t><h4><code>
    SA::is_saving
  </code></h4></dt>
  <dd>
    Returns the Boost MPL Integral Constant type boost::mpl::bool_&lt;true&gt;
  </dd>   
  <dt><h4><code>
    SA::is_loading
  </code></h4></dt>
  <dd>
    Returns the Boost MPL Integral Constant type boost::mpl::bool_&lt;false&gt;
  </dd>   
  <dt><h4><code>
    sa &lt;&lt; x
    <br>
    sa &amp; x
  </code></h4></dt>
  <dd>
    These expressions must perform exactly the same function.  They append the
    value of <code style="white-space: normal