diff -r 6986e9ed70f3 -r dd9dcbb39c2f src/map.c
--- a/src/map.c	Fri Oct 24 21:15:14 2025 +0200
+++ b/src/map.c	Sat Oct 25 21:12:59 2025 +0200
@@ -138,38 +138,37 @@
     map->collection.advanced_destructor = destr2_bak;
 }
 
-size_t cxMapClone(CxMap *dst, const CxMap *src, cx_clone_func clone_func,
+int cxMapClone(CxMap *dst, const CxMap *src, cx_clone_func clone_func,
         const CxAllocator *clone_allocator, void *data) {
     CxMapIterator src_iter = cxMapIterator(src);
-    size_t i = 0;
     if (cxCollectionStoresPointers(dst)) {
-        for (; i < cxMapSize(src); i++) {
+        for (size_t i = 0; i < cxMapSize(src); i++) {
             const CxMapEntry *entry = cxIteratorCurrent(src_iter);
             void **dst_mem = cxMapEmplace(dst, *(entry->key));
             if (dst_mem == NULL) {
-                return i;
+                return 1;
             }
             void *dst_ptr = clone_func(NULL, entry->value, clone_allocator, data);
             if (dst_ptr == NULL) {
                 cx_map_remove_uninitialized_entry(dst, *(entry->key));
-                return i;
+                return 1;
             }
             *dst_mem = dst_ptr;
             cxIteratorNext(src_iter);
         }
     } else {
-        for (; i < cxMapSize(src); i++) {
+        for (size_t i = 0; i < cxMapSize(src); i++) {
             const CxMapEntry *entry = cxIteratorCurrent(src_iter);
             void *dst_mem = cxMapEmplace(dst, *(entry->key));
             if (dst_mem == NULL) {
-                return i;
+                return 1;
             }
             if (clone_func(dst_mem, entry->value, clone_allocator, data) == NULL) {
                 cx_map_remove_uninitialized_entry(dst, *(entry->key));
-                return i;
+                return 1;
             }
             cxIteratorNext(src_iter);
         }
     }
-    return i;
-}
\ No newline at end of file
+    return 0;
+}