This patch implements C++26 function_ref as specified in P0792R14,
with correction for constraints for constructor accepting nontype_t
parameter from LWG 4256.
As function_ref may store a pointer to the const object, __Ptrs::_M_obj is
changed to const void*, so again we do not cast away const from
This patch implements C++26 function_ref as specified in P0792R14,
with correction for constraints for constructor accepting nontype_t
parameter from LWG 4256.
As function_ref may store a pointer to the const object, __Ptrs::_M_obj is
changed to const void*, so again we do not cast away const from
