https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98924
Bug ID: 98924
Summary: Ambiguous name in concept-id diagnosed as parser error
Product: gcc
Version: 11.0
URL: https://godbolt.org/z/Txrvos
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: johelegp at gmail dot com
CC: johelegp at gmail dot com
Target Milestone: ---
See https://godbolt.org/z/Txrvos.
```C++
namespace A{bool X;}
namespace B{bool X;}
using namespace A;
using namespace B;
template<bool>concept C=true;
bool b=C<X>;
```
```
<source>:6:8: error: parse error in template argument list
6 | bool b=C<X>;
| ^~~~
<source>:6:8: error: template argument 1 is invalid
Compiler returned: 1
```
