// PR c++/91353 - P1331R2: Allow trivial default init in constexpr contexts. // { dg-do compile { target c++20 } } /* We used to get the "constexpr constructor for union S:: must initialize exactly one non-static data member" error, but not anymore in C++20. */ struct S { union { int i; double d; }; constexpr S() { } }; union U { int a; constexpr U() { } }; struct W { union { int a; }; constexpr W() { } };