2 // { dg-do compile { target c++20 } }
4 template <class T, class U>
5 concept Same = __is_same_as(T, U);
8 concept C = requires (T t) { // { dg-error "invalid parameter|in requirements" }
9 requires Same<decltype(t),void>;
14 constexpr bool is_c() { return true; }
16 static_assert(is_c<void>(), ""); // { dg-error "" }