How to deprecate member function from outside?

[Dru via Digitalmars-d-learn]

Hi,
I would like to use "deprecated" on a member function, but do it 
from a separate file

this works:
///
void func() {}

deprecated {
  void func();
}
////

this doesn't work:
////
class C{
  void func() {}
}

deprecated {
  void C.func();
}
////

I get: Error: semicolon expected, not .

Thanks