Rollup merge of #117678 - niklasf:stabilize-slice_group_by, r=dtolnay

Stabilize `slice_group_by`

Renamed "group by" to "chunk by" a per #80552.

Newly stable items:

* `core::slice::ChunkBy`
* `core::slice::ChunkByMut`
* `[T]::chunk`
* `[T]::chunk_by`

Closes #80552.

compiler/rustc_codegen_cranelift/patches/0027-coretests-128bit-atomic-operations.patch

@@ -21,7 +21,7 @@ index 897a5e9..331f66f 100644
 -#![cfg_attr(target_has_atomic = "128", feature(integer_atomics))]
  #![cfg_attr(test, feature(cfg_match))]
  #![feature(int_roundings)]
- #![feature(slice_group_by)]
+ #![feature(split_array)]
 diff --git a/atomic.rs b/atomic.rs
 index b735957..ea728b6 100644
 --- a/atomic.rs

compiler/rustc_passes/src/dead.rs

@@ -917,7 +917,7 @@ impl<'tcx> DeadVisitor<'tcx> {
             return;
         }
         dead_codes.sort_by_key(|v| v.level);
-        for group in dead_codes[..].group_by(|a, b| a.level == b.level) {
+        for group in dead_codes[..].chunk_by(|a, b| a.level == b.level) {
             self.lint_at_single_level(&group, participle, Some(def_id), report_on);
         }
     }

compiler/rustc_passes/src/lib.rs

@@ -11,7 +11,6 @@
 #![feature(let_chains)]
 #![feature(map_try_insert)]
 #![feature(min_specialization)]
-#![feature(slice_group_by)]
 #![feature(try_blocks)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]

library/alloc/src/lib.rs

@@ -149,7 +149,6 @@
 #![feature(set_ptr_value)]
 #![feature(sized_type_properties)]
 #![feature(slice_from_ptr_range)]
-#![feature(slice_group_by)]
 #![feature(slice_ptr_get)]
 #![feature(slice_ptr_len)]
 #![feature(slice_range)]

library/alloc/src/slice.rs

@@ -51,14 +51,14 @@ pub use core::slice::{from_mut, from_ref};
 pub use core::slice::{from_mut_ptr_range, from_ptr_range};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::slice::{from_raw_parts, from_raw_parts_mut};
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+pub use core::slice::{ChunkBy, ChunkByMut};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::slice::{Chunks, Windows};
 #[stable(feature = "chunks_exact", since = "1.31.0")]
 pub use core::slice::{ChunksExact, ChunksExactMut};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::slice::{ChunksMut, Split, SplitMut};
-#[unstable(feature = "slice_group_by", issue = "80552")]
-pub use core::slice::{GroupBy, GroupByMut};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::slice::{Iter, IterMut};
 #[stable(feature = "rchunks", since = "1.31.0")]

library/alloc/tests/lib.rs

@@ -29,7 +29,6 @@
 #![feature(iter_advance_by)]
 #![feature(iter_next_chunk)]
 #![feature(round_char_boundary)]
-#![feature(slice_group_by)]
 #![feature(slice_partition_dedup)]
 #![feature(string_remove_matches)]
 #![feature(const_btree_len)]

library/alloc/tests/slice.rs

@@ -1614,10 +1614,10 @@ fn subslice_patterns() {
 }
 
 #[test]
-fn test_group_by() {
+fn test_chunk_by() {
     let slice = &[1, 1, 1, 3, 3, 2, 2, 2, 1, 0];
 
-    let mut iter = slice.group_by(|a, b| a == b);
+    let mut iter = slice.chunk_by(|a, b| a == b);
     assert_eq!(iter.next(), Some(&[1, 1, 1][..]));
     assert_eq!(iter.next(), Some(&[3, 3][..]));
     assert_eq!(iter.next(), Some(&[2, 2, 2][..]));
@@ -1625,7 +1625,7 @@ fn test_group_by() {
     assert_eq!(iter.next(), Some(&[0][..]));
     assert_eq!(iter.next(), None);
 
-    let mut iter = slice.group_by(|a, b| a == b);
+    let mut iter = slice.chunk_by(|a, b| a == b);
     assert_eq!(iter.next_back(), Some(&[0][..]));
     assert_eq!(iter.next_back(), Some(&[1][..]));
     assert_eq!(iter.next_back(), Some(&[2, 2, 2][..]));
@@ -1633,7 +1633,7 @@ fn test_group_by() {
     assert_eq!(iter.next_back(), Some(&[1, 1, 1][..]));
     assert_eq!(iter.next_back(), None);
 
-    let mut iter = slice.group_by(|a, b| a == b);
+    let mut iter = slice.chunk_by(|a, b| a == b);
     assert_eq!(iter.next(), Some(&[1, 1, 1][..]));
     assert_eq!(iter.next_back(), Some(&[0][..]));
     assert_eq!(iter.next(), Some(&[3, 3][..]));
@@ -1643,10 +1643,10 @@ fn test_group_by() {
 }
 
 #[test]
-fn test_group_by_mut() {
+fn test_chunk_by_mut() {
     let slice = &mut [1, 1, 1, 3, 3, 2, 2, 2, 1, 0];
 
-    let mut iter = slice.group_by_mut(|a, b| a == b);
+    let mut iter = slice.chunk_by_mut(|a, b| a == b);
     assert_eq!(iter.next(), Some(&mut [1, 1, 1][..]));
     assert_eq!(iter.next(), Some(&mut [3, 3][..]));
     assert_eq!(iter.next(), Some(&mut [2, 2, 2][..]));
@@ -1654,7 +1654,7 @@ fn test_group_by_mut() {
     assert_eq!(iter.next(), Some(&mut [0][..]));
     assert_eq!(iter.next(), None);
 
-    let mut iter = slice.group_by_mut(|a, b| a == b);
+    let mut iter = slice.chunk_by_mut(|a, b| a == b);
     assert_eq!(iter.next_back(), Some(&mut [0][..]));
     assert_eq!(iter.next_back(), Some(&mut [1][..]));
     assert_eq!(iter.next_back(), Some(&mut [2, 2, 2][..]));
@@ -1662,7 +1662,7 @@ fn test_group_by_mut() {
     assert_eq!(iter.next_back(), Some(&mut [1, 1, 1][..]));
     assert_eq!(iter.next_back(), None);
 
-    let mut iter = slice.group_by_mut(|a, b| a == b);
+    let mut iter = slice.chunk_by_mut(|a, b| a == b);
     assert_eq!(iter.next(), Some(&mut [1, 1, 1][..]));
     assert_eq!(iter.next_back(), Some(&mut [0][..]));
     assert_eq!(iter.next(), Some(&mut [3, 3][..]));

library/core/src/slice/iter.rs

@@ -3248,26 +3248,26 @@ unsafe impl<'a, T> TrustedRandomAccessNoCoerce for IterMut<'a, T> {
 
 /// An iterator over slice in (non-overlapping) chunks separated by a predicate.
 ///
-/// This struct is created by the [`group_by`] method on [slices].
+/// This struct is created by the [`chunk_by`] method on [slices].
 ///
-/// [`group_by`]: slice::group_by
+/// [`chunk_by`]: slice::chunk_by
 /// [slices]: slice
-#[unstable(feature = "slice_group_by", issue = "80552")]
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
 #[must_use = "iterators are lazy and do nothing unless consumed"]
-pub struct GroupBy<'a, T: 'a, P> {
+pub struct ChunkBy<'a, T: 'a, P> {
     slice: &'a [T],
     predicate: P,
 }
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a, P> GroupBy<'a, T, P> {
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a, P> ChunkBy<'a, T, P> {
     pub(super) fn new(slice: &'a [T], predicate: P) -> Self {
-        GroupBy { slice, predicate }
+        ChunkBy { slice, predicate }
     }
 }
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a, P> Iterator for GroupBy<'a, T, P>
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a, P> Iterator for ChunkBy<'a, T, P>
 where
     P: FnMut(&T, &T) -> bool,
 {
@@ -3300,8 +3300,8 @@ where
     }
 }
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a, P> DoubleEndedIterator for GroupBy<'a, T, P>
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a, P> DoubleEndedIterator for ChunkBy<'a, T, P>
 where
     P: FnMut(&T, &T) -> bool,
 {
@@ -3322,39 +3322,39 @@ where
     }
 }
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a, P> FusedIterator for GroupBy<'a, T, P> where P: FnMut(&T, &T) -> bool {}
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a, P> FusedIterator for ChunkBy<'a, T, P> where P: FnMut(&T, &T) -> bool {}
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for GroupBy<'a, T, P> {
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for ChunkBy<'a, T, P> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("GroupBy").field("slice", &self.slice).finish()
+        f.debug_struct("ChunkBy").field("slice", &self.slice).finish()
     }
 }
 
 /// An iterator over slice in (non-overlapping) mutable chunks separated
 /// by a predicate.
 ///
-/// This struct is created by the [`group_by_mut`] method on [slices].
+/// This struct is created by the [`chunk_by_mut`] method on [slices].
 ///
-/// [`group_by_mut`]: slice::group_by_mut
+/// [`chunk_by_mut`]: slice::chunk_by_mut
 /// [slices]: slice
-#[unstable(feature = "slice_group_by", issue = "80552")]
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
 #[must_use = "iterators are lazy and do nothing unless consumed"]
-pub struct GroupByMut<'a, T: 'a, P> {
+pub struct ChunkByMut<'a, T: 'a, P> {
     slice: &'a mut [T],
     predicate: P,
 }
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a, P> GroupByMut<'a, T, P> {
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a, P> ChunkByMut<'a, T, P> {
     pub(super) fn new(slice: &'a mut [T], predicate: P) -> Self {
-        GroupByMut { slice, predicate }
+        ChunkByMut { slice, predicate }
     }
 }
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a, P> Iterator for GroupByMut<'a, T, P>
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a, P> Iterator for ChunkByMut<'a, T, P>
 where
     P: FnMut(&T, &T) -> bool,
 {
@@ -3388,8 +3388,8 @@ where
     }
 }
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a, P> DoubleEndedIterator for GroupByMut<'a, T, P>
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a, P> DoubleEndedIterator for ChunkByMut<'a, T, P>
 where
     P: FnMut(&T, &T) -> bool,
 {
@@ -3411,12 +3411,12 @@ where
     }
 }
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a, P> FusedIterator for GroupByMut<'a, T, P> where P: FnMut(&T, &T) -> bool {}
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a, P> FusedIterator for ChunkByMut<'a, T, P> where P: FnMut(&T, &T) -> bool {}
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for GroupByMut<'a, T, P> {
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+impl<'a, T: 'a + fmt::Debug, P> fmt::Debug for ChunkByMut<'a, T, P> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("GroupByMut").field("slice", &self.slice).finish()
+        f.debug_struct("ChunkByMut").field("slice", &self.slice).finish()
     }
 }

library/core/src/slice/mod.rs

@@ -68,8 +68,8 @@ pub use iter::{ArrayChunks, ArrayChunksMut};
 #[unstable(feature = "array_windows", issue = "75027")]
 pub use iter::ArrayWindows;
 
-#[unstable(feature = "slice_group_by", issue = "80552")]
-pub use iter::{GroupBy, GroupByMut};
+#[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
+pub use iter::{ChunkBy, ChunkByMut};
 
 #[stable(feature = "split_inclusive", since = "1.51.0")]
 pub use iter::{SplitInclusive, SplitInclusiveMut};
@@ -1748,18 +1748,16 @@ impl<T> [T] {
     /// Returns an iterator over the slice producing non-overlapping runs
     /// of elements using the predicate to separate them.
     ///
-    /// The predicate is called on two elements following themselves,
-    /// it means the predicate is called on `slice[0]` and `slice[1]`
-    /// then on `slice[1]` and `slice[2]` and so on.
+    /// The predicate is called for every pair of consecutive elements,
+    /// meaning that it is called on `slice[0]` and `slice[1]`,
+    /// followed by `slice[1]` and `slice[2]`, and so on.
     ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(slice_group_by)]
-    ///
     /// let slice = &[1, 1, 1, 3, 3, 2, 2, 2];
     ///
-    /// let mut iter = slice.group_by(|a, b| a == b);
+    /// let mut iter = slice.chunk_by(|a, b| a == b);
     ///
     /// assert_eq!(iter.next(), Some(&[1, 1, 1][..]));
     /// assert_eq!(iter.next(), Some(&[3, 3][..]));
@@ -1770,41 +1768,37 @@ impl<T> [T] {
     /// This method can be used to extract the sorted subslices:
     ///
     /// ```
-    /// #![feature(slice_group_by)]
-    ///
     /// let slice = &[1, 1, 2, 3, 2, 3, 2, 3, 4];
     ///
-    /// let mut iter = slice.group_by(|a, b| a <= b);
+    /// let mut iter = slice.chunk_by(|a, b| a <= b);
     ///
     /// assert_eq!(iter.next(), Some(&[1, 1, 2, 3][..]));
     /// assert_eq!(iter.next(), Some(&[2, 3][..]));
     /// assert_eq!(iter.next(), Some(&[2, 3, 4][..]));
     /// assert_eq!(iter.next(), None);
     /// ```
-    #[unstable(feature = "slice_group_by", issue = "80552")]
+    #[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
-    pub fn group_by<F>(&self, pred: F) -> GroupBy<'_, T, F>
+    pub fn chunk_by<F>(&self, pred: F) -> ChunkBy<'_, T, F>
     where
         F: FnMut(&T, &T) -> bool,
     {
-        GroupBy::new(self, pred)
+        ChunkBy::new(self, pred)
     }
 
     /// Returns an iterator over the slice producing non-overlapping mutable
     /// runs of elements using the predicate to separate them.
     ///
-    /// The predicate is called on two elements following themselves,
-    /// it means the predicate is called on `slice[0]` and `slice[1]`
-    /// then on `slice[1]` and `slice[2]` and so on.
+    /// The predicate is called for every pair of consecutive elements,
+    /// meaning that it is called on `slice[0]` and `slice[1]`,
+    /// followed by `slice[1]` and `slice[2]`, and so on.
     ///
     /// # Examples
     ///
     /// ```
-    /// #![feature(slice_group_by)]
-    ///
     /// let slice = &mut [1, 1, 1, 3, 3, 2, 2, 2];
     ///
-    /// let mut iter = slice.group_by_mut(|a, b| a == b);
+    /// let mut iter = slice.chunk_by_mut(|a, b| a == b);
     ///
     /// assert_eq!(iter.next(), Some(&mut [1, 1, 1][..]));
     /// assert_eq!(iter.next(), Some(&mut [3, 3][..]));
@@ -1815,24 +1809,22 @@ impl<T> [T] {
     /// This method can be used to extract the sorted subslices:
     ///
     /// ```
-    /// #![feature(slice_group_by)]
-    ///
     /// let slice = &mut [1, 1, 2, 3, 2, 3, 2, 3, 4];
     ///
-    /// let mut iter = slice.group_by_mut(|a, b| a <= b);
+    /// let mut iter = slice.chunk_by_mut(|a, b| a <= b);
     ///
     /// assert_eq!(iter.next(), Some(&mut [1, 1, 2, 3][..]));
     /// assert_eq!(iter.next(), Some(&mut [2, 3][..]));
     /// assert_eq!(iter.next(), Some(&mut [2, 3, 4][..]));
     /// assert_eq!(iter.next(), None);
     /// ```
-    #[unstable(feature = "slice_group_by", issue = "80552")]
+    #[stable(feature = "slice_group_by", since = "CURRENT_RUSTC_VERSION")]
     #[inline]
-    pub fn group_by_mut<F>(&mut self, pred: F) -> GroupByMut<'_, T, F>
+    pub fn chunk_by_mut<F>(&mut self, pred: F) -> ChunkByMut<'_, T, F>
     where
         F: FnMut(&T, &T) -> bool,
     {
-        GroupByMut::new(self, pred)
+        ChunkByMut::new(self, pred)
     }
 
     /// Divides one slice into two at an index.

library/core/tests/lib.rs

@@ -101,7 +101,6 @@
 #![cfg_attr(target_has_atomic = "128", feature(integer_atomics))]
 #![cfg_attr(test, feature(cfg_match))]
 #![feature(int_roundings)]
-#![feature(slice_group_by)]
 #![feature(split_array)]
 #![feature(strict_provenance)]
 #![feature(strict_provenance_atomic_ptr)]