random_access_iterator
using __STD::random_access_iterator;
: public random_access_iterator<bool, ptrdiff_t>
struct _Bit_iterator : public random_access_iterator<bool, ptrdiff_t> {
iterator_category(const random_access_iterator<_Tp, _Distance>&)
inline _Tp* value_type(const random_access_iterator<_Tp, _Distance>&)
distance_type(const random_access_iterator<_Tp, _Distance>&)
: public random_access_iterator<_CharT, ptrdiff_t> {