// 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 or the MIT license // , 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(&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, 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; /// 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(&self, pred: F) -> Split 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(&self, n: usize, pred: F) -> SplitN 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(&self, n: usize, pred: F) -> RSplitN 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; /// 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; /// 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(&self, f: F) -> Result 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; /// 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(&mut self, pred: F) -> SplitMut 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(&mut self, n: usize, pred: F) -> SplitNMut 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(&mut self, n: usize, pred: F) -> RSplitNMut 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; /// 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 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 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 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 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 where Self::Item: PartialEq; /// Find the last index containing a matching value. #[unstable(feature = "collections")] fn rposition_elem(&self, t: &Self::Item) -> Option 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) -> Vec; } #[stable(feature = "rust1", since = "1.0.0")] impl SliceExt for [T] { type Item = T; #[inline] fn sort_by(&mut self, compare: F) where F: FnMut(&T, &T) -> Ordering { merge_sort(self, compare) } #[inline] fn move_from(&mut self, mut src: Vec, 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 { core_slice::SliceExt::iter(self) } #[inline] fn split(&self, pred: F) -> Split where F: FnMut(&T) -> bool { core_slice::SliceExt::split(self, pred) } #[inline] fn splitn(&self, n: usize, pred: F) -> SplitN where F: FnMut(&T) -> bool { core_slice::SliceExt::splitn(self, n, pred) } #[inline] fn rsplitn(&self, n: usize, pred: F) -> RSplitN where F: FnMut(&T) -> bool { core_slice::SliceExt::rsplitn(self, n, pred) } #[inline] fn windows(&self, size: usize) -> Windows { core_slice::SliceExt::windows(self, size) } #[inline] fn chunks(&self, size: usize) -> Chunks { 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(&self, f: F) -> Result 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 { 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(&mut self, pred: F) -> SplitMut where F: FnMut(&T) -> bool { core_slice::SliceExt::split_mut(self, pred) } #[inline] fn splitn_mut(&mut self, n: usize, pred: F) -> SplitNMut where F: FnMut(&T) -> bool { core_slice::SliceExt::splitn_mut(self, n, pred) } #[inline] fn rsplitn_mut(&mut self, n: usize, pred: F) -> RSplitNMut where F: FnMut(&T) -> bool { core_slice::SliceExt::rsplitn_mut(self, n, pred) } #[inline] fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut { 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 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 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 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 where T: PartialEq { core_slice::SliceExt::position_elem(self, t) } fn rposition_elem(&self, t: &T) -> Option 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) -> Vec { 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 { /// 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> SliceConcatExt> for [V] { fn concat(&self) -> Vec { 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 { 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, /// 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 Borrow<[T]> for Vec { fn borrow(&self) -> &[T] { &self[..] } } #[stable(feature = "rust1", since = "1.0.0")] impl BorrowMut<[T]> for Vec { fn borrow_mut(&mut self) -> &mut [T] { &mut self[..] } } #[stable(feature = "rust1", since = "1.0.0")] impl ToOwned for [T] { type Owned = Vec; fn to_owned(&self) -> Vec { 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) { // 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 { swaps: ElementSwaps, v: Vec, } #[unstable(feature = "collections", reason = "trait is unstable")] impl Iterator for Permutations { type Item = Vec; #[inline] fn next(&mut self) -> Option> { 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) { self.swaps.size_hint() } } //////////////////////////////////////////////////////////////////////////////// // Sorting //////////////////////////////////////////////////////////////////////////////// fn insertion_sort(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(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::() <= 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::(); ptr::copy_nonoverlapping(out, &*right, elems); break; } else if right == right_end { let elems = (right_start as usize - left as usize) / mem::size_of::(); 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(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::(), 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::::new(); a.tail(); } #[test] #[should_panic] fn test_tail_mut_empty() { let mut a = Vec::::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::::new(); a.init(); } #[test] #[should_panic] fn test_init_mut_empty() { let mut a = Vec::::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> = 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> = 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> = 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, b: Vec) { 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> = vec![box 1, box 1, box 2, box 3]; v0.dedup(); let mut v1: Vec> = vec![box 1, box 2, box 2, box 3]; v1.dedup(); let mut v2: Vec> = 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> = vec![box 1, box 1, box 2, box 3]; v0.dedup(); let mut v1: Vec> = vec![box 1, box 2, box 2, box 3]; v1.dedup(); let mut v2: Vec> = 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::::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::().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::() % 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; 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; 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::>(), splits); let splits: &[&[_]] = &[&[], &[2,3,4,5]]; assert_eq!(xs.split(|x| *x == 1).collect::>(), splits); let splits: &[&[_]] = &[&[1,2,3,4], &[]]; assert_eq!(xs.split(|x| *x == 5).collect::>(), splits); let splits: &[&[_]] = &[&[1,2,3,4,5]]; assert_eq!(xs.split(|x| *x == 10).collect::>(), splits); let splits: &[&[_]] = &[&[], &[], &[], &[], &[], &[]]; assert_eq!(xs.split(|_| true).collect::>(), splits); let xs: &[i32] = &[]; let splits: &[&[i32]] = &[&[]]; assert_eq!(xs.split(|x| *x == 5).collect::>(), 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::>(), splits); let splits: &[&[_]] = &[&[1], &[3,4,5]]; assert_eq!(xs.splitn(1, |x| *x % 2 == 0).collect::>(), splits); let splits: &[&[_]] = &[&[], &[], &[], &[4,5]]; assert_eq!(xs.splitn(3, |_| true).collect::>(), splits); let xs: &[i32] = &[]; let splits: &[&[i32]] = &[&[]]; assert_eq!(xs.splitn(1, |x| *x == 5).collect::>(), 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::>(), splits); let splits: &[&mut[_]] = &[&mut [1], &mut [3,4,5]]; assert_eq!(xs.splitn_mut(1, |x| *x % 2 == 0).collect::>(), splits); let splits: &[&mut[_]] = &[&mut [], &mut [], &mut [], &mut [4,5]]; assert_eq!(xs.splitn_mut(3, |_| true).collect::>(), splits); let xs: &mut [i32] = &mut []; let splits: &[&mut[i32]] = &[&mut []]; assert_eq!(xs.splitn_mut(1, |x| *x == 5).collect::>(), 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::>(), splits); let splits: &[&[_]] = &[&[2,3,4,5], &[]]; assert_eq!(xs.split(|x| *x == 1).rev().collect::>(), splits); let splits: &[&[_]] = &[&[], &[1,2,3,4]]; assert_eq!(xs.split(|x| *x == 5).rev().collect::>(), splits); let splits: &[&[_]] = &[&[1,2,3,4,5]]; assert_eq!(xs.split(|x| *x == 10).rev().collect::>(), splits); let xs: &[i32] = &[]; let splits: &[&[i32]] = &[&[]]; assert_eq!(xs.split(|x| *x == 5).rev().collect::>(), 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::>(), splits); let splits: &[&[_]] = &[&[5], &[1,2,3]]; assert_eq!(xs.rsplitn(1, |x| *x % 2 == 0).collect::>(), splits); let splits: &[&[_]] = &[&[], &[], &[], &[1,2]]; assert_eq!(xs.rsplitn(3, |_| true).collect::>(), splits); let xs: &[i32] = &[]; let splits: &[&[i32]] = &[&[]]; assert_eq!(xs.rsplitn(1, |x| *x == 5).collect::>(), 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::>(), wins); let wins: &[&[_]] = &[&[1,2,3], &[2,3,4]]; assert_eq!(v.windows(3).collect::>(), wins); assert!(v.windows(6).next().is_none()); let wins: &[&[_]] = &[&[3,4], &[2,3], &[1,2]]; assert_eq!(v.windows(2).rev().collect::>(), 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::>(), chunks); let chunks: &[&[_]] = &[&[1,2,3], &[4,5]]; assert_eq!(v.chunks(3).collect::>(), chunks); let chunks: &[&[_]] = &[&[1,2,3,4,5]]; assert_eq!(v.chunks(6).collect::>(), chunks); let chunks: &[&[_]] = &[&[5], &[3,4], &[1,2]]; assert_eq!(v.chunks(2).rev().collect::>(), 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, $x_str); assert_eq!(format!("{:?}", x), x_str); assert_eq!(format!("{:?}", x), x_str); }) } let empty = Vec::::new(); test_show_vec!(empty, "[]"); test_show_vec!(vec![1], "[1]"); test_show_vec!(vec![1, 2, 3], "[1, 2, 3]"); test_show_vec!(vec![vec![], vec![1], vec![1, 1]], "[[], [1], [1, 1]]"); let empty_mut: &mut [i32] = &mut[]; test_show_vec!(empty_mut, "[]"); let v = &mut[1]; test_show_vec!(v, "[1]"); let v = &mut[1, 2, 3]; test_show_vec!(v, "[1, 2, 3]"); let v: &mut[&mut[_]] = &mut[&mut[], &mut[1], &mut[1, 1]]; test_show_vec!(v, "[[], [1], [1, 1]]"); } #[test] fn test_vec_default() { macro_rules! t { ($ty:ty) => {{ let v: $ty = Default::default(); assert!(v.is_empty()); }} } t!(&[i32]); t!(Vec); } #[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::>()); } #[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> = (0..100).map(|i| (0..i).collect()).collect(); b.iter(|| { xss.concat(); }); } #[bench] fn connect(b: &mut Bencher) { let xss: Vec> = (0..100).map(|i| (0..i).collect()).collect(); b.iter(|| { xss.connect(&0) }); } #[bench] fn push(b: &mut Bencher) { let mut vec = Vec::::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::>() }); } #[bench] fn zero_1kb_set_memory(b: &mut Bencher) { b.iter(|| { let mut v = Vec::::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::::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::::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::() % (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::() % l); } }) } #[bench] fn sort_random_small(b: &mut Bencher) { let mut rng = weak_rng(); b.iter(|| { let mut v: Vec<_> = rng.gen_iter::().take(5).collect(); v.sort(); }); b.bytes = 5 * mem::size_of::() as u64; } #[bench] fn sort_random_medium(b: &mut Bencher) { let mut rng = weak_rng(); b.iter(|| { let mut v: Vec<_> = rng.gen_iter::().take(100).collect(); v.sort(); }); b.bytes = 100 * mem::size_of::() as u64; } #[bench] fn sort_random_large(b: &mut Bencher) { let mut rng = weak_rng(); b.iter(|| { let mut v: Vec<_> = rng.gen_iter::().take(10000).collect(); v.sort(); }); b.bytes = 10000 * mem::size_of::() 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::().take(5) .collect::>(); v.sort(); }); b.bytes = 5 * mem::size_of::() as u64; } #[bench] fn sort_big_random_medium(b: &mut Bencher) { let mut rng = weak_rng(); b.iter(|| { let mut v = rng.gen_iter::().take(100) .collect::>(); v.sort(); }); b.bytes = 100 * mem::size_of::() as u64; } #[bench] fn sort_big_random_large(b: &mut Bencher) { let mut rng = weak_rng(); b.iter(|| { let mut v = rng.gen_iter::().take(10000) .collect::>(); v.sort(); }); b.bytes = 10000 * mem::size_of::() as u64; } #[bench] fn sort_big_sorted(b: &mut Bencher) { let mut v: Vec = (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; } }