w element yields
<code>self.endIndex</code>.</p>

<p>Complexity: amortized O(1).</p>

    <h4>Declaration</h4>    
    <code class="language-swift">mutating func append(x: Self.Generator.Element)</code>
    
        <h4>Declared In</h4>
        <a href="../../protocol/_ExtensibleCollectionType/"><code>_ExtensibleCollectionType</code></a>    
</div></div>
</div>
<div class="declaration inherited" id="func-extend_">
<a class="toggle-link" data-toggle="collapse" href="#comment-func-extend_">mutating func exten