title: shortest expression to return false for negative number and the number itself for positive number (or zero)
body: <p>What is the shortest expression I can use to return <code>false</code> for all <code>numbers &lt; 0</code> and the number itself for all <code>numbers &gt;= 0</code>?</p>
  
  <p>Left is what I have, right is want I want to be returned.</p>
  
  <pre><code>-3: false
  -1: false
   0:  0
   1:  1
  23: 23
  </code></pre>
  
  <p>Something really short like:</p>
  
  <pre><code>(!!number)   &lt;-- (doenst work)
  </code></pre>