title: How big is the performance gap between std::sort and std::stable_sort in practice?
body: <p>Both should run in O(n log n), but in general sort is faster than stable_sort. How big is the performance gap in practice? Do you have some experience about that?</p>
  
  <p>I want to sort a very large number of structs that have a size of about 20 bytes. The stability of the result would be nice in my case, but it is not a must. At the moment the underlying container is a plain array, perhaps it could be changed to a std::deque later on.</p>