title: Passing lists from one function to another in Swift
body: <p>I can't quite understand why I can't past an Int[] from one function to another:</p>
  
  <pre><code>func sumOf(numbers: Int...) -&gt; Int {
      var sum = 0
      for number in numbers {
          sum += number
      }
      return sum
  }
  
  func average(numbers:Int...) -&gt; Double {
      var sum = sumOf(numbers)
  
      return Double(sum) / Double(numbers.count)
  }
  </code></pre>
  
  <p>This gives me the following error:</p>
  
  <p><code>Playground execution failed: error: &lt;REPL&gt;:138:19: error: could not find an overload for '__conversion' that accepts the supplied arguments</code></p>
  
  <pre><code>var sum = sumOf(numbers)
            ^~~~~~~~~~~~~~
  </code></pre>
  
  <p>Thanks for your help!</p>