diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs index 6b6ec7147b306..72036d6d3a248 100644 --- a/src/libcore/slice/mod.rs +++ b/src/libcore/slice/mod.rs @@ -2117,6 +2117,14 @@ impl<'a, T> ExactSizeIterator for Windows<'a, T> {} #[unstable(feature = "fused", issue = "35602")] impl<'a, T> FusedIterator for Windows<'a, T> {} +#[doc(hidden)] +unsafe impl<'a, T> TrustedRandomAccess for Windows<'a, T> { + unsafe fn get_unchecked(&mut self, i: usize) -> &'a [T] { + from_raw_parts(self.v.as_ptr().offset(i as isize), self.size) + } + fn may_have_side_effect() -> bool { false } +} + /// An iterator over a slice in (non-overlapping) chunks (`chunk_size` elements at a /// time). /// @@ -2228,6 +2236,19 @@ impl<'a, T> ExactSizeIterator for Chunks<'a, T> {} #[unstable(feature = "fused", issue = "35602")] impl<'a, T> FusedIterator for Chunks<'a, T> {} +#[doc(hidden)] +unsafe impl<'a, T> TrustedRandomAccess for Chunks<'a, T> { + unsafe fn get_unchecked(&mut self, i: usize) -> &'a [T] { + let start = i * self.chunk_size; + let end = match start.checked_add(self.chunk_size) { + None => self.v.len(), + Some(end) => cmp::min(end, self.v.len()), + }; + from_raw_parts(self.v.as_ptr().offset(start as isize), end - start) + } + fn may_have_side_effect() -> bool { false } +} + /// An iterator over a slice in (non-overlapping) mutable chunks (`chunk_size` /// elements at a time). When the slice len is not evenly divided by the chunk /// size, the last slice of the iteration will be the remainder. @@ -2331,6 +2352,19 @@ impl<'a, T> ExactSizeIterator for ChunksMut<'a, T> {} #[unstable(feature = "fused", issue = "35602")] impl<'a, T> FusedIterator for ChunksMut<'a, T> {} +#[doc(hidden)] +unsafe impl<'a, T> TrustedRandomAccess for ChunksMut<'a, T> { + unsafe fn get_unchecked(&mut self, i: usize) -> &'a mut [T] { + let start = i * self.chunk_size; + let end = match start.checked_add(self.chunk_size) { + None => self.v.len(), + Some(end) => cmp::min(end, self.v.len()), + }; + from_raw_parts_mut(self.v.as_mut_ptr().offset(start as isize), end - start) + } + fn may_have_side_effect() -> bool { false } +} + // // Free functions // diff --git a/src/libcore/tests/slice.rs b/src/libcore/tests/slice.rs index fa4c2e9b3736f..d6230e93f998d 100644 --- a/src/libcore/tests/slice.rs +++ b/src/libcore/tests/slice.rs @@ -137,6 +137,18 @@ fn test_chunks_last() { assert_eq!(c2.last().unwrap()[0], 4); } +#[test] +fn test_chunks_zip() { + let v1: &[i32] = &[0, 1, 2, 3, 4]; + let v2: &[i32] = &[6, 7, 8, 9, 10]; + + let res = v1.chunks(2) + .zip(v2.chunks(2)) + .map(|(a, b)| a.iter().sum::() + b.iter().sum::()) + .collect::>(); + assert_eq!(res, vec![14, 22, 14]); +} + #[test] fn test_chunks_mut_count() { let v: &mut [i32] = &mut [0, 1, 2, 3, 4, 5]; @@ -176,6 +188,20 @@ fn test_chunks_mut_last() { assert_eq!(c2.last().unwrap()[0], 4); } +#[test] +fn test_chunks_mut_zip() { + let v1: &mut [i32] = &mut [0, 1, 2, 3, 4]; + let v2: &[i32] = &[6, 7, 8, 9, 10]; + + for (a, b) in v1.chunks_mut(2).zip(v2.chunks(2)) { + let sum = b.iter().sum::(); + for v in a { + *v += sum; + } + } + assert_eq!(v1, [13, 14, 19, 20, 14]); +} + #[test] fn test_windows_count() { let v: &[i32] = &[0, 1, 2, 3, 4, 5]; @@ -215,6 +241,19 @@ fn test_windows_last() { assert_eq!(c2.last().unwrap()[0], 3); } +#[test] +fn test_windows_zip() { + let v1: &[i32] = &[0, 1, 2, 3, 4]; + let v2: &[i32] = &[6, 7, 8, 9, 10]; + + let res = v1.windows(2) + .zip(v2.windows(2)) + .map(|(a, b)| a.iter().sum::() + b.iter().sum::()) + .collect::>(); + + assert_eq!(res, [14, 18, 22, 26]); +} + #[test] fn get_range() { let v: &[i32] = &[0, 1, 2, 3, 4, 5];