The situation is a bit better than just generics (as they are in Java). For instance, if I had a List<Int>, I can treat it like a List<I>, but why can't I treat

The situation is a bit better than just generics (as they are in Java). For instance, if I had a List<Int>, I can treat it like a List<I>, but why can't I treat it like an <L>Int? Or an <L><I>?