keyword">class</span> <span class="identifier">UnaryFunction</span><span class="special">&gt;</span>
<span class="keyword">class</span> <span class="identifier">function_output_iterator</span> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
  <span class="keyword">typedef</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">output_iterator_tag</span> <span class="identifier">iterator_category</span><span class="spe