title: performSelector:onThread: in Swift?
body: <p>In a current iOS app I am using this perform selector approach:    </p>
  
  <pre><code>[self performSelector:@selector(doSomething)
               onThread:myThread
             withObject:nil
          waitUntilDone:NO
                  modes:[NSArray arrayWithObject:NSRunLoopCommonModes]];
  </code></pre>
  
  <p>I am not sure how to make a selector run on a specific thread in swift. Any suggestions?</p>