https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102975
Bug ID: 102975
Summary: Local alias diagnosed as unused when used in failing
constraint
Product: gcc
Version: 12.0
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/aePcW8WjK.
```C++
template<class> concept Never = false;
template<class T> concept C = Never<typename T::type>;
void f() {
struct X {
using type = int;
};
static_assert(not C<X>);
}
```
```
<source>: In function 'void f()':
<source>:5:11: warning: typedef 'using type = int' locally defined but not used
[-Wunused-local-typedefs]
5 | using type = int;
| ^~~~
```
