title: Make a UIBarButtonItem disappear using swift IOS
body: <p>I have an IBOutlet that I have linked to from the storyboard</p>
  
  <pre><code>@IBOutlet var creeLigueBouton: UIBarButtonItem!
  </code></pre>
  
  <p>and I want to make it disappear if a condition is true</p>
  
  <pre><code>if(condition == true)
  {
      // Make it disappear
  }
  </code></pre>