title: Cannot override initializer of NSDictionary in Swift
body: <p>I'm trying to extend the class NSDictionary in Swift to contain an NSDate that is set on init(). When I add my custom init(), I get the complier error:</p>
  
  <blockquote>
    <p>'required' initializer 'init(dictionaryLiteral:)' must be provided by
    subclass of 'NSDictionary'</p>
  </blockquote>
  
  <p>However, when I add that initializer using auto-complete, I get the following error:</p>
  
  <blockquote>
    <p>Declarations from extensions cannot be overridden yet</p>
  </blockquote>
  
  <p>Is there any way to override the initializer of NSDictionary or can Swift just not handle that yet?</p>
  
  <p>Here's my class:</p>
  
  <pre><code>class DateParam : NSDictionary {
      let date : NSDate
  
      init(date: NSDate) {
          super.init()
          self.date = date
      }
  
      required init(coder aDecoder: NSCoder) {
          fatalError("init(coder:) has not been implemented")
      }
  
      required convenience init(dictionaryLiteral elements: (NSCopying, AnyObject)...) {
          fatalError("init(dictionaryLiteral:) has not been implemented")
      }
  }
  </code></pre>