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 5ADF53858D3C; Mon, 28 Nov 2022 09:28:21 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5ADF53858D3C
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1669627701;
	bh=qSpWFKys/E55ztwlQVX+zUpZfXfMRjjx7MEgovyjOJs=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=KBQ1ptCeAzS5CjNMrPx61pdG3iILFdkOCpjXvl6oT9dl1oab6D9RAr3i7ZMwPbMIO
	 wMlKptq2VBhN1NbtahUBwgNgEUri6M1C4lEqhMkwEcMdjJ4jULoYLYDf0/CKK9m9Qd
	 QbX6ShUWXdjSbVPbLXNzHh4H7TkC490vtpah6/tQ=
From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/107889] Incorrect parsing of qualified friend function
 returning decltype(auto)
Date: Mon, 28 Nov 2022 09:28:21 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 12.2.0
X-Bugzilla-Keywords: rejects-valid
X-Bugzilla-Severity: normal
X-Bugzilla-Who: redi at gcc dot gnu.org
X-Bugzilla-Status: NEW
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: 
Message-ID: <bug-107889-4-cdexWzCja5@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-107889-4@http.gcc.gnu.org/bugzilla/>
References: <bug-107889-4@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=3D107889

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to David Mazi=C3=A8res from comment #0)
> A similar problem was reported in bug #59766 for friend functions returni=
ng
> auto.

That's unrelated.

The problem here is that decltype(auto)::f is a nested-name-specifier for a
member 'f' so is parsed as part of the return type, not the function name. =
This
is what C++20 (and all earlier standards) said. The ambiguity has been reso=
lved
as a DR against earlier standards, but GCC doesn't implement that change ye=
t,
as shown at https://gcc.gnu.org/projects/cxx-status.html#cxx23=