> It requires deciding on a variance policy (to determine the subtyping relationships among the generic types)
Why does it? In C#, for example, variance policy for generic type parameters is expressed explicitly - invariant by default, covariant or contravariant if you ask for it. While C# also has reified generics, I don't see why this couldn't be done with non-reified ones.
Why does it? In C#, for example, variance policy for generic type parameters is expressed explicitly - invariant by default, covariant or contravariant if you ask for it. While C# also has reified generics, I don't see why this couldn't be done with non-reified ones.