v><div class="line"><span class="preprocessor">#include &lt;utility&gt;</span></div><div class="line"><span class="keyword">namespace </span>hana = <a class="code" href="namespaceboost_1_1hana.html">boost::hana</a>;</div><div class="line"></div><div class="line"></div><div class="line"><span class="comment">// Sample implementation of a compile-time set data structure. Of course,</span></div><div class="line"><span class="comment">// this naive implementation only works when no two elements of the same</spa