title: Iterate an array with index in Swift 3
body: <p>I'm trying to iterate an array with an index in Swift 3 but keep getting</p>
  
  <blockquote>
    <p>Expression type '[Int]' is ambiguous without more context</p>
  </blockquote>
  
  <p>this is reproducible with the following example in a playground:</p>
  
  <pre><code>var a = [Int]()
  a.append(1)
  a.append(2)
  // Gives above error
  for (index, value) in a {
    print("\(index): \(value)")
  }
  </code></pre>
  
  <p>I'm not sure what context it is asking for.</p>