diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs
index ff926c517bc7c..84ad126b07b7b 100644
--- a/library/core/src/slice/mod.rs
+++ b/library/core/src/slice/mod.rs
@@ -2055,12 +2055,12 @@ impl<T> [T] {
/// # Examples
///
/// ```
- /// #![feature(slice_partition_at_index)]
+ /// #![feature(slice_select_nth_unstable)]
///
/// let mut v = [-5i32, 4, 1, -3, 2];
///
/// // Find the median
- /// v.partition_at_index(2);
+ /// v.select_nth_unstable(2);
///
/// // We are only guaranteed the slice will be one of the following, based on the way we sort
/// // about the specified index.
@@ -2069,14 +2069,14 @@ impl<T> [T] {
/// v == [-3, -5, 1, 4, 2] ||
/// v == [-5, -3, 1, 4, 2]);
/// ```
- #[unstable(feature = "slice_partition_at_index", issue = "55300")]
+ #[unstable(feature = "slice_select_nth_unstable", issue = "55300")]
#[inline]
- pub fn partition_at_index(&mut self, index: usize) -> (&mut [T], &mut T, &mut [T])
+ pub fn select_nth_unstable(&mut self, index: usize) -> (&mut [T], &mut T, &mut [T])
where
T: Ord,
{
let mut f = |a: &T, b: &T| a.lt(b);
- sort::partition_at_index(self, index, &mut f)
+ sort::select_nth_unstable(self, index, &mut f)
}
/// Reorder the slice with a comparator function such that the element at `index` is at its
@@ -2105,12 +2105,12 @@ impl<T> [T] {
/// # Examples
///
/// ```
- /// #![feature(slice_partition_at_index)]
+ /// #![feature(slice_select_nth_unstable)]
///
/// let mut v = [-5i32, 4, 1, -3, 2];
///
/// // Find the median as if the slice were sorted in descending order.
- /// v.partition_at_index_by(2, |a, b| b.cmp(a));
+ /// v.select_nth_unstable_by(2, |a, b| b.cmp(a));
///
/// // We are only guaranteed the slice will be one of the following, based on the way we sort
/// // about the specified index.
@@ -2119,9 +2119,9 @@ impl<T> [T] {
/// v == [4, 2, 1, -5, -3] ||
/// v == [4, 2, 1, -3, -5]);
/// ```
- #[unstable(feature = "slice_partition_at_index", issue = "55300")]
+ #[unstable(feature = "slice_select_nth_unstable", issue = "55300")]
#[inline]
- pub fn partition_at_index_by<F>(
+ pub fn select_nth_unstable_by<F>(
&mut self,
index: usize,
mut compare: F,
@@ -2130,7 +2130,7 @@ impl<T> [T] {
F: FnMut(&T, &T) -> Ordering,
{
let mut f = |a: &T, b: &T| compare(a, b) == Less;
- sort::partition_at_index(self, index, &mut f)
+ sort::select_nth_unstable(self, index, &mut f)
}
/// Reorder the slice with a key extraction function such that the element at `index` is at its
@@ -2159,12 +2159,12 @@ impl<T> [T] {
/// # Examples
///
/// ```
- /// #![feature(slice_partition_at_index)]
+ /// #![feature(slice_select_nth_unstable)]
///
/// let mut v = [-5i32, 4, 1, -3, 2];
///
/// // Return the median as if the array were sorted according to absolute value.
- /// v.partition_at_index_by_key(2, |a| a.abs());
+ /// v.select_nth_unstable_by_key(2, |a| a.abs());
///
/// // We are only guaranteed the slice will be one of the following, based on the way we sort
/// // about the specified index.
@@ -2173,9 +2173,9 @@ impl<T> [T] {
/// v == [2, 1, -3, 4, -5] ||
/// v == [2, 1, -3, -5, 4]);
/// ```
- #[unstable(feature = "slice_partition_at_index", issue = "55300")]
+ #[unstable(feature = "slice_select_nth_unstable", issue = "55300")]
#[inline]
- pub fn partition_at_index_by_key<K, F>(
+ pub fn select_nth_unstable_by_key<K, F>(
&mut self,
index: usize,
mut f: F,
@@ -2185,7 +2185,7 @@ impl<T> [T] {
K: Ord,
{
let mut g = |a: &T, b: &T| f(a).lt(&f(b));
- sort::partition_at_index(self, index, &mut g)
+ sort::select_nth_unstable(self, index, &mut g)
}
/// Moves all consecutive repeated elements to the end of the slice according to the
diff --git a/library/core/src/slice/sort.rs b/library/core/src/slice/sort.rs
index 71d2c2c9b2f4c..9ce3628733cfe 100644
--- a/library/core/src/slice/sort.rs
+++ b/library/core/src/slice/sort.rs
@@ -768,7 +768,7 @@ where
recurse(v, &mut is_less, None, limit);
}
-fn partition_at_index_loop<'a, T, F>(
+fn select_nth_unstable_loop<'a, T, F>(
mut v: &'a mut [T],
mut index: usize,
is_less: &mut F,
@@ -828,7 +828,7 @@ fn partition_at_index_loop<'a, T, F>(
}
}
-pub fn partition_at_index<T, F>(
+pub fn select_nth_unstable<T, F>(
v: &mut [T],
index: usize,
mut is_less: F,
@@ -840,7 +840,7 @@ where
use cmp::Ordering::Less;
if index >= v.len() {
- panic!("partition_at_index index {} greater than length of slice {}", index, v.len());
+ panic!("select_nth_unstable index {} greater than length of slice {}", index, v.len());
}
if mem::size_of::<T>() == 0 {
@@ -864,7 +864,7 @@ where
.unwrap();
v.swap(min_index, index);
} else {
- partition_at_index_loop(v, index, &mut is_less, None);
+ select_nth_unstable_loop(v, index, &mut is_less, None);
}
let (left, right) = v.split_at_mut(index);
diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs
index 4db391f3e567e..31b20f4523183 100644
--- a/library/core/tests/lib.rs
+++ b/library/core/tests/lib.rs
@@ -26,7 +26,7 @@
#![feature(pattern)]
#![feature(raw)]
#![feature(sort_internals)]
-#![feature(slice_partition_at_index)]
+#![feature(slice_select_nth_unstable)]
#![feature(min_specialization)]
#![feature(step_trait)]
#![feature(step_trait_ext)]
diff --git a/library/core/tests/slice.rs b/library/core/tests/slice.rs
index 9556d43f9d78b..9e01a2c885c8b 100644
--- a/library/core/tests/slice.rs
+++ b/library/core/tests/slice.rs
@@ -1570,7 +1570,7 @@ fn sort_unstable() {
#[test]
#[cfg(not(target_arch = "wasm32"))]
#[cfg_attr(miri, ignore)] // Miri is too slow
-fn partition_at_index() {
+fn select_nth_unstable() {
use core::cmp::Ordering::{Equal, Greater, Less};
use rand::rngs::StdRng;
use rand::seq::SliceRandom;
@@ -1596,7 +1596,7 @@ fn partition_at_index() {
// Sort in default order.
for pivot in 0..len {
let mut v = orig.clone();
- v.partition_at_index(pivot);
+ v.select_nth_unstable(pivot);
assert_eq!(v_sorted[pivot], v[pivot]);
for i in 0..pivot {
@@ -1609,7 +1609,7 @@ fn partition_at_index() {
// Sort in ascending order.
for pivot in 0..len {
let mut v = orig.clone();
- let (left, pivot, right) = v.partition_at_index_by(pivot, |a, b| a.cmp(b));
+ let (left, pivot, right) = v.select_nth_unstable_by(pivot, |a, b| a.cmp(b));
assert_eq!(left.len() + right.len(), len - 1);
@@ -1632,7 +1632,7 @@ fn partition_at_index() {
for pivot in 0..len {
let mut v = orig.clone();
- v.partition_at_index_by(pivot, sort_descending_comparator);
+ v.select_nth_unstable_by(pivot, sort_descending_comparator);
assert_eq!(v_sorted_descending[pivot], v[pivot]);
for i in 0..pivot {
@@ -1653,7 +1653,7 @@ fn partition_at_index() {
}
for pivot in 0..v.len() {
- v.partition_at_index_by(pivot, |_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
+ v.select_nth_unstable_by(pivot, |_, _| *[Less, Equal, Greater].choose(&mut rng).unwrap());
v.sort();
for i in 0..v.len() {
assert_eq!(v[i], i as i32);
@@ -1661,28 +1661,28 @@ fn partition_at_index() {
}
// Should not panic.
- [(); 10].partition_at_index(0);
- [(); 10].partition_at_index(5);
- [(); 10].partition_at_index(9);
- [(); 100].partition_at_index(0);
- [(); 100].partition_at_index(50);
- [(); 100].partition_at_index(99);
+ [(); 10].select_nth_unstable(0);
+ [(); 10].select_nth_unstable(5);
+ [(); 10].select_nth_unstable(9);
+ [(); 100].select_nth_unstable(0);
+ [(); 100].select_nth_unstable(50);
+ [(); 100].select_nth_unstable(99);
let mut v = [0xDEADBEEFu64];
- v.partition_at_index(0);
+ v.select_nth_unstable(0);
assert!(v == [0xDEADBEEF]);
}
#[test]
#[should_panic(expected = "index 0 greater than length of slice")]
-fn partition_at_index_zero_length() {
- [0i32; 0].partition_at_index(0);
+fn select_nth_unstable_zero_length() {
+ [0i32; 0].select_nth_unstable(0);
}
#[test]
#[should_panic(expected = "index 20 greater than length of slice")]
-fn partition_at_index_past_length() {
- [0i32; 10].partition_at_index(20);
+fn select_nth_unstable_past_length() {
+ [0i32; 10].select_nth_unstable(20);
}
pub mod memchr {