title: How to use ? and catch in Rust?
body: <p>It seems that <a href="https://www.reddit.com/r/rust/comments/44chyr/the_traitbased_exceptions_rfc_has_been_accepted/" rel="nofollow noreferrer"><code>?</code> and <code>catch</code> have been accepted into Rust</a>, but I am not able to use it properly:</p>
  
  <pre><code>let x = catch {
      1
  }
  </code></pre>
  
  <p>I think this should give me <code>Ok(1)</code>. Instead, I get the error:</p>
  
  <pre class="lang-none prettyprint-override"><code>error: expected identifier, found `1`
    --&gt; src/main.rs:15:9
     |
  15 |         1
     |         ^
  </code></pre>
  
  <p>Is this syntax not yet supported in Rust, or is there a problem with my code?</p>