[Bug c++/65790] compilation error : receive std::index_sequnece

["redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65790

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-04-17
     Ever confirmed|0                           |1
      Known to fail|                            |4.8.3, 4.9.2, 5.0, 6.0

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Confirmed, Clang and EDG accept this:

extern "C" int printf(const char* ...);

namespace std
{
  typedef decltype(sizeof(0)) size_t;

  template<typename _Tp, _Tp... _Idx>
    struct integer_sequence
    {
      typedef _Tp value_type;
      static constexpr size_t size() { return sizeof...(_Idx); }
    };

  template<size_t... _Idx>
    using index_sequence = integer_sequence<size_t, _Idx...>;
}

void g(std::size_t a, std::size_t b, std::size_t c)
{
  printf("%zu, %zu, %zu\n", a, b, c);
}

template <std::size_t... Seq>
void f(std::index_sequence<Seq...>)
{
  g(Seq...);
}

int main()
{
  f(std::index_sequence<0, 1, 2>());
}