title: Swift string from optional Double
body: <p>Is there a shortcut to specify placeholder text when the value is nil in Swift?</p>
  
  <p>Right now I do:</p>
  
  <pre><code>let myText:String!
  if myDouble != nil{
    myText = "\(myDouble!)"
  }else{
    myText = "Value not provided"
  }
  </code></pre>
  
  <p>That works, but it's very annoying to have to do that all the time. Is there a way to do something like</p>
  
  <pre><code>let myText:String = "\(myDouble ?? "Value no provided")"
  </code></pre>
  
  <p>That fails because it wants a default Double value, but I really want a String value.</p>