From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-365966-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 396 invoked by alias); 20 Aug 2011 20:37:41 -0000
Received: (qmail 387 invoked by uid 22791); 20 Aug 2011 20:37:39 -0000
X-SWARE-Spam-Status: No, hits=-2.3 required=5.0	tests=ALL_TRUSTED,AWL,BAYES_00,SARE_HEAD_8BIT_SPAM,SARE_SUB_ENC_UTF8x2
X-Spam-Check-By: sourceware.org
Received: from localhost (HELO gcc.gnu.org) (127.0.0.1)    by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sat, 20 Aug 2011 20:37:25 +0000
From: "lcid-fire at gmx dot net" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/50140] New: sorry, unimplemented:=?UTF-8?Q?=20cannot=20expand=20=E2=80=98T=20?=...=?UTF-8?Q?=E2=80=99=20into=20a=20fixed=2Dlength=20argument=20list?=
Date: Sat, 20 Aug 2011 20:52:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: lcid-fire at gmx dot net
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Changed-Fields:
Message-ID: <bug-50140-4@http.gcc.gnu.org/bugzilla/>
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
X-SW-Source: 2011-08/txt/msg01740.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D50140

             Bug #: 50140
           Summary: sorry, unimplemented: cannot expand =E2=80=98T ...=E2=
=80=99 into a
                    fixed-length argument list
    Classification: Unclassified
           Product: gcc
           Version: 4.5.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: lcid-fire@gmx.net


Trying to use metaprogramming with variadic templates g++ chokes on the
following code:

template<GLenum One, GLenum... Others>
class Eval
{
public:
    bool eval(GLenum value)
    {
        if( value =3D=3D One )
            return true;

        Eval<Others...> recurse();
        // Try out the rest
        return recurse.eval(value);
    };
};

template<>
class Eval
{
public:
    bool eval(GLenum value)
    {
        return false;
    };
};

template<GLenum... ValidEnums>
class GLPart
{
protected:
    GLPart()
    {
    };
public:
    bool Evaluate(GLenum value)
    {
        Eval<ValidEnums...> ev();
        bool isValid =3D ev.eval(value);

        if( !isValid )
            glSetError(GL_INVALID_ENUM);

        return isValid;
    };
};

which gives the error:
sorry, unimplemented: cannot expand =E2=80=98Others ...=E2=80=99 into a fix=
ed-length argument
list