Structs implementing interfaces in D1

[grauzone]

> Now this would be so much nicer if there was a way to iterate the 
> functions of an interface at compile time in D1... Can we have D1 plus 
> __traits? Pleaaaase? Pretty please with a cherry on top?

Seriously, this is one of the only things that make me actually want to 
use D1.0. Seems like I'm not the only one.

Therefore, it will never happen. Walter wants people to use D2.0, of course.