title: Is there any trait that specifies numeric functionality?
body: <p>I'd like to use a trait to bound a generic type, like this hypothetical <code>HasSQRT</code>:</p>
  
  <pre><code>fn some_generic_function&lt;T&gt;(input: &amp;T)
  where
      T: HasSQRT,
  {
      // ...
      input.sqrt()
      // ...
  }
  </code></pre>