title: UuidToString on WinRT
body: <p>I have a C++ WinRT (Windows Phone) project and need to work with UUIDs.</p>
  
  <p>I have code like this:</p>
  
  <pre><code>UUID vol_uuid;
  CoCreateGuid(&amp;vol_uuid);
  RPC_WSTR    volbuf[256];
  UuidToString(&amp;vol_uuid, volbuf);
  </code></pre>
  
  <p>However, Visual Studio gives me a <code>UuidToString undefined</code> error on the last line. (CoCreateGuid seems OK).
  I did include <code>&lt;rpc.h&gt;</code> but the <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/aa379352%28v=vs.85%29.aspx" rel="nofollow">reference</a> states this function is desktop only.</p>
  
  <p>Is there any other library function to convert the UUID to a string?</p>