diff -r 488178e3e328 -r 9b5948aa5b90 ucx/map.c
--- a/ucx/map.c	Sun Nov 30 18:15:46 2025 +0100
+++ b/ucx/map.c	Sun Nov 30 18:17:49 2025 +0100
@@ -29,6 +29,8 @@
 #include "cx/map.h"
 #include <string.h>
 
+#include "cx/list.h"
+
 // <editor-fold desc="empty map implementation">
 
 static void cx_empty_map_noop(cx_attr_unused CxMap *map) {
@@ -127,3 +129,200 @@
     if (map == NULL) return;
     map->cl->deallocate(map);
 }
+
+static void cx_map_remove_uninitialized_entry(CxMap *map, CxHashKey key) {
+    cx_destructor_func destr_bak = map->collection.simple_destructor;
+    cx_destructor_func2 destr2_bak = map->collection.advanced_destructor;
+    map->collection.simple_destructor = NULL;
+    map->collection.advanced_destructor = NULL;
+    cxMapRemove(map, key);
+    map->collection.simple_destructor = destr_bak;
+    map->collection.advanced_destructor = destr2_bak;
+}
+
+static void* cx_map_simple_clone_func(void *dst, const void *src, const CxAllocator *al, void *data) {
+    size_t elem_size = *(size_t*)data;
+    if (dst == NULL) dst = cxMalloc(al, elem_size);
+    if (dst != NULL) memcpy(dst, src, elem_size);
+    return dst;
+}
+
+#define use_simple_clone_func(map) cx_map_simple_clone_func, NULL, (void*)&((map)->collection.elem_size)
+
+int cxMapClone(CxMap *dst, const CxMap *src, cx_clone_func clone_func,
+        const CxAllocator *clone_allocator, void *data) {
+    if (clone_allocator == NULL) clone_allocator = cxDefaultAllocator;
+    CxMapIterator src_iter = cxMapIterator(src);
+    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 1; // LCOV_EXCL_LINE
+        }
+        void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
+        void *dst_ptr = clone_func(target, entry->value, clone_allocator, data);
+        if (dst_ptr == NULL) {
+            cx_map_remove_uninitialized_entry(dst, *(entry->key));
+            return 1;
+        }
+        if (cxCollectionStoresPointers(dst)) {
+            *dst_mem = dst_ptr;
+        }
+        cxIteratorNext(src_iter);
+    }
+    return 0;
+}
+
+int cxMapDifference(CxMap *dst, const CxMap *minuend, const CxMap *subtrahend,
+        cx_clone_func clone_func, const CxAllocator *clone_allocator, void *data) {
+    if (clone_allocator == NULL) clone_allocator = cxDefaultAllocator;
+
+    CxMapIterator src_iter = cxMapIterator(minuend);
+    cx_foreach(const CxMapEntry *, entry, src_iter) {
+        if (cxMapContains(subtrahend, *entry->key)) {
+            continue;
+        }
+        void** dst_mem = cxMapEmplace(dst, *entry->key);
+        if (dst_mem == NULL) {
+            return 1; // LCOV_EXCL_LINE
+        }
+        void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
+        void* dst_ptr = clone_func(target, entry->value, clone_allocator, data);
+        if (dst_ptr == NULL) {
+            cx_map_remove_uninitialized_entry(dst, *(entry->key));
+            return 1;
+        }
+        if (cxCollectionStoresPointers(dst)) {
+            *dst_mem = dst_ptr;
+        }
+    }
+    return 0;
+}
+
+int cxMapListDifference(CxMap *dst, const CxMap *src, const CxList *keys,
+        cx_clone_func clone_func, const CxAllocator *clone_allocator, void *data) {
+    if (clone_allocator == NULL) clone_allocator = cxDefaultAllocator;
+
+    CxMapIterator src_iter = cxMapIterator(src);
+    cx_foreach(const CxMapEntry *, entry, src_iter) {
+        if (cxListContains(keys, entry->key)) {
+            continue;
+        }
+        void** dst_mem = cxMapEmplace(dst, *entry->key);
+        if (dst_mem == NULL) {
+            return 1; // LCOV_EXCL_LINE
+        }
+        void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
+        void* dst_ptr = clone_func(target, entry->value, clone_allocator, data);
+        if (dst_ptr == NULL) {
+            cx_map_remove_uninitialized_entry(dst, *(entry->key));
+            return 1;
+        }
+        if (cxCollectionStoresPointers(dst)) {
+            *dst_mem = dst_ptr;
+        }
+    }
+    return 0;
+}
+
+int cxMapIntersection(CxMap *dst, const CxMap *src, const CxMap *other,
+        cx_clone_func clone_func, const CxAllocator *clone_allocator, void *data) {
+    if (clone_allocator == NULL) clone_allocator = cxDefaultAllocator;
+
+    CxMapIterator src_iter = cxMapIterator(src);
+    cx_foreach(const CxMapEntry *, entry, src_iter) {
+        if (!cxMapContains(other, *entry->key)) {
+            continue;
+        }
+        void** dst_mem = cxMapEmplace(dst, *entry->key);
+        if (dst_mem == NULL) {
+            return 1; // LCOV_EXCL_LINE
+        }
+        void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
+        void* dst_ptr = clone_func(target, entry->value, clone_allocator, data);
+        if (dst_ptr == NULL) {
+            cx_map_remove_uninitialized_entry(dst, *(entry->key));
+            return 1;
+        }
+        if (cxCollectionStoresPointers(dst)) {
+            *dst_mem = dst_ptr;
+        }
+    }
+    return 0;
+}
+
+int cxMapListIntersection(CxMap *dst, const CxMap *src, const CxList *keys,
+        cx_clone_func clone_func, const CxAllocator *clone_allocator, void *data) {
+    if (clone_allocator == NULL) clone_allocator = cxDefaultAllocator;
+
+    CxMapIterator src_iter = cxMapIterator(src);
+    cx_foreach(const CxMapEntry *, entry, src_iter) {
+        if (!cxListContains(keys, entry->key)) {
+            continue;
+        }
+        void** dst_mem = cxMapEmplace(dst, *entry->key);
+        if (dst_mem == NULL) {
+            return 1; // LCOV_EXCL_LINE
+        }
+        void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
+        void* dst_ptr = clone_func(target, entry->value, clone_allocator, data);
+        if (dst_ptr == NULL) {
+            cx_map_remove_uninitialized_entry(dst, *(entry->key));
+            return 1;
+        }
+        if (cxCollectionStoresPointers(dst)) {
+            *dst_mem = dst_ptr;
+        }
+    }
+    return 0;
+}
+
+int cxMapUnion(CxMap *dst, const CxMap *src,
+        cx_clone_func clone_func, const CxAllocator *clone_allocator, void *data) {
+    if (clone_allocator == NULL) clone_allocator = cxDefaultAllocator;
+
+    CxMapIterator src_iter = cxMapIterator(src);
+    cx_foreach(const CxMapEntry *, entry, src_iter) {
+        if (cxMapContains(dst, *entry->key)) {
+            continue;
+        }
+        void** dst_mem = cxMapEmplace(dst, *entry->key);
+        if (dst_mem == NULL) {
+            return 1; // LCOV_EXCL_LINE
+        }
+        void *target = cxCollectionStoresPointers(dst) ? NULL : dst_mem;
+        void* dst_ptr = clone_func(target, entry->value, clone_allocator, data);
+        if (dst_ptr == NULL) {
+            cx_map_remove_uninitialized_entry(dst, *(entry->key));
+            return 1;
+        }
+        if (cxCollectionStoresPointers(dst)) {
+            *dst_mem = dst_ptr;
+        }
+    }
+    return 0;
+}
+
+int cxMapCloneSimple(CxMap *dst, const CxMap *src) {
+    return cxMapClone(dst, src, use_simple_clone_func(src));
+}
+
+int cxMapDifferenceSimple(CxMap *dst, const CxMap *minuend, const CxMap *subtrahend) {
+    return cxMapDifference(dst, minuend, subtrahend, use_simple_clone_func(minuend));
+}
+
+int cxMapListDifferenceSimple(CxMap *dst, const CxMap *src, const CxList *keys) {
+    return cxMapListDifference(dst, src, keys, use_simple_clone_func(src));
+}
+
+int cxMapIntersectionSimple(CxMap *dst, const CxMap *src, const CxMap *other) {
+    return cxMapIntersection(dst, src, other, use_simple_clone_func(src));
+}
+
+int cxMapListIntersectionSimple(CxMap *dst, const CxMap *src, const CxList *keys) {
+    return cxMapListIntersection(dst, src, keys, use_simple_clone_func(src));
+}
+
+int cxMapUnionSimple(CxMap *dst, const CxMap *src) {
+    return cxMapUnion(dst, src, use_simple_clone_func(src));
+}