| // PR c++/71568 | |
| // { dg-do compile { target c++11 } } | |
| template <typename T> class F : T {}; | |
| template <typename> using void_t = void; | |
| template <class, class = void> struct G; | |
| template <typename T> struct G<T, void_t<decltype(&T::nlog_custom)>> {}; | |
| struct D { | |
| void nlog_custom(); | |
| }; | |
| G<F<D>> g; // { dg-error "incomplete" } | |