This feature was implemented a long time ago and is available on every branch of Copper
Creating classes is an interesting paradigm (should be spelled “paradym”, but nobody asked me). Many languages implement such a feature (C++, Ruby, PHP, etc.), some languages make the feature so terse it’s hard to recognize without reading docs, some languages don’t even bother with it, but you can still implement it with some work. There have been a number of arguments about whether closures and classes are essentially the same thing with different names, but I’m on the side that thinks otherwise. It’s a matter of construction, and certainly closures are far easier to create in some languages than in others. I won’t go into a discussion of class versus closure, but I will admit that the line is certainly very blurry, and Copper adds another dimension to it.