My understanding is that Go provides for this by a mechanism called embedding. You can place an object i:Inner in class c:Outer and then Outer acquires all of Inner's public interface.
I think it's a nice idea. In general, Go seems to provide the language mechanism without the "moral" aspect. In other words, it saves you typing without forcing you to accept the OO paradigm (Liskov substituion etc.).
It's always felt like something you should be able to do in C++. That is, tell it to apply interface X to class Y. If the interface and class have matching function signatures, the mapping should be automatic.
