FLTK native in 'D'. Would that be useful?

[MatthiasM]

Dave wrote:
> I just happened to notice that there are no private class members in 
> window.d (for example) and looking at the original window.h there 
> probably should be.

Ouch, I did not know that. Evil little details. Yes, we assume that the 
first members without a modifier are private.

I did find two or three "friend" declarations in the source. Is there 
some equivalent in "D" or a good way to replace it?