Swift: Is there a way to test if object cast as AnyObject conforms to Equatable?

Question

I have an object that has keyed properties:

func value(key: String) -> AnyObject?
func setValue(value: AnyObject?, key: String)

I wish to check if the value returned from the value function with the same key from two different objects are Equatable. Swift complains because Equatable has a Self reference and can only be used in generics. Is there a way I can check to see if the AnyObject object returned from the value function conforms to Equatable?

Answer 1

Due to changes in Swift 2, I'm editing m'y answer

To check protocol conformance, simply use is keyword.

But you can't do it when the protocol is using Self (note the capital S).

So you could do:

if let myValue = myObject.value(myKey) as? Equatable {
    ...
}