title: Cannot assign JSON array or JSON object to a JSON using SwiftyJson in iOS
body: <p>I have a JSON object:</p>
  
  <pre><code>var x: JSON = JSON([:])
  x["1"].intValue = 1                      //Correct
  x["2"].arrayValue = [JSON("2")]          //Error
  x["3"].dictionaryValue = [3:JSON("3")]   //Error
  </code></pre>
  
  <p>I am able to assign an integer to x, but I am not able to assign any JSON array or any JSON dictionary. What am I doing wrong and how do I solve it?</p>