Probably you're asking about what here is discussed: [https://forum.nim-lang.org/t/3150](https://forum.nim-lang.org/t/3150); that is, on storing different (concrete) type values in one container. You have to choose between casts, object variants, refs to objects + dynamic dispatch (methods), maybe something else, depending on your task. Just generics/concepts by themselves cannot be instantiated and so stored in containers, because of not having any run-time representation (not just now, it cannot be otherwise).
With just creating generic containers, storing values of one type for each instantiation, there's nothing special to do: just `type MyContainer[T] = seq[MyObject[T]]` and the like.
