--- a/src/cx/array_list.h	Sun Nov 20 16:28:03 2022 +0100
+++ b/src/cx/array_list.h	Sun Nov 20 16:58:51 2022 +0100
@@ -132,6 +132,22 @@
         struct cx_array_reallocator_s *reallocator
 ) __attribute__((__nonnull__(1, 2, 5)));
 
+
+/**
+ * Swaps two array elements.
+ *
+ * @param arr the array
+ * @param elem_size the element size
+ * @param idx1 index of first element
+ * @param idx2 index of second element
+ */
+void cx_array_swap(
+        void *arr,
+        size_t elem_size,
+        size_t idx1,
+        size_t idx2
+) __attribute__((__nonnull__));
+
 /**
  * Allocates an array list for storing elements with \p item_size bytes each.
  *