https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72842
--- Comment #6 from Daniel Krügler <daniel.kruegler at googlemail dot com> --- (In reply to Daniel Krügler from comment #5) > (In reply to Barry Revzin from comment #4) > > I'll just email. Instantiating foo<void> creates a function template with a > > non-type template parameter of type void. That's not an allowed type of a > > non-type template parameter, so I think it should be ill-formed. > > It truely is ill-formed, but the question is whether an implementation is > required to diagnose it. For the non-depending case the diagnostics is a > hard requirement. But for the dependent case we have [temp.res] p8: > > "The program is ill-formed, no diagnostic required, if: > [..] > — every valid specialization of a variadic template requires an empty > template parameter pack, or [..]" > > My argument is that this is the case we are entering here: Ill-formed, but > no diagnostics required. Having said that, it might be worth to point out that there are at least two core issues involving this area: http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#1785 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#2067
