title: Replace a key in a std::map
body: <p>I'm using the std::map to save some stuff, the key is Guid*.</p>
  
  <pre><code>typedef boost::tuple&lt;c_ptr, handler_ptr&gt; ctuple;
  typedef std::map&lt;GUID *, ctuple&gt; c_map;
  </code></pre>
  
  <p>My question is:
  Do I have a way to change the key of an item in the std::map? <strong>OTHER THAN</strong> copy the existing data to a new item that have the new key and remove the prev/old item (with the old key)</p>
  
  <p>Thanks </p>