an class="special">::</span><span class="identifier">tuple</span><span class="special">&lt;&gt;</span></code> or a similar <a href="../../../../../../../libs/fusion/doc/html/index.html" target="_top">Boost.Fusion</a>
          data structure. Fortunately, starting with Boost V1.43 it is possible to
          adapt any data structure (not only, as before, structures with publicly
          accessible members) as a <a href="../../../../../../../libs/fusion/doc/html/index.html" target="_top">Boost.Fusion</a>
 