| // PR c++/69694 |
| // { dg-do compile { target c++11 } } |
| |
| // n3911: TransformationTrait Alias `void_t` |
| template<typename...> struct make_void { using type = void; }; |
| template<typename... Ts> using void_t = typename make_void<Ts...>::type; |
| |
| // std::declval<void*&> |
| void*& declval_void(); |
| |
| template<typename, typename = void> struct Fun; |
| template<typename R> |
| struct Fun<R(), void> |
| { |
| void fun(); |
| }; |
| template<typename Desc> |
| struct Fun<Desc, void_t<decltype (declval_void() = Desc::name)>> |
| : Fun<void()> |
| { |
| }; |
| |
| struct Tag { static constexpr void* name = 0; }; |
| |
| template<typename> void a() |
| { |
| Fun<Tag>{}.fun(); |
| } |
| |
| void b() { a<int>(); } |
