title: Which is correct? catch (_com_error e) or catch (_com_error& e)?
body: <p>Which one should I use?</p>
  
  <pre><code>catch (_com_error e)  
  </code></pre>
  
  <p>or  </p>
  
  <pre><code>catch (_com_error&amp; e)
  </code></pre>