title: How to get enum's numeric value?
body: <p>Suppose you have</p>
  
  <pre><code>public enum Week {
      SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY
  }
  </code></pre>
  
  <p>How can one get <code>int</code> representing that Sunday is 0, Wednesday is 3 etc?</p>