[Bug c++/109625] [14 regression] 'error: use of built-in trait ‘__type_pack_element’ in function signature; use library traits instead' when building folly

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109625

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #3)
> Folly should not use internal functions which is not designed for other than
> libstdc++.

The function wasn't designed for libstdc++, Clang had it first.

But Folly shouldn't assume that non-standard extensions have a
consistent/portable mangling suitable for use in APIs. In this case, it can't
be mangled at all.