void rb_tree_init (rb_tree_t * rt);
rb_node_index_t rb_tree_add (rb_tree_t * rt, u32 key);
rb_node_index_t rb_tree_add2 (rb_tree_t * rt, u32 key, uword opaque);
void rb_tree_init (rb_tree_t * rt);
rb_node_index_t rb_tree_add (rb_tree_t * rt, u32 key);
rb_node_index_t rb_tree_add2 (rb_tree_t * rt, u32 key, uword opaque);
void rb_tree_free_nodes (rb_tree_t * rt);
u32 rb_tree_n_nodes (rb_tree_t * rt);
rb_node_t *rb_tree_min_subtree (rb_tree_t * rt, rb_node_t * x);
rb_node_t *rb_tree_max_subtree (rb_tree_t * rt, rb_node_t * x);
rb_node_t *rb_tree_search_subtree (rb_tree_t * rt, rb_node_t * x, u32 key);
void rb_tree_free_nodes (rb_tree_t * rt);
u32 rb_tree_n_nodes (rb_tree_t * rt);
rb_node_t *rb_tree_min_subtree (rb_tree_t * rt, rb_node_t * x);
rb_node_t *rb_tree_max_subtree (rb_tree_t * rt, rb_node_t * x);
rb_node_t *rb_tree_search_subtree (rb_tree_t * rt, rb_node_t * x, u32 key);
rb_node_t *rb_tree_successor (rb_tree_t * rt, rb_node_t * x);
rb_node_t *rb_tree_predecessor (rb_tree_t * rt, rb_node_t * x);
rb_node_t *rb_tree_successor (rb_tree_t * rt, rb_node_t * x);
rb_node_t *rb_tree_predecessor (rb_tree_t * rt, rb_node_t * x);