[Bug c++/53862] New: [GCC 4.7.1] sorry, unimplemented: use of 'type_pack_expansion' in template

["likan_999.student at sina dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53862

             Bug #: 53862
           Summary: [GCC 4.7.1] sorry, unimplemented: use of
                    'type_pack_expansion' in template
    Classification: Unclassified
           Product: gcc
           Version: 4.7.1
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: likan_999.student@sina.com


The following code is complained by gcc 4.7.1:

[hidden]$ cat c.cpp 
#include <type_traits>

using namespace std;

template <size_t N, typename... Args>
void f(Args...) {}

template <size_t N, typename T, typename... Args>
typename enable_if<is_scalar<T>::value, void>::type f(T, Args...) {}

int main() {
    f<1>(1);
}

[hidden]$ g++ -std=gnu++11 c.cpp 
c.cpp: In function 'int main()':
c.cpp:12:11: sorry, unimplemented: use of 'type_pack_expansion' in template


All "Possible Duplicates" shown to me are in "RESOLVED FIXED" status, but
sorry, looks like not fixed yet.  This needs to get some attention otherwise
this long standing bugs won't be fixed soon.