diff -r c331add0d9f8 -r dde4903c0fd7 src/cx/map.h
--- a/src/cx/map.h	Tue Oct 21 17:06:17 2025 +0200
+++ b/src/cx/map.h	Wed Oct 22 23:28:07 2025 +0200
@@ -464,6 +464,32 @@
  */
 #define cxMapRemoveAndGet(map, key, targetbuf) cx_map_remove(map, CX_HASH_KEY(key), targetbuf)
 
+
+/**
+ * Performs a deep clone of one map into another.
+ *
+ * If the destination map already contains entries, the cloned entries
+ * are added to that map, possibly overwriting existing elements when
+ * the keys already exist.
+ *
+ * When elements in the destination map need to be replaced, any destructor
+ * function is called on the replaced elements before replacing them.
+ *
+ * @attention If the cloned elements need to be destroyed by a destructor
+ * function, you must make sure that the destination map also uses this
+ * destructor function.
+ *
+ * @param dst the destination map
+ * @param src the source map
+ * @param clone_func the clone function for the values
+ * @param clone_allocator the allocator that is passed to the clone function
+ * @param data optional additional data that is passed to the clone function
+ * @return the number of elements that have been successfully cloned
+ */
+cx_attr_nonnull_arg(1, 2, 3)
+CX_EXPORT size_t cxMapClone(CxMap *dst, const CxMap *src,
+        cx_clone_func clone_func, const CxAllocator *clone_allocator, void *data);
+
 #ifdef    __cplusplus
 } // extern "C"
 #endif