title: Access newtype in Rust
body: <p>I'm using a newtype, wrapping an array of integers:</p>
  
  <pre><code>struct Foo([int, ..5]);
  </code></pre>
  
  <p>Since, apparently, I cannot simply do this:</p>
  
  <pre><code>let foo = Foo([1,2,3,4,5]);
  let bar = foo[2];
  </code></pre>
  
  <p>How exacty do I access the wrapped array?</p>