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From: "m.cencora at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/98122] New: [regression] Accessing union member through pointer-to-member is not a constant expression
Date: Thu, 03 Dec 2020 13:50:12 +0000	[thread overview]
Message-ID: <bug-98122-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98122

            Bug ID: 98122
           Summary: [regression] Accessing union member through
                    pointer-to-member is not a constant expression
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: m.cencora at gmail dot com
  Target Milestone: ---

Following code does not compile on gcc-10 and newer in all std C++14-20 modes.

This used to work in gcc-9 and earlier.

union foo
{
    int a;
};

constexpr bool test()
{
    foo f{ .a = 42 };

    constexpr auto memPtr = &foo::a;

    return (f.*memPtr) == 42;
}

// error: accessing value of 'f' through a 'int' glvalue in a constant
expression
//     return (f.*memPtr) == 42;
static_assert(test(), "");

             reply	other threads:[~2020-12-03 13:50 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-03 13:50 m.cencora at gmail dot com [this message]
2020-12-03 18:09 ` [Bug c++/98122] [10/11 Regression] " mpolacek at gcc dot gnu.org
2020-12-03 18:10 ` mpolacek at gcc dot gnu.org
2020-12-04 12:09 ` jakub at gcc dot gnu.org
2020-12-04 13:23 ` jakub at gcc dot gnu.org
2020-12-05  0:32 ` cvs-commit at gcc dot gnu.org
2020-12-05  0:34 ` [Bug c++/98122] [10 " jakub at gcc dot gnu.org
2021-01-06  9:39 ` cvs-commit at gcc dot gnu.org
2021-01-06  9:44 ` jakub at gcc dot gnu.org

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