mentation</span> <span class=identifier>defined</span></b> <span class=identifier>type</span><span class=special>;};</span>
  <span class=keyword>template</span><span class=special>&lt;</span><span class=keyword>int</span> <span class=identifier>N</span><span class=special>&gt;</span>
  <span class=keyword>struct</span> <span class=identifier>nth_index_const_iterator</span>  <span class=comment><b>// deprecated</b></span>
  <span class=special>{</span><span class=keyword>typedef</span> <b><span class=identi