title: How to make a custom array class return boolean value when it is empty
body: <p>I have a class as below:</p>
  
  <pre><code>class Fields implements ArrayAccess, Countable, SeekableIterator 
  {
     $this-&gt;_fields = array();
  
     ...continue
  }
  </code></pre>
  
  <p>I want to have my class have the following boolean capability</p>
  
  <pre><code>$myArray = new Fields();
  if($myArray == false)
  {
     echo 'It is empty';
  }
  </code></pre>
  
  <p>How the above behaviour to be implemented in my class</p>