title: get comma separated list of enumeration's integers
body: <p>This:</p>
  
  <pre><code>string csvEnums = string.Join(",", Enum.GetNames(typeof(Bla)));
  </code></pre>
  
  <p>returns:</p>
  
  <pre><code>X1,Y1
  </code></pre>
  
  <p>given this enumeration:</p>
  
  <pre><code>public enum Bla
  {
      [Description("X")]
      X1 = 1,
      [Description("Y")]
      Y1 = 2
  }
  </code></pre>
  
  <p>Is there a similar efficient way to obtain the comma separated list:</p>
  
  <pre><code>1,2
  </code></pre>