https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115814
Bug ID: 115814 Summary: class template argument deduction failed in C++20 Product: gcc Version: 15.0 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... Ts> struct overloaded : Ts... { }; // explicit deduction guide (not needed as of C++20) // template<class... Ts> // overloaded(Ts...) -> overloaded<Ts...>; int main() { auto s = overloaded([]{}, []{}); } GCC rejects this, and changes (...) to {...} can work, but I think the above should be well-formed. https://godbolt.org/z/xah5fr8rn