title: Swift: assign optional value into non-optional var
body: <p>Is there any concise way built into the language to <em>attempt</em> to assign the contents of a Swift optional into a non-optional <code>var</code>, simply doing nothing if the optional contains <code>nil</code>?</p>
  
  <p>Essentially I'm imagining something like optional chaining ("execute this method call on this optional only if the optional is non-<code>nil</code>") but for assignment, e.g.:</p>
  
  <pre><code>// Fictional code. Assigns into nonOptional if non-nil; does nothing if nil:
  nonOptional =? mightBeNil
  
  // Equivalent but less concise real code:
  if let notNil = mightBeNil {
      nonOptional = notNil
  }
  </code></pre>