Declare variable of type UIView conforming to a protocol in Swift 2

Make your class a generic class as follows,

protocol MyProtocol: class {
    func foobar()
}

class MyClass<T:MyProtocol where T:UIView> {
    var myView: T!
}

The error above says that UIView cannot specialise to protocol MyProtocol, so, the solution here would be to make your class a generic class which takes generic parameter which conforms to MyProtocol and is subclass of UIView.

Probably the best way to solve this is to use a protocol where all UIViews conform to:

protocol UIViewType {
    var view: UIView { get }
}

extension UIView: UIViewType {
    var view: UIView { return self }
}

// the variable
var myView: protocol<UIViewType, MyProtocol>

Use the view property to access UIView specific functionality.