[Bug c++/31141] New: [4.3 regression] ICE with ellipsis in template parameter list

["reichelt at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

The following invalid code snippet triggers an ICE on mainline:

========================================
template<int N...> void foo(int x[1][N]);

void bar()
{
  int x[1][1];
  foo(x);
}
========================================

bug.cc:1: error: ISO C++ does not include variadic templates
bug.cc: In function 'void bar()':
bug.cc:1: internal compiler error: tree check: expected class 'expression',
have 'constant' (integer_cst) in tsubst_pack_expansion, at cp/pt.c:6829
Please submit a full bug report, [etc.]

Looks like this was caused by your patch for variadic templates, Douglas:

2007-03-09  Douglas Gregor  <doug.gregor@gmail.com>

        PR c++/20599
        * typeck.c (check_return_expr): Check for bare parameter packs.
        (comptypes): Compare template parameter packs and
        type pack expansions.
        ...


-- 
           Summary: [4.3 regression] ICE with ellipsis in template parameter
                    list
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code, monitored
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: reichelt at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31141