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* [Bug libstdc++/106793] New: std::barrier missing default template argument?
@ 2022-08-31 15:35 gonzalo.gadeschi at gmail dot com
2022-09-01 6:02 ` [Bug libstdc++/106793] " hewillk at gmail dot com
` (5 more replies)
0 siblings, 6 replies; 7+ messages in thread
From: gonzalo.gadeschi at gmail dot com @ 2022-08-31 15:35 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106793
Bug ID: 106793
Summary: std::barrier missing default template argument?
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: gonzalo.gadeschi at gmail dot com
Target Milestone: ---
The following example fails:
#include <barrier>
void test(std::barrier& b) { b.arrive_and_wait(); }
with the following error when compiled using g++ -std=c++20 and trunk:
<source>:3:11: error: template placeholder type 'barrier<...auto...>' must be
followed by a simple declarator-id
3 | void test(std::barrier& b) {
| ^~~
In file included from <source>:1:
/opt/compiler-explorer/gcc-trunk-20220825/include/c++/13.0.0/barrier:204:11:
note: 'template<class _CompletionF> class std::barrier' declared here
204 | class barrier
| ^~~~~~~
<source>: In function 'void test(...)'
godbolt: https://gcc.godbolt.org/z/7fE1PGq6o
My reading of the standard, here, http://eel.is/c++draft/thread.barrier#class-6
is that the standard requires barrier to have a default template argument, and
therefore, the above should work.
Is this a bug or am I misunderstanding this?
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug libstdc++/106793] std::barrier missing default template argument?
2022-08-31 15:35 [Bug libstdc++/106793] New: std::barrier missing default template argument? gonzalo.gadeschi at gmail dot com
@ 2022-09-01 6:02 ` hewillk at gmail dot com
2022-09-01 6:42 ` redi at gcc dot gnu.org
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: hewillk at gmail dot com @ 2022-09-01 6:02 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106793
康桓瑋 <hewillk at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hewillk at gmail dot com
--- Comment #1 from 康桓瑋 <hewillk at gmail dot com> ---
C++ does not allow omitting <> for function parameters like:
template<class = void>
struct S { };
void test(S& s);
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug libstdc++/106793] std::barrier missing default template argument?
2022-08-31 15:35 [Bug libstdc++/106793] New: std::barrier missing default template argument? gonzalo.gadeschi at gmail dot com
2022-09-01 6:02 ` [Bug libstdc++/106793] " hewillk at gmail dot com
@ 2022-09-01 6:42 ` redi at gcc dot gnu.org
2022-09-01 14:07 ` redi at gcc dot gnu.org
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: redi at gcc dot gnu.org @ 2022-09-01 6:42 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106793
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Indeed, you need to use barrier<>
You can clearly see the default template argument is present:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=libstdc%2B%2B-v3/include/std/barrier;h=2a2650546add5cce7b2af2c294672eaa3c03fc7e;hb=HEAD#l203
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug libstdc++/106793] std::barrier missing default template argument?
2022-08-31 15:35 [Bug libstdc++/106793] New: std::barrier missing default template argument? gonzalo.gadeschi at gmail dot com
2022-09-01 6:02 ` [Bug libstdc++/106793] " hewillk at gmail dot com
2022-09-01 6:42 ` redi at gcc dot gnu.org
@ 2022-09-01 14:07 ` redi at gcc dot gnu.org
2022-09-07 15:27 ` [Bug c++/106793] poor diagnostic for missing template argument list on function parameter jason at gcc dot gnu.org
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: redi at gcc dot gnu.org @ 2022-09-01 14:07 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106793
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
GCC's error is not helpful, but clang clearly explains what's wrong:
error: use of class template 'barrier' requires template arguments; argument
deduction not allowed in function prototype
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/106793] poor diagnostic for missing template argument list on function parameter
2022-08-31 15:35 [Bug libstdc++/106793] New: std::barrier missing default template argument? gonzalo.gadeschi at gmail dot com
` (2 preceding siblings ...)
2022-09-01 14:07 ` redi at gcc dot gnu.org
@ 2022-09-07 15:27 ` jason at gcc dot gnu.org
2022-09-07 17:37 ` cvs-commit at gcc dot gnu.org
2022-09-07 17:38 ` jason at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: jason at gcc dot gnu.org @ 2022-09-07 15:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106793
Jason Merrill <jason at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
CC| |jason at gcc dot gnu.org
Assignee|unassigned at gcc dot gnu.org |jason at gcc dot gnu.org
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/106793] poor diagnostic for missing template argument list on function parameter
2022-08-31 15:35 [Bug libstdc++/106793] New: std::barrier missing default template argument? gonzalo.gadeschi at gmail dot com
` (3 preceding siblings ...)
2022-09-07 15:27 ` [Bug c++/106793] poor diagnostic for missing template argument list on function parameter jason at gcc dot gnu.org
@ 2022-09-07 17:37 ` cvs-commit at gcc dot gnu.org
2022-09-07 17:38 ` jason at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2022-09-07 17:37 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106793
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jason Merrill <jason@gcc.gnu.org>:
https://gcc.gnu.org/g:b9cb441c98f265bff86a1c228932524c5fd37dd3
commit r13-2527-gb9cb441c98f265bff86a1c228932524c5fd37dd3
Author: Jason Merrill <jason@redhat.com>
Date: Fri Sep 2 08:45:02 2022 -0400
c++: diagnostic for template placeholder in parm [PR106793]
Talking about the declarator form doesn't help when fixing that would get
you a different error about placeholders not being valid in a parameter.
This also adds a <> fixit, which isn't enough for most templates, but is a
start.
PR c++/106793
gcc/cp/ChangeLog:
* decl.cc (grokdeclarator): Improve placeholder diagnostics.
* parser.cc (cp_parser_type_id_1): Add fixit.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/auto-array2.C: Adjust.
* g++.dg/cpp1z/class-deduction113.C: New test.
^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug c++/106793] poor diagnostic for missing template argument list on function parameter
2022-08-31 15:35 [Bug libstdc++/106793] New: std::barrier missing default template argument? gonzalo.gadeschi at gmail dot com
` (4 preceding siblings ...)
2022-09-07 17:37 ` cvs-commit at gcc dot gnu.org
@ 2022-09-07 17:38 ` jason at gcc dot gnu.org
5 siblings, 0 replies; 7+ messages in thread
From: jason at gcc dot gnu.org @ 2022-09-07 17:38 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106793
Jason Merrill <jason at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |FIXED
Target Milestone|--- |13.0
Status|ASSIGNED |RESOLVED
--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-09-07 17:38 UTC | newest]
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2022-08-31 15:35 [Bug libstdc++/106793] New: std::barrier missing default template argument? gonzalo.gadeschi at gmail dot com
2022-09-01 6:02 ` [Bug libstdc++/106793] " hewillk at gmail dot com
2022-09-01 6:42 ` redi at gcc dot gnu.org
2022-09-01 14:07 ` redi at gcc dot gnu.org
2022-09-07 15:27 ` [Bug c++/106793] poor diagnostic for missing template argument list on function parameter jason at gcc dot gnu.org
2022-09-07 17:37 ` cvs-commit at gcc dot gnu.org
2022-09-07 17:38 ` jason at gcc dot gnu.org
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