* [Bug c++/85723] [C++17][DR 1496] __is_trivial intrinsic fails with no trivial non-deleted default c'tor
[not found] <bug-85723-4@http.gcc.gnu.org/bugzilla/>
@ 2024-06-18 12:15 ` redi at gcc dot gnu.org
2024-06-18 16:54 ` pinskia at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 5+ messages in thread
From: redi at gcc dot gnu.org @ 2024-06-18 12:15 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85723
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
And again, causing PR 115522
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug c++/85723] [C++17][DR 1496] __is_trivial intrinsic fails with no trivial non-deleted default c'tor
[not found] <bug-85723-4@http.gcc.gnu.org/bugzilla/>
2024-06-18 12:15 ` [Bug c++/85723] [C++17][DR 1496] __is_trivial intrinsic fails with no trivial non-deleted default c'tor redi at gcc dot gnu.org
@ 2024-06-18 16:54 ` pinskia at gcc dot gnu.org
2024-06-18 17:06 ` mpolacek at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 5+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-06-18 16:54 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85723
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #3)
> And again, causing PR 115522
oh and clang has not implemented this DR either which made me think that was
more of a libstdc++ issue :).
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug c++/85723] [C++17][DR 1496] __is_trivial intrinsic fails with no trivial non-deleted default c'tor
[not found] <bug-85723-4@http.gcc.gnu.org/bugzilla/>
2024-06-18 12:15 ` [Bug c++/85723] [C++17][DR 1496] __is_trivial intrinsic fails with no trivial non-deleted default c'tor redi at gcc dot gnu.org
2024-06-18 16:54 ` pinskia at gcc dot gnu.org
@ 2024-06-18 17:06 ` mpolacek at gcc dot gnu.org
2024-06-19 13:56 ` mpolacek at gcc dot gnu.org
2024-06-21 9:15 ` cvs-commit at gcc dot gnu.org
4 siblings, 0 replies; 5+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2024-06-18 17:06 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85723
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
CC| |mpolacek at gcc dot gnu.org
Assignee|unassigned at gcc dot gnu.org |mpolacek at gcc dot gnu.org
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[not found] <bug-85723-4@http.gcc.gnu.org/bugzilla/>
` (2 preceding siblings ...)
2024-06-18 17:06 ` mpolacek at gcc dot gnu.org
@ 2024-06-19 13:56 ` mpolacek at gcc dot gnu.org
2024-06-21 9:15 ` cvs-commit at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2024-06-19 13:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85723
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |patch
--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Patch posted:
https://gcc.gnu.org/pipermail/gcc-patches/2024-June/655124.html
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug c++/85723] [C++17][DR 1496] __is_trivial intrinsic fails with no trivial non-deleted default c'tor
[not found] <bug-85723-4@http.gcc.gnu.org/bugzilla/>
` (3 preceding siblings ...)
2024-06-19 13:56 ` mpolacek at gcc dot gnu.org
@ 2024-06-21 9:15 ` cvs-commit at gcc dot gnu.org
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From: cvs-commit at gcc dot gnu.org @ 2024-06-21 9:15 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85723
--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jonathan Wakely <redi@gcc.gnu.org>:
https://gcc.gnu.org/g:510ce5eed69ee1bea9c2c696fe3b2301e16d1486
commit r15-1533-g510ce5eed69ee1bea9c2c696fe3b2301e16d1486
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue Jun 18 13:27:02 2024 +0100
libstdc++: Fix std::to_array for trivial-ish types [PR115522]
Due to PR c++/85723 the std::is_trivial trait is true for types with a
deleted default constructor, so the use of std::is_trivial in
std::to_array is not sufficient to ensure the type can be trivially
default constructed then filled using memcpy.
I also forgot that a type with a deleted assignment operator can still
be trivial, so we also need to check that it's assignable because the
is_constant_evaluated() path can't use memcpy.
Replace the uses of std::is_trivial with std::is_trivially_copyable
(needed for memcpy), std::is_trivially_default_constructible (needed so
that the default construction is valid and does no work) and
std::is_copy_assignable (needed for the constant evaluation case).
libstdc++-v3/ChangeLog:
PR libstdc++/115522
* include/std/array (to_array): Workaround the fact that
std::is_trivial is not sufficient to check that a type is
trivially default constructible and assignable.
* testsuite/23_containers/array/creation/115522.cc: New test.
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