title: How do I "export" things from a submodule?
body: <p>I'd like to write a <code>mod.rs</code> file like:</p>
  
  <pre><code>pub use foo::*;
  
  mod foo;
  pub mod bar;
  </code></pre>
  
  <p>But I get the error <code>unresolved import <code>foo</code></code>. What's the correct way to do this?</p>