/* no set_remove2 */
/* no set_remove_value */
-int set_remove_and_put(Set *s, const void *old_key, const void *new_key);
+// UNNEEDED int set_remove_and_put(Set *s, const void *old_key, const void *new_key);
/* no set_remove_and_replace */
int set_merge(Set *s, Set *other);