diff -r 6bbbf219251d -r 4d12e34bb130 src/cx/collection.h
--- a/src/cx/collection.h	Thu May 23 20:43:04 2024 +0200
+++ b/src/cx/collection.h	Thu May 23 22:06:32 2024 +0200
@@ -100,6 +100,25 @@
 #define CX_COLLECTION_BASE struct cx_collection_s collection
 
 /**
+ * Sets a simple destructor function for this collection.
+ *
+ * @param c the collection
+ * @param destr the destructor function
+ */
+#define cxDefineDestructor(c, destr) \
+    (c)->collection.simple_destructor = (cx_destructor_func) destr
+
+/**
+ * Sets a simple destructor function for this collection.
+ *
+ * @param c the collection
+ * @param destr the destructor function
+ */
+#define cxDefineAdvancedDestructor(c, destr, data) \
+    (c)->collection.advanced_destructor = (cx_destructor_func2) destr; \
+    (c)->collection.destructor_data = data
+
+/**
  * Invokes the simple destructor function for a specific element.
  *
  * Usually only used by collection implementations. There should be no need