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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/89074] valid pointer equality constexpr comparison rejected
Date: Thu, 18 Nov 2021 14:18:05 +0000	[thread overview]
Message-ID: <bug-89074-4-73cl5yt9yi@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-89074-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89074

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think this is another case of the same bug:

constexpr bool
test()
{
  int a[] = { 1, 2 };
  int b[] = { 3, 4 };

  if (a+0 == b+0)       // OK
    return false;

  if (a+1 == b+0)       // ERROR
    return false;

  return true;
}

static_assert( test() );


g++ -std=c++20 ce.C -c

ce.C:16:20: error: non-constant condition for static assertion
   16 | static_assert( test() );
      |                ~~~~^~
ce.C:16:20:   in 'constexpr' expansion of 'test()'
ce.C:10:11: error: '((((int*)(& a)) + 4) == ((int*)(& b)))' is not a constant
expression
   10 |   if (a+1 == b+0)       // ERROR
      |       ~~~~^~~~~~

  parent reply	other threads:[~2021-11-18 14:18 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-89074-4@http.gcc.gnu.org/bugzilla/>
2021-07-27  9:30 ` pinskia at gcc dot gnu.org
2021-11-18 14:18 ` redi at gcc dot gnu.org [this message]
2021-11-18 16:14 ` cvs-commit at gcc dot gnu.org
2022-01-05 16:38 ` ppalka at gcc dot gnu.org
2022-01-05 16:56 ` jakub at gcc dot gnu.org
2022-01-05 17:07 ` ppalka at gcc dot gnu.org
2022-01-05 19:45 ` jakub at gcc dot gnu.org
2022-01-05 19:56 ` jakub at gcc dot gnu.org
2022-01-05 22:07 ` cvs-commit at gcc dot gnu.org
2022-01-05 22:07 ` cvs-commit at gcc dot gnu.org
2022-01-06 20:01 ` jakub at gcc dot gnu.org
2022-01-08  8:54 ` cvs-commit at gcc dot gnu.org
2022-01-14 11:08 ` cvs-commit at gcc dot gnu.org
2022-01-19  8:26 ` cvs-commit at gcc dot gnu.org
2022-02-06 10:21 ` cvs-commit at gcc dot gnu.org
2022-07-07 16:38 ` cvs-commit at gcc dot gnu.org
2022-11-07 14:16 ` ppalka at gcc dot gnu.org

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