title: How to iterate a Vec<T> with the indexed position?
body: <p>I need to iterate a <code>Vec</code> including the position for each iterated element. I'm sure this is already in the API but I cannot see it. </p>
  
  <p>I need something like this:</p>
  
  <pre><code>fn main() {
      let v = vec![1; 10];
      for (pos, e) in v.iter() {
          // do something here
      }
  }
  </code></pre>