[Bug c++/120340] New: Can define a struct type with a trailing return type on a function type as decl inside a function

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120340

            Bug ID: 120340
           Summary: Can define a struct type with a trailing return type
                    on a function type as decl inside a function
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: accepts-invalid
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

```
void f() {
  auto(*x)()->struct{};
}
```

Should be rejected as the trailing return type is a new type def.

Outside of a function we have a parse error for the new type for the trailing
return type.

Note if we try to use x, x says it is not declared in the scope.
So this might be just an invalid code which will never really show up unless
you are looking for it.