| // { dg-do compile { target c++20 } } | |
| template <class T> struct A { static const int x = 42; }; | |
| template <class Ta> concept A42 = A<Ta>::x == 42; | |
| template <class Tv> concept Void = __is_same_as(Tv, void); | |
| template <class Tb, class Ub> concept A42b = Void<Tb> || A42<Ub>; | |
| template <class Tc> concept R42c = A42b<Tc, Tc&>; | |
| static_assert (R42c<void>); |