[Bug c++/82316] unexpected warning for using 'register' storage class in extern "C" declarations

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82316

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
extern "C" just means the linkage and not actual C code.

This is true with other differences between C and C++ like auto and typedef of
void types and arguments.