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 E37D43858423; Tue, 14 Mar 2023 22:25:56 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E37D43858423
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1678832756;
	bh=5GJUTkVibg07JSzasYdIxeV2x/ghbSbLPVkgowmWWdc=;
	h=From:To:Subject:Date:From;
	b=d9gRenx3HOLndqboqQ1r/TMcm1eq6dG35Gxsc5mdGQmQtwvbrsSIBdflMi05aeGzi
	 DKhjwnYidFd+tSDhUvjAxeXA4Ijh2qfzdir+BVTqSPegB68RfZ2Mk6CzOOSyb2e/J7
	 eLG+5TB8X23DddpsBXHzMtdps/0vhE+3rW3c/Alc=
From: "ldalessandro at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/109136] New: [concepts] initializer_list constructor
 constraint should require static_cast for explicit conversion operator
Date: Tue, 14 Mar 2023 22:25:56 +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: 13.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: ldalessandro at gmail dot com
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-109136-4@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=3D109136

            Bug ID: 109136
           Summary: [concepts] initializer_list constructor constraint
                    should require static_cast for explicit conversion
                    operator
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ldalessandro at gmail dot com
  Target Milestone: ---

The following concept should fail the static_assert, but passes (I should n=
eed
a static_cast here).

```
    #include <initializer_list>

    template <class From, class To>
    concept implicit_convertible_to =3D requires(From x) {=20
        std::initializer_list<To>{ x };=20
    };

    struct foo {
        explicit operator int();
    };

    static_assert(implicit_convertible_to<foo, int>);

```

Live: https://godbolt.org/z/GffP9f8o7=