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 765D7385802F; Tue, 21 Mar 2023 15:23:23 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 765D7385802F
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1679412203;
	bh=udyhqe7bqdh07trbVtPDRe63iXkXC5TozjrYwjXEdeY=;
	h=From:To:Subject:Date:From;
	b=ZEtMu7vAedu4R2Zq4pdOc0dTq0PcpuUocP5JesCOwlxUKpkIfgWlDc/yCYe6OzalL
	 bRoEB7T47ReTrHk2hadLrOElLG6DfrC/pZP91doj4ctXWEMa5GWmrI9sMUFAUSOs4U
	 AnZcAo0rzO7LNv1TiFjM4ViGSlvB8Doxpf8s9C3o=
From: "tejo@bang-olufsen.dk" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/109235] New: nodiscard attribute ignored with deduction
 guide
Date: Tue, 21 Mar 2023 15:23:23 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 12.2.1
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: tejo@bang-olufsen.dk
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-109235-4@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=3D109235

            Bug ID: 109235
           Summary: nodiscard attribute ignored with deduction guide
           Product: gcc
           Version: 12.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tejo@bang-olufsen.dk
  Target Milestone: ---

I have tried implementing std::experimental::scope_exit and since this is a
RAII object, I marked it with [[nodiscard]] to ensure all instances are
assigned to a variable.

It appears, however, that GCC ignores the nodiscard attribute when a deduct=
ion
guide is present. See this Godbolt link for an example:

https://godbolt.org/z/v9e8dqW1o

Notice how Clang correctly flags the problem.=