title: Best way to combine integer flags using Kotlin?
body: <p>In java we regularly combine flags via the | operator.</p>
  
  <p>e.g. </p>
  
  <pre><code>getWindow().getDecorView().setSystemUiVisibility(
    View.SYSTEM_UI_FLAG_LAYOUT_STABLE | 
    View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION | 
    View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
  );
  </code></pre>
  
  <p>I can't seem to find the equivalent operator in Kotlin. Anyone know a convenient way to combine integer flags in Kotlin?</p>