Hi Jeffrey, Jeffrey Schwab wrote: > If the method only exists in a library class, how do you know what it > would do to your class? It sounds like the best way to get the effect > you want might be the same thing you would do in C++ or Java, viz. to > let C2 have a member of type C1, and forward method calls to the member > object according to the "Law" of Demeter. Yes, I think you're entirely right on this. If C2 doesn't know how C1#f is implemented, it's no used copying the method's implementation or even copying the implementation won't work in C2's context. Now I know that my imaginary problem was totally non-sense. Thank you for enlightening me. Sam