-.2C_and_ref-qualified_member_functions">ref-qualified</a>,
does not match exactly what <code>const_mem_fun</code> expects. Fortunately, Boost.MultiIndex
provides a variant to fit:
</p>

<blockquote><pre>
<span class=keyword>typedef</span> <span class=identifier>multi_index_container</span><span class=special>&lt;</span>
  <span class=identifier>employee</span><span class=special>,</span>
  <span class=identifier>indexed_by</span><span class=special>&lt;</span>
    <span class=special>...</span>
    <span c