[Bug c++/60579] New: Segmentation fault on variadic 'using' within variadic template class

[charlie at charliedyson dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60579

            Bug ID: 60579
           Summary: Segmentation fault on variadic 'using' within variadic
                    template class
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: charlie at charliedyson dot net

The following causes a segfault on gcc 4.8.1 and earlier versions:

template <typename... Args>
struct X
{
  template <typename Head, typename... Tail>
  using First = Head;

  using Y = First<Args...>;
};

Steps to reproduce: http://goo.gl/bBYNJU (GCC Explorer)