u32 key, rb_tree_lt_fn ltfn);
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);
u32 key, rb_tree_lt_fn ltfn);
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);