 class="discussion comment">
    <p>A type that provides subscript access to its elements, with bidirectional
index traversal.</p>

<p>In most cases, it&#39;s best to ignore this protocol and use the
<code>BidirectionalCollection</code> protocol instead, because it has a more complete
interface.</p>

<p><em>Deprecated:</em> it will be removed in Swift 4.0.  Please use &#39;BidirectionalCollection&#39; instead.</p>
</div>

<table class="standard">
<tr>
<th id="inheritance">Inheritance</th>
<td>
<code class="