48     requires(_Tp&& __t) {  in requires()  function
60     requires(_Tp && __t) {
67       requires (sizeof(_Tp) >= 0)  // Disallow incomplete element types.  in operator()
74       requires (sizeof(_Tp) >= 0)  // Disallow incomplete element types.  in operator()
80       requires __member_begin<_Tp>
88       requires __unqualified_begin<_Tp>
119     requires(_Tp&& __t) {  in requires()  function
132     requires(_Tp && __t) {
140       requires (sizeof(_Tp) >= 0)  // Disallow incomplete element types.  in operator()
146       requires __member_end<_Tp>
154       requires __unqualified_end<_Tp>
176       requires is_lvalue_reference_v<_Tp&&>
184       requires is_rvalue_reference_v<_Tp&&>
204       requires is_lvalue_reference_v<_Tp&&>
212       requires is_rvalue_reference_v<_Tp&&>