title: Swift 2 API Availability Check for storyboard
body: <p>I have an existing iOS application which is supports from iOS 8. i want to add new features only for iOS 9.</p>
  
  <p>I have created a new storyboard for iOS 9 which is using the iOS 9 features like UIStackView. Appropriate storyboard file is instantiated based on the Device OS version.  </p>
  
  <pre><code>func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -&gt; Bool {
  
      let storyboard: UIStoryboard
      if #available(iOS 9, *, *) {
          storyboard = UIStoryboard(name: "Main", bundle: nil)
      } else {
          storyboard = UIStoryboard(name: "MainOld", bundle: nil)
      }
      let mainViewController = storyboard.instantiateInitialViewController()
      window?.rootViewController = mainViewController
      window?.makeKeyAndVisible()
      return true
  }
  </code></pre>
  
  <p>But i am getting compilation error on Main.storyboard "UIStackView before iOS 9.0"</p>
  
  <p>I am using Xcode 7 beta 5.</p>
  
  <p>How to use the iOS 9 related features on the iOS 8 supported projects using Swift 2 #availability check </p>