diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs index 227fcfabcf1..4e91be365e2 100644 --- a/src/liballoc/lib.rs +++ b/src/liballoc/lib.rs @@ -121,7 +121,7 @@ #![feature(unsize)] #![feature(allocator_internals)] -#![cfg_attr(not(test), feature(fused, fn_traits, placement_new_protocol))] +#![cfg_attr(not(test), feature(fused, fn_traits, placement_new_protocol, swap_with_slice))] #![cfg_attr(test, feature(test, box_heap))] // Allow testing this library diff --git a/src/liballoc/slice.rs b/src/liballoc/slice.rs index 356ca7a5f5e..cbf242e884a 100644 --- a/src/liballoc/slice.rs +++ b/src/liballoc/slice.rs @@ -1461,6 +1461,31 @@ 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 `src`. + /// + /// The length of `src` must be the same as `self`. + /// + /// # Panics + /// + /// This function will panic if the two slices have different lengths. + /// + /// # Example + /// + /// ``` + /// #![feature(swap_with_slice)] + /// + /// let mut src = [1, 2, 3]; + /// let mut dst = [7, 8, 9]; + /// + /// src.swap_with_slice(&mut dst); + /// assert_eq!(src, [7, 8, 9]); + /// assert_eq!(dst, [1, 2, 3]); + /// ``` + #[unstable(feature = "swap_with_slice", issue = "44030")] + pub fn swap_with_slice(&mut self, src: &mut [T]) { + core_slice::SliceExt::swap_with_slice(self, src) + } + /// Copies `self` into a new `Vec`. /// /// # Examples diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs index 0509936153c..31d8266510a 100644 --- a/src/libcore/slice/mod.rs +++ b/src/libcore/slice/mod.rs @@ -212,6 +212,9 @@ unsafe fn get_unchecked_mut(&mut self, index: I) -> &mut I::Output #[stable(feature = "copy_from_slice", since = "1.9.0")] fn copy_from_slice(&mut self, src: &[Self::Item]) where Self::Item: Copy; + #[unstable(feature = "swap_with_slice", issue = "44030")] + fn swap_with_slice(&mut self, src: &mut [Self::Item]); + #[stable(feature = "sort_unstable", since = "1.20.0")] fn sort_unstable(&mut self) where Self::Item: Ord; @@ -673,6 +676,16 @@ fn copy_from_slice(&mut self, src: &[T]) where T: Copy { } } + #[inline] + fn swap_with_slice(&mut self, src: &mut [T]) { + assert!(self.len() == src.len(), + "destination and source slices have different lengths"); + unsafe { + ptr::swap_nonoverlapping( + self.as_mut_ptr(), src.as_mut_ptr(), self.len()); + } + } + #[inline] fn binary_search_by_key<'a, B, F, Q: ?Sized>(&'a self, b: &Q, mut f: F) -> Result where F: FnMut(&'a Self::Item) -> B,