title: What are the 'ref' and 'sealed' keywords in C++?
body: <p>I've just seen some (presumably) C++ code which sports two "keywords" unknown to me (I'm assuming keywords but, since I have no context, they may be simple <code>#define</code> things).</p>
  
  <p>They also don't seem to appear in the C++11 standard, at least the draft I have but, since that's a pretty late draft, I can't imagine them being just dropped into the standard at the last minute. They are <code>ref</code> and <code>sealed</code>.</p>
  
  <p>The code I found them in was something like:</p>
  
  <pre><code>public ref class DevIface sealed {
      private:
          int currOffset;
  public:
          DevIface (int initOffset);
          : : :
  </code></pre>
  
  <p>Does anyone know what these keywords are, and what they're meant to achieve?</p>