title: How to get the current queue name in swift 3
body: <p>We have function like this in swift 2.2 for printing a log message with the current running thread: </p>
  
  <pre><code>func MyLog(_ message: String) {
      if Thread.isMainThread {
          print("[MyLog]", message)
      } else {
          let queuename = String(UTF8String: dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL))! // Error: Cannot convert value of type '()' to expected argument type 'DispatchQueue?'
          print("[MyLog] [\(queuename)]", message)
      }
  }
  </code></pre>
  
  <p>These code no longer compile in swift 3.0. How do we obtain the queue name now? </p>