title: Is Swift’s filter method stable?
body: <p>When I filter an array in Swift, can I expect the results to be in the same order as the original? For example, can I count on:</p>
  
  <pre><code>[3, 1, 4, 1, 5, 9, 2, 7].filter{$0 &gt; 4}
  </code></pre>
  
  <p>always returning:</p>
  
  <pre><code>[5, 9, 7]
  </code></pre>
  
  <p>?</p>