h:
<pre><code>#include &quot;boost/tuple/tuple_comparison.hpp&quot;</code></pre>

<p>To use tuple input and output operators,

<pre><code>#include &quot;boost/tuple/tuple_io.hpp&quot;</code></pre>

Both <code>tuple_io.hpp</code> and <code>tuple_comparison.hpp</code> include <code>tuple.hpp</code>.

<p>All definitions are in namespace <code>::boost::tuples</code>, but the most common names are lifted to namespace <code>::boost</code> with using declarations. These names are: <code>tuple</code>, <code>make_tu