_Rb_tree_base_iterator
struct _Rb_tree_iterator : public _Rb_tree_base_iterator
inline bool operator==(const _Rb_tree_base_iterator& __x,
const _Rb_tree_base_iterator& __y) {
inline bool operator!=(const _Rb_tree_base_iterator& __x,
const _Rb_tree_base_iterator& __y) {
iterator_category(const _Rb_tree_base_iterator&) {
inline _Rb_tree_base_iterator::difference_type*
distance_type(const _Rb_tree_base_iterator&) {
return (_Rb_tree_base_iterator::difference_type*) 0;