-extern rbl_t rbl_search(rbltree_t *, void *);
-extern rbl_t rbl_search_closest(rbltree_t *, void *);
-extern rbl_t rbl_insert(rbltree_t *, void *);
-extern rbl_t rbl_unlink(rbltree_t *, void *);
-extern rbl_t rbl_delete(rbltree_t *, void *);
-extern rbl_t rbl_insert_rbl(rbltree_t *, rbl_t *);
-extern rbl_t rbl_unlink_rbl(rbltree_t *, rbl_t *);
-extern rbl_t rbl_delete_rbl(rbltree_t *, rbl_t *);
-extern rbl_t rbl_prev(rbl_t *);
-extern rbl_t rbl_next(rbl_t *);
+extern rbl_t *new_rbltree(rbl_compare_t *, rbl_delete_t *);
+extern void free_rbltree(rbltree_t *);
+extern rbl_t *new_rbl(void);
+extern void free_rbl(rbl_t *);
+
+extern rbl_t *rbl_search(rbltree_t *, void *);
+extern rbl_t *rbl_search_closest(rbltree_t *, void *);
+extern rbl_t *rbl_insert(rbltree_t *, void *);
+extern rbl_t *rbl_unlink(rbltree_t *, void *);
+extern rbl_t *rbl_delete(rbltree_t *, void *);
+extern rbl_t *rbl_insert_rbl(rbltree_t *, rbl_t *);
+extern rbl_t *rbl_unlink_rbl(rbltree_t *, rbl_t *);
+extern rbl_t *rbl_delete_rbl(rbltree_t *, rbl_t *);