diff --git a/langext/array.go b/langext/array.go
index af12982..433686f 100644
--- a/langext/array.go
+++ b/langext/array.go
@@ -290,3 +290,19 @@ func ArrSum[T NumberConstraint](arr []T) T {
 	}
 	return r
 }
+
+func ArrFlatten[T1 any, T2 any](arr []T1, conv func(v T1) []T2) []T2 {
+	r := make([]T2, 0, len(arr))
+	for _, v1 := range arr {
+		r = append(r, conv(v1)...)
+	}
+	return r
+}
+
+func ArrFlattenDirect[T1 any](arr [][]T1) []T1 {
+	r := make([]T1, 0, len(arr))
+	for _, v1 := range arr {
+		r = append(r, v1...)
+	}
+	return r
+}