35   concept __member_empty = requires(_Tp&& __t) {  in requires()  argument
36     bool(_VSTD::forward<_Tp>(__t).empty());  in requires()
42     requires(_Tp&& __t) { ranges::size(_VSTD::forward<_Tp>(__t)); };
48     requires(_Tp&& __t) {
49       bool(ranges::begin(__t) == ranges::end(__t));
50       { ranges::begin(__t) } -> forward_iterator;
55     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t) const  in operator()
56         noexcept(noexcept(bool(__t.empty()))) {  in operator()
57       return __t.empty();  in operator()
61     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t) const  in operator()
62         noexcept(noexcept(ranges::size(_VSTD::forward<_Tp>(__t)))) {  in operator()
63       return ranges::size(_VSTD::forward<_Tp>(__t)) == 0;  in operator()
67     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t) const  in operator()
68         noexcept(noexcept(bool(ranges::begin(__t) == ranges::end(__t)))) {  in operator()
69       return ranges::begin(__t) == ranges::end(__t);  in operator()