Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 52 insertions, 0 deletions

diff --git a/src/sort/slice.go b/src/sort/slice.go
new file mode 100644
index 0000000..d0b2102
--- /dev/null
+++ b/src/sort/slice.go
@@ -0,0 +1,52 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package sort
+
+import (
+	"internal/reflectlite"
+	"math/bits"
+)
+
+// Slice sorts the slice x given the provided less function.
+// It panics if x is not a slice.
+//
+// The sort is not guaranteed to be stable: equal elements
+// may be reversed from their original order.
+// For a stable sort, use SliceStable.
+//
+// The less function must satisfy the same requirements as
+// the Interface type's Less method.
+func Slice(x any, less func(i, j int) bool) {
+	rv := reflectlite.ValueOf(x)
+	swap := reflectlite.Swapper(x)
+	length := rv.Len()
+	limit := bits.Len(uint(length))
+	pdqsort_func(lessSwap{less, swap}, 0, length, limit)
+}
+
+// SliceStable sorts the slice x using the provided less
+// function, keeping equal elements in their original order.
+// It panics if x is not a slice.
+//
+// The less function must satisfy the same requirements as
+// the Interface type's Less method.
+func SliceStable(x any, less func(i, j int) bool) {
+	rv := reflectlite.ValueOf(x)
+	swap := reflectlite.Swapper(x)
+	stable_func(lessSwap{less, swap}, rv.Len())
+}
+
+// SliceIsSorted reports whether the slice x is sorted according to the provided less function.
+// It panics if x is not a slice.
+func SliceIsSorted(x any, less func(i, j int) bool) bool {
+	rv := reflectlite.ValueOf(x)
+	n := rv.Len()
+	for i := n - 1; i > 0; i-- {
+		if less(i, i-1) {
+			return false
+		}
+	}
+	return true
+}