title: Best way to concatenate vectors in Rust
body: <p>Is it even possible to concatenate vectors in Rust? If so, is there an elegant way to do so? I have something like this:</p>
  
  <pre><code>let mut a = vec![1, 2, 3];
  let b = vec![4, 5, 6];
  
  for val in &amp;b {
      a.push(val);
  }
  </code></pre>
  
  <p>Does anyone know of a better way?</p>