I understand that concepts are about **constraining** the parameters of generics and are not analogous to Java interfaces, nor to Julia abstract types, which drive the Julia multiple dispatch. They're more like C++ concepts. In the long excised concepts section of the manual, there were ideas (never implemented) to use the concept machinery to introduce vtables, but I guess that never panned out. I'd like to see a new concept RFC, certainly.
Now that you mention that concepts don't extend what you **can** do, quite the opposite, I'll mention that I've wanted rough feature parity between Nim generics and C++/D templates, which means template template parameters as well as variadic templates. I would prefer those to concepts, but you haven't been receptive to the idea, so I assume those won't happen. BTW, generic methods, concepts and static[T] both seem to be part of the type system. If you wouldn't call these "type system issues", what would you call them?
