title: Swift string length strange behavior
body: <p>As a swift newbie, I find this behavior very odd. What's going on here? </p>
  
  <pre><code>"asdf".length  # 4 
  var s = "asdf"
  s.length # error: String does not have a member named length
  </code></pre>
  
  <p>I know you're supposed to use <code>count(s)</code> instead of <code>s.length</code> in swift 1.2. But why does <code>"asdf".length</code> work? </p>