>template</span><span class=special>&lt;</span><span class=keyword>typename</span> <span class=identifier>Tag</span><span class=special>,</span><span class=keyword>typename</span> <span class=identifier>IteratorType</span><span class=special>&gt;</span>
    <span class=keyword>typename</span> <span class=identifier>index</span><span class=special>&lt;</span><span class=identifier>Tag</span><span class=special>&gt;::</span><span class=identifier>type</span><span class=special>::</span><span class=identifier>