From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 8A0CC3857C42; Wed, 19 Aug 2020 15:08:58 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8A0CC3857C42
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1597849738;
 bh=NNgtM2lqiXoa2/KFm0xF1opVfjHbkD47aOdV2JYAMWM=;
 h=From:To:Subject:Date:From;
 b=ooFWmsmzMnHQchkE+BDykusxPuTkq4x+I8/pgeyU7lLoDJm2qBWh1N6i5A8Zz30iA
 sABacjIPOycEytAyjcH+yx5sPndDlKjLrA/e8VGoD4+6DCaRQHeUdNqf7vxwZUYQ0G
 JRAYyfA2eeG3DAx9047p550F1F5pCVxp7Mog41hs=
From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/96710] New: __int128 vs <type_traits>
Date: Wed, 19 Aug 2020 15:08:58 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libstdc++
X-Bugzilla-Version: 11.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: redi at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-96710-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Wed, 19 Aug 2020 15:08:58 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D96710

            Bug ID: 96710
           Summary: __int128 vs <type_traits>
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org
  Target Milestone: ---

In strict modes (e.g. -std=3Dc++17) the __int128 type does not belong to an=
y of
the standard type categories, because is_integer<__int128> is false, which
means is_arithmetic<__int128> is false.

Our definitions of is_scalar depends on is_arithmetic, so is_scalar<__int12=
8>
is false, and therefore is_object<__int128> is false. This is clearly nonse=
nse.

We should fix this, so that even when is_integer<__int128> is false, we can
still give sensible answers for __int128 that do not (unsucessfully) try to
deny its existence.

Of course the ideal would be for WG14 to accept
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2425.pdf and then we can j=
ust
say is_integer<__int128> is true even in strict modes and everybody rejoice=
s.=