Custom Covariance/Contravariance

(Peter Livesey) #1

I'm working on a proposal for adding covariance and contravariance to
custom classes. For instance:

let a = MyBag<Dog>()
let b: MyBag<Animal> = a

I cannot find any threads which have discussed this yet, but maybe I'm
missing something. Has this been discussed?

If not, I'll continue with my proposal and have something more soon.