diff -r 1f40ca07ae1b -r 839fefbdedc7 ucx/cx/map.h
--- a/ucx/cx/map.h	Sat Apr 20 13:01:58 2024 +0200
+++ b/ucx/cx/map.h	Thu May 23 22:35:45 2024 +0200
@@ -30,7 +30,6 @@
  * \brief Interface for map implementations.
  * \author Mike Becker
  * \author Olaf Wintermann
- * \version 3.0
  * \copyright 2-Clause BSD License
  */
 
@@ -57,7 +56,10 @@
 
 /** Structure for the UCX map. */
 struct cx_map_s {
-    CX_COLLECTION_MEMBERS
+    /**
+     * Base attributes.
+     */
+    CX_COLLECTION_BASE;
     /** The map class definition. */
     cx_map_class *cl;
 };
@@ -164,7 +166,7 @@
  */
 __attribute__((__nonnull__))
 static inline void cxMapStoreObjects(CxMap *map) {
-    map->store_pointer = false;
+    map->collection.store_pointer = false;
 }
 
 /**
@@ -181,10 +183,21 @@
  */
 __attribute__((__nonnull__))
 static inline void cxMapStorePointers(CxMap *map) {
-    map->store_pointer = true;
-    map->item_size = sizeof(void *);
+    map->collection.store_pointer = true;
+    map->collection.elem_size = sizeof(void *);
 }
 
+/**
+ * Returns true, if this map is storing pointers instead of the actual data.
+ *
+ * @param map
+ * @return true, if this map is storing pointers
+ * @see cxMapStorePointers()
+ */
+__attribute__((__nonnull__))
+static inline bool cxMapIsStoringPointers(CxMap const *map) {
+    return map->collection.store_pointer;
+}
 
 /**
  * Deallocates the memory of the specified map.
@@ -207,6 +220,17 @@
     map->cl->clear(map);
 }
 
+/**
+ * Returns the number of elements in this map.
+ *
+ * @param map the map
+ * @return the number of stored elements
+ */
+__attribute__((__nonnull__))
+static inline size_t cxMapSize(CxMap const *map) {
+    return map->collection.size;
+}
+
 
 // TODO: set-like map operations (union, intersect, difference)
 
@@ -269,7 +293,7 @@
  * @return an iterator for the currently stored values
  */
 __attribute__((__nonnull__, __warn_unused_result__))
-CxMutIterator cxMapMutIteratorValues(CxMap *map);
+CxIterator cxMapMutIteratorValues(CxMap *map);
 
 /**
  * Creates a mutating iterator over the keys of a map.
@@ -283,7 +307,7 @@
  * @return an iterator for the currently stored keys
  */
 __attribute__((__nonnull__, __warn_unused_result__))
-CxMutIterator cxMapMutIteratorKeys(CxMap *map);
+CxIterator cxMapMutIteratorKeys(CxMap *map);
 
 /**
  * Creates a mutating iterator for a map.
@@ -299,7 +323,7 @@
  * @see cxMapMutIteratorValues()
  */
 __attribute__((__nonnull__, __warn_unused_result__))
-CxMutIterator cxMapMutIterator(CxMap *map);
+CxIterator cxMapMutIterator(CxMap *map);
 
 #ifdef __cplusplus
 } // end the extern "C" block here, because we want to start overloading
@@ -1051,7 +1075,7 @@
         CxMap *map,
         CxHashKey key
 ) {
-    return map->cl->remove(map, key, !map->store_pointer);
+    return map->cl->remove(map, key, !map->collection.store_pointer);
 }
 
 /**
@@ -1067,7 +1091,7 @@
         CxMap *map,
         cxstring key
 ) {
-    return map->cl->remove(map, cx_hash_key_cxstr(key), !map->store_pointer);
+    return map->cl->remove(map, cx_hash_key_cxstr(key), !map->collection.store_pointer);
 }
 
 /**
@@ -1083,7 +1107,7 @@
         CxMap *map,
         cxmutstr key
 ) {
-    return map->cl->remove(map, cx_hash_key_cxstr(key), !map->store_pointer);
+    return map->cl->remove(map, cx_hash_key_cxstr(key), !map->collection.store_pointer);
 }
 
 /**
@@ -1099,7 +1123,7 @@
         CxMap *map,
         char const *key
 ) {
-    return map->cl->remove(map, cx_hash_key_str(key), !map->store_pointer);
+    return map->cl->remove(map, cx_hash_key_str(key), !map->collection.store_pointer);
 }
 
 /**