title: Using "if let..." with many expressions
body: <p>This idiom of Swift makes good sense</p>
  
  <pre><code>if let x = someDict[someKey] { ... }
  </code></pre>
  
  <p>However, what I <em>really</em> want is </p>
  
  <pre><code>if let x = someDict[someKey], y = someDict[someOtherKey] { ... }
  </code></pre>
  
  <p>As written this is not incorrect, but is this idea possible?</p>