title: Is there any easy way to merge two arrays in swift along with removing duplicates?
body: <p>Basically I need a version of <code>appendContentsOf:</code> which does not append <strong>duplicate</strong> elements.</p>
  
  <p><strong>Example</strong></p>
  
  <pre><code>var a = [1, 2, 3]
  let b = [3, 4, 5]
  
  a.mergeElements(b)
  //gives a = [1, 2, 3, 4, 5] //order does not matter
  </code></pre>