https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98939
--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
(In reply to Marek Polacek from comment #2)
> class C {
> template <typename...> struct _List;
>
> template <unsigned long, typename, bool B = value> struct S; // #1
>
> template <unsigned long _Sz, typename _Uint, typename... _UInts>
> struct S<_Sz, _List<_Uint, _UInts...>>; // #2
>
> static constexpr bool value = false;
> };
>
> #2 wants to lookup_template_class S, but S can contain a DEFERRED_PARSE, so
> that's not going to work. Perhaps we have to delay finish_template_type
> until the end of class somehow...
As I was saying in our meeting, I think in this testcase #2 is ill-formed
because it depends on a default argument that hasn't been parsed yet.
