title: Symfony2: class MapClassLoader not found
body: <p>I'm trying to use <code>MapClassLoader</code> in <code>autoload.php</code> but for some reason I keep getting errors saying</p>
  
  <pre><code>Class 'Symfony\Component\ClassLoader\MapClassLoader' not found in ...\autoload.php
  </code></pre>
  
  <p>autoload.php:</p>
  
  <pre><code>&lt;?php
  
  use Symfony\Component\ClassLoader\UniversalClassLoader;
  use Symfony\Component\ClassLoader\MapClassLoader;
  use Doctrine\Common\Annotations\AnnotationRegistry;
  
  $loader = new UniversalClassLoader();
  $loader-&gt;registerNamespaces(array(
      //some values
  ));
  
  $mapLoader = new MapClassLoader(array(
      //some values
  ));
  
  $mapLoader-&gt;register();
  </code></pre>
  
  <p>I double checked and <code>MapClassLoader.php</code> <strong>does</strong> exist in <code>Symfony\Component\ClassLoader</code></p>
  
  <p>Any idea why is it happening? :/</p>