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* [Bug c++/110216] New: Outdated implementation of tuple_size requirements for structured binding @ 2023-06-12 9:09 gnaggnoyil at gmail dot com 2023-06-12 19:24 ` [Bug c++/110216] " pinskia at gcc dot gnu.org ` (4 more replies) 0 siblings, 5 replies; 6+ messages in thread From: gnaggnoyil at gmail dot com @ 2023-06-12 9:09 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110216 Bug ID: 110216 Summary: Outdated implementation of tuple_size requirements for structured binding Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: gnaggnoyil at gmail dot com Target Milestone: --- The following code is rejected with `g++ -std=c++20` as of GCC 13.1: #include <tuple> struct A { int x; }; namespace std { template<> struct tuple_size<::A> {}; } auto [x] = A{}; Clang 16.0 on the other hand accepts this code with `-std=c++20` flag. Wording of N4849 (and also the latest working draft as of today) specifies the expected behavior in [dcl.struct.bind]#4 as follows: Otherwise, if the qualified-id std::tuple_size<E> names a complete class type with a member named value, ... Therefore, the above code shouldn't follow the requirements specified in [dcl.struct.bind]#4 as tuple-like types. Instead, it should follow those in [dcl.struct.bind]#5 and do the binding to data members. This behavior change was introduced by CWG 2386 and corresponding wording change can be found at https://github.com/cplusplus/draft/commit/498092ced200140801180dcc9c2878a49350f946 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/110216] Outdated implementation of tuple_size requirements for structured binding 2023-06-12 9:09 [Bug c++/110216] New: Outdated implementation of tuple_size requirements for structured binding gnaggnoyil at gmail dot com @ 2023-06-12 19:24 ` pinskia at gcc dot gnu.org 2023-06-12 19:25 ` [Bug c++/110216] tuple_size requirements for structured binding has not been updated after DR 2386 pinskia at gcc dot gnu.org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-06-12 19:24 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110216 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Alias| |cwg2386 Ever confirmed|0 |1 Keywords| |rejects-valid Status|UNCONFIRMED |NEW Last reconfirmed| |2023-06-12 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/110216] tuple_size requirements for structured binding has not been updated after DR 2386 2023-06-12 9:09 [Bug c++/110216] New: Outdated implementation of tuple_size requirements for structured binding gnaggnoyil at gmail dot com 2023-06-12 19:24 ` [Bug c++/110216] " pinskia at gcc dot gnu.org @ 2023-06-12 19:25 ` pinskia at gcc dot gnu.org 2023-06-13 0:10 ` mpolacek at gcc dot gnu.org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-06-12 19:25 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110216 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- https://gcc.gnu.org/projects/cxx-dr-status.html listed as ? there. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/110216] tuple_size requirements for structured binding has not been updated after DR 2386 2023-06-12 9:09 [Bug c++/110216] New: Outdated implementation of tuple_size requirements for structured binding gnaggnoyil at gmail dot com 2023-06-12 19:24 ` [Bug c++/110216] " pinskia at gcc dot gnu.org 2023-06-12 19:25 ` [Bug c++/110216] tuple_size requirements for structured binding has not been updated after DR 2386 pinskia at gcc dot gnu.org @ 2023-06-13 0:10 ` mpolacek at gcc dot gnu.org 2023-08-14 17:35 ` cvs-commit at gcc dot gnu.org 2024-04-11 18:39 ` mpolacek at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: mpolacek at gcc dot gnu.org @ 2023-06-13 0:10 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110216 Marek Polacek <mpolacek at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mpolacek at gcc dot gnu.org --- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> --- (In reply to Andrew Pinski from comment #2) > https://gcc.gnu.org/projects/cxx-dr-status.html > > listed as ? there. Updated to say "No". ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/110216] tuple_size requirements for structured binding has not been updated after DR 2386 2023-06-12 9:09 [Bug c++/110216] New: Outdated implementation of tuple_size requirements for structured binding gnaggnoyil at gmail dot com ` (2 preceding siblings ...) 2023-06-13 0:10 ` mpolacek at gcc dot gnu.org @ 2023-08-14 17:35 ` cvs-commit at gcc dot gnu.org 2024-04-11 18:39 ` mpolacek at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: cvs-commit at gcc dot gnu.org @ 2023-08-14 17:35 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110216 --- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Jason Merrill <jason@gcc.gnu.org>: https://gcc.gnu.org/g:1a43af04dd62b80f45700f94ed241347263ed773 commit r14-3204-g1a43af04dd62b80f45700f94ed241347263ed773 Author: gnaggnoyil <gnaggnoyil@gmail.com> Date: Sat Aug 12 16:16:52 2023 +0800 c++: follow DR 2386 and update implementation of get_tuple_size [PR110216] DR 2386 updated the tuple_size requirements for structured binding and it now requires tuple_size to be considered only if std::tuple_size<TYPE> names a complete class type with member value. GCC before this patch does not follow the updated requrements, and this patch is intended to implement it. (jason) Accepting pseudonym sign-off because a change this small is not legally significant for copyright. DR 2386 PR c++/110216 gcc/cp/ChangeLog: * decl.cc (get_tuple_size): Update implementation for DR 2386. gcc/testsuite/ChangeLog: * g++.dg/cpp1z/decomp10.C: Update expected error for DR 2386. * g++.dg/cpp1z/pr110216.C: New test. Signed-off-by: gnaggnoyil <gnaggnoyil@gmail.com> Reviewed-by: Jason Merrill <jason@redhat.com> ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug c++/110216] tuple_size requirements for structured binding has not been updated after DR 2386 2023-06-12 9:09 [Bug c++/110216] New: Outdated implementation of tuple_size requirements for structured binding gnaggnoyil at gmail dot com ` (3 preceding siblings ...) 2023-08-14 17:35 ` cvs-commit at gcc dot gnu.org @ 2024-04-11 18:39 ` mpolacek at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: mpolacek at gcc dot gnu.org @ 2024-04-11 18:39 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110216 Marek Polacek <mpolacek at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Seems to be fixed; I'm updating cxx-dr-status.html. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-04-11 18:39 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-06-12 9:09 [Bug c++/110216] New: Outdated implementation of tuple_size requirements for structured binding gnaggnoyil at gmail dot com 2023-06-12 19:24 ` [Bug c++/110216] " pinskia at gcc dot gnu.org 2023-06-12 19:25 ` [Bug c++/110216] tuple_size requirements for structured binding has not been updated after DR 2386 pinskia at gcc dot gnu.org 2023-06-13 0:10 ` mpolacek at gcc dot gnu.org 2023-08-14 17:35 ` cvs-commit at gcc dot gnu.org 2024-04-11 18:39 ` mpolacek at gcc dot gnu.org
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