1 // PR c++/71966 2 // { dg-do compile { target c++11 } } 3 4 struct A 5 { 6 constexpr A (int); // { dg-message "never defined" } 7 constexpr operator int () const { return 0; } 8 int c; 9 }; 10 11 template <int> 12 struct B {}; 13 14 constexpr A a = 0; // { dg-error "before its definition" } 15 B<a> b; 16