Eczbek

struct as{template<class as>struct final{
as defined;template<class final>decltype(
static_cast<final>(as(defined)))constexpr
operator->*(final(::as::*)())noexcept(
noexcept(final(as(defined)))){return(final
)as(defined);}};template<class as>operator
as(){throw;}template<class as>constexpr
friend final<as&&>operator->*(as&&final
,::as)noexcept{return{(as&&)final};}};
#define as ->*::as()->*&::as::operator