make slices.Shuffle an in-place operation

life4 · Dec 21, 2021 · de813b3 · de813b3
1 parent bc0ff61
commit de813b3
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Showing 2 changed files with 7 additions and 6 deletions.
diff --git a/slices/slice.go b/slices/slice.go
@@ -437,10 +437,12 @@ func Same[S ~[]T, T comparable](items S) bool {
 	return true
 }
 
-// Shuffle in random order arr elements
-func Shuffle[S ~[]T, T any](items S, seed int64) S {
+// Shuffle in random order the given elements
+//
+// This is an in-place operation, it modifies the passed slice.
+func Shuffle[S ~[]T, T any](items S, seed int64) {
 	if len(items) <= 1 {
-		return items
+		return
 	}
 	if seed == 0 {
 		seed = time.Now().UnixNano()
@@ -450,7 +452,6 @@ func Shuffle[S ~[]T, T any](items S, seed int64) S {
 		items[i], items[j] = items[j], items[i]
 	}
 	rand.Shuffle(len(items), swap)
-	return items
 }
 
 // Sort returns sorted slice

diff --git a/slices/slice_test.go b/slices/slice_test.go
@@ -376,8 +376,8 @@ func TestSame(t *testing.T) {
 func TestShuffle(t *testing.T) {
 	is := is.New(t)
 	f := func(given []int, seed int64, expected []int) {
-		actual := slices.Shuffle(given, seed)
-		is.Equal(expected, actual)
+		slices.Shuffle(given, seed)
+		is.Equal(given, expected)
 	}
 	f([]int{}, 0, []int{})
 	f([]int{1}, 0, []int{1})