| // PR c++/91923 - failure-to-SFINAE with class type NTTP in C++17. | |
| // { dg-do compile { target c++11 } } | |
| template<typename T> | |
| constexpr bool is_integral_(...) { | |
| return false; | |
| } | |
| template<typename T, T = 1> | |
| constexpr bool is_integral_(long) { | |
| return true; | |
| } | |
| static_assert(is_integral_<int>(42), ""); | |
| static_assert(!is_integral_<void>(42), ""); | |
| struct S {}; | |
| static_assert(!is_integral_<S>(42), ""); |