https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85128
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
template <class T> class a;
struct b {
typedef a<b> a;
};
Is the reduced testcase. The C++ standard is clear here about this case too.
A diagnostic is not required either. Gcc generates one as it can.
