Friends?

[Jeremy DeHaan]

Hey guys!

I think I understand the reasoning behind the idea that classes 
in the same module are automatically "friends", but why isn't 
there any way to have this sort of relationship between classes 
outside of a module? I feel like there are times when it doesn't 
always make sense to have two(or more) classes in the same 
module, but you would still need to make them interact like 
"friends."

Is there any kind of work around for this functionality?

And in case you were curious, my main problem with this is that I 
think it is a lot cleaner when writing code and easier to manage 
my projects when I can split things up into different files. I'm 
currently working on a wrapper for a C++ api and started wishing 
I could do this a few days ago.