Swift Protocol Extensions: Adding #selector for a UIViewController

Question

I am trying to add a UITapGestureRecognizer to a UIViewController via a swift protocol extension. I run into a problem when I try intialize the tapGestureRecognizer with a #selector. I have setup the following in a playground

protocol Tapable {
    func setupTapGestureRecognizerInView(view: UIView)
    func didTap(sender: UITapGestureRecognizer)
}

extension Tapable where Self: UIViewController {
    func setupTapGestureRecognizerInView(view: UIView) {
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.didTap(_:)))
        tapGesture.numberOfTapsRequired = 1
        view.addGestureRecognizer(tapGesture)
    }

    func didTap(sender: UITapGestureRecognizer) {
    }
}

class SomeViewController: UIViewController, Tapable {

}

In the above scenario, I get a compiler error with the message "Argument of #selector refers to a method that is not exposed to Objective-C

I can fix the compiler error if I prepend the protocol declaration with @objc i.e

@objc protocol Tapable {
    func setupTapGestureRecognizerInView(view: UIView)
    func didTap(sender: UITapGestureRecognizer)
}

However, if I add the @objc, I get a compiler error in the UIViewController saying that "Type SomeViewController does not conform to protocol 'Tapable'". It also suggests a Fix-it "Canditate is not @objc but protocol requires it".

Tapping this Fix-it prepends the setupTapGestureRecognizer with @objc in the extension (i.e. @objc func setupTapGestureRecognizerInView(view: UIView) {, however this does not resolve the compiler error and also causes a second compiler error which tells me to do delete the @objc that the Fix-it just added

How can I add a #selector via a protocol extension for a UIViewController?