title: Get matched expression inside match block
body: <p>Is it possible to access the matched expression inside a match block?</p>
  <p>Considering this example, with what should I replace <code>HERE</code>?</p>
  <pre><code>fn fetch_u32(args: &amp;mut Vec&lt;&amp;str&gt;) -&gt; Result&lt;u32,String&gt; {
      match args.remove(0).parse::&lt;u32&gt;() {
          Ok(result) =&gt; Ok(result),
          Err(_) =&gt; Err(&quot;Argument '&quot; + HERE + &quot;' is not of type uint32&quot;.to_string())
      };
  }
  </code></pre>