rs are the arguments to the meta-function and a typedef 
      within the class is the meta-function's return type. Here is the corresponding 
      meta-function:<code><br>
      <br>
      <span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">typename</span> 
      ArgT<span class="special">&gt;</span><br>
      <span class="keyword">struct</span> identity_meta_func<br>
      <span class="special">{</span> <span class="keyword">typedef</span> ArgT 
      type<span cl