[Bug c++/59498] [DR 1430][4.9/4.10 Regression] Pack expansion error in template alias

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59498

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
And the current development version of clang also rejects this testcase:

wa.C:5:34: error: pack expansion used as argument for non-pack parameter of
      alias template
    using variadic_alias = alias<T...>;
                                 ^~~~
wa.C:1:24: note: template parameter is declared here
    template <typename T, typename ...>
                       ^