title: What is the Swift 3 equivalent of NSURL.URLByAppendingPathComponent()?
body: <p>I'm following <a href="https://developer.apple.com/library/ios/referencelibrary/GettingStarted/DevelopiOSAppsSwift/Lesson10.html#//apple_ref/doc/uid/TP40015214-CH14-SW1" rel="noreferrer">a basic tutorial</a> on building a simple iOS app in Swift.</p>
  
  <p>It is written in Swift 2.x, and I work with XCode 8 Beta and Swift 3. </p>
  
  <p>The tutorial suggests using <code>NSFileManager</code> to find a data directory. Class names have changed, so the auto-fixed Swift 3 looks like this:</p>
  
  <pre><code>static let DocumentsDirectory = FileManager().urlsForDirectory(.documentDirectory, inDomains:.userDomainMask).first!
  static let ArchiveURL = DocumentsDirectory.URLByAppendingPathComponent("meals")
  </code></pre>
  
  <p>However, Xcode now complains that </p>
  
  <pre><code>Value of type 'URL' has no member 'URLByAddingPathComponent'
  </code></pre>
  
  <p>I am unable to find out what the method is called now.</p>
  
  <p>The <a href="https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSURL_Class/" rel="noreferrer">NSURL Class Reference</a> doesn't contain any hints as to how to address it from Swift 3</p>
  
  <ul>
  <li><p>What is the new method name?</p></li>
  <li><p>Where do I have to go to find a complete class reference for Swift 3 (or, the Swift 3 interface to the library the <code>URL</code> class is defined in - I still don't completely understand the nomenclature) so I can research these myself in the future?</p></li>
  </ul>