 type of <code>xk</code>, or the type contained in <code>xk</code> if <code>xk</code> is a <code><a class="el" href="structboost_1_1hana_1_1type.html" title="C++ type in value-level representation. ">hana::type</a></code>. </p><dl class="section warning"><dt>Warning</dt><dd>The limitations on the size of <code><a class="el" href="structboost_1_1mpl_1_1list.html" title="Adapter for Boost.MPL lists. ">mpl::list</a></code>s are inherited by this conversion utility, and hence trying to convert a <code>Foldable<