[Bug c++/124381] New: [reflection] substituting into an annotation is not in the immediate context

[mpolacek at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124381

            Bug ID: 124381
           Summary: [reflection] substituting into an annotation is not in
                    the immediate context
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

I noticed that we don't issue an error in the test in [dcl.attr.annotation] for
/4: "Substituting into an annotation is not in the immediate context":

```
template<class T>
  [[=T::type()]] void f(T t);

void f(int);

void g() {
  f(0);         // OK
  f('0');       // error, substituting into the annotation results in an
invalid expression
}
```