diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs index 163aef61b43..52011303543 100644 --- a/src/liballoc/lib.rs +++ b/src/liballoc/lib.rs @@ -90,6 +90,7 @@ #![feature(collections_range)] #![feature(const_fn)] #![feature(core_intrinsics)] +#![cfg_attr(stage0, feature(core_slice_ext))] #![feature(custom_attribute)] #![feature(dropck_eyepatch)] #![feature(exact_size_is_empty)] diff --git a/src/liballoc/slice.rs b/src/liballoc/slice.rs index 70945a791f6..4594263c01f 100644 --- a/src/liballoc/slice.rs +++ b/src/liballoc/slice.rs @@ -101,7 +101,7 @@ use core::cmp::Ordering::{self, Less}; use core::mem::size_of; use core::mem; use core::ptr; -use core::slice as core_slice; +#[cfg(stage0)] use core::slice::SliceExt; use core::{u8, u16, u32}; use borrow::{Borrow, BorrowMut, ToOwned}; @@ -171,1059 +171,12 @@ mod hack { } } -#[lang = "slice"] +#[cfg_attr(stage0, lang = "slice")] +#[cfg_attr(not(stage0), lang = "slice_alloc")] #[cfg(not(test))] impl [T] { - /// Returns 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")] - #[inline] - pub fn len(&self) -> usize { - core_slice::SliceExt::len(self) - } - - /// Returns `true` if the slice has a length of 0. - /// - /// # Examples - /// - /// ``` - /// let a = [1, 2, 3]; - /// assert!(!a.is_empty()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_empty(&self) -> bool { - core_slice::SliceExt::is_empty(self) - } - - /// Returns the first element of the 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")] - #[inline] - pub fn first(&self) -> Option<&T> { - core_slice::SliceExt::first(self) - } - - /// Returns a mutable pointer to the first element of the slice, or `None` if it is empty. - /// - /// # Examples - /// - /// ``` - /// let x = &mut [0, 1, 2]; - /// - /// if let Some(first) = x.first_mut() { - /// *first = 5; - /// } - /// assert_eq!(x, &[5, 1, 2]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn first_mut(&mut self) -> Option<&mut T> { - core_slice::SliceExt::first_mut(self) - } - - /// Returns the first and all the rest of the elements of the slice, or `None` if it is empty. - /// - /// # Examples - /// - /// ``` - /// let x = &[0, 1, 2]; - /// - /// if let Some((first, elements)) = x.split_first() { - /// assert_eq!(first, &0); - /// assert_eq!(elements, &[1, 2]); - /// } - /// ``` - #[stable(feature = "slice_splits", since = "1.5.0")] - #[inline] - pub fn split_first(&self) -> Option<(&T, &[T])> { - core_slice::SliceExt::split_first(self) - } - - /// Returns the first and all the rest of the elements of the slice, or `None` if it is empty. - /// - /// # Examples - /// - /// ``` - /// let x = &mut [0, 1, 2]; - /// - /// if let Some((first, elements)) = x.split_first_mut() { - /// *first = 3; - /// elements[0] = 4; - /// elements[1] = 5; - /// } - /// assert_eq!(x, &[3, 4, 5]); - /// ``` - #[stable(feature = "slice_splits", since = "1.5.0")] - #[inline] - pub fn split_first_mut(&mut self) -> Option<(&mut T, &mut [T])> { - core_slice::SliceExt::split_first_mut(self) - } - - /// Returns the last and all the rest of the elements of the slice, or `None` if it is empty. - /// - /// # Examples - /// - /// ``` - /// let x = &[0, 1, 2]; - /// - /// if let Some((last, elements)) = x.split_last() { - /// assert_eq!(last, &2); - /// assert_eq!(elements, &[0, 1]); - /// } - /// ``` - #[stable(feature = "slice_splits", since = "1.5.0")] - #[inline] - pub fn split_last(&self) -> Option<(&T, &[T])> { - core_slice::SliceExt::split_last(self) - - } - - /// Returns the last and all the rest of the elements of the slice, or `None` if it is empty. - /// - /// # Examples - /// - /// ``` - /// let x = &mut [0, 1, 2]; - /// - /// if let Some((last, elements)) = x.split_last_mut() { - /// *last = 3; - /// elements[0] = 4; - /// elements[1] = 5; - /// } - /// assert_eq!(x, &[4, 5, 3]); - /// ``` - #[stable(feature = "slice_splits", since = "1.5.0")] - #[inline] - pub fn split_last_mut(&mut self) -> Option<(&mut T, &mut [T])> { - core_slice::SliceExt::split_last_mut(self) - } - - /// Returns the last element of the 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")] - #[inline] - pub fn last(&self) -> Option<&T> { - core_slice::SliceExt::last(self) - } - - /// Returns a mutable pointer to the last item in the slice. - /// - /// # Examples - /// - /// ``` - /// let x = &mut [0, 1, 2]; - /// - /// if let Some(last) = x.last_mut() { - /// *last = 10; - /// } - /// assert_eq!(x, &[0, 1, 10]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn last_mut(&mut self) -> Option<&mut T> { - core_slice::SliceExt::last_mut(self) - } - - /// Returns a reference to an element or subslice depending on the type of - /// index. - /// - /// - If given a position, returns a reference to the element at that - /// position or `None` if out of bounds. - /// - If given a range, returns the subslice corresponding to that range, - /// or `None` if out of bounds. - /// - /// # Examples - /// - /// ``` - /// let v = [10, 40, 30]; - /// assert_eq!(Some(&40), v.get(1)); - /// assert_eq!(Some(&[10, 40][..]), v.get(0..2)); - /// assert_eq!(None, v.get(3)); - /// assert_eq!(None, v.get(0..4)); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn get(&self, index: I) -> Option<&I::Output> - where I: SliceIndex - { - core_slice::SliceExt::get(self, index) - } - - /// Returns a mutable reference to an element or subslice depending on the - /// type of index (see [`get`]) or `None` if the index is out of bounds. - /// - /// [`get`]: #method.get - /// - /// # Examples - /// - /// ``` - /// let x = &mut [0, 1, 2]; - /// - /// if let Some(elem) = x.get_mut(1) { - /// *elem = 42; - /// } - /// assert_eq!(x, &[0, 42, 2]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn get_mut(&mut self, index: I) -> Option<&mut I::Output> - where I: SliceIndex - { - core_slice::SliceExt::get_mut(self, index) - } - - /// Returns a reference to an element or subslice, without doing bounds - /// checking. - /// - /// This is generally not recommended, use with caution! For a safe - /// alternative see [`get`]. - /// - /// [`get`]: #method.get - /// - /// # Examples - /// - /// ``` - /// let x = &[1, 2, 4]; - /// - /// unsafe { - /// assert_eq!(x.get_unchecked(1), &2); - /// } - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub unsafe fn get_unchecked(&self, index: I) -> &I::Output - where I: SliceIndex - { - core_slice::SliceExt::get_unchecked(self, index) - } - - /// Returns a mutable reference to an element or subslice, without doing - /// bounds checking. - /// - /// This is generally not recommended, use with caution! For a safe - /// alternative see [`get_mut`]. - /// - /// [`get_mut`]: #method.get_mut - /// - /// # Examples - /// - /// ``` - /// let x = &mut [1, 2, 4]; - /// - /// unsafe { - /// let elem = x.get_unchecked_mut(1); - /// *elem = 13; - /// } - /// assert_eq!(x, &[1, 13, 4]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub unsafe fn get_unchecked_mut(&mut self, index: I) -> &mut I::Output - where I: SliceIndex - { - core_slice::SliceExt::get_unchecked_mut(self, index) - } - - /// Returns a raw 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 container referenced by this slice may cause its buffer - /// to be reallocated, which would also make any pointers to it invalid. - /// - /// # Examples - /// - /// ``` - /// let x = &[1, 2, 4]; - /// let x_ptr = x.as_ptr(); - /// - /// unsafe { - /// for i in 0..x.len() { - /// assert_eq!(x.get_unchecked(i), &*x_ptr.offset(i as isize)); - /// } - /// } - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn as_ptr(&self) -> *const T { - core_slice::SliceExt::as_ptr(self) - } - - /// Returns 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 container referenced by this slice may cause its buffer - /// to be reallocated, which would also make any pointers to it invalid. - /// - /// # Examples - /// - /// ``` - /// let x = &mut [1, 2, 4]; - /// let x_ptr = x.as_mut_ptr(); - /// - /// unsafe { - /// for i in 0..x.len() { - /// *x_ptr.offset(i as isize) += 2; - /// } - /// } - /// assert_eq!(x, &[3, 4, 6]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn as_mut_ptr(&mut self) -> *mut T { - core_slice::SliceExt::as_mut_ptr(self) - } - - /// Swaps two elements in the 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 - /// - /// ``` - /// let mut v = ["a", "b", "c", "d"]; - /// v.swap(1, 3); - /// assert!(v == ["a", "d", "c", "b"]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn swap(&mut self, a: usize, b: usize) { - core_slice::SliceExt::swap(self, a, b) - } - - /// Reverses the order of elements in the slice, in place. - /// - /// # Examples - /// - /// ``` - /// let mut v = [1, 2, 3]; - /// v.reverse(); - /// assert!(v == [3, 2, 1]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn reverse(&mut self) { - core_slice::SliceExt::reverse(self) - } - - /// Returns an iterator over the slice. - /// - /// # Examples - /// - /// ``` - /// let x = &[1, 2, 4]; - /// let mut iterator = x.iter(); - /// - /// assert_eq!(iterator.next(), Some(&1)); - /// assert_eq!(iterator.next(), Some(&2)); - /// assert_eq!(iterator.next(), Some(&4)); - /// assert_eq!(iterator.next(), None); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn iter(&self) -> Iter { - core_slice::SliceExt::iter(self) - } - - /// Returns an iterator that allows modifying each value. - /// - /// # Examples - /// - /// ``` - /// let x = &mut [1, 2, 4]; - /// for elem in x.iter_mut() { - /// *elem += 2; - /// } - /// assert_eq!(x, &[3, 4, 6]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn iter_mut(&mut self) -> IterMut { - core_slice::SliceExt::iter_mut(self) - } - - /// 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 - /// - /// ``` - /// let slice = ['r', 'u', 's', 't']; - /// let mut iter = slice.windows(2); - /// assert_eq!(iter.next().unwrap(), &['r', 'u']); - /// assert_eq!(iter.next().unwrap(), &['u', 's']); - /// assert_eq!(iter.next().unwrap(), &['s', 't']); - /// assert!(iter.next().is_none()); - /// ``` - /// - /// If the slice is shorter than `size`: - /// - /// ``` - /// let slice = ['f', 'o', 'o']; - /// let mut iter = slice.windows(4); - /// assert!(iter.next().is_none()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn windows(&self, size: usize) -> Windows { - core_slice::SliceExt::windows(self, size) - } - - /// Returns an iterator over `chunk_size` elements of the slice at a - /// time. The chunks are slices 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`. - /// - /// See [`exact_chunks`] for a variant of this iterator that returns chunks - /// of always exactly `chunk_size` elements. - /// - /// # Panics - /// - /// Panics if `chunk_size` is 0. - /// - /// # Examples - /// - /// ``` - /// let slice = ['l', 'o', 'r', 'e', 'm']; - /// let mut iter = slice.chunks(2); - /// assert_eq!(iter.next().unwrap(), &['l', 'o']); - /// assert_eq!(iter.next().unwrap(), &['r', 'e']); - /// assert_eq!(iter.next().unwrap(), &['m']); - /// assert!(iter.next().is_none()); - /// ``` - /// - /// [`exact_chunks`]: #method.exact_chunks - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn chunks(&self, chunk_size: usize) -> Chunks { - core_slice::SliceExt::chunks(self, chunk_size) - } - - /// Returns an iterator over `chunk_size` elements of the slice at a - /// time. The chunks are slices and do not overlap. If `chunk_size` does - /// not divide the length of the slice, then the last up to `chunk_size-1` - /// elements will be omitted. - /// - /// Due to each chunk having exactly `chunk_size` elements, the compiler - /// can often optimize the resulting code better than in the case of - /// [`chunks`]. - /// - /// # Panics - /// - /// Panics if `chunk_size` is 0. - /// - /// # Examples - /// - /// ``` - /// #![feature(exact_chunks)] - /// - /// let slice = ['l', 'o', 'r', 'e', 'm']; - /// let mut iter = slice.exact_chunks(2); - /// assert_eq!(iter.next().unwrap(), &['l', 'o']); - /// assert_eq!(iter.next().unwrap(), &['r', 'e']); - /// assert!(iter.next().is_none()); - /// ``` - /// - /// [`chunks`]: #method.chunks - #[unstable(feature = "exact_chunks", issue = "47115")] - #[inline] - pub fn exact_chunks(&self, chunk_size: usize) -> ExactChunks { - core_slice::SliceExt::exact_chunks(self, chunk_size) - } - - /// Returns an iterator over `chunk_size` elements of the slice at a time. - /// The chunks are mutable slices, 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`. - /// - /// See [`exact_chunks_mut`] for a variant of this iterator that returns chunks - /// of always exactly `chunk_size` elements. - /// - /// # Panics - /// - /// Panics if `chunk_size` is 0. - /// - /// # Examples - /// - /// ``` - /// let v = &mut [0, 0, 0, 0, 0]; - /// let mut count = 1; - /// - /// for chunk in v.chunks_mut(2) { - /// for elem in chunk.iter_mut() { - /// *elem += count; - /// } - /// count += 1; - /// } - /// assert_eq!(v, &[1, 1, 2, 2, 3]); - /// ``` - /// - /// [`exact_chunks_mut`]: #method.exact_chunks_mut - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut { - core_slice::SliceExt::chunks_mut(self, chunk_size) - } - - /// Returns an iterator over `chunk_size` elements of the slice at a time. - /// The chunks are mutable slices, and do not overlap. If `chunk_size` does - /// not divide the length of the slice, then the last up to `chunk_size-1` - /// elements will be omitted. - /// - /// - /// Due to each chunk having exactly `chunk_size` elements, the compiler - /// can often optimize the resulting code better than in the case of - /// [`chunks_mut`]. - /// - /// # Panics - /// - /// Panics if `chunk_size` is 0. - /// - /// # Examples - /// - /// ``` - /// #![feature(exact_chunks)] - /// - /// let v = &mut [0, 0, 0, 0, 0]; - /// let mut count = 1; - /// - /// for chunk in v.exact_chunks_mut(2) { - /// for elem in chunk.iter_mut() { - /// *elem += count; - /// } - /// count += 1; - /// } - /// assert_eq!(v, &[1, 1, 2, 2, 0]); - /// ``` - /// - /// [`chunks_mut`]: #method.chunks_mut - #[unstable(feature = "exact_chunks", issue = "47115")] - #[inline] - pub fn exact_chunks_mut(&mut self, chunk_size: usize) -> ExactChunksMut { - core_slice::SliceExt::exact_chunks_mut(self, chunk_size) - } - - /// 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 - /// - /// Panics if `mid > len`. - /// - /// # Examples - /// - /// ``` - /// let v = [1, 2, 3, 4, 5, 6]; - /// - /// { - /// let (left, right) = v.split_at(0); - /// assert!(left == []); - /// assert!(right == [1, 2, 3, 4, 5, 6]); - /// } - /// - /// { - /// let (left, right) = v.split_at(2); - /// assert!(left == [1, 2]); - /// assert!(right == [3, 4, 5, 6]); - /// } - /// - /// { - /// let (left, right) = v.split_at(6); - /// assert!(left == [1, 2, 3, 4, 5, 6]); - /// assert!(right == []); - /// } - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn split_at(&self, mid: usize) -> (&[T], &[T]) { - core_slice::SliceExt::split_at(self, mid) - } - - /// Divides one mutable 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 - /// - /// Panics if `mid > len`. - /// - /// # Examples - /// - /// ``` - /// let mut v = [1, 0, 3, 0, 5, 6]; - /// // scoped to restrict the lifetime of the borrows - /// { - /// let (left, right) = v.split_at_mut(2); - /// assert!(left == [1, 0]); - /// assert!(right == [3, 0, 5, 6]); - /// left[1] = 2; - /// right[1] = 4; - /// } - /// assert!(v == [1, 2, 3, 4, 5, 6]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T]) { - core_slice::SliceExt::split_at_mut(self, mid) - } - - /// Returns an iterator over subslices separated by elements that match - /// `pred`. The matched element is not contained in the subslices. - /// - /// # Examples - /// - /// ``` - /// let slice = [10, 40, 33, 20]; - /// let mut iter = slice.split(|num| num % 3 == 0); - /// - /// assert_eq!(iter.next().unwrap(), &[10, 40]); - /// assert_eq!(iter.next().unwrap(), &[20]); - /// assert!(iter.next().is_none()); - /// ``` - /// - /// If the first element is matched, an empty slice will be the first item - /// returned by the iterator. Similarly, if the last element in the slice - /// is matched, an empty slice will be the last item returned by the - /// iterator: - /// - /// ``` - /// let slice = [10, 40, 33]; - /// let mut iter = slice.split(|num| num % 3 == 0); - /// - /// assert_eq!(iter.next().unwrap(), &[10, 40]); - /// assert_eq!(iter.next().unwrap(), &[]); - /// assert!(iter.next().is_none()); - /// ``` - /// - /// If two matched elements are directly adjacent, an empty slice will be - /// present between them: - /// - /// ``` - /// let slice = [10, 6, 33, 20]; - /// let mut iter = slice.split(|num| num % 3 == 0); - /// - /// assert_eq!(iter.next().unwrap(), &[10]); - /// assert_eq!(iter.next().unwrap(), &[]); - /// assert_eq!(iter.next().unwrap(), &[20]); - /// assert!(iter.next().is_none()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn split(&self, pred: F) -> Split - where F: FnMut(&T) -> bool - { - core_slice::SliceExt::split(self, pred) - } - - /// Returns an iterator over mutable subslices separated by elements that - /// match `pred`. The matched element is not contained in the subslices. - /// - /// # Examples - /// - /// ``` - /// let mut v = [10, 40, 30, 20, 60, 50]; - /// - /// for group in v.split_mut(|num| *num % 3 == 0) { - /// group[0] = 1; - /// } - /// assert_eq!(v, [1, 40, 30, 1, 60, 1]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn split_mut(&mut self, pred: F) -> SplitMut - where F: FnMut(&T) -> bool - { - core_slice::SliceExt::split_mut(self, pred) - } - - /// Returns an iterator over subslices separated by elements that match - /// `pred`, starting at the end of the slice and working backwards. - /// The matched element is not contained in the subslices. - /// - /// # Examples - /// - /// ``` - /// - /// let slice = [11, 22, 33, 0, 44, 55]; - /// let mut iter = slice.rsplit(|num| *num == 0); - /// - /// assert_eq!(iter.next().unwrap(), &[44, 55]); - /// assert_eq!(iter.next().unwrap(), &[11, 22, 33]); - /// assert_eq!(iter.next(), None); - /// ``` - /// - /// As with `split()`, if the first or last element is matched, an empty - /// slice will be the first (or last) item returned by the iterator. - /// - /// ``` - /// let v = &[0, 1, 1, 2, 3, 5, 8]; - /// let mut it = v.rsplit(|n| *n % 2 == 0); - /// assert_eq!(it.next().unwrap(), &[]); - /// assert_eq!(it.next().unwrap(), &[3, 5]); - /// assert_eq!(it.next().unwrap(), &[1, 1]); - /// assert_eq!(it.next().unwrap(), &[]); - /// assert_eq!(it.next(), None); - /// ``` - #[stable(feature = "slice_rsplit", since = "1.27.0")] - #[inline] - pub fn rsplit(&self, pred: F) -> RSplit - where F: FnMut(&T) -> bool - { - core_slice::SliceExt::rsplit(self, pred) - } - - /// Returns an iterator over mutable subslices separated by elements that - /// match `pred`, starting at the end of the slice and working - /// backwards. The matched element is not contained in the subslices. - /// - /// # Examples - /// - /// ``` - /// let mut v = [100, 400, 300, 200, 600, 500]; - /// - /// let mut count = 0; - /// for group in v.rsplit_mut(|num| *num % 3 == 0) { - /// count += 1; - /// group[0] = count; - /// } - /// assert_eq!(v, [3, 400, 300, 2, 600, 1]); - /// ``` - /// - #[stable(feature = "slice_rsplit", since = "1.27.0")] - #[inline] - pub fn rsplit_mut(&mut self, pred: F) -> RSplitMut - where F: FnMut(&T) -> bool - { - core_slice::SliceExt::rsplit_mut(self, pred) - } - - /// Returns an iterator over subslices separated by elements that match - /// `pred`, limited to returning at most `n` items. The matched element is - /// not contained in the subslices. - /// - /// The last element returned, if any, will contain the remainder of the - /// slice. - /// - /// # 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(2, |num| *num % 3 == 0) { - /// println!("{:?}", group); - /// } - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn splitn(&self, n: usize, pred: F) -> SplitN - where F: FnMut(&T) -> bool - { - core_slice::SliceExt::splitn(self, n, pred) - } - - /// Returns an iterator over subslices separated by elements that match - /// `pred`, limited to returning at most `n` items. The matched element is - /// not contained in the subslices. - /// - /// The last element returned, if any, will contain the remainder of the - /// slice. - /// - /// # Examples - /// - /// ``` - /// let mut v = [10, 40, 30, 20, 60, 50]; - /// - /// for group in v.splitn_mut(2, |num| *num % 3 == 0) { - /// group[0] = 1; - /// } - /// assert_eq!(v, [1, 40, 30, 1, 60, 50]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn splitn_mut(&mut self, n: usize, pred: F) -> SplitNMut - where F: FnMut(&T) -> bool - { - core_slice::SliceExt::splitn_mut(self, n, pred) - } - - /// Returns an iterator over subslices separated by elements that match - /// `pred` limited to returning at most `n` items. This starts at the end of - /// the slice and works backwards. The matched element is not contained in - /// the subslices. - /// - /// The last element returned, if any, will contain the remainder of the - /// slice. - /// - /// # 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(2, |num| *num % 3 == 0) { - /// println!("{:?}", group); - /// } - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn rsplitn(&self, n: usize, pred: F) -> RSplitN - where F: FnMut(&T) -> bool - { - core_slice::SliceExt::rsplitn(self, n, pred) - } - - /// Returns an iterator over subslices separated by elements that match - /// `pred` limited to returning at most `n` items. This starts at the end of - /// the slice and works backwards. The matched element is not contained in - /// the subslices. - /// - /// The last element returned, if any, will contain the remainder of the - /// slice. - /// - /// # Examples - /// - /// ``` - /// let mut s = [10, 40, 30, 20, 60, 50]; - /// - /// for group in s.rsplitn_mut(2, |num| *num % 3 == 0) { - /// group[0] = 1; - /// } - /// assert_eq!(s, [1, 40, 30, 20, 60, 1]); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn rsplitn_mut(&mut self, n: usize, pred: F) -> RSplitNMut - where F: FnMut(&T) -> bool - { - core_slice::SliceExt::rsplitn_mut(self, n, pred) - } - - /// 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")] - pub fn contains(&self, x: &T) -> bool - where T: PartialEq - { - core_slice::SliceExt::contains(self, x) - } - - /// 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])); - /// ``` - /// - /// Always returns `true` if `needle` is an empty slice: - /// - /// ``` - /// let v = &[10, 40, 30]; - /// assert!(v.starts_with(&[])); - /// let v: &[u8] = &[]; - /// assert!(v.starts_with(&[])); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - pub fn starts_with(&self, needle: &[T]) -> bool - where T: PartialEq - { - core_slice::SliceExt::starts_with(self, needle) - } - - /// 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])); - /// ``` - /// - /// Always returns `true` if `needle` is an empty slice: - /// - /// ``` - /// let v = &[10, 40, 30]; - /// assert!(v.ends_with(&[])); - /// let v: &[u8] = &[]; - /// assert!(v.ends_with(&[])); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - pub fn ends_with(&self, needle: &[T]) -> bool - where T: PartialEq - { - core_slice::SliceExt::ends_with(self, needle) - } - - /// Binary searches this 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]`. - /// - /// ``` - /// let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]; - /// - /// 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")] - pub fn binary_search(&self, x: &T) -> Result - where T: Ord - { - core_slice::SliceExt::binary_search(self, x) - } - - /// Binary searches this 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]`. - /// - /// ``` - /// let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]; - /// - /// 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")] - #[inline] - pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result - where F: FnMut(&'a T) -> Ordering - { - core_slice::SliceExt::binary_search_by(self, f) - } - - /// Binary searches this sorted slice with a key extraction function. - /// - /// Assumes that the slice is sorted by the key, for instance with - /// [`sort_by_key`] using the same key extraction function. - /// - /// 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. - /// - /// [`sort_by_key`]: #method.sort_by_key - /// - /// # Examples - /// - /// Looks up a series of four elements in a slice of pairs sorted by - /// their second 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]`. - /// - /// ``` - /// let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1), - /// (1, 2), (2, 3), (4, 5), (5, 8), (3, 13), - /// (1, 21), (2, 34), (4, 55)]; - /// - /// assert_eq!(s.binary_search_by_key(&13, |&(a,b)| b), Ok(9)); - /// assert_eq!(s.binary_search_by_key(&4, |&(a,b)| b), Err(7)); - /// assert_eq!(s.binary_search_by_key(&100, |&(a,b)| b), Err(13)); - /// let r = s.binary_search_by_key(&1, |&(a,b)| b); - /// assert!(match r { Ok(1...4) => true, _ => false, }); - /// ``` - #[stable(feature = "slice_binary_search_by_key", since = "1.10.0")] - #[inline] - pub fn binary_search_by_key<'a, B, F>(&'a self, b: &B, f: F) -> Result - where F: FnMut(&'a T) -> B, - B: Ord - { - core_slice::SliceExt::binary_search_by_key(self, b, f) - } + #[cfg(stage0)] + slice_core_methods!(); /// Sorts the slice. /// @@ -1402,345 +355,6 @@ impl [T] { sort_by_key!(usize, self, f) } - /// Sorts the slice, but may not preserve the order of equal elements. - /// - /// This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), - /// and `O(n log n)` worst-case. - /// - /// # Current implementation - /// - /// The current algorithm is based on [pattern-defeating quicksort][pdqsort] by Orson Peters, - /// which combines the fast average case of randomized quicksort with the fast worst case of - /// heapsort, while achieving linear time on slices with certain patterns. It uses some - /// randomization to avoid degenerate cases, but with a fixed seed to always provide - /// deterministic behavior. - /// - /// It is typically faster than stable sorting, except in a few special cases, e.g. when the - /// slice consists of several concatenated sorted sequences. - /// - /// # Examples - /// - /// ``` - /// let mut v = [-5, 4, 1, -3, 2]; - /// - /// v.sort_unstable(); - /// assert!(v == [-5, -3, 1, 2, 4]); - /// ``` - /// - /// [pdqsort]: https://github.com/orlp/pdqsort - #[stable(feature = "sort_unstable", since = "1.20.0")] - #[inline] - pub fn sort_unstable(&mut self) - where T: Ord - { - core_slice::SliceExt::sort_unstable(self); - } - - /// Sorts the slice with a comparator function, but may not preserve the order of equal - /// elements. - /// - /// This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), - /// and `O(n log n)` worst-case. - /// - /// # Current implementation - /// - /// The current algorithm is based on [pattern-defeating quicksort][pdqsort] by Orson Peters, - /// which combines the fast average case of randomized quicksort with the fast worst case of - /// heapsort, while achieving linear time on slices with certain patterns. It uses some - /// randomization to avoid degenerate cases, but with a fixed seed to always provide - /// deterministic behavior. - /// - /// It is typically faster than stable sorting, except in a few special cases, e.g. when the - /// slice consists of several concatenated sorted sequences. - /// - /// # Examples - /// - /// ``` - /// let mut v = [5, 4, 1, 3, 2]; - /// v.sort_unstable_by(|a, b| a.cmp(b)); - /// assert!(v == [1, 2, 3, 4, 5]); - /// - /// // reverse sorting - /// v.sort_unstable_by(|a, b| b.cmp(a)); - /// assert!(v == [5, 4, 3, 2, 1]); - /// ``` - /// - /// [pdqsort]: https://github.com/orlp/pdqsort - #[stable(feature = "sort_unstable", since = "1.20.0")] - #[inline] - pub fn sort_unstable_by(&mut self, compare: F) - where F: FnMut(&T, &T) -> Ordering - { - core_slice::SliceExt::sort_unstable_by(self, compare); - } - - /// Sorts the slice with a key extraction function, but may not preserve the order of equal - /// elements. - /// - /// This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), - /// and `O(m n log(m n))` worst-case, where the key function is `O(m)`. - /// - /// # Current implementation - /// - /// The current algorithm is based on [pattern-defeating quicksort][pdqsort] by Orson Peters, - /// which combines the fast average case of randomized quicksort with the fast worst case of - /// heapsort, while achieving linear time on slices with certain patterns. It uses some - /// randomization to avoid degenerate cases, but with a fixed seed to always provide - /// deterministic behavior. - /// - /// # Examples - /// - /// ``` - /// let mut v = [-5i32, 4, 1, -3, 2]; - /// - /// v.sort_unstable_by_key(|k| k.abs()); - /// assert!(v == [1, 2, -3, 4, -5]); - /// ``` - /// - /// [pdqsort]: https://github.com/orlp/pdqsort - #[stable(feature = "sort_unstable", since = "1.20.0")] - #[inline] - pub fn sort_unstable_by_key(&mut self, f: F) - where F: FnMut(&T) -> K, K: Ord - { - core_slice::SliceExt::sort_unstable_by_key(self, f); - } - - /// Rotates the slice in-place such that the first `mid` elements of the - /// slice move to the end while the last `self.len() - mid` elements move to - /// the front. After calling `rotate_left`, the element previously at index - /// `mid` will become the first element in the slice. - /// - /// # Panics - /// - /// This function will panic if `mid` is greater than the length of the - /// slice. Note that `mid == self.len()` does _not_ panic and is a no-op - /// rotation. - /// - /// # Complexity - /// - /// Takes linear (in `self.len()`) time. - /// - /// # Examples - /// - /// ``` - /// let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; - /// a.rotate_left(2); - /// assert_eq!(a, ['c', 'd', 'e', 'f', 'a', 'b']); - /// ``` - /// - /// Rotating a subslice: - /// - /// ``` - /// let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; - /// a[1..5].rotate_left(1); - /// assert_eq!(a, ['a', 'c', 'd', 'e', 'b', 'f']); - /// ``` - #[stable(feature = "slice_rotate", since = "1.26.0")] - pub fn rotate_left(&mut self, mid: usize) { - core_slice::SliceExt::rotate_left(self, mid); - } - - /// Rotates the slice in-place such that the first `self.len() - k` - /// elements of the slice move to the end while the last `k` elements move - /// to the front. After calling `rotate_right`, the element previously at - /// index `self.len() - k` will become the first element in the slice. - /// - /// # Panics - /// - /// This function will panic if `k` is greater than the length of the - /// slice. Note that `k == self.len()` does _not_ panic and is a no-op - /// rotation. - /// - /// # Complexity - /// - /// Takes linear (in `self.len()`) time. - /// - /// # Examples - /// - /// ``` - /// let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; - /// a.rotate_right(2); - /// assert_eq!(a, ['e', 'f', 'a', 'b', 'c', 'd']); - /// ``` - /// - /// Rotate a subslice: - /// - /// ``` - /// let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; - /// a[1..5].rotate_right(1); - /// assert_eq!(a, ['a', 'e', 'b', 'c', 'd', 'f']); - /// ``` - #[stable(feature = "slice_rotate", since = "1.26.0")] - pub fn rotate_right(&mut self, k: usize) { - core_slice::SliceExt::rotate_right(self, k); - } - - /// Copies the elements from `src` into `self`. - /// - /// The length of `src` must be the same as `self`. - /// - /// If `src` implements `Copy`, it can be more performant to use - /// [`copy_from_slice`]. - /// - /// # Panics - /// - /// This function will panic if the two slices have different lengths. - /// - /// # Examples - /// - /// Cloning two elements from a slice into another: - /// - /// ``` - /// let src = [1, 2, 3, 4]; - /// let mut dst = [0, 0]; - /// - /// dst.clone_from_slice(&src[2..]); - /// - /// assert_eq!(src, [1, 2, 3, 4]); - /// assert_eq!(dst, [3, 4]); - /// ``` - /// - /// Rust enforces that there can only be one mutable reference with no - /// immutable references to a particular piece of data in a particular - /// scope. Because of this, attempting to use `clone_from_slice` on a - /// single slice will result in a compile failure: - /// - /// ```compile_fail - /// let mut slice = [1, 2, 3, 4, 5]; - /// - /// slice[..2].clone_from_slice(&slice[3..]); // compile fail! - /// ``` - /// - /// To work around this, we can use [`split_at_mut`] to create two distinct - /// sub-slices from a slice: - /// - /// ``` - /// let mut slice = [1, 2, 3, 4, 5]; - /// - /// { - /// let (left, right) = slice.split_at_mut(2); - /// left.clone_from_slice(&right[1..]); - /// } - /// - /// assert_eq!(slice, [4, 5, 3, 4, 5]); - /// ``` - /// - /// [`copy_from_slice`]: #method.copy_from_slice - /// [`split_at_mut`]: #method.split_at_mut - #[stable(feature = "clone_from_slice", since = "1.7.0")] - pub fn clone_from_slice(&mut self, src: &[T]) where T: Clone { - core_slice::SliceExt::clone_from_slice(self, src) - } - - /// Copies all elements from `src` into `self`, using a memcpy. - /// - /// The length of `src` must be the same as `self`. - /// - /// If `src` does not implement `Copy`, use [`clone_from_slice`]. - /// - /// # Panics - /// - /// This function will panic if the two slices have different lengths. - /// - /// # Examples - /// - /// Copying two elements from a slice into another: - /// - /// ``` - /// let src = [1, 2, 3, 4]; - /// let mut dst = [0, 0]; - /// - /// dst.copy_from_slice(&src[2..]); - /// - /// assert_eq!(src, [1, 2, 3, 4]); - /// assert_eq!(dst, [3, 4]); - /// ``` - /// - /// Rust enforces that there can only be one mutable reference with no - /// immutable references to a particular piece of data in a particular - /// scope. Because of this, attempting to use `copy_from_slice` on a - /// single slice will result in a compile failure: - /// - /// ```compile_fail - /// let mut slice = [1, 2, 3, 4, 5]; - /// - /// slice[..2].copy_from_slice(&slice[3..]); // compile fail! - /// ``` - /// - /// To work around this, we can use [`split_at_mut`] to create two distinct - /// sub-slices from a slice: - /// - /// ``` - /// let mut slice = [1, 2, 3, 4, 5]; - /// - /// { - /// let (left, right) = slice.split_at_mut(2); - /// left.copy_from_slice(&right[1..]); - /// } - /// - /// assert_eq!(slice, [4, 5, 3, 4, 5]); - /// ``` - /// - /// [`clone_from_slice`]: #method.clone_from_slice - /// [`split_at_mut`]: #method.split_at_mut - #[stable(feature = "copy_from_slice", since = "1.9.0")] - pub fn copy_from_slice(&mut self, src: &[T]) where T: Copy { - core_slice::SliceExt::copy_from_slice(self, src) - } - - /// Swaps all elements in `self` with those in `other`. - /// - /// The length of `other` must be the same as `self`. - /// - /// # Panics - /// - /// This function will panic if the two slices have different lengths. - /// - /// # Example - /// - /// Swapping two elements across slices: - /// - /// ``` - /// let mut slice1 = [0, 0]; - /// let mut slice2 = [1, 2, 3, 4]; - /// - /// slice1.swap_with_slice(&mut slice2[2..]); - /// - /// assert_eq!(slice1, [3, 4]); - /// assert_eq!(slice2, [1, 2, 0, 0]); - /// ``` - /// - /// Rust enforces that there can only be one mutable reference to a - /// particular piece of data in a particular scope. Because of this, - /// attempting to use `swap_with_slice` on a single slice will result in - /// a compile failure: - /// - /// ```compile_fail - /// let mut slice = [1, 2, 3, 4, 5]; - /// slice[..2].swap_with_slice(&mut slice[3..]); // compile fail! - /// ``` - /// - /// To work around this, we can use [`split_at_mut`] to create two distinct - /// mutable sub-slices from a slice: - /// - /// ``` - /// let mut slice = [1, 2, 3, 4, 5]; - /// - /// { - /// let (left, right) = slice.split_at_mut(2); - /// left.swap_with_slice(&mut right[1..]); - /// } - /// - /// assert_eq!(slice, [4, 5, 3, 1, 2]); - /// ``` - /// - /// [`split_at_mut`]: #method.split_at_mut - #[stable(feature = "swap_with_slice", since = "1.27.0")] - pub fn swap_with_slice(&mut self, other: &mut [T]) { - core_slice::SliceExt::swap_with_slice(self, other) - } - /// Copies `self` into a new `Vec`. /// /// # Examples diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs index 88bd0444233..f4fafe304c0 100644 --- a/src/libcore/lib.rs +++ b/src/libcore/lib.rs @@ -229,7 +229,7 @@ macro_rules! test_v512 { ($item:item) => {}; } #[allow(unused_macros)] macro_rules! vector_impl { ($([$f:ident, $($args:tt)*]),*) => { $($f!($($args)*);)* } } #[path = "../stdsimd/coresimd/mod.rs"] -#[allow(missing_docs, missing_debug_implementations, dead_code)] +#[allow(missing_docs, missing_debug_implementations, dead_code, unused_imports)] #[unstable(feature = "stdsimd", issue = "48556")] #[cfg(not(stage0))] // allow changes to how stdsimd works in stage0 mod coresimd; diff --git a/src/libcore/prelude/v1.rs b/src/libcore/prelude/v1.rs index cc3ad71117a..32c1531bdc0 100644 --- a/src/libcore/prelude/v1.rs +++ b/src/libcore/prelude/v1.rs @@ -58,6 +58,7 @@ pub use result::Result::{self, Ok, Err}; // Re-exported extension traits for primitive types #[stable(feature = "core_prelude", since = "1.4.0")] #[doc(no_inline)] +#[cfg(stage0)] pub use slice::SliceExt; #[stable(feature = "core_prelude", since = "1.4.0")] #[doc(no_inline)] diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs index 4cda1c8778a..0a260c663c2 100644 --- a/src/libcore/slice/mod.rs +++ b/src/libcore/slice/mod.rs @@ -755,6 +755,1410 @@ impl SliceExt for [T] { } } +// FIXME: remove (inline) this macro and the SliceExt trait +// when updating to a bootstrap compiler that has the new lang items. +#[cfg_attr(stage0, macro_export)] +#[unstable(feature = "core_slice_ext", issue = "32110")] +macro_rules! slice_core_methods { () => { + /// Returns 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")] + #[inline] + pub fn len(&self) -> usize { + SliceExt::len(self) + } + + /// Returns `true` if the slice has a length of 0. + /// + /// # Examples + /// + /// ``` + /// let a = [1, 2, 3]; + /// assert!(!a.is_empty()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn is_empty(&self) -> bool { + SliceExt::is_empty(self) + } + + /// Returns the first element of the 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")] + #[inline] + pub fn first(&self) -> Option<&T> { + SliceExt::first(self) + } + + /// Returns a mutable pointer to the first element of the slice, or `None` if it is empty. + /// + /// # Examples + /// + /// ``` + /// let x = &mut [0, 1, 2]; + /// + /// if let Some(first) = x.first_mut() { + /// *first = 5; + /// } + /// assert_eq!(x, &[5, 1, 2]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn first_mut(&mut self) -> Option<&mut T> { + SliceExt::first_mut(self) + } + + /// Returns the first and all the rest of the elements of the slice, or `None` if it is empty. + /// + /// # Examples + /// + /// ``` + /// let x = &[0, 1, 2]; + /// + /// if let Some((first, elements)) = x.split_first() { + /// assert_eq!(first, &0); + /// assert_eq!(elements, &[1, 2]); + /// } + /// ``` + #[stable(feature = "slice_splits", since = "1.5.0")] + #[inline] + pub fn split_first(&self) -> Option<(&T, &[T])> { + SliceExt::split_first(self) + } + + /// Returns the first and all the rest of the elements of the slice, or `None` if it is empty. + /// + /// # Examples + /// + /// ``` + /// let x = &mut [0, 1, 2]; + /// + /// if let Some((first, elements)) = x.split_first_mut() { + /// *first = 3; + /// elements[0] = 4; + /// elements[1] = 5; + /// } + /// assert_eq!(x, &[3, 4, 5]); + /// ``` + #[stable(feature = "slice_splits", since = "1.5.0")] + #[inline] + pub fn split_first_mut(&mut self) -> Option<(&mut T, &mut [T])> { + SliceExt::split_first_mut(self) + } + + /// Returns the last and all the rest of the elements of the slice, or `None` if it is empty. + /// + /// # Examples + /// + /// ``` + /// let x = &[0, 1, 2]; + /// + /// if let Some((last, elements)) = x.split_last() { + /// assert_eq!(last, &2); + /// assert_eq!(elements, &[0, 1]); + /// } + /// ``` + #[stable(feature = "slice_splits", since = "1.5.0")] + #[inline] + pub fn split_last(&self) -> Option<(&T, &[T])> { + SliceExt::split_last(self) + + } + + /// Returns the last and all the rest of the elements of the slice, or `None` if it is empty. + /// + /// # Examples + /// + /// ``` + /// let x = &mut [0, 1, 2]; + /// + /// if let Some((last, elements)) = x.split_last_mut() { + /// *last = 3; + /// elements[0] = 4; + /// elements[1] = 5; + /// } + /// assert_eq!(x, &[4, 5, 3]); + /// ``` + #[stable(feature = "slice_splits", since = "1.5.0")] + #[inline] + pub fn split_last_mut(&mut self) -> Option<(&mut T, &mut [T])> { + SliceExt::split_last_mut(self) + } + + /// Returns the last element of the 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")] + #[inline] + pub fn last(&self) -> Option<&T> { + SliceExt::last(self) + } + + /// Returns a mutable pointer to the last item in the slice. + /// + /// # Examples + /// + /// ``` + /// let x = &mut [0, 1, 2]; + /// + /// if let Some(last) = x.last_mut() { + /// *last = 10; + /// } + /// assert_eq!(x, &[0, 1, 10]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn last_mut(&mut self) -> Option<&mut T> { + SliceExt::last_mut(self) + } + + /// Returns a reference to an element or subslice depending on the type of + /// index. + /// + /// - If given a position, returns a reference to the element at that + /// position or `None` if out of bounds. + /// - If given a range, returns the subslice corresponding to that range, + /// or `None` if out of bounds. + /// + /// # Examples + /// + /// ``` + /// let v = [10, 40, 30]; + /// assert_eq!(Some(&40), v.get(1)); + /// assert_eq!(Some(&[10, 40][..]), v.get(0..2)); + /// assert_eq!(None, v.get(3)); + /// assert_eq!(None, v.get(0..4)); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn get(&self, index: I) -> Option<&I::Output> + where I: SliceIndex + { + SliceExt::get(self, index) + } + + /// Returns a mutable reference to an element or subslice depending on the + /// type of index (see [`get`]) or `None` if the index is out of bounds. + /// + /// [`get`]: #method.get + /// + /// # Examples + /// + /// ``` + /// let x = &mut [0, 1, 2]; + /// + /// if let Some(elem) = x.get_mut(1) { + /// *elem = 42; + /// } + /// assert_eq!(x, &[0, 42, 2]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn get_mut(&mut self, index: I) -> Option<&mut I::Output> + where I: SliceIndex + { + SliceExt::get_mut(self, index) + } + + /// Returns a reference to an element or subslice, without doing bounds + /// checking. + /// + /// This is generally not recommended, use with caution! For a safe + /// alternative see [`get`]. + /// + /// [`get`]: #method.get + /// + /// # Examples + /// + /// ``` + /// let x = &[1, 2, 4]; + /// + /// unsafe { + /// assert_eq!(x.get_unchecked(1), &2); + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub unsafe fn get_unchecked(&self, index: I) -> &I::Output + where I: SliceIndex + { + SliceExt::get_unchecked(self, index) + } + + /// Returns a mutable reference to an element or subslice, without doing + /// bounds checking. + /// + /// This is generally not recommended, use with caution! For a safe + /// alternative see [`get_mut`]. + /// + /// [`get_mut`]: #method.get_mut + /// + /// # Examples + /// + /// ``` + /// let x = &mut [1, 2, 4]; + /// + /// unsafe { + /// let elem = x.get_unchecked_mut(1); + /// *elem = 13; + /// } + /// assert_eq!(x, &[1, 13, 4]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub unsafe fn get_unchecked_mut(&mut self, index: I) -> &mut I::Output + where I: SliceIndex + { + SliceExt::get_unchecked_mut(self, index) + } + + /// Returns a raw 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 container referenced by this slice may cause its buffer + /// to be reallocated, which would also make any pointers to it invalid. + /// + /// # Examples + /// + /// ``` + /// let x = &[1, 2, 4]; + /// let x_ptr = x.as_ptr(); + /// + /// unsafe { + /// for i in 0..x.len() { + /// assert_eq!(x.get_unchecked(i), &*x_ptr.offset(i as isize)); + /// } + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn as_ptr(&self) -> *const T { + SliceExt::as_ptr(self) + } + + /// Returns 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 container referenced by this slice may cause its buffer + /// to be reallocated, which would also make any pointers to it invalid. + /// + /// # Examples + /// + /// ``` + /// let x = &mut [1, 2, 4]; + /// let x_ptr = x.as_mut_ptr(); + /// + /// unsafe { + /// for i in 0..x.len() { + /// *x_ptr.offset(i as isize) += 2; + /// } + /// } + /// assert_eq!(x, &[3, 4, 6]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn as_mut_ptr(&mut self) -> *mut T { + SliceExt::as_mut_ptr(self) + } + + /// Swaps two elements in the 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 + /// + /// ``` + /// let mut v = ["a", "b", "c", "d"]; + /// v.swap(1, 3); + /// assert!(v == ["a", "d", "c", "b"]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn swap(&mut self, a: usize, b: usize) { + SliceExt::swap(self, a, b) + } + + /// Reverses the order of elements in the slice, in place. + /// + /// # Examples + /// + /// ``` + /// let mut v = [1, 2, 3]; + /// v.reverse(); + /// assert!(v == [3, 2, 1]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn reverse(&mut self) { + SliceExt::reverse(self) + } + + /// Returns an iterator over the slice. + /// + /// # Examples + /// + /// ``` + /// let x = &[1, 2, 4]; + /// let mut iterator = x.iter(); + /// + /// assert_eq!(iterator.next(), Some(&1)); + /// assert_eq!(iterator.next(), Some(&2)); + /// assert_eq!(iterator.next(), Some(&4)); + /// assert_eq!(iterator.next(), None); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn iter(&self) -> Iter { + SliceExt::iter(self) + } + + /// Returns an iterator that allows modifying each value. + /// + /// # Examples + /// + /// ``` + /// let x = &mut [1, 2, 4]; + /// for elem in x.iter_mut() { + /// *elem += 2; + /// } + /// assert_eq!(x, &[3, 4, 6]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn iter_mut(&mut self) -> IterMut { + SliceExt::iter_mut(self) + } + + /// 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 + /// + /// ``` + /// let slice = ['r', 'u', 's', 't']; + /// let mut iter = slice.windows(2); + /// assert_eq!(iter.next().unwrap(), &['r', 'u']); + /// assert_eq!(iter.next().unwrap(), &['u', 's']); + /// assert_eq!(iter.next().unwrap(), &['s', 't']); + /// assert!(iter.next().is_none()); + /// ``` + /// + /// If the slice is shorter than `size`: + /// + /// ``` + /// let slice = ['f', 'o', 'o']; + /// let mut iter = slice.windows(4); + /// assert!(iter.next().is_none()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn windows(&self, size: usize) -> Windows { + SliceExt::windows(self, size) + } + + /// Returns an iterator over `chunk_size` elements of the slice at a + /// time. The chunks are slices 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`. + /// + /// See [`exact_chunks`] for a variant of this iterator that returns chunks + /// of always exactly `chunk_size` elements. + /// + /// # Panics + /// + /// Panics if `chunk_size` is 0. + /// + /// # Examples + /// + /// ``` + /// let slice = ['l', 'o', 'r', 'e', 'm']; + /// let mut iter = slice.chunks(2); + /// assert_eq!(iter.next().unwrap(), &['l', 'o']); + /// assert_eq!(iter.next().unwrap(), &['r', 'e']); + /// assert_eq!(iter.next().unwrap(), &['m']); + /// assert!(iter.next().is_none()); + /// ``` + /// + /// [`exact_chunks`]: #method.exact_chunks + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn chunks(&self, chunk_size: usize) -> Chunks { + SliceExt::chunks(self, chunk_size) + } + + /// Returns an iterator over `chunk_size` elements of the slice at a + /// time. The chunks are slices and do not overlap. If `chunk_size` does + /// not divide the length of the slice, then the last up to `chunk_size-1` + /// elements will be omitted. + /// + /// Due to each chunk having exactly `chunk_size` elements, the compiler + /// can often optimize the resulting code better than in the case of + /// [`chunks`]. + /// + /// # Panics + /// + /// Panics if `chunk_size` is 0. + /// + /// # Examples + /// + /// ``` + /// #![feature(exact_chunks)] + /// + /// let slice = ['l', 'o', 'r', 'e', 'm']; + /// let mut iter = slice.exact_chunks(2); + /// assert_eq!(iter.next().unwrap(), &['l', 'o']); + /// assert_eq!(iter.next().unwrap(), &['r', 'e']); + /// assert!(iter.next().is_none()); + /// ``` + /// + /// [`chunks`]: #method.chunks + #[unstable(feature = "exact_chunks", issue = "47115")] + #[inline] + pub fn exact_chunks(&self, chunk_size: usize) -> ExactChunks { + SliceExt::exact_chunks(self, chunk_size) + } + + /// Returns an iterator over `chunk_size` elements of the slice at a time. + /// The chunks are mutable slices, 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`. + /// + /// See [`exact_chunks_mut`] for a variant of this iterator that returns chunks + /// of always exactly `chunk_size` elements. + /// + /// # Panics + /// + /// Panics if `chunk_size` is 0. + /// + /// # Examples + /// + /// ``` + /// let v = &mut [0, 0, 0, 0, 0]; + /// let mut count = 1; + /// + /// for chunk in v.chunks_mut(2) { + /// for elem in chunk.iter_mut() { + /// *elem += count; + /// } + /// count += 1; + /// } + /// assert_eq!(v, &[1, 1, 2, 2, 3]); + /// ``` + /// + /// [`exact_chunks_mut`]: #method.exact_chunks_mut + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut { + SliceExt::chunks_mut(self, chunk_size) + } + + /// Returns an iterator over `chunk_size` elements of the slice at a time. + /// The chunks are mutable slices, and do not overlap. If `chunk_size` does + /// not divide the length of the slice, then the last up to `chunk_size-1` + /// elements will be omitted. + /// + /// + /// Due to each chunk having exactly `chunk_size` elements, the compiler + /// can often optimize the resulting code better than in the case of + /// [`chunks_mut`]. + /// + /// # Panics + /// + /// Panics if `chunk_size` is 0. + /// + /// # Examples + /// + /// ``` + /// #![feature(exact_chunks)] + /// + /// let v = &mut [0, 0, 0, 0, 0]; + /// let mut count = 1; + /// + /// for chunk in v.exact_chunks_mut(2) { + /// for elem in chunk.iter_mut() { + /// *elem += count; + /// } + /// count += 1; + /// } + /// assert_eq!(v, &[1, 1, 2, 2, 0]); + /// ``` + /// + /// [`chunks_mut`]: #method.chunks_mut + #[unstable(feature = "exact_chunks", issue = "47115")] + #[inline] + pub fn exact_chunks_mut(&mut self, chunk_size: usize) -> ExactChunksMut { + SliceExt::exact_chunks_mut(self, chunk_size) + } + + /// 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 + /// + /// Panics if `mid > len`. + /// + /// # Examples + /// + /// ``` + /// let v = [1, 2, 3, 4, 5, 6]; + /// + /// { + /// let (left, right) = v.split_at(0); + /// assert!(left == []); + /// assert!(right == [1, 2, 3, 4, 5, 6]); + /// } + /// + /// { + /// let (left, right) = v.split_at(2); + /// assert!(left == [1, 2]); + /// assert!(right == [3, 4, 5, 6]); + /// } + /// + /// { + /// let (left, right) = v.split_at(6); + /// assert!(left == [1, 2, 3, 4, 5, 6]); + /// assert!(right == []); + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn split_at(&self, mid: usize) -> (&[T], &[T]) { + SliceExt::split_at(self, mid) + } + + /// Divides one mutable 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 + /// + /// Panics if `mid > len`. + /// + /// # Examples + /// + /// ``` + /// let mut v = [1, 0, 3, 0, 5, 6]; + /// // scoped to restrict the lifetime of the borrows + /// { + /// let (left, right) = v.split_at_mut(2); + /// assert!(left == [1, 0]); + /// assert!(right == [3, 0, 5, 6]); + /// left[1] = 2; + /// right[1] = 4; + /// } + /// assert!(v == [1, 2, 3, 4, 5, 6]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn split_at_mut(&mut self, mid: usize) -> (&mut [T], &mut [T]) { + SliceExt::split_at_mut(self, mid) + } + + /// Returns an iterator over subslices separated by elements that match + /// `pred`. The matched element is not contained in the subslices. + /// + /// # Examples + /// + /// ``` + /// let slice = [10, 40, 33, 20]; + /// let mut iter = slice.split(|num| num % 3 == 0); + /// + /// assert_eq!(iter.next().unwrap(), &[10, 40]); + /// assert_eq!(iter.next().unwrap(), &[20]); + /// assert!(iter.next().is_none()); + /// ``` + /// + /// If the first element is matched, an empty slice will be the first item + /// returned by the iterator. Similarly, if the last element in the slice + /// is matched, an empty slice will be the last item returned by the + /// iterator: + /// + /// ``` + /// let slice = [10, 40, 33]; + /// let mut iter = slice.split(|num| num % 3 == 0); + /// + /// assert_eq!(iter.next().unwrap(), &[10, 40]); + /// assert_eq!(iter.next().unwrap(), &[]); + /// assert!(iter.next().is_none()); + /// ``` + /// + /// If two matched elements are directly adjacent, an empty slice will be + /// present between them: + /// + /// ``` + /// let slice = [10, 6, 33, 20]; + /// let mut iter = slice.split(|num| num % 3 == 0); + /// + /// assert_eq!(iter.next().unwrap(), &[10]); + /// assert_eq!(iter.next().unwrap(), &[]); + /// assert_eq!(iter.next().unwrap(), &[20]); + /// assert!(iter.next().is_none()); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn split(&self, pred: F) -> Split + where F: FnMut(&T) -> bool + { + SliceExt::split(self, pred) + } + + /// Returns an iterator over mutable subslices separated by elements that + /// match `pred`. The matched element is not contained in the subslices. + /// + /// # Examples + /// + /// ``` + /// let mut v = [10, 40, 30, 20, 60, 50]; + /// + /// for group in v.split_mut(|num| *num % 3 == 0) { + /// group[0] = 1; + /// } + /// assert_eq!(v, [1, 40, 30, 1, 60, 1]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn split_mut(&mut self, pred: F) -> SplitMut + where F: FnMut(&T) -> bool + { + SliceExt::split_mut(self, pred) + } + + /// Returns an iterator over subslices separated by elements that match + /// `pred`, starting at the end of the slice and working backwards. + /// The matched element is not contained in the subslices. + /// + /// # Examples + /// + /// ``` + /// let slice = [11, 22, 33, 0, 44, 55]; + /// let mut iter = slice.rsplit(|num| *num == 0); + /// + /// assert_eq!(iter.next().unwrap(), &[44, 55]); + /// assert_eq!(iter.next().unwrap(), &[11, 22, 33]); + /// assert_eq!(iter.next(), None); + /// ``` + /// + /// As with `split()`, if the first or last element is matched, an empty + /// slice will be the first (or last) item returned by the iterator. + /// + /// ``` + /// let v = &[0, 1, 1, 2, 3, 5, 8]; + /// let mut it = v.rsplit(|n| *n % 2 == 0); + /// assert_eq!(it.next().unwrap(), &[]); + /// assert_eq!(it.next().unwrap(), &[3, 5]); + /// assert_eq!(it.next().unwrap(), &[1, 1]); + /// assert_eq!(it.next().unwrap(), &[]); + /// assert_eq!(it.next(), None); + /// ``` + #[stable(feature = "slice_rsplit", since = "1.27.0")] + #[inline] + pub fn rsplit(&self, pred: F) -> RSplit + where F: FnMut(&T) -> bool + { + SliceExt::rsplit(self, pred) + } + + /// Returns an iterator over mutable subslices separated by elements that + /// match `pred`, starting at the end of the slice and working + /// backwards. The matched element is not contained in the subslices. + /// + /// # Examples + /// + /// ``` + /// let mut v = [100, 400, 300, 200, 600, 500]; + /// + /// let mut count = 0; + /// for group in v.rsplit_mut(|num| *num % 3 == 0) { + /// count += 1; + /// group[0] = count; + /// } + /// assert_eq!(v, [3, 400, 300, 2, 600, 1]); + /// ``` + /// + #[stable(feature = "slice_rsplit", since = "1.27.0")] + #[inline] + pub fn rsplit_mut(&mut self, pred: F) -> RSplitMut + where F: FnMut(&T) -> bool + { + SliceExt::rsplit_mut(self, pred) + } + + /// Returns an iterator over subslices separated by elements that match + /// `pred`, limited to returning at most `n` items. The matched element is + /// not contained in the subslices. + /// + /// The last element returned, if any, will contain the remainder of the + /// slice. + /// + /// # 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(2, |num| *num % 3 == 0) { + /// println!("{:?}", group); + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn splitn(&self, n: usize, pred: F) -> SplitN + where F: FnMut(&T) -> bool + { + SliceExt::splitn(self, n, pred) + } + + /// Returns an iterator over subslices separated by elements that match + /// `pred`, limited to returning at most `n` items. The matched element is + /// not contained in the subslices. + /// + /// The last element returned, if any, will contain the remainder of the + /// slice. + /// + /// # Examples + /// + /// ``` + /// let mut v = [10, 40, 30, 20, 60, 50]; + /// + /// for group in v.splitn_mut(2, |num| *num % 3 == 0) { + /// group[0] = 1; + /// } + /// assert_eq!(v, [1, 40, 30, 1, 60, 50]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn splitn_mut(&mut self, n: usize, pred: F) -> SplitNMut + where F: FnMut(&T) -> bool + { + SliceExt::splitn_mut(self, n, pred) + } + + /// Returns an iterator over subslices separated by elements that match + /// `pred` limited to returning at most `n` items. This starts at the end of + /// the slice and works backwards. The matched element is not contained in + /// the subslices. + /// + /// The last element returned, if any, will contain the remainder of the + /// slice. + /// + /// # 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(2, |num| *num % 3 == 0) { + /// println!("{:?}", group); + /// } + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn rsplitn(&self, n: usize, pred: F) -> RSplitN + where F: FnMut(&T) -> bool + { + SliceExt::rsplitn(self, n, pred) + } + + /// Returns an iterator over subslices separated by elements that match + /// `pred` limited to returning at most `n` items. This starts at the end of + /// the slice and works backwards. The matched element is not contained in + /// the subslices. + /// + /// The last element returned, if any, will contain the remainder of the + /// slice. + /// + /// # Examples + /// + /// ``` + /// let mut s = [10, 40, 30, 20, 60, 50]; + /// + /// for group in s.rsplitn_mut(2, |num| *num % 3 == 0) { + /// group[0] = 1; + /// } + /// assert_eq!(s, [1, 40, 30, 20, 60, 1]); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + #[inline] + pub fn rsplitn_mut(&mut self, n: usize, pred: F) -> RSplitNMut + where F: FnMut(&T) -> bool + { + SliceExt::rsplitn_mut(self, n, pred) + } + + /// 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")] + pub fn contains(&self, x: &T) -> bool + where T: PartialEq + { + SliceExt::contains(self, x) + } + + /// 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])); + /// ``` + /// + /// Always returns `true` if `needle` is an empty slice: + /// + /// ``` + /// let v = &[10, 40, 30]; + /// assert!(v.starts_with(&[])); + /// let v: &[u8] = &[]; + /// assert!(v.starts_with(&[])); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn starts_with(&self, needle: &[T]) -> bool + where T: PartialEq + { + SliceExt::starts_with(self, needle) + } + + /// 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])); + /// ``` + /// + /// Always returns `true` if `needle` is an empty slice: + /// + /// ``` + /// let v = &[10, 40, 30]; + /// assert!(v.ends_with(&[])); + /// let v: &[u8] = &[]; + /// assert!(v.ends_with(&[])); + /// ``` + #[stable(feature = "rust1", since = "1.0.0")] + pub fn ends_with(&self, needle: &[T]) -> bool + where T: PartialEq + { + SliceExt::ends_with(self, needle) + } + + /// Binary searches this 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]`. + /// + /// ``` + /// let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]; + /// + /// 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")] + pub fn binary_search(&self, x: &T) -> Result + where T: Ord + { + SliceExt::binary_search(self, x) + } + + /// Binary searches this 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]`. + /// + /// ``` + /// let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]; + /// + /// 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")] + #[inline] + pub fn binary_search_by<'a, F>(&'a self, f: F) -> Result + where F: FnMut(&'a T) -> Ordering + { + SliceExt::binary_search_by(self, f) + } + + /// Binary searches this sorted slice with a key extraction function. + /// + /// Assumes that the slice is sorted by the key, for instance with + /// [`sort_by_key`] using the same key extraction function. + /// + /// 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. + /// + /// [`sort_by_key`]: #method.sort_by_key + /// + /// # Examples + /// + /// Looks up a series of four elements in a slice of pairs sorted by + /// their second 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]`. + /// + /// ``` + /// let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1), + /// (1, 2), (2, 3), (4, 5), (5, 8), (3, 13), + /// (1, 21), (2, 34), (4, 55)]; + /// + /// assert_eq!(s.binary_search_by_key(&13, |&(a,b)| b), Ok(9)); + /// assert_eq!(s.binary_search_by_key(&4, |&(a,b)| b), Err(7)); + /// assert_eq!(s.binary_search_by_key(&100, |&(a,b)| b), Err(13)); + /// let r = s.binary_search_by_key(&1, |&(a,b)| b); + /// assert!(match r { Ok(1...4) => true, _ => false, }); + /// ``` + #[stable(feature = "slice_binary_search_by_key", since = "1.10.0")] + #[inline] + pub fn binary_search_by_key<'a, B, F>(&'a self, b: &B, f: F) -> Result + where F: FnMut(&'a T) -> B, + B: Ord + { + SliceExt::binary_search_by_key(self, b, f) + } + + /// Sorts the slice, but may not preserve the order of equal elements. + /// + /// This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), + /// and `O(n log n)` worst-case. + /// + /// # Current implementation + /// + /// The current algorithm is based on [pattern-defeating quicksort][pdqsort] by Orson Peters, + /// which combines the fast average case of randomized quicksort with the fast worst case of + /// heapsort, while achieving linear time on slices with certain patterns. It uses some + /// randomization to avoid degenerate cases, but with a fixed seed to always provide + /// deterministic behavior. + /// + /// It is typically faster than stable sorting, except in a few special cases, e.g. when the + /// slice consists of several concatenated sorted sequences. + /// + /// # Examples + /// + /// ``` + /// let mut v = [-5, 4, 1, -3, 2]; + /// + /// v.sort_unstable(); + /// assert!(v == [-5, -3, 1, 2, 4]); + /// ``` + /// + /// [pdqsort]: https://github.com/orlp/pdqsort + #[stable(feature = "sort_unstable", since = "1.20.0")] + #[inline] + pub fn sort_unstable(&mut self) + where T: Ord + { + SliceExt::sort_unstable(self); + } + + /// Sorts the slice with a comparator function, but may not preserve the order of equal + /// elements. + /// + /// This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), + /// and `O(n log n)` worst-case. + /// + /// # Current implementation + /// + /// The current algorithm is based on [pattern-defeating quicksort][pdqsort] by Orson Peters, + /// which combines the fast average case of randomized quicksort with the fast worst case of + /// heapsort, while achieving linear time on slices with certain patterns. It uses some + /// randomization to avoid degenerate cases, but with a fixed seed to always provide + /// deterministic behavior. + /// + /// It is typically faster than stable sorting, except in a few special cases, e.g. when the + /// slice consists of several concatenated sorted sequences. + /// + /// # Examples + /// + /// ``` + /// let mut v = [5, 4, 1, 3, 2]; + /// v.sort_unstable_by(|a, b| a.cmp(b)); + /// assert!(v == [1, 2, 3, 4, 5]); + /// + /// // reverse sorting + /// v.sort_unstable_by(|a, b| b.cmp(a)); + /// assert!(v == [5, 4, 3, 2, 1]); + /// ``` + /// + /// [pdqsort]: https://github.com/orlp/pdqsort + #[stable(feature = "sort_unstable", since = "1.20.0")] + #[inline] + pub fn sort_unstable_by(&mut self, compare: F) + where F: FnMut(&T, &T) -> Ordering + { + SliceExt::sort_unstable_by(self, compare); + } + + /// Sorts the slice with a key extraction function, but may not preserve the order of equal + /// elements. + /// + /// This sort is unstable (i.e. may reorder equal elements), in-place (i.e. does not allocate), + /// and `O(m n log(m n))` worst-case, where the key function is `O(m)`. + /// + /// # Current implementation + /// + /// The current algorithm is based on [pattern-defeating quicksort][pdqsort] by Orson Peters, + /// which combines the fast average case of randomized quicksort with the fast worst case of + /// heapsort, while achieving linear time on slices with certain patterns. It uses some + /// randomization to avoid degenerate cases, but with a fixed seed to always provide + /// deterministic behavior. + /// + /// # Examples + /// + /// ``` + /// let mut v = [-5i32, 4, 1, -3, 2]; + /// + /// v.sort_unstable_by_key(|k| k.abs()); + /// assert!(v == [1, 2, -3, 4, -5]); + /// ``` + /// + /// [pdqsort]: https://github.com/orlp/pdqsort + #[stable(feature = "sort_unstable", since = "1.20.0")] + #[inline] + pub fn sort_unstable_by_key(&mut self, f: F) + where F: FnMut(&T) -> K, K: Ord + { + SliceExt::sort_unstable_by_key(self, f); + } + + /// Rotates the slice in-place such that the first `mid` elements of the + /// slice move to the end while the last `self.len() - mid` elements move to + /// the front. After calling `rotate_left`, the element previously at index + /// `mid` will become the first element in the slice. + /// + /// # Panics + /// + /// This function will panic if `mid` is greater than the length of the + /// slice. Note that `mid == self.len()` does _not_ panic and is a no-op + /// rotation. + /// + /// # Complexity + /// + /// Takes linear (in `self.len()`) time. + /// + /// # Examples + /// + /// ``` + /// let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; + /// a.rotate_left(2); + /// assert_eq!(a, ['c', 'd', 'e', 'f', 'a', 'b']); + /// ``` + /// + /// Rotating a subslice: + /// + /// ``` + /// let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; + /// a[1..5].rotate_left(1); + /// assert_eq!(a, ['a', 'c', 'd', 'e', 'b', 'f']); + /// ``` + #[stable(feature = "slice_rotate", since = "1.26.0")] + pub fn rotate_left(&mut self, mid: usize) { + SliceExt::rotate_left(self, mid); + } + + /// Rotates the slice in-place such that the first `self.len() - k` + /// elements of the slice move to the end while the last `k` elements move + /// to the front. After calling `rotate_right`, the element previously at + /// index `self.len() - k` will become the first element in the slice. + /// + /// # Panics + /// + /// This function will panic if `k` is greater than the length of the + /// slice. Note that `k == self.len()` does _not_ panic and is a no-op + /// rotation. + /// + /// # Complexity + /// + /// Takes linear (in `self.len()`) time. + /// + /// # Examples + /// + /// ``` + /// let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; + /// a.rotate_right(2); + /// assert_eq!(a, ['e', 'f', 'a', 'b', 'c', 'd']); + /// ``` + /// + /// Rotate a subslice: + /// + /// ``` + /// let mut a = ['a', 'b', 'c', 'd', 'e', 'f']; + /// a[1..5].rotate_right(1); + /// assert_eq!(a, ['a', 'e', 'b', 'c', 'd', 'f']); + /// ``` + #[stable(feature = "slice_rotate", since = "1.26.0")] + pub fn rotate_right(&mut self, k: usize) { + SliceExt::rotate_right(self, k); + } + + /// Copies the elements from `src` into `self`. + /// + /// The length of `src` must be the same as `self`. + /// + /// If `src` implements `Copy`, it can be more performant to use + /// [`copy_from_slice`]. + /// + /// # Panics + /// + /// This function will panic if the two slices have different lengths. + /// + /// # Examples + /// + /// Cloning two elements from a slice into another: + /// + /// ``` + /// let src = [1, 2, 3, 4]; + /// let mut dst = [0, 0]; + /// + /// dst.clone_from_slice(&src[2..]); + /// + /// assert_eq!(src, [1, 2, 3, 4]); + /// assert_eq!(dst, [3, 4]); + /// ``` + /// + /// Rust enforces that there can only be one mutable reference with no + /// immutable references to a particular piece of data in a particular + /// scope. Because of this, attempting to use `clone_from_slice` on a + /// single slice will result in a compile failure: + /// + /// ```compile_fail + /// let mut slice = [1, 2, 3, 4, 5]; + /// + /// slice[..2].clone_from_slice(&slice[3..]); // compile fail! + /// ``` + /// + /// To work around this, we can use [`split_at_mut`] to create two distinct + /// sub-slices from a slice: + /// + /// ``` + /// let mut slice = [1, 2, 3, 4, 5]; + /// + /// { + /// let (left, right) = slice.split_at_mut(2); + /// left.clone_from_slice(&right[1..]); + /// } + /// + /// assert_eq!(slice, [4, 5, 3, 4, 5]); + /// ``` + /// + /// [`copy_from_slice`]: #method.copy_from_slice + /// [`split_at_mut`]: #method.split_at_mut + #[stable(feature = "clone_from_slice", since = "1.7.0")] + pub fn clone_from_slice(&mut self, src: &[T]) where T: Clone { + SliceExt::clone_from_slice(self, src) + } + + /// Copies all elements from `src` into `self`, using a memcpy. + /// + /// The length of `src` must be the same as `self`. + /// + /// If `src` does not implement `Copy`, use [`clone_from_slice`]. + /// + /// # Panics + /// + /// This function will panic if the two slices have different lengths. + /// + /// # Examples + /// + /// Copying two elements from a slice into another: + /// + /// ``` + /// let src = [1, 2, 3, 4]; + /// let mut dst = [0, 0]; + /// + /// dst.copy_from_slice(&src[2..]); + /// + /// assert_eq!(src, [1, 2, 3, 4]); + /// assert_eq!(dst, [3, 4]); + /// ``` + /// + /// Rust enforces that there can only be one mutable reference with no + /// immutable references to a particular piece of data in a particular + /// scope. Because of this, attempting to use `copy_from_slice` on a + /// single slice will result in a compile failure: + /// + /// ```compile_fail + /// let mut slice = [1, 2, 3, 4, 5]; + /// + /// slice[..2].copy_from_slice(&slice[3..]); // compile fail! + /// ``` + /// + /// To work around this, we can use [`split_at_mut`] to create two distinct + /// sub-slices from a slice: + /// + /// ``` + /// let mut slice = [1, 2, 3, 4, 5]; + /// + /// { + /// let (left, right) = slice.split_at_mut(2); + /// left.copy_from_slice(&right[1..]); + /// } + /// + /// assert_eq!(slice, [4, 5, 3, 4, 5]); + /// ``` + /// + /// [`clone_from_slice`]: #method.clone_from_slice + /// [`split_at_mut`]: #method.split_at_mut + #[stable(feature = "copy_from_slice", since = "1.9.0")] + pub fn copy_from_slice(&mut self, src: &[T]) where T: Copy { + SliceExt::copy_from_slice(self, src) + } + + /// Swaps all elements in `self` with those in `other`. + /// + /// The length of `other` must be the same as `self`. + /// + /// # Panics + /// + /// This function will panic if the two slices have different lengths. + /// + /// # Example + /// + /// Swapping two elements across slices: + /// + /// ``` + /// let mut slice1 = [0, 0]; + /// let mut slice2 = [1, 2, 3, 4]; + /// + /// slice1.swap_with_slice(&mut slice2[2..]); + /// + /// assert_eq!(slice1, [3, 4]); + /// assert_eq!(slice2, [1, 2, 0, 0]); + /// ``` + /// + /// Rust enforces that there can only be one mutable reference to a + /// particular piece of data in a particular scope. Because of this, + /// attempting to use `swap_with_slice` on a single slice will result in + /// a compile failure: + /// + /// ```compile_fail + /// let mut slice = [1, 2, 3, 4, 5]; + /// slice[..2].swap_with_slice(&mut slice[3..]); // compile fail! + /// ``` + /// + /// To work around this, we can use [`split_at_mut`] to create two distinct + /// mutable sub-slices from a slice: + /// + /// ``` + /// let mut slice = [1, 2, 3, 4, 5]; + /// + /// { + /// let (left, right) = slice.split_at_mut(2); + /// left.swap_with_slice(&mut right[1..]); + /// } + /// + /// assert_eq!(slice, [4, 5, 3, 1, 2]); + /// ``` + /// + /// [`split_at_mut`]: #method.split_at_mut + #[stable(feature = "swap_with_slice", since = "1.27.0")] + pub fn swap_with_slice(&mut self, other: &mut [T]) { + SliceExt::swap_with_slice(self, other) + } +}} + +#[lang = "slice"] +#[cfg(not(test))] +#[cfg(not(stage0))] +impl [T] { + slice_core_methods!(); +} + +// FIXME: remove (inline) this macro +// when updating to a bootstrap compiler that has the new lang items. #[cfg_attr(stage0, macro_export)] #[unstable(feature = "core_slice_ext", issue = "32110")] macro_rules! slice_u8_core_methods { () => { diff --git a/src/librustc/middle/lang_items.rs b/src/librustc/middle/lang_items.rs index f8cff8b186c..237a22925b4 100644 --- a/src/librustc/middle/lang_items.rs +++ b/src/librustc/middle/lang_items.rs @@ -214,6 +214,7 @@ language_item_table! { StrImplItem, "str", str_impl; SliceImplItem, "slice", slice_impl; SliceU8ImplItem, "slice_u8", slice_u8_impl; + SliceAllocImplItem, "slice_alloc", slice_alloc_impl; SliceU8AllocImplItem, "slice_u8_alloc", slice_u8_alloc_impl; ConstPtrImplItem, "const_ptr", const_ptr_impl; MutPtrImplItem, "mut_ptr", mut_ptr_impl; diff --git a/src/librustc_typeck/check/method/probe.rs b/src/librustc_typeck/check/method/probe.rs index 7ba60f62791..ea4c2c08817 100644 --- a/src/librustc_typeck/check/method/probe.rs +++ b/src/librustc_typeck/check/method/probe.rs @@ -479,6 +479,9 @@ impl<'a, 'gcx, 'tcx> ProbeContext<'a, 'gcx, 'tcx> { let lang_def_id = lang_items.slice_u8_impl(); self.assemble_inherent_impl_for_primitive(lang_def_id); + let lang_def_id = lang_items.slice_alloc_impl(); + self.assemble_inherent_impl_for_primitive(lang_def_id); + let lang_def_id = lang_items.slice_u8_alloc_impl(); self.assemble_inherent_impl_for_primitive(lang_def_id); } diff --git a/src/librustc_typeck/coherence/inherent_impls.rs b/src/librustc_typeck/coherence/inherent_impls.rs index d7657bae8c5..91f9e3e6fba 100644 --- a/src/librustc_typeck/coherence/inherent_impls.rs +++ b/src/librustc_typeck/coherence/inherent_impls.rs @@ -138,7 +138,7 @@ impl<'a, 'tcx, 'v> ItemLikeVisitor<'v> for InherentCollect<'a, 'tcx> { ty::TySlice(_) => { self.check_primitive_impl(def_id, lang_items.slice_impl(), - None, + lang_items.slice_alloc_impl(), "slice", "[T]", item.span); diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs index 4acd12e5862..38af4350815 100644 --- a/src/librustdoc/clean/inline.rs +++ b/src/librustdoc/clean/inline.rs @@ -290,6 +290,7 @@ pub fn build_impls(cx: &DocContext, did: DefId, auto_traits: bool) -> Vec