sandofsky

typealias Callback = () -> ()

// Both methods are required
class Something {
   var calledOnce:Callback?
   var calledMultipleTimes:Callback?
}

sandofsky

import UIKit

protocol StoryboardBacked:class {
    static func newFromStoryboardWithName(name:String?, bundle:NSBundle?) -> Self
}

extension StoryboardBacked {
    static func newFromStoryboardWithName(name:String?, bundle:NSBundle?) -> Self {
        let realName = name ?? NSStringFromClass(self as AnyClass).componentsSeparatedByString(".").last!
        let storyboard = UIStoryboard(name: realName, bundle: bundle)

sandofsky

import AVFoundation
import UIKit

class ViewController: UIViewController {

    var discoverSession:MyDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInDualCamera, .builtInWideAngleCamera, .builtInTelephotoCamera], mediaType: .video, position: .back)

    @IBAction func didTapCrashButton(_ sender: Any) {
        let devices = discoverSession.myDevices
        print("Got devices: \(devices)")