title: What's the standard way to create custom conversion between types in Rust?
body: <p>If I defined some enum and wanted to create a parser from string to that type, is there something better than just:</p>
  
  <pre><code>impl TheType {
      fn from_str(s: &amp;str) -&gt; TheType { 
          // ...
      }
  }
  </code></pre>