Declare class variable as conforming to Swift protocol

Question

In Swift, how would I declare a variable that explicitly states that it conforms to some protocol? The objective-c equivalent would be @property id<NSObject> From my understanding, doing this:

var a: NSObject

declares a variable that is of type NSObject protocol but I don't to do that, I want to declare a variable of type AnyObject that conforms. I'm also interested in finding out how to declare an array of objects in which each object conforms to that protocol.

Answer 1

There is really no need for AnyObject here; if all you care about is conformance to a protocol Proto, you can simply write var a: Proto. (In some cases your protocol may use Self or other things that require it to be used as a generic constraint; you would then use class C<T: Proto> { var a: T }.