https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100157
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- GCC doesn't support template-like built-ins, but I have a patch to add a function-like __builtin_type_pack_element(N, T...) instead. I don't like the name "type pack element" much though. To me that doesn't really suggest selecting an element by its index.
