Rollup merge of #106248 - dtolnay:revertupcastlint, r=jackh726

[rust.git] / library / core / src / slice / mod.rs

diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs
index 3d7a7cfaf35fb5a13ee4d7ea4f4132dcdf152c3e..2995cf0c6443f8a03eb37ae1201a0ecffeb1b272 100644 (file)
--- a/library/core/src/slice/mod.rs
+++ b/library/core/src/slice/mod.rs
@@ -465,7 +465,7 @@ pub const fn get_mut<I>(&mut self, index: I) -> Option<&mut I::Output>
     /// [`as_mut_ptr`]: slice::as_mut_ptr
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_slice_as_ptr", since = "1.32.0")]
-    #[inline]
+    #[inline(always)]
     #[must_use]
     pub const fn as_ptr(&self) -> *const T {
         self as *const [T] as *const T
@@ -495,7 +495,7 @@ pub const fn as_ptr(&self) -> *const T {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")]
     #[rustc_allow_const_fn_unstable(const_mut_refs)]
-    #[inline]
+    #[inline(always)]
     #[must_use]
     pub const fn as_mut_ptr(&mut self) -> *mut T {
         self as *mut [T] as *mut T
@@ -893,7 +893,7 @@ pub fn chunks_mut(&mut self, chunk_size: usize) -> ChunksMut<'_, T> {
     #[stable(feature = "chunks_exact", since = "1.31.0")]
     #[inline]
     pub fn chunks_exact(&self, chunk_size: usize) -> ChunksExact<'_, T> {
-        assert_ne!(chunk_size, 0);
+        assert_ne!(chunk_size, 0, "chunks cannot have a size of zero");
         ChunksExact::new(self, chunk_size)
     }
 
@@ -935,7 +935,7 @@ pub fn chunks_exact(&self, chunk_size: usize) -> ChunksExact<'_, T> {
     #[stable(feature = "chunks_exact", since = "1.31.0")]
     #[inline]
     pub fn chunks_exact_mut(&mut self, chunk_size: usize) -> ChunksExactMut<'_, T> {
-        assert_ne!(chunk_size, 0);
+        assert_ne!(chunk_size, 0, "chunks cannot have a size of zero");
         ChunksExactMut::new(self, chunk_size)
     }
 
@@ -1002,11 +1002,22 @@ pub fn chunks_exact_mut(&mut self, chunk_size: usize) -> ChunksExactMut<'_, T> {
     /// assert_eq!(chunks, &[['l', 'o'], ['r', 'e']]);
     /// assert_eq!(remainder, &['m']);
     /// ```
+    ///
+    /// If you expect the slice to be an exact multiple, you can combine
+    /// `let`-`else` with an empty slice pattern:
+    /// ```
+    /// #![feature(slice_as_chunks)]
+    /// let slice = ['R', 'u', 's', 't'];
+    /// let (chunks, []) = slice.as_chunks::<2>() else {
+    ///     panic!("slice didn't have even length")
+    /// };
+    /// assert_eq!(chunks, &[['R', 'u'], ['s', 't']]);
+    /// ```
     #[unstable(feature = "slice_as_chunks", issue = "74985")]
     #[inline]
     #[must_use]
     pub fn as_chunks<const N: usize>(&self) -> (&[[T; N]], &[T]) {
-        assert_ne!(N, 0);
+        assert_ne!(N, 0, "chunks cannot have a size of zero");
         let len = self.len() / N;
         let (multiple_of_n, remainder) = self.split_at(len * N);
         // SAFETY: We already panicked for zero, and ensured by construction
@@ -1037,7 +1048,7 @@ pub fn chunks_exact_mut(&mut self, chunk_size: usize) -> ChunksExactMut<'_, T> {
     #[inline]
     #[must_use]
     pub fn as_rchunks<const N: usize>(&self) -> (&[T], &[[T; N]]) {
-        assert_ne!(N, 0);
+        assert_ne!(N, 0, "chunks cannot have a size of zero");
         let len = self.len() / N;
         let (remainder, multiple_of_n) = self.split_at(self.len() - len * N);
         // SAFETY: We already panicked for zero, and ensured by construction
@@ -1076,7 +1087,7 @@ pub fn chunks_exact_mut(&mut self, chunk_size: usize) -> ChunksExactMut<'_, T> {
     #[unstable(feature = "array_chunks", issue = "74985")]
     #[inline]
     pub fn array_chunks<const N: usize>(&self) -> ArrayChunks<'_, T, N> {
-        assert_ne!(N, 0);
+        assert_ne!(N, 0, "chunks cannot have a size of zero");
         ArrayChunks::new(self)
     }
 
@@ -1155,7 +1166,7 @@ pub fn array_chunks<const N: usize>(&self) -> ArrayChunks<'_, T, N> {
     #[inline]
     #[must_use]
     pub fn as_chunks_mut<const N: usize>(&mut self) -> (&mut [[T; N]], &mut [T]) {
-        assert_ne!(N, 0);
+        assert_ne!(N, 0, "chunks cannot have a size of zero");
         let len = self.len() / N;
         let (multiple_of_n, remainder) = self.split_at_mut(len * N);
         // SAFETY: We already panicked for zero, and ensured by construction
@@ -1192,7 +1203,7 @@ pub fn array_chunks<const N: usize>(&self) -> ArrayChunks<'_, T, N> {
     #[inline]
     #[must_use]
     pub fn as_rchunks_mut<const N: usize>(&mut self) -> (&mut [T], &mut [[T; N]]) {
-        assert_ne!(N, 0);
+        assert_ne!(N, 0, "chunks cannot have a size of zero");
         let len = self.len() / N;
         let (remainder, multiple_of_n) = self.split_at_mut(self.len() - len * N);
         // SAFETY: We already panicked for zero, and ensured by construction
@@ -1233,7 +1244,7 @@ pub fn array_chunks<const N: usize>(&self) -> ArrayChunks<'_, T, N> {
     #[unstable(feature = "array_chunks", issue = "74985")]
     #[inline]
     pub fn array_chunks_mut<const N: usize>(&mut self) -> ArrayChunksMut<'_, T, N> {
-        assert_ne!(N, 0);
+        assert_ne!(N, 0, "chunks cannot have a size of zero");
         ArrayChunksMut::new(self)
     }
 
@@ -1265,7 +1276,7 @@ pub fn array_chunks_mut<const N: usize>(&mut self) -> ArrayChunksMut<'_, T, N> {
     #[unstable(feature = "array_windows", issue = "75027")]
     #[inline]
     pub fn array_windows<const N: usize>(&self) -> ArrayWindows<'_, T, N> {
-        assert_ne!(N, 0);
+        assert_ne!(N, 0, "windows cannot have a size of zero");
         ArrayWindows::new(self)
     }
 
@@ -3795,7 +3806,7 @@ pub fn is_sorted_by_key<'a, F, K>(&'a self, f: F) -> bool
     /// The slice is assumed to be partitioned according to the given predicate.
     /// This means that all elements for which the predicate returns true are at the start of the slice
     /// and all elements for which the predicate returns false are at the end.
-    /// For example, [7, 15, 3, 5, 4, 12, 6] is a partitioned under the predicate x % 2 != 0
+    /// For example, `[7, 15, 3, 5, 4, 12, 6]` is partitioned under the predicate `x % 2 != 0`
     /// (all odd numbers are at the start, all even at the end).
     ///
     /// If this slice is not partitioned, the returned result is unspecified and meaningless,