title: How to append a character to a string in Swift?
body: <p>This used to work in Xcode 6: Beta 5. Now I'm getting a compilation error in Beta 6.</p>
  
  <pre><code>for aCharacter: Character in aString {
      var str: String = ""
      var newStr: String = str.append(aCharacter) // ERROR
      ...
  }
  </code></pre>
  
  <p><strong>Error</strong>: Cannot invoke <code>append</code> with an argument of type <code>Character</code></p>