[Bug c++/35297] New: Compiling error with variadic template with fixed parameter with default type.

[Bug c++/35297] New: Compiling error with variadic template with fixed parameter with default type.

[rodolfo at rodsoft dot org]

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Hi,
the following code fails to compile with gcc-4.3-20080215

template <class T=int, class... ARGS> 
struct test {};

int main()
{
        test<> a;
        return 0;
}

According to N2242 section 3.6, page 7:

If a template-parameter of a class template has a default template-argument,
each subsequent template-parameter shall either have a default
template-argument supplied or be a template parameter pack. If a
template-parameter of a class template is a template parameter pack, it must be
the last template-parameter. 

The compiler issues the following error: no default argument for ‘ARGS’  at
line 1 above.


-- 
           Summary: Compiling error with variadic template with fixed
                    parameter with default type.
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rodolfo at rodsoft dot org
 GCC build triplet: *-*-*-*
  GCC host triplet: *-*-*-*
GCC target triplet: *-*-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35297

[Bug c++/35297] Compiling error with variadic template with fixed parameter with default type.

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|critical                    |normal


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35297

[Bug c++/35297] Compiling error with variadic template with fixed parameter with default type.

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2008-12-29 06:44 -------
Confirmed.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
      Known to fail|                            |4.4.0
   Last reconfirmed|0000-00-00 00:00:00         |2008-12-29 06:44:53
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35297

[Bug c++/35297] Compiling error with variadic template with fixed parameter with default type.

[jason at gcc dot gnu dot org]

-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jason at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-12-29 06:44:53         |2009-01-06 16:17:16
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35297

[Bug c++/35297] Compiling error with variadic template with fixed parameter with default type.

[jason at gcc dot gnu dot org]

------- Comment #2 from jason at gcc dot gnu dot org  2009-01-07 20:43 -------
Subject: Bug 35297

Author: jason
Date: Wed Jan  7 20:43:01 2009
New Revision: 143166

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143166
Log:
        PR c++/35297
        PR c++/35477
        PR c++/35784
        PR c++/36846
        PR c++/38276
        * pt.c (check_default_tmpl_args): Don't complain about
        out-of-order parameter packs in the enclosing class
        or parameter packs after default args.
        (coerce_template_parms): If we have more than one
        parameter pack, don't flatten argument packs.
        (template_args_equal): Handle argument packs.
        (comp_template_args): Don't flatten argument packs.
        (check_instantiated_arg): Split out from...
        (check_instantiated_args): Here.  Handle arg packs.
        (convert_template_argument): Just check that nontype argument
        packs have the right type.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/variadic92.C
    trunk/gcc/testsuite/g++.dg/cpp0x/variadic93.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/pt.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/cpp0x/variadic65.C
    trunk/gcc/testsuite/g++.dg/cpp0x/variadic82.C
    trunk/gcc/testsuite/g++.dg/cpp0x/variadic83.C


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35297

[Bug c++/35297] Compiling error with variadic template with fixed parameter with default type.

[jason at gcc dot gnu dot org]

------- Comment #3 from jason at gcc dot gnu dot org  2009-01-07 20:56 -------
Fixed.


-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35297