How does Optional covariance work in Swift

Question

How does covariance work for Optionals in Swift?

Say I write the following code:

var nativeOptionalView: Optional
let button =         


        

Answer 1

While I agree that there is probably some "compiler magic" going on, this can be accomplished in your custom implementation by casting the button to a UIView, e.g.

var myOptionalButton = MyOptional.Some(button as UIView)

or

var myOptionalButton: MyOptional = .Some(button)