_const_iterator</code> is deprecated.
</blockquote>

<code>template&lt;typename Tag> struct index_iterator</code>

<blockquote>
<code>index_iterator&lt;Tag>::type</code> is equivalent to
<code>index&lt;Tag>::type::iterator</code>.<br>
<b>Note:</b> The use of <code>index_iterator</code> is deprecated.
</blockquote>

<code>template&lt;typename Tag> struct index_const_iterator</code>

<blockquote>
<code>index_const_iterator&lt;Tag>::type</code> is equivalent to
<code>index&lt;Tag>::type::const_iterator</code>.