Swift Typealias for Class and Protocol

Question

I have a variable that must be a UIView that also implements the protocol MTMathKeyboard.

I've tried,

var keyboard: (UIView & MTMathKeyboard)
var keyboard: UIView<MTMathKeyboard>

What's the syntax for a non-generic class instance that implements a protocol?

Answer 1

In Swift 4 you can use:

let keyboard: UIView & MTMathKeyboard

Answer 2

I think you should go this way:

protocol MTMathKeyboard: class {

}

class YourClass<MTMathKeyboard where T:UIView> {
    var keyboard: T!
}