title: When to use main queue
body: <p>I know any updates to UI should be run inside the main queue using the below syntax:</p>
  
  <pre><code>dispatch_async(dispatch_get_main_queue()) {
     UI update code here
  }
  </code></pre>
  
  <p>What about these other cases?</p>
  
  <p>In my viewDidLoad(), I have code to stylize the navbar and toolbar, like below:</p>
  
  <pre><code>    let nav = self.navigationController?.navigationBar
      nav?.barStyle = UIBarStyle.Default
      nav?.tintColor = UIColor.blackColor()
      nav?.barTintColor = UIColor(red:133.0/255, green:182.0/255, blue:189.0/255, alpha:1.0)
  
      let toolBar = self.navigationController?.toolbar
      toolBar?.barTintColor = UIColor(red:231/255, green:111/255, blue:19.0/255, alpha:1.0)
      toolBar?.tintColor = UIColor.blackColor()
  </code></pre>
  
  <p>Should I wrap this code inside the main queue as well?</p>
  
  <p>In my tableView cellForRowAtIndexPath function, should I wrap all the code setting up the UI of each table cell in the main queue as well?</p>
  
  <p>When I present a new modal controller (self.presentViewController(modalController, animated: true, completion: nil), should I wrap this inside the main queue?</p>