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?
