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>) {
self.swaps.size_hint()
}
}
////////////////////////////////////////////////////////////////////////////////
// Sorting
////////////////////////////////////////////////////////////////////////////////
fn insertion_sort<T, F>(v: &mut [T], mut compare: F) where F: FnMut(&T, &T) -> Ordering {
let len = v.len() as isize;
let buf_v = v.as_mut_ptr();
// 1 <= i < len;
for i in 1..len {
// j satisfies: 0 <= j <= i;
let mut j = i;
unsafe {
// `i` is in bounds.
let read_ptr = buf_v.offset(i) as *const T;
// find where to insert, we need to do strict <,
// rather than <=, to maintain stability.
// 0 <= j - 1 < len, so .offset(j - 1) is in bounds.
while j > 0 &&
compare(&*read_ptr, &*buf_v.offset(j - 1)) == Less {
j -= 1;
}
// shift everything to the right, to make space to
// insert this value.
// j + 1 could be `len` (for the last `i`), but in
// that case, `i == j` so we don't copy. The
// `.offset(j)` is always in bounds.
if i != j {
let tmp = ptr::read(read_ptr);
ptr::copy(buf_v.offset(j + 1),
&*buf_v.offset(j),
(i - j) as usize);
ptr::copy_nonoverlapping(buf_v.offset(j), &tmp, 1);
mem::forget(tmp);
}
}
}
}
fn merge_sort<T, F>(v: &mut [T], mut compare: F) where F: FnMut(&T, &T) -> Ordering {
// warning: this wildly uses unsafe.
const BASE_INSERTION: usize = 32;
const LARGE_INSERTION: usize = 16;
// FIXME #12092: smaller insertion runs seems to make sorting
// vectors of large elements a little faster on some platforms,
// but hasn't been tested/tuned extensively
let insertion = if size_of::<T>() <= 16 {
BASE_INSERTION
} else {
LARGE_INSERTION
};
let len = v.len();
// short vectors get sorted in-place via insertion sort to avoid allocations
if len <= insertion {
insertion_sort(v, compare);
return;
}
// allocate some memory to use as scratch memory, we keep the
// length 0 so we can keep shallow copies of the contents of `v`
// without risking the dtors running on an object twice if
// `compare` panics.
let mut working_space = Vec::with_capacity(2 * len);
// these both are buffers of length `len`.
let mut buf_dat = working_space.as_mut_ptr();
let mut buf_tmp = unsafe {buf_dat.offset(len as isize)};
// length `len`.
let buf_v = v.as_ptr();
// step 1. sort short runs with insertion sort. This takes the
// values from `v` and sorts them into `buf_dat`, leaving that
// with sorted runs of length INSERTION.
// We could hardcode the sorting comparisons here, and we could
// manipulate/step the pointers themselves, rather than repeatedly
// .offset-ing.
for start in range_step(0, len, insertion) {
// start <= i < len;
for i in start..cmp::min(start + insertion, len) {
// j satisfies: start <= j <= i;
let mut j = i as isize;
unsafe {
// `i` is in bounds.
let read_ptr = buf_v.offset(i as isize);
// find where to insert, we need to do strict <,
// rather than <=, to maintain stability.
// start <= j - 1 < len, so .offset(j - 1) is in
// bounds.
while j > start as isize &&
compare(&*read_ptr, &*buf_dat.offset(j - 1)) == Less {
j -= 1;
}
// shift everything to the right, to make space to
// insert this value.
// j + 1 could be `len` (for the last `i`), but in
// that case, `i == j` so we don't copy. The
// `.offset(j)` is always in bounds.
ptr::copy(buf_dat.offset(j + 1),
&*buf_dat.offset(j),
i - j as usize);
ptr::copy_nonoverlapping(buf_dat.offset(j), read_ptr, 1);
}
}
}
// step 2. merge the sorted runs.
let mut width = insertion;
while width < len {
// merge the sorted runs of length `width` in `buf_dat` two at
// a time, placing the result in `buf_tmp`.
// 0 <= start <= len.
for start in range_step(0, len, 2 * width) {
// manipulate pointers directly for speed (rather than
// using a `for` loop with `range` and `.offset` inside
// that loop).
unsafe {
// the end of the first run & start of the
// second. Offset of `len` is defined, since this is
// precisely one byte past the end of the object.
let right_start = buf_dat.offset(cmp::min(start + width, len) as isize);
// end of the second. Similar reasoning to the above re safety.
let right_end_idx = cmp::min(start + 2 * width, len);
let right_end = buf_dat.offset(right_end_idx as isize);
// the pointers to the elements under consideration
// from the two runs.
// both of these are in bounds.
let mut left = buf_dat.offset(start as isize);
let mut right = right_start;
// where we're putting the results, it is a run of
// length `2*width`, so we step it once for each step
// of either `left` or `right`. `buf_tmp` has length
// `len`, so these are in bounds.
let mut out = buf_tmp.offset(start as isize);
let out_end = buf_tmp.offset(right_end_idx as isize);
while out < out_end {
// Either the left or the right run are exhausted,
// so just copy the remainder from the other run
// and move on; this gives a huge speed-up (order
// of 25%) for mostly sorted vectors (the best
// case).
if left == right_start {
// the number remaining in this run.
let elems = (right_end as usize - right as usize) / mem::size_of::<T>();
ptr::copy_nonoverlapping(out, &*right, elems);
break;
} else if right == right_end {
let elems = (right_start as usize - left as usize) / mem::size_of::<T>();
ptr::copy_nonoverlapping(out, &*left, elems);
break;
}
// check which side is smaller, and that's the
// next element for the new run.
// `left < right_start` and `right < right_end`,
// so these are valid.
let to_copy = if compare(&*left, &*right) == Greater {
step(&mut right)
} else {
step(&mut left)
};
ptr::copy_nonoverlapping(out, &*to_copy, 1);
step(&mut out);
}
}
}
mem::swap(&mut buf_dat, &mut buf_tmp);
width *= 2;
}
// write the result to `v` in one go, so that there are never two copies
// of the same object in `v`.
unsafe {
ptr::copy_nonoverlapping(v.as_mut_ptr(), &*buf_dat, len);
}
// increment the pointer, returning the old pointer.
#[inline(always)]
unsafe fn step<T>(ptr: &mut *mut T) -> *mut T {
let old = *ptr;
*ptr = ptr.offset(1);
old
}
}
#[cfg(test)]
mod tests {
use alloc::boxed::Box;
use core::cmp::Ordering::{Greater, Less, Equal};
use core::prelude::{Some, None, Clone};
use core::prelude::{Iterator, IteratorExt};
use core::prelude::{AsSlice};
use core::prelude::Ord;
use core::default::Default;
use core::mem;
use std::iter::RandomAccessIterator;
use std::rand::{Rng, thread_rng};
use std::rc::Rc;
use string::ToString;
use vec::Vec;
use super::{ElementSwaps, SliceConcatExt, SliceExt};
fn square(n: usize) -> usize { n * n }
fn is_odd(n: &usize) -> bool { *n % 2 == 1 }
#[test]
fn test_from_fn() {
// Test on-stack from_fn.
let mut v: Vec<_> = (0..3).map(square).collect();
{
let v = v;
assert_eq!(v.len(), 3);
assert_eq!(v[0], 0);
assert_eq!(v[1], 1);
assert_eq!(v[2], 4);
}
// Test on-heap from_fn.
v = (0..5).map(square).collect();
{
let v = v;
assert_eq!(v.len(), 5);
assert_eq!(v[0], 0);
assert_eq!(v[1], 1);
assert_eq!(v[2], 4);
assert_eq!(v[3], 9);
assert_eq!(v[4], 16);
}
}
#[test]
fn test_from_elem() {
// Test on-stack from_elem.
let mut v = vec![10, 10];
{
let v = v;
assert_eq!(v.len(), 2);
assert_eq!(v[0], 10);
assert_eq!(v[1], 10);
}
// Test on-heap from_elem.
v = vec![20; 6];
{
let v = v.as_slice();
assert_eq!(v[0], 20);
assert_eq!(v[1], 20);
assert_eq!(v[2], 20);
assert_eq!(v[3], 20);
assert_eq!(v[4], 20);
assert_eq!(v[5], 20);
}
}
#[test]
fn test_is_empty() {
let xs: [i32; 0] = [];
assert!(xs.is_empty());
assert!(![0].is_empty());
}
#[test]
fn test_len_divzero() {
type Z = [i8; 0];
let v0 : &[Z] = &[];
let v1 : &[Z] = &[[]];
let v2 : &[Z] = &[[], []];
assert_eq!(mem::size_of::<Z>(), 0);
assert_eq!(v0.len(), 0);
assert_eq!(v1.len(), 1);
assert_eq!(v2.len(), 2);
}
#[test]
fn test_get() {
let mut a = vec![11];
assert_eq!(a.get(1), None);
a = vec![11, 12];
assert_eq!(a.get(1).unwrap(), &12);
a = vec![11, 12, 13];
assert_eq!(a.get(1).unwrap(), &12);
}
#[test]
fn test_first() {
let mut a = vec![];
assert_eq!(a.first(), None);
a = vec![11];
assert_eq!(a.first().unwrap(), &11);
a = vec![11, 12];
assert_eq!(a.first().unwrap(), &11);
}
#[test]
fn test_first_mut() {
let mut a = vec![];
assert_eq!(a.first_mut(), None);
a = vec![11];
assert_eq!(*a.first_mut().unwrap(), 11);
a = vec![11, 12];
assert_eq!(*a.first_mut().unwrap(), 11);
}
#[test]
fn test_tail() {
let mut a = vec![11];
let b: &[i32] = &[];
assert_eq!(a.tail(), b);
a = vec![11, 12];
let b: &[i32] = &[12];
assert_eq!(a.tail(), b);
}
#[test]
fn test_tail_mut() {
let mut a = vec![11];
let b: &mut [i32] = &mut [];
assert!(a.tail_mut() == b);
a = vec![11, 12];
let b: &mut [_] = &mut [12];
assert!(a.tail_mut() == b);
}
#[test]
#[should_panic]
fn test_tail_empty() {
let a = Vec::<i32>::new();
a.tail();
}
#[test]
#[should_panic]
fn test_tail_mut_empty() {
let mut a = Vec::<i32>::new();
a.tail_mut();
}
#[test]
fn test_init() {
let mut a = vec![11];
let b: &[i32] = &[];
assert_eq!(a.init(), b);
a = vec![11, 12];
let b: &[_] = &[11];
assert_eq!(a.init(), b);
}
#[test]
fn test_init_mut() {
let mut a = vec![11];
let b: &mut [i32] = &mut [];
assert!(a.init_mut() == b);
a = vec![11, 12];
let b: &mut [_] = &mut [11];
assert!(a.init_mut() == b);
}
#[test]
#[should_panic]
fn test_init_empty() {
let a = Vec::<i32>::new();
a.init();
}
#[test]
#[should_panic]
fn test_init_mut_empty() {
let mut a = Vec::<i32>::new();
a.init_mut();
}
#[test]
fn test_last() {
let mut a = vec![];
assert_eq!(a.last(), None);
a = vec![11];
assert_eq!(a.last().unwrap(), &11);
a = vec![11, 12];
assert_eq!(a.last().unwrap(), &12);
}
#[test]
fn test_last_mut() {
let mut a = vec![];
assert_eq!(a.last_mut(), None);
a = vec![11];
assert_eq!(*a.last_mut().unwrap(), 11);
a = vec![11, 12];
assert_eq!(*a.last_mut().unwrap(), 12);
}
#[test]
fn test_slice() {
// Test fixed length vector.
let vec_fixed = [1, 2, 3, 4];
let v_a = vec_fixed[1..vec_fixed.len()].to_vec();
assert_eq!(v_a.len(), 3);
assert_eq!(v_a[0], 2);
assert_eq!(v_a[1], 3);
assert_eq!(v_a[2], 4);
// Test on stack.
let vec_stack: &[_] = &[1, 2, 3];
let v_b = vec_stack[1..3].to_vec();
assert_eq!(v_b.len(), 2);
assert_eq!(v_b[0], 2);
assert_eq!(v_b[1], 3);
// Test `Box<[T]>`
let vec_unique = vec![1, 2, 3, 4, 5, 6];
let v_d = vec_unique[1..6].to_vec();
assert_eq!(v_d.len(), 5);
assert_eq!(v_d[0], 2);
assert_eq!(v_d[1], 3);
assert_eq!(v_d[2], 4);
assert_eq!(v_d[3], 5);
assert_eq!(v_d[4], 6);
}
#[test]
fn test_slice_from() {
let vec: &[_] = &[1, 2, 3, 4];
assert_eq!(&vec[..], vec);
let b: &[_] = &[3, 4];
assert_eq!(&vec[2..], b);
let b: &[_] = &[];
assert_eq!(&vec[4..], b);
}
#[test]
fn test_slice_to() {
let vec: &[_] = &[1, 2, 3, 4];
assert_eq!(&vec[..4], vec);
let b: &[_] = &[1, 2];
assert_eq!(&vec[..2], b);
let b: &[_] = &[];
assert_eq!(&vec[..0], b);
}
#[test]
fn test_pop() {
let mut v = vec![5];
let e = v.pop();
assert_eq!(v.len(), 0);
assert_eq!(e, Some(5));
let f = v.pop();
assert_eq!(f, None);
let g = v.pop();
assert_eq!(g, None);
}
#[test]
fn test_swap_remove() {
let mut v = vec![1, 2, 3, 4, 5];
let mut e = v.swap_remove(0);
assert_eq!(e, 1);
assert_eq!(v, [5, 2, 3, 4]);
e = v.swap_remove(3);
assert_eq!(e, 4);
assert_eq!(v, [5, 2, 3]);
}
#[test]
#[should_panic]
fn test_swap_remove_fail() {
let mut v = vec![1];
let _ = v.swap_remove(0);
let _ = v.swap_remove(0);
}
#[test]
fn test_swap_remove_noncopyable() {
// Tests that we don't accidentally run destructors twice.
let mut v: Vec<Box<_>> = Vec::new();
v.push(box 0u8);
v.push(box 0u8);
v.push(box 0u8);
let mut _e = v.swap_remove(0);
assert_eq!(v.len(), 2);
_e = v.swap_remove(1);
assert_eq!(v.len(), 1);
_e = v.swap_remove(0);
assert_eq!(v.len(), 0);
}
#[test]
fn test_push() {
// Test on-stack push().
let mut v = vec![];
v.push(1);
assert_eq!(v.len(), 1);
assert_eq!(v[0], 1);
// Test on-heap push().
v.push(2);
assert_eq!(v.len(), 2);
assert_eq!(v[0], 1);
assert_eq!(v[1], 2);
}
#[test]
fn test_truncate() {
let mut v: Vec<Box<_>> = vec![box 6,box 5,box 4];
v.truncate(1);
let v = v;
assert_eq!(v.len(), 1);
assert_eq!(*(v[0]), 6);
// If the unsafe block didn't drop things properly, we blow up here.
}
#[test]
fn test_clear() {
let mut v: Vec<Box<_>> = vec![box 6,box 5,box 4];
v.clear();
assert_eq!(v.len(), 0);
// If the unsafe block didn't drop things properly, we blow up here.
}
#[test]
fn test_dedup() {
fn case(a: Vec<i32>, b: Vec<i32>) {
let mut v = a;
v.dedup();
assert_eq!(v, b);
}
case(vec![], vec![]);
case(vec![1], vec![1]);
case(vec![1,1], vec![1]);
case(vec![1,2,3], vec![1,2,3]);
case(vec![1,1,2,3], vec![1,2,3]);
case(vec![1,2,2,3], vec![1,2,3]);
case(vec![1,2,3,3], vec![1,2,3]);
case(vec![1,1,2,2,2,3,3], vec![1,2,3]);
}
#[test]
fn test_dedup_unique() {
let mut v0: Vec<Box<_>> = vec![box 1, box 1, box 2, box 3];
v0.dedup();
let mut v1: Vec<Box<_>> = vec![box 1, box 2, box 2, box 3];
v1.dedup();
let mut v2: Vec<Box<_>> = vec![box 1, box 2, box 3, box 3];
v2.dedup();
/*
* If the boxed pointers were leaked or otherwise misused, valgrind
* and/or rt should raise errors.
*/
}
#[test]
fn test_dedup_shared() {
let mut v0: Vec<Box<_>> = vec![box 1, box 1, box 2, box 3];
v0.dedup();
let mut v1: Vec<Box<_>> = vec![box 1, box 2, box 2, box 3];
v1.dedup();
let mut v2: Vec<Box<_>> = vec![box 1, box 2, box 3, box 3];
v2.dedup();
/*
* If the pointers were leaked or otherwise misused, valgrind and/or
* rt should raise errors.
*/
}
#[test]
fn test_retain() {
let mut v = vec![1, 2, 3, 4, 5];
v.retain(is_odd);
assert_eq!(v, [1, 3, 5]);
}
#[test]
fn test_element_swaps() {
let mut v = [1, 2, 3];
for (i, (a, b)) in ElementSwaps::new(v.len()).enumerate() {
v.swap(a, b);
match i {
0 => assert!(v == [1, 3, 2]),
1 => assert!(v == [3, 1, 2]),
2 => assert!(v == [3, 2, 1]),
3 => assert!(v == [2, 3, 1]),
4 => assert!(v == [2, 1, 3]),
5 => assert!(v == [1, 2, 3]),
_ => panic!(),
}
}
}
#[test]
fn test_permutations() {
{
let v: [i32; 0] = [];
let mut it = v.permutations();
let (min_size, max_opt) = it.size_hint();
assert_eq!(min_size, 1);
assert_eq!(max_opt.unwrap(), 1);
assert_eq!(it.next(), Some(v.to_vec()));
assert_eq!(it.next(), None);
}
{
let v = ["Hello".to_string()];
let mut it = v.permutations();
let (min_size, max_opt) = it.size_hint();
assert_eq!(min_size, 1);
assert_eq!(max_opt.unwrap(), 1);
assert_eq!(it.next(), Some(v.to_vec()));
assert_eq!(it.next(), None);
}
{
let v = [1, 2, 3];
let mut it = v.permutations();
let (min_size, max_opt) = it.size_hint();
assert_eq!(min_size, 3*2);
assert_eq!(max_opt.unwrap(), 3*2);
assert_eq!(it.next(), Some(vec![1,2,3]));
assert_eq!(it.next(), Some(vec![1,3,2]));
assert_eq!(it.next(), Some(vec![3,1,2]));
let (min_size, max_opt) = it.size_hint();
assert_eq!(min_size, 3);
assert_eq!(max_opt.unwrap(), 3);
assert_eq!(it.next(), Some(vec![3,2,1]));
assert_eq!(it.next(), Some(vec![2,3,1]));
assert_eq!(it.next(), Some(vec![2,1,3]));
assert_eq!(it.next(), None);
}
{
// check that we have N! permutations
let v = ['A', 'B', 'C', 'D', 'E', 'F'];
let mut amt = 0;
let mut it = v.permutations();
let (min_size, max_opt) = it.size_hint();
for _perm in it.by_ref() {
amt += 1;
}
assert_eq!(amt, it.swaps.swaps_made);
assert_eq!(amt, min_size);
assert_eq!(amt, 2 * 3 * 4 * 5 * 6);
assert_eq!(amt, max_opt.unwrap());
}
}
#[test]
fn test_lexicographic_permutations() {
let v : &mut[_] = &mut[1, 2, 3, 4, 5];
assert!(v.prev_permutation() == false);
assert!(v.next_permutation());
let b: &mut[_] = &mut[1, 2, 3, 5, 4];
assert!(v == b);
assert!(v.prev_permutation());
let b: &mut[_] = &mut[1, 2, 3, 4, 5];
assert!(v == b);
assert!(v.next_permutation());
assert!(v.next_permutation());
let b: &mut[_] = &mut[1, 2, 4, 3, 5];
assert!(v == b);
assert!(v.next_permutation());
let b: &mut[_] = &mut[1, 2, 4, 5, 3];
assert!(v == b);
let v : &mut[_] = &mut[1, 0, 0, 0];
assert!(v.next_permutation() == false);
assert!(v.prev_permutation());
let b: &mut[_] = &mut[0, 1, 0, 0];
assert!(v == b);
assert!(v.prev_permutation());
let b: &mut[_] = &mut[0, 0, 1, 0];
assert!(v == b);
assert!(v.prev_permutation());
let b: &mut[_] = &mut[0, 0, 0, 1];
assert!(v == b);
assert!(v.prev_permutation() == false);
}
#[test]
fn test_lexicographic_permutations_empty_and_short() {
let empty : &mut[i32] = &mut[];
assert!(empty.next_permutation() == false);
let b: &mut[i32] = &mut[];
assert!(empty == b);
assert!(empty.prev_permutation() == false);
assert!(empty == b);
let one_elem : &mut[_] = &mut[4];
assert!(one_elem.prev_permutation() == false);
let b: &mut[_] = &mut[4];
assert!(one_elem == b);
assert!(one_elem.next_permutation() == false);
assert!(one_elem == b);
let two_elem : &mut[_] = &mut[1, 2];
assert!(two_elem.prev_permutation() == false);
let b : &mut[_] = &mut[1, 2];
let c : &mut[_] = &mut[2, 1];
assert!(two_elem == b);
assert!(two_elem.next_permutation());
assert!(two_elem == c);
assert!(two_elem.next_permutation() == false);
assert!(two_elem == c);
assert!(two_elem.prev_permutation());
assert!(two_elem == b);
assert!(two_elem.prev_permutation() == false);
assert!(two_elem == b);
}
#[test]
fn test_position_elem() {
assert!([].position_elem(&1).is_none());
let v1 = vec![1, 2, 3, 3, 2, 5];
assert_eq!(v1.position_elem(&1), Some(0));
assert_eq!(v1.position_elem(&2), Some(1));
assert_eq!(v1.position_elem(&5), Some(5));
assert!(v1.position_elem(&4).is_none());
}
#[test]
fn test_binary_search() {
assert_eq!([1,2,3,4,5].binary_search(&5).ok(), Some(4));
assert_eq!([1,2,3,4,5].binary_search(&4).ok(), Some(3));
assert_eq!([1,2,3,4,5].binary_search(&3).ok(), Some(2));
assert_eq!([1,2,3,4,5].binary_search(&2).ok(), Some(1));
assert_eq!([1,2,3,4,5].binary_search(&1).ok(), Some(0));
assert_eq!([2,4,6,8,10].binary_search(&1).ok(), None);
assert_eq!([2,4,6,8,10].binary_search(&5).ok(), None);
assert_eq!([2,4,6,8,10].binary_search(&4).ok(), Some(1));
assert_eq!([2,4,6,8,10].binary_search(&10).ok(), Some(4));
assert_eq!([2,4,6,8].binary_search(&1).ok(), None);
assert_eq!([2,4,6,8].binary_search(&5).ok(), None);
assert_eq!([2,4,6,8].binary_search(&4).ok(), Some(1));
assert_eq!([2,4,6,8].binary_search(&8).ok(), Some(3));
assert_eq!([2,4,6].binary_search(&1).ok(), None);
assert_eq!([2,4,6].binary_search(&5).ok(), None);
assert_eq!([2,4,6].binary_search(&4).ok(), Some(1));
assert_eq!([2,4,6].binary_search(&6).ok(), Some(2));
assert_eq!([2,4].binary_search(&1).ok(), None);
assert_eq!([2,4].binary_search(&5).ok(), None);
assert_eq!([2,4].binary_search(&2).ok(), Some(0));
assert_eq!([2,4].binary_search(&4).ok(), Some(1));
assert_eq!([2].binary_search(&1).ok(), None);
assert_eq!([2].binary_search(&5).ok(), None);
assert_eq!([2].binary_search(&2).ok(), Some(0));
assert_eq!([].binary_search(&1).ok(), None);
assert_eq!([].binary_search(&5).ok(), None);
assert!([1,1,1,1,1].binary_search(&1).ok() != None);
assert!([1,1,1,1,2].binary_search(&1).ok() != None);
assert!([1,1,1,2,2].binary_search(&1).ok() != None);
assert!([1,1,2,2,2].binary_search(&1).ok() != None);
assert_eq!([1,2,2,2,2].binary_search(&1).ok(), Some(0));
assert_eq!([1,2,3,4,5].binary_search(&6).ok(), None);
assert_eq!([1,2,3,4,5].binary_search(&0).ok(), None);
}
#[test]
fn test_reverse() {
let mut v = vec![10, 20];
assert_eq!(v[0], 10);
assert_eq!(v[1], 20);
v.reverse();
assert_eq!(v[0], 20);
assert_eq!(v[1], 10);
let mut v3 = Vec::<i32>::new();
v3.reverse();
assert!(v3.is_empty());
}
#[test]
fn test_sort() {
for len in 4..25 {
for _ in 0..100 {
let mut v: Vec<_> = thread_rng().gen_iter::<i32>().take(len).collect();
let mut v1 = v.clone();
v.sort();
assert!(v.windows(2).all(|w| w[0] <= w[1]));
v1.sort_by(|a, b| a.cmp(b));
assert!(v1.windows(2).all(|w| w[0] <= w[1]));
v1.sort_by(|a, b| b.cmp(a));
assert!(v1.windows(2).all(|w| w[0] >= w[1]));
}
}
// shouldn't panic
let mut v: [i32; 0] = [];
v.sort();
let mut v = [0xDEADBEEFu64];
v.sort();
assert!(v == [0xDEADBEEF]);
}
#[test]
fn test_sort_stability() {
for len in 4..25 {
for _ in 0..10 {
let mut counts = [0; 10];
// create a vector like [(6, 1), (5, 1), (6, 2), ...],
// where the first item of each tuple is random, but
// the second item represents which occurrence of that
// number this element is, i.e. the second elements
// will occur in sorted order.
let mut v: Vec<_> = (0..len).map(|_| {
let n = thread_rng().gen::<usize>() % 10;
counts[n] += 1;
(n, counts[n])
}).collect();
// only sort on the first element, so an unstable sort
// may mix up the counts.
v.sort_by(|&(a,_), &(b,_)| a.cmp(&b));
// this comparison includes the count (the second item
// of the tuple), so elements with equal first items
// will need to be ordered with increasing
// counts... i.e. exactly asserting that this sort is
// stable.
assert!(v.windows(2).all(|w| w[0] <= w[1]));
}
}
}
#[test]
fn test_concat() {
let v: [Vec<i32>; 0] = [];
let c = v.concat();
assert_eq!(c, []);
let d = [vec![1], vec![2, 3]].concat();
assert_eq!(d, [1, 2, 3]);
let v: &[&[_]] = &[&[1], &[2, 3]];
assert_eq!(v.connect(&0), [1, 0, 2, 3]);
let v: &[&[_]] = &[&[1], &[2], &[3]];
assert_eq!(v.connect(&0), [1, 0, 2, 0, 3]);
}
#[test]
fn test_connect() {
let v: [Vec<i32>; 0] = [];
assert_eq!(v.connect(&0), []);
assert_eq!([vec![1], vec![2, 3]].connect(&0), [1, 0, 2, 3]);
assert_eq!([vec![1], vec![2], vec![3]].connect(&0), [1, 0, 2, 0, 3]);
let v: [&[_]; 2] = [&[1], &[2, 3]];
assert_eq!(v.connect(&0), [1, 0, 2, 3]);
let v: [&[_]; 3] = [&[1], &[2], &[3]];
assert_eq!(v.connect(&0), [1, 0, 2, 0, 3]);
}
#[test]
fn test_insert() {
let mut a = vec![1, 2, 4];
a.insert(2, 3);
assert_eq!(a, [1, 2, 3, 4]);
let mut a = vec![1, 2, 3];
a.insert(0, 0);
assert_eq!(a, [0, 1, 2, 3]);
let mut a = vec![1, 2, 3];
a.insert(3, 4);
assert_eq!(a, [1, 2, 3, 4]);
let mut a = vec![];
a.insert(0, 1);
assert_eq!(a, [1]);
}
#[test]
#[should_panic]
fn test_insert_oob() {
let mut a = vec![1, 2, 3];
a.insert(4, 5);
}
#[test]
fn test_remove() {
let mut a = vec![1, 2, 3, 4];
assert_eq!(a.remove(2), 3);
assert_eq!(a, [1, 2, 4]);
assert_eq!(a.remove(2), 4);
assert_eq!(a, [1, 2]);
assert_eq!(a.remove(0), 1);
assert_eq!(a, [2]);
assert_eq!(a.remove(0), 2);
assert_eq!(a, []);
}
#[test]
#[should_panic]
fn test_remove_fail() {
let mut a = vec![1];
let _ = a.remove(0);
let _ = a.remove(0);
}
#[test]
fn test_capacity() {
let mut v = vec![0];
v.reserve_exact(10);
assert!(v.capacity() >= 11);
}
#[test]
fn test_slice_2() {
let v = vec![1, 2, 3, 4, 5];
let v = v.slice(1, 3);
assert_eq!(v.len(), 2);
assert_eq!(v[0], 2);
assert_eq!(v[1], 3);
}
#[test]
#[should_panic]
fn test_permute_fail() {
let v: [(Box<_>, Rc<_>); 4] =
[(box 0, Rc::new(0)), (box 0, Rc::new(0)),
(box 0, Rc::new(0)), (box 0, Rc::new(0))];
let mut i = 0;
for _ in v.permutations() {
if i == 2 {
panic!()
}
i += 1;
}
}
#[test]
fn test_total_ord() {
let c = &[1, 2, 3];
[1, 2, 3, 4][..].cmp(c) == Greater;
let c = &[1, 2, 3, 4];
[1, 2, 3][..].cmp(c) == Less;
let c = &[1, 2, 3, 6];
[1, 2, 3, 4][..].cmp(c) == Equal;
let c = &[1, 2, 3, 4, 5, 6];
[1, 2, 3, 4, 5, 5, 5, 5][..].cmp(c) == Less;
let c = &[1, 2, 3, 4];
[2, 2][..].cmp(c) == Greater;
}
#[test]
fn test_iterator() {
let xs = [1, 2, 5, 10, 11];
let mut it = xs.iter();
assert_eq!(it.size_hint(), (5, Some(5)));
assert_eq!(it.next().unwrap(), &1);
assert_eq!(it.size_hint(), (4, Some(4)));
assert_eq!(it.next().unwrap(), &2);
assert_eq!(it.size_hint(), (3, Some(3)));
assert_eq!(it.next().unwrap(), &5);
assert_eq!(it.size_hint(), (2, Some(2)));
assert_eq!(it.next().unwrap(), &10);
assert_eq!(it.size_hint(), (1, Some(1)));
assert_eq!(it.next().unwrap(), &11);
assert_eq!(it.size_hint(), (0, Some(0)));
assert!(it.next().is_none());
}
#[test]
fn test_random_access_iterator() {
let xs = [1, 2, 5, 10, 11];
let mut it = xs.iter();
assert_eq!(it.indexable(), 5);
assert_eq!(it.idx(0).unwrap(), &1);
assert_eq!(it.idx(2).unwrap(), &5);
assert_eq!(it.idx(4).unwrap(), &11);
assert!(it.idx(5).is_none());
assert_eq!(it.next().unwrap(), &1);
assert_eq!(it.indexable(), 4);
assert_eq!(it.idx(0).unwrap(), &2);
assert_eq!(it.idx(3).unwrap(), &11);
assert!(it.idx(4).is_none());
assert_eq!(it.next().unwrap(), &2);
assert_eq!(it.indexable(), 3);
assert_eq!(it.idx(1).unwrap(), &10);
assert!(it.idx(3).is_none());
assert_eq!(it.next().unwrap(), &5);
assert_eq!(it.indexable(), 2);
assert_eq!(it.idx(1).unwrap(), &11);
assert_eq!(it.next().unwrap(), &10);
assert_eq!(it.indexable(), 1);
assert_eq!(it.idx(0).unwrap(), &11);
assert!(it.idx(1).is_none());
assert_eq!(it.next().unwrap(), &11);
assert_eq!(it.indexable(), 0);
assert!(it.idx(0).is_none());
assert!(it.next().is_none());
}
#[test]
fn test_iter_size_hints() {
let mut xs = [1, 2, 5, 10, 11];
assert_eq!(xs.iter().size_hint(), (5, Some(5)));
assert_eq!(xs.iter_mut().size_hint(), (5, Some(5)));
}
#[test]
fn test_iter_clone() {
let xs = [1, 2, 5];
let mut it = xs.iter();
it.next();
let mut jt = it.clone();
assert_eq!(it.next(), jt.next());
assert_eq!(it.next(), jt.next());
assert_eq!(it.next(), jt.next());
}
#[test]
fn test_mut_iterator() {
let mut xs = [1, 2, 3, 4, 5];
for x in &mut xs {
*x += 1;
}
assert!(xs == [2, 3, 4, 5, 6])
}
#[test]
fn test_rev_iterator() {
let xs = [1, 2, 5, 10, 11];
let ys = [11, 10, 5, 2, 1];
let mut i = 0;
for &x in xs.iter().rev() {
assert_eq!(x, ys[i]);
i += 1;
}
assert_eq!(i, 5);
}
#[test]
fn test_mut_rev_iterator() {
let mut xs = [1, 2, 3, 4, 5];
for (i,x) in xs.iter_mut().rev().enumerate() {
*x += i;
}
assert!(xs == [5, 5, 5, 5, 5])
}
#[test]
fn test_move_iterator() {
let xs = vec![1,2,3,4,5];
assert_eq!(xs.into_iter().fold(0, |a: usize, b: usize| 10*a + b), 12345);
}
#[test]
fn test_move_rev_iterator() {
let xs = vec![1,2,3,4,5];
assert_eq!(xs.into_iter().rev().fold(0, |a: usize, b: usize| 10*a + b), 54321);
}
#[test]
fn test_splitator() {
let xs = &[1,2,3,4,5];
let splits: &[&[_]] = &[&[1], &[3], &[5]];
assert_eq!(xs.split(|x| *x % 2 == 0).collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[], &[2,3,4,5]];
assert_eq!(xs.split(|x| *x == 1).collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[1,2,3,4], &[]];
assert_eq!(xs.split(|x| *x == 5).collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[1,2,3,4,5]];
assert_eq!(xs.split(|x| *x == 10).collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[], &[], &[], &[], &[], &[]];
assert_eq!(xs.split(|_| true).collect::<Vec<&[i32]>>(),
splits);
let xs: &[i32] = &[];
let splits: &[&[i32]] = &[&[]];
assert_eq!(xs.split(|x| *x == 5).collect::<Vec<&[i32]>>(), splits);
}
#[test]
fn test_splitnator() {
let xs = &[1,2,3,4,5];
let splits: &[&[_]] = &[&[1,2,3,4,5]];
assert_eq!(xs.splitn(0, |x| *x % 2 == 0).collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[1], &[3,4,5]];
assert_eq!(xs.splitn(1, |x| *x % 2 == 0).collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[], &[], &[], &[4,5]];
assert_eq!(xs.splitn(3, |_| true).collect::<Vec<_>>(),
splits);
let xs: &[i32] = &[];
let splits: &[&[i32]] = &[&[]];
assert_eq!(xs.splitn(1, |x| *x == 5).collect::<Vec<_>>(), splits);
}
#[test]
fn test_splitnator_mut() {
let xs = &mut [1,2,3,4,5];
let splits: &[&mut[_]] = &[&mut [1,2,3,4,5]];
assert_eq!(xs.splitn_mut(0, |x| *x % 2 == 0).collect::<Vec<_>>(),
splits);
let splits: &[&mut[_]] = &[&mut [1], &mut [3,4,5]];
assert_eq!(xs.splitn_mut(1, |x| *x % 2 == 0).collect::<Vec<_>>(),
splits);
let splits: &[&mut[_]] = &[&mut [], &mut [], &mut [], &mut [4,5]];
assert_eq!(xs.splitn_mut(3, |_| true).collect::<Vec<_>>(),
splits);
let xs: &mut [i32] = &mut [];
let splits: &[&mut[i32]] = &[&mut []];
assert_eq!(xs.splitn_mut(1, |x| *x == 5).collect::<Vec<_>>(),
splits);
}
#[test]
fn test_rsplitator() {
let xs = &[1,2,3,4,5];
let splits: &[&[_]] = &[&[5], &[3], &[1]];
assert_eq!(xs.split(|x| *x % 2 == 0).rev().collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[2,3,4,5], &[]];
assert_eq!(xs.split(|x| *x == 1).rev().collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[], &[1,2,3,4]];
assert_eq!(xs.split(|x| *x == 5).rev().collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[1,2,3,4,5]];
assert_eq!(xs.split(|x| *x == 10).rev().collect::<Vec<_>>(),
splits);
let xs: &[i32] = &[];
let splits: &[&[i32]] = &[&[]];
assert_eq!(xs.split(|x| *x == 5).rev().collect::<Vec<&[i32]>>(), splits);
}
#[test]
fn test_rsplitnator() {
let xs = &[1,2,3,4,5];
let splits: &[&[_]] = &[&[1,2,3,4,5]];
assert_eq!(xs.rsplitn(0, |x| *x % 2 == 0).collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[5], &[1,2,3]];
assert_eq!(xs.rsplitn(1, |x| *x % 2 == 0).collect::<Vec<_>>(),
splits);
let splits: &[&[_]] = &[&[], &[], &[], &[1,2]];
assert_eq!(xs.rsplitn(3, |_| true).collect::<Vec<_>>(),
splits);
let xs: &[i32] = &[];
let splits: &[&[i32]] = &[&[]];
assert_eq!(xs.rsplitn(1, |x| *x == 5).collect::<Vec<&[i32]>>(), splits);
}
#[test]
fn test_windowsator() {
let v = &[1,2,3,4];
let wins: &[&[_]] = &[&[1,2], &[2,3], &[3,4]];
assert_eq!(v.windows(2).collect::<Vec<_>>(), wins);
let wins: &[&[_]] = &[&[1,2,3], &[2,3,4]];
assert_eq!(v.windows(3).collect::<Vec<_>>(), wins);
assert!(v.windows(6).next().is_none());
let wins: &[&[_]] = &[&[3,4], &[2,3], &[1,2]];
assert_eq!(v.windows(2).rev().collect::<Vec<&[_]>>(), wins);
let mut it = v.windows(2);
assert_eq!(it.indexable(), 3);
let win: &[_] = &[1,2];
assert_eq!(it.idx(0).unwrap(), win);
let win: &[_] = &[2,3];
assert_eq!(it.idx(1).unwrap(), win);
let win: &[_] = &[3,4];
assert_eq!(it.idx(2).unwrap(), win);
assert_eq!(it.idx(3), None);
}
#[test]
#[should_panic]
fn test_windowsator_0() {
let v = &[1,2,3,4];
let _it = v.windows(0);
}
#[test]
fn test_chunksator() {
use core::iter::ExactSizeIterator;
let v = &[1,2,3,4,5];
assert_eq!(v.chunks(2).len(), 3);
let chunks: &[&[_]] = &[&[1,2], &[3,4], &[5]];
assert_eq!(v.chunks(2).collect::<Vec<_>>(), chunks);
let chunks: &[&[_]] = &[&[1,2,3], &[4,5]];
assert_eq!(v.chunks(3).collect::<Vec<_>>(), chunks);
let chunks: &[&[_]] = &[&[1,2,3,4,5]];
assert_eq!(v.chunks(6).collect::<Vec<_>>(), chunks);
let chunks: &[&[_]] = &[&[5], &[3,4], &[1,2]];
assert_eq!(v.chunks(2).rev().collect::<Vec<_>>(), chunks);
let mut it = v.chunks(2);
assert_eq!(it.indexable(), 3);
let chunk: &[_] = &[1,2];
assert_eq!(it.idx(0).unwrap(), chunk);
let chunk: &[_] = &[3,4];
assert_eq!(it.idx(1).unwrap(), chunk);
let chunk: &[_] = &[5];
assert_eq!(it.idx(2).unwrap(), chunk);
assert_eq!(it.idx(3), None);
}
#[test]
#[should_panic]
fn test_chunksator_0() {
let v = &[1,2,3,4];
let _it = v.chunks(0);
}
#[test]
fn test_move_from() {
let mut a = [1,2,3,4,5];
let b = vec![6,7,8];
assert_eq!(a.move_from(b, 0, 3), 3);
assert!(a == [6,7,8,4,5]);
let mut a = [7,2,8,1];
let b = vec![3,1,4,1,5,9];
assert_eq!(a.move_from(b, 0, 6), 4);
assert!(a == [3,1,4,1]);
let mut a = [1,2,3,4];
let b = vec![5,6,7,8,9,0];
assert_eq!(a.move_from(b, 2, 3), 1);
assert!(a == [7,2,3,4]);
let mut a = [1,2,3,4,5];
let b = vec![5,6,7,8,9,0];
assert_eq!(a[2..4].move_from(b,1,6), 2);
assert!(a == [1,2,6,7,5]);
}
#[test]
fn test_reverse_part() {
let mut values = [1,2,3,4,5];
values[1..4].reverse();
assert!(values == [1,4,3,2,5]);
}
#[test]
fn test_show() {
macro_rules! test_show_vec {
($x:expr, $x_str:expr) => ({
let (x, x_str) = ($x, $x_str);
assert_eq!(format!("{:?}", x), x_str);
assert_eq!(format!("{:?}", x), x_str);
})
}
let empty = Vec::<i32>::new();
test_show_vec!(empty, "[]");
test_show_vec!(vec![1], "[1]");
test_show_vec!(vec![1, 2, 3], "[1, 2, 3]");
test_show_vec!(vec![vec![], vec![1], vec![1, 1]],
"[[], [1], [1, 1]]");
let empty_mut: &mut [i32] = &mut[];
test_show_vec!(empty_mut, "[]");
let v = &mut[1];
test_show_vec!(v, "[1]");
let v = &mut[1, 2, 3];
test_show_vec!(v, "[1, 2, 3]");
let v: &mut[&mut[_]] = &mut[&mut[], &mut[1], &mut[1, 1]];
test_show_vec!(v, "[[], [1], [1, 1]]");
}
#[test]
fn test_vec_default() {
macro_rules! t {
($ty:ty) => {{
let v: $ty = Default::default();
assert!(v.is_empty());
}}
}
t!(&[i32]);
t!(Vec<i32>);
}
#[test]
fn test_bytes_set_memory() {
use slice::bytes::MutableByteVector;
let mut values = [1,2,3,4,5];
values[0..5].set_memory(0xAB);
assert!(values == [0xAB, 0xAB, 0xAB, 0xAB, 0xAB]);
values[2..4].set_memory(0xFF);
assert!(values == [0xAB, 0xAB, 0xFF, 0xFF, 0xAB]);
}
#[test]
#[should_panic]
fn test_overflow_does_not_cause_segfault() {
let mut v = vec![];
v.reserve_exact(-1);
v.push(1);
v.push(2);
}
#[test]
#[should_panic]
fn test_overflow_does_not_cause_segfault_managed() {
let mut v = vec![Rc::new(1)];
v.reserve_exact(-1);
v.push(Rc::new(2));
}
#[test]
fn test_mut_split_at() {
let mut values = [1u8,2,3,4,5];
{
let (left, right) = values.split_at_mut(2);
{
let left: &[_] = left;
assert!(left[..left.len()] == [1, 2]);
}
for p in left {
*p += 1;
}
{
let right: &[_] = right;
assert!(right[..right.len()] == [3, 4, 5]);
}
for p in right {
*p += 2;
}
}
assert!(values == [2, 3, 5, 6, 7]);
}
#[derive(Clone, PartialEq)]
struct Foo;
#[test]
fn test_iter_zero_sized() {
let mut v = vec![Foo, Foo, Foo];
assert_eq!(v.len(), 3);
let mut cnt = 0;
for f in &v {
assert!(*f == Foo);
cnt += 1;
}
assert_eq!(cnt, 3);
for f in &v[1..3] {
assert!(*f == Foo);
cnt += 1;
}
assert_eq!(cnt, 5);
for f in &mut v {
assert!(*f == Foo);
cnt += 1;
}
assert_eq!(cnt, 8);
for f in v {
assert!(f == Foo);
cnt += 1;
}
assert_eq!(cnt, 11);
let xs: [Foo; 3] = [Foo, Foo, Foo];
cnt = 0;
for f in &xs {
assert!(*f == Foo);
cnt += 1;
}
assert!(cnt == 3);
}
#[test]
fn test_shrink_to_fit() {
let mut xs = vec![0, 1, 2, 3];
for i in 4..100 {
xs.push(i)
}
assert_eq!(xs.capacity(), 128);
xs.shrink_to_fit();
assert_eq!(xs.capacity(), 100);
assert_eq!(xs, (0..100).collect::<Vec<_>>());
}
#[test]
fn test_starts_with() {
assert!(b"foobar".starts_with(b"foo"));
assert!(!b"foobar".starts_with(b"oob"));
assert!(!b"foobar".starts_with(b"bar"));
assert!(!b"foo".starts_with(b"foobar"));
assert!(!b"bar".starts_with(b"foobar"));
assert!(b"foobar".starts_with(b"foobar"));
let empty: &[u8] = &[];
assert!(empty.starts_with(empty));
assert!(!empty.starts_with(b"foo"));
assert!(b"foobar".starts_with(empty));
}
#[test]
fn test_ends_with() {
assert!(b"foobar".ends_with(b"bar"));
assert!(!b"foobar".ends_with(b"oba"));
assert!(!b"foobar".ends_with(b"foo"));
assert!(!b"foo".ends_with(b"foobar"));
assert!(!b"bar".ends_with(b"foobar"));
assert!(b"foobar".ends_with(b"foobar"));
let empty: &[u8] = &[];
assert!(empty.ends_with(empty));
assert!(!empty.ends_with(b"foo"));
assert!(b"foobar".ends_with(empty));
}
#[test]
fn test_mut_splitator() {
let mut xs = [0,1,0,2,3,0,0,4,5,0];
assert_eq!(xs.split_mut(|x| *x == 0).count(), 6);
for slice in xs.split_mut(|x| *x == 0) {
slice.reverse();
}
assert!(xs == [0,1,0,3,2,0,0,5,4,0]);
let mut xs = [0,1,0,2,3,0,0,4,5,0,6,7];
for slice in xs.split_mut(|x| *x == 0).take(5) {
slice.reverse();
}
assert!(xs == [0,1,0,3,2,0,0,5,4,0,6,7]);
}
#[test]
fn test_mut_splitator_rev() {
let mut xs = [1,2,0,3,4,0,0,5,6,0];
for slice in xs.split_mut(|x| *x == 0).rev().take(4) {
slice.reverse();
}
assert!(xs == [1,2,0,4,3,0,0,6,5,0]);
}
#[test]
fn test_get_mut() {
let mut v = [0,1,2];
assert_eq!(v.get_mut(3), None);
v.get_mut(1).map(|e| *e = 7);
assert_eq!(v[1], 7);
let mut x = 2;
assert_eq!(v.get_mut(2), Some(&mut x));
}
#[test]
fn test_mut_chunks() {
use core::iter::ExactSizeIterator;
let mut v = [0, 1, 2, 3, 4, 5, 6];
assert_eq!(v.chunks_mut(2).len(), 4);
for (i, chunk) in v.chunks_mut(3).enumerate() {
for x in chunk {
*x = i as u8;
}
}
let result = [0, 0, 0, 1, 1, 1, 2];
assert!(v == result);
}
#[test]
fn test_mut_chunks_rev() {
let mut v = [0, 1, 2, 3, 4, 5, 6];
for (i, chunk) in v.chunks_mut(3).rev().enumerate() {
for x in chunk {
*x = i as u8;
}
}
let result = [2, 2, 2, 1, 1, 1, 0];
assert!(v == result);
}
#[test]
#[should_panic]
fn test_mut_chunks_0() {
let mut v = [1, 2, 3, 4];
let _it = v.chunks_mut(0);
}
#[test]
fn test_mut_last() {
let mut x = [1, 2, 3, 4, 5];
let h = x.last_mut();
assert_eq!(*h.unwrap(), 5);
let y: &mut [i32] = &mut [];
assert!(y.last_mut().is_none());
}
#[test]
fn test_to_vec() {
let xs: Box<_> = box [1, 2, 3];
let ys = xs.to_vec();
assert_eq!(ys, [1, 2, 3]);
}
}
#[cfg(test)]
mod bench {
use prelude::*;
use core::mem;
use core::ptr;
use core::iter::repeat;
use std::rand::{weak_rng, Rng};
use test::{Bencher, black_box};
#[bench]
fn iterator(b: &mut Bencher) {
// peculiar numbers to stop LLVM from optimising the summation
// out.
let v: Vec<_> = (0..100).map(|i| i ^ (i << 1) ^ (i >> 1)).collect();
b.iter(|| {
let mut sum = 0;
for x in &v {
sum += *x;
}
// sum == 11806, to stop dead code elimination.
if sum == 0 {panic!()}
})
}
#[bench]
fn mut_iterator(b: &mut Bencher) {
let mut v: Vec<_> = repeat(0).take(100).collect();
b.iter(|| {
let mut i = 0;
for x in &mut v {
*x = i;
i += 1;
}
})
}
#[bench]
fn concat(b: &mut Bencher) {
let xss: Vec<Vec<i32>> =
(0..100).map(|i| (0..i).collect()).collect();
b.iter(|| {
xss.concat();
});
}
#[bench]
fn connect(b: &mut Bencher) {
let xss: Vec<Vec<i32>> =
(0..100).map(|i| (0..i).collect()).collect();
b.iter(|| {
xss.connect(&0)
});
}
#[bench]
fn push(b: &mut Bencher) {
let mut vec = Vec::<i32>::new();
b.iter(|| {
vec.push(0);
black_box(&vec);
});
}
#[bench]
fn starts_with_same_vector(b: &mut Bencher) {
let vec: Vec<_> = (0..100).collect();
b.iter(|| {
vec.starts_with(&vec)
})
}
#[bench]
fn starts_with_single_element(b: &mut Bencher) {
let vec: Vec<_> = vec![0];
b.iter(|| {
vec.starts_with(&vec)
})
}
#[bench]
fn starts_with_diff_one_element_at_end(b: &mut Bencher) {
let vec: Vec<_> = (0..100).collect();
let mut match_vec: Vec<_> = (0..99).collect();
match_vec.push(0);
b.iter(|| {
vec.starts_with(&match_vec)
})
}
#[bench]
fn ends_with_same_vector(b: &mut Bencher) {
let vec: Vec<_> = (0..100).collect();
b.iter(|| {
vec.ends_with(&vec)
})
}
#[bench]
fn ends_with_single_element(b: &mut Bencher) {
let vec: Vec<_> = vec![0];
b.iter(|| {
vec.ends_with(&vec)
})
}
#[bench]
fn ends_with_diff_one_element_at_beginning(b: &mut Bencher) {
let vec: Vec<_> = (0..100).collect();
let mut match_vec: Vec<_> = (0..100).collect();
match_vec[0] = 200;
b.iter(|| {
vec.starts_with(&match_vec)
})
}
#[bench]
fn contains_last_element(b: &mut Bencher) {
let vec: Vec<_> = (0..100).collect();
b.iter(|| {
vec.contains(&99)
})
}
#[bench]
fn zero_1kb_from_elem(b: &mut Bencher) {
b.iter(|| {
repeat(0u8).take(1024).collect::<Vec<_>>()
});
}
#[bench]
fn zero_1kb_set_memory(b: &mut Bencher) {
b.iter(|| {
let mut v = Vec::<u8>::with_capacity(1024);
unsafe {
let vp = v.as_mut_ptr();
ptr::set_memory(vp, 0, 1024);
v.set_len(1024);
}
v
});
}
#[bench]
fn zero_1kb_loop_set(b: &mut Bencher) {
b.iter(|| {
let mut v = Vec::<u8>::with_capacity(1024);
unsafe {
v.set_len(1024);
}
for i in 0..1024 {
v[i] = 0;
}
});
}
#[bench]
fn zero_1kb_mut_iter(b: &mut Bencher) {
b.iter(|| {
let mut v = Vec::<u8>::with_capacity(1024);
unsafe {
v.set_len(1024);
}
for x in &mut v {
*x = 0;
}
v
});
}
#[bench]
fn random_inserts(b: &mut Bencher) {
let mut rng = weak_rng();
b.iter(|| {
let mut v: Vec<_> = repeat((0, 0)).take(30).collect();
for _ in 0..100 {
let l = v.len();
v.insert(rng.gen::<usize>() % (l + 1),
(1, 1));
}
})
}
#[bench]
fn random_removes(b: &mut Bencher) {
let mut rng = weak_rng();
b.iter(|| {
let mut v: Vec<_> = repeat((0, 0)).take(130).collect();
for _ in 0..100 {
let l = v.len();
v.remove(rng.gen::<usize>() % l);
}
})
}
#[bench]
fn sort_random_small(b: &mut Bencher) {
let mut rng = weak_rng();
b.iter(|| {
let mut v: Vec<_> = rng.gen_iter::<u64>().take(5).collect();
v.sort();
});
b.bytes = 5 * mem::size_of::<u64>() as u64;
}
#[bench]
fn sort_random_medium(b: &mut Bencher) {
let mut rng = weak_rng();
b.iter(|| {
let mut v: Vec<_> = rng.gen_iter::<u64>().take(100).collect();
v.sort();
});
b.bytes = 100 * mem::size_of::<u64>() as u64;
}
#[bench]
fn sort_random_large(b: &mut Bencher) {
let mut rng = weak_rng();
b.iter(|| {
let mut v: Vec<_> = rng.gen_iter::<u64>().take(10000).collect();
v.sort();
});
b.bytes = 10000 * mem::size_of::<u64>() as u64;
}
#[bench]
fn sort_sorted(b: &mut Bencher) {
let mut v: Vec<_> = (0..10000).collect();
b.iter(|| {
v.sort();
});
b.bytes = (v.len() * mem::size_of_val(&v[0])) as u64;
}
type BigSortable = (u64, u64, u64, u64);
#[bench]
fn sort_big_random_small(b: &mut Bencher) {
let mut rng = weak_rng();
b.iter(|| {
let mut v = rng.gen_iter::<BigSortable>().take(5)
.collect::<Vec<BigSortable>>();
v.sort();
});
b.bytes = 5 * mem::size_of::<BigSortable>() as u64;
}
#[bench]
fn sort_big_random_medium(b: &mut Bencher) {
let mut rng = weak_rng();
b.iter(|| {
let mut v = rng.gen_iter::<BigSortable>().take(100)
.collect::<Vec<BigSortable>>();
v.sort();
});
b.bytes = 100 * mem::size_of::<BigSortable>() as u64;
}
#[bench]
fn sort_big_random_large(b: &mut Bencher) {
let mut rng = weak_rng();
b.iter(|| {
let mut v = rng.gen_iter::<BigSortable>().take(10000)
.collect::<Vec<BigSortable>>();
v.sort();
});
b.bytes = 10000 * mem::size_of::<BigSortable>() as u64;
}
#[bench]
fn sort_big_sorted(b: &mut Bencher) {
let mut v: Vec<BigSortable> = (0..10000).map(|i| (i, i, i, i)).collect();
b.iter(|| {
v.sort();
});
b.bytes = (v.len() * mem::size_of_val(&v[0])) as u64;
}
}
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