https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90782
--- Comment #6 from getchar_gnu at hotmail dot com --- https://gcc.godbolt.org/z/qzG9jj template<class... A> struct bar { template<class B> bar(B& obj, void(B::*f)(A...)const=&B::operator()){} }; int main() { const auto f1 = [](){}; bar f8(f1); } This compiles on clang and ice on gcc