https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104847
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- struct S { int i; }; union U { S k; }; template <class T, class... Ts> T sink(T&&, Ts&&...); template <class T> decltype(sink(U{.k={.i=1}},T())) f(T) { return U{1}; } int main() { f(3); } compiles fine. I guess the question is if ce->index == NULL should be mangled without the di production of <braced-expression>, or we should implicitly find the first initializable field and use that with di, i.e. if this should mangle as _Z1fIiEDTcl4sinktl1Udi1kilLi1EEEcvT__EEES1_ or as _Z1fIiEDTcl4sinktl1ULi1EEcvT__EEES1_