r.complexity">Complexity</a>
          </h6>
<p>
            Constant.
          </p>
<h6>
<a name="fusion.algorithm.transformation.metafunctions.filter.h4"></a>
            <span class="phrase"><a name="fusion.algorithm.transformation.metafunctions.filter.header"></a></span><a class="link" href="filter.html#fusion.algorithm.transformation.metafunctions.filter.header">Header</a>
          </h6>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span clas