code>Value</code> is serializable (XML-serializable). Additionally,
each of the indices of <code>m</code> can impose another requirements.<br>
<b>Exception safety:</b> Strong with respect to <code>m</code>. If an exception
is thrown, <code>ar</code> may be left in an inconsistent state.
</blockquote>

Operation: loading of a <code>multi_index_container</code> <code>m'</code> from an
input archive (XML archive) <code>ar</code>.

<blockquote>
<b>Requires:</b> <code>Value</code> is serializable (XML-serializab