title: Merging a lot of containers with STL Algorithms
body: <p>I have a lot of lists, vectors, sets ... (what ever you prefer) of pointers called <code>RealAlgebraicNumberPtr</code> to certain class. They are sorted.</p>
  
  <p>I want to merge them and of course I want to do it fast and efficient.</p>
  
  <p>What is the best choice? <code>std::merge</code> ? Or maybe <code>std::set</code>? I can provide both an &lt; and == ordering.</p>
  
  <p>Any ideas?</p>