title: Use of unresolved identifier 'UIUserInterfaceIdiomPad'
body: <p>I've created a new Swift-based project using Xcode 7.2. Upon writing the following code within the viewDidLoad() method in my ViewController.swift file:</p>
  
  <pre><code>if UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad {
  
  }
  </code></pre>
  
  <p>I get the error message "Use of unresolved identifier 'UIUserInterfaceIdiomPad'", and the compiler won't proceed.</p>
  
  <p>I suspected it was something to do with the "import UIKit" at the top? For some reason if I delete that line and begin typing "import UI" it doesn't provide me autocomplete options at all.</p>
  
  <p>Things I've tried:</p>
  
  <ul>
  <li>Restarting computer and Xcode</li>
  <li>Deleting derived data folder</li>
  <li>Creating a new project in Swift</li>
  <li>Trying out the code in an Objective-C based project (works!)</li>
  </ul>
  
  <p>Questions:</p>
  
  <ul>
  <li>Why am I getting this error message?</li>
  <li>Why doesn't "import UIKit" autocomplete?</li>
  </ul>
  
  <p>Thanks!</p>