[Bug c++/92505] Using mutable in constexpr

[Bug c++/92505] Using mutable in constexpr

[cjdb.ns at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92505

Christopher Di Bella <cjdb.ns at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |cjdb.ns at gmail dot com

--- Comment #3 from Christopher Di Bella <cjdb.ns at gmail dot com> ---
Gentle ping, this has started to cause issues in the libc++ GCC CI for ranges.

[Bug c++/92505] Using mutable in constexpr

[arthur.j.odwyer at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92505

Arthur O'Dwyer <arthur.j.odwyer at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |arthur.j.odwyer at gmail dot com

--- Comment #4 from Arthur O'Dwyer <arthur.j.odwyer at gmail dot com> ---
Confirmed; the test case can be as simple as

// https://godbolt.org/z/M9rf31qqq
struct S { mutable int m; };
static_assert(S{42}.m == 42);

(Removing the "mutable" keyword makes GCC happy.)

[Bug c++/92505] Using mutable in constexpr

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92505

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |ppalka at gcc dot gnu.org
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |ppalka at gcc dot gnu.org

[Bug c++/92505] Using mutable in constexpr

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92505

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:7107ea6fb933f1e928593c7e92edfd64ccf0df63

commit r13-2701-g7107ea6fb933f1e928593c7e92edfd64ccf0df63
Author: Patrick Palka <ppalka@redhat.com>
Date:   Fri Sep 16 11:10:43 2022 -0400

    c++: 'mutable' member within constexpr [PR92505]

    This patch permits accessing 'mutable' members of local objects during
    constexpr evaluation, while continuing to reject it for global objects
    (as in the last line of cpp0x/constexpr-mutable1.C).  To distinguish
    between the two cases, it looks like it suffices to just check
    CONSTRUCTOR_MUTABLE_POSION in cxx_eval_component_reference before
    deciding to reject a DECL_MUTABLE_P member access.

            PR c++/92505

    gcc/cp/ChangeLog:

            * constexpr.cc (cxx_eval_component_reference): Check non_constant_p
            sooner.  In C++14 or later, reject a DECL_MUTABLE_P member access
            only if CONSTRUCTOR_MUTABLE_POISION is also set.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/constexpr-mutable3.C: New test.
            * g++.dg/cpp1y/constexpr-mutable1.C: New test.

[Bug c++/92505] Using mutable in constexpr

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92505

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |13.0
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #6 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed for GCC 13.