title: Fast data structure for small sets
body: <p>I'm in need for a data structure that can handle small sets (10-20 strings, at most 50,  of varying length) very fast. False positives is ok, but false negatives are not. </p>
  
  <p>The last requirement makes bloom filters seem like a good fit, but I'm not sure about their speed, any other recommendations?</p>
  
  <p><em>Edit: The set only needs to support insert + membership test.</em></p>