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 02E223858288; Thu, 10 Aug 2023 09:52:44 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 02E223858288
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1691661165;
	bh=HPS1zx7KAtxYvjdZJdQW3wQ4WqHU4odw8hUm1KbUmXk=;
	h=From:To:Subject:Date:From;
	b=B6FPcDV8Z8mVUoULqn84sPr2+6WRmhPklAXIH9UZzqw4sIHO+p/K/xzErZ5wRzHri
	 JT/b6UiguSTrM9QZgoCJFEH40g/SLUdiKag7Lat3qF8umlBNIHcypFxpFEn2jP60Vy
	 Rm1xhbPSb+wipSL4jLAfc5sYahNEuHYHnzPSpIgI=
From: "gcc-bugzilla at zulan dot net" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/110970] New: clang / c++23 missing 'typename' prior
 to dependent type name 'iterator_traits<_It>::iterator_category'
Date: Thu, 10 Aug 2023 09:52:43 +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: 13.2.1
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: gcc-bugzilla at zulan dot net
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-110970-4@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
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110970

            Bug ID: 110970
           Summary: clang / c++23 missing 'typename' prior to dependent
                    type name 'iterator_traits<_It>::iterator_category'
           Product: gcc
           Version: 13.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gcc-bugzilla at zulan dot net
  Target Milestone: ---

Using clang with the current libstdc++ and c++23 (2b) fails:

echo "#include <algorithm>" | clang++ -std=3Dc++2b -stdlib=3Dlibstdc++ -c -=
x c++ -
In file included from <stdin>:1:
In file included from
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../include/c++/13=
.2.1/algorithm:60:
In file included from
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../include/c++/13=
.2.1/bits/stl_algobase.h:67:
/usr/bin/../lib64/gcc/x86_64-pc-linux-gnu/13.2.1/../../../../include/c++/13=
.2.1/bits/stl_iterator.h:2618:35:
error: missing 'typename' prior to dependent type name
'iterator_traits<_It>::iterator_category'
      { using iterator_category =3D iterator_traits<_It>::iterator_category=
; };


The line is unchanged in the current git, so I presume this is not fixed ye=
t.

Simply adding `typename` to the line does fix the issue with clang.

This is similar to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100900. I=
 won't
try to language lawyer what is technically correct here. In the other issue=
 it
was decided to be nice and support other implementations even though it is a
(very low cost) workaround.=