--- a/src/cx/map.h	Tue Jun 20 18:29:12 2023 +0200
+++ b/src/cx/map.h	Tue Jun 20 18:30:13 2023 +0200
@@ -146,6 +146,11 @@
     void *value;
 };
 
+/**
+ * A shared instance of an empty map.
+ *
+ * Writing to that map is undefined.
+ */
 extern CxMap *const cxEmptyMap;
 
 /**