https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104294
Bug ID: 104294 Summary: ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.cc:13130 Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: hewillk at gmail dot com Target Milestone: --- template<class> struct B; template <class R, class... Args> struct B<R(Args...)> { template<class T> struct C { C(T); }; }; int main() { B<void(int)>::C{0}; } https://godbolt.org/z/h1jGhc5b4