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 77C113857C59; Thu, 19 Aug 2021 23:01:10 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 77C113857C59
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/101988] [12 Regression] Accepts invalid new-expression of
 array of deduced class template
Date: Thu, 19 Aug 2021 23:01:10 +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: 12.0
X-Bugzilla-Keywords: accepts-invalid
X-Bugzilla-Severity: normal
X-Bugzilla-Who: pinskia 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: 12.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-101988-4-elmiW2JUF9@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-101988-4@http.gcc.gnu.org/bugzilla/>
References: <bug-101988-4@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: Thu, 19 Aug 2021 23:01:10 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101988

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> I also noticed, GCC accepts while clang rejects:
> template<class T> struct A { A(T); };
> auto p =3D new A<int>[]{A(1),A(1)};
>=20
> While changing it to [2], both GCC and clang accepts it.

Note ICC and MSVC accepts the above so I think it is a clang bug.


Oh and GCC rejects this:
template<class T> struct A { A(T); };
auto p =3D new A[]{1,2};

But thinks A[] is really A:
<source>:2:21: error: class template argument deduction failed:
    2 | auto p =3D new A[]{1,2};
      |                     ^
<source>:2:21: error: no matching function for call to 'A(int, int)'
<source>:1:30: note: candidate: 'template<class T> A(T)-> A<T>'
    1 | template<class T> struct A { A(T); };
      |                              ^
<source>:1:30: note:   template argument deduction/substitution failed:
<source>:2:21: note:   candidate expects 1 argument, 2 provided
    2 | auto p =3D new A[]{1,2};
      |                     ^
<source>:1:26: note: candidate: 'template<class T> A(A<T>)-> A<T>'
    1 | template<class T> struct A { A(T); };
      |                          ^
<source>:1:26: note:   template argument deduction/substitution failed:
<source>:2:21: note:   mismatched types 'A<T>' and 'int'
    2 | auto p =3D new A[]{1,2};
      |                     ^

So that might get the hint of the problem.=