title: Ruby |= assignment operator
body: <p>Found table <a href="http://phrogz.net/programmingruby/language.html#table_18.4" rel="noreferrer">http://phrogz.net/programmingruby/language.html#table_18.4</a> but unable to find description for <code>|=</code></p>
  
  <p>How the <code>|=</code> assignment operator works?</p>