title: Ruby Select and Reject in one method
body: <p>Is there any built in method that would combine the functions of <code>Enumerable.select</code> (find all which the block equates to true) and <code>Enumerable.reject</code> (find all which the block equates to false)?</p>
  
  <p>Something like</p>
  
  <pre><code>good, bad = list.magic_method { |obj| obj.good? }
  </code></pre>