Which is the fastest STL container for find?

Question

Alright as a preface I have a need to cache a relatively small subset of rarely modified data to avoid querying the database as frequently for performance reasons. This data

Answer 1

For searching a particular value, with std::set and std::map it takes O(log N) time, while with the other two it takes O(N) time; So, std::set or std::map are probably better. Since you have access to C++0x, you could also use std::unordered_set or std::unordered_map which take constant time on average.

For find_if, there's little difference between them, because it takes an arbitrary predicate and containers cannot optimize arbitrarily, of course.

However if you will be calling find_if frequently with a certain predicate, you can optimize yourself: use a std::map or std::set with a custom comparator or special keys and use find instead.