_custom_relation</span></code>
          method:
        </p>
<p>
</p>
<pre class="programlisting"><span class="comment">// The function checks if the point is inside the rectangle</span>
<span class="keyword">bool</span> <span class="identifier">is_in_rectangle</span><span class="special">(</span><span class="identifier">logging</span><span class="special">::</span><span class="identifier">value_ref</span><span class="special">&lt;</span> <span class="identifier">point</span> <span class="special">&gt;</sp