pan>       <a name="boost.icl.unit_element_b_idp40217488.first_argument_type"></a><span class="identifier">first_argument_type</span><span class="special">;</span> 
  <span class="keyword">typedef</span> <span class="keyword">const</span> <span class="identifier">Type</span> <span class="special">&amp;</span> <a name="boost.icl.unit_element_b_idp40217488.second_argument_type"></a><span class="identifier">second_argument_type</span><span class="special">;</span>
  <span class="keyword">typedef</span> <span c