https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86998
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #0)
> I don't know why all of GCC, Clang and EDG say something about a
> nested-name-specifier or qualified name for the first template-parameter. I
> don't think the grammar allows a qualified-id there, only a plain identifier.
It is allowed, when naming a non-type template parameter using a qualiflied-id
e.g.
template<typename T>
struct X {
template<typename T::U> struct Y { };
};
The rest of the PR still stands, we should add a fix-it for the comma.
