https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115911
Bug ID: 115911
Summary: [OpenMP]gcc rejects valid user defined openmp
reduction in template class with default argument
Product: gcc
Version: 13.2.0
Status: UNCONFIRMED
Keywords: openmp, rejects-valid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: rush102333 at gmail dot com
Target Milestone: ---
The following code is rejected by gcc-13.2:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
$g++ -fsyntax-only -fopenmp tst.cpp
template<typename T,int=0> struct A
{
#pragma omp declare reduction (add : T : omp_out += omp_in) initializer
(omp_priv = 0)
};
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The compiler outputs the following error message:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<source>:3:44: error: default argument for template parameter for class
enclosing 'static void A<T, <anonymous> >::omp declare reduction add(T&)'
3 | #pragma omp declare reduction (add : T : omp_out += omp_in)
initializer (omp_priv = 0)
| ^
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Removing class A's default template argument "int=0" can eliminate the
diagnostic. Clang and icc always accept the code.
https://godbolt.org/z/3z36M8chv
