https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86918
Marek Polacek <mpolacek at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |ice-on-invalid-code --- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> --- I guess invalid: $ clang++ -c 86918.C -std=c++17 86918.C:8:15: error: non-type template parameter conflicts with previous non-type template parameter pack template<bool v> ^ 86918.C:3:21: note: previous non-type template parameter pack declared here template<bool...> ^ 86918.C:13:23: error: implicit instantiation of undefined template 'S<int>::X<true>' static_assert(S<int>::X<true>::value); ^ 86918.C:4:12: note: template is declared here struct X; ^ 2 errors generated.