ifference_type</span> <a name="boost.compute.transform_iterator.difference_type"></a><span class="identifier">difference_type</span><span class="special">;</span>
  <span class="keyword">typedef</span> <span class="identifier">UnaryFunction</span>               <a name="boost.compute.transform_iterator.unary_function"></a><span class="identifier">unary_function</span><span class="special">;</span> 

  <span class="comment">// <a class="link" href="transform_iterator.html#boost.compute.transform_iteratorcons