title: C++ in condition
body: <p>How to check if a value is in a on-the-fly created set. I'm looking for some syntactic sugar, like we have in python</p>
  
  <pre><code>if s in set(['first','second','third','fourth']):
      print "It's one of first,second,third,fourth";
  </code></pre>
  
  <p>How can it be done efficiently in C++?</p>