title: Divide ints into doubles using Swift
body: <pre><code>func avg(numbers: Int...) -&gt; Double {
      var sum = 0;
      var i = 0;
      for number in numbers {
          sum += number;
          ++i;
      }
      return sum / i;
  }
  avg(42, 597, 12);
  </code></pre>
  
  <p>The line <code>return sum / i</code> results in an error <code>Could not find an overload for '/' that accepts the supplied arguments.</code></p>
  
  <p>What am I supposed to be doing here?</p>