| // PR c++/83918 |
| // { dg-do compile { target c++17 } } |
| |
| constexpr unsigned |
| foo (unsigned x, unsigned y) |
| { |
| return x > y ? x : y; |
| } |
| |
| template <typename, typename> struct A; |
| template <auto ...> struct B; |
| template <auto S, auto ... T, auto U, auto ... V> |
| struct A <B <S, T...>, B <U, V...>> |
| { |
| enum : unsigned |
| { |
| u = foo (sizeof (S), sizeof (U)), |
| v = A <B <T...>, B <V...>>::w, |
| w = foo (u, v) |
| }; |
| }; |
| |
| template <> |
| struct A <B <>, B <>> |
| { |
| enum : unsigned { w = 0 }; |
| }; |
| |
| constexpr static const auto v { A <B <1,2,3,4,5,6,7,8,9>, |
| B <9,8,7,6,5,4,3,2,1>>::w }; |
| static_assert (v == sizeof (int)); |
