What's the replacement of '++' and '--' in swift3? : <p>Since the expression '++' and '--' will be removed in Swift 3, the follow code will be invalid.</p>

<pre><code> return i &lt; 0 ? nil : i-- 
</code></pre>

<p>Now I just rewrite it like this</p>

<pre><code>if i &lt; 0 {
   return nil
}
let res = i
i -= 1
return res
</code></pre>

<p>But it looks too .... cumbersome.</p>

<p>How to rewrite this code as short as possible in Swift 3?</p>
