title: Can't use method return value in write context
body: <p>I would think the following piece of code should work, but it doesn't <strong>(Edited: Now works in PHP 5.5+)</strong>:</p>
  
  <pre><code>if (!empty($r-&gt;getError()))
  </code></pre>
  
  <p>Where <code>getError()</code> is simply:</p>
  
  <pre><code>public function getError()
  {
      return $this-&gt;error;
  }
  </code></pre>
  
  <p>Yet I end up with this error:</p>
  
  <blockquote>
    <p>can't use method return value in write context</p>
  </blockquote>
  
  <p>What does this mean? Isn't this just a read?</p>