calling class name in the header file
<p>I just stumbled a c++ code with a calling of a class name in the upper part of the header file for example</p>

<pre><code>class CFoo;
class CBar
{
  ....
};
</code></pre>

<p>My question is, what is <code>class CFoo</code> for?</p>

<p>Thanks alot!</p>
