Usage of where in if let assignment in Swift
<p>The Swift documentation at page 61 of the Swift manual hints to the possibility of using <code>where</code> to join an optional binding with a regular condition. Yet when I do it I have a warning suggesting me to substitute the <code>where</code> with a comma like in the following piece of code:</p>

<pre><code>if let geocodingError = error as? NSError where geocodingError.code == 2
</code></pre>