STL: Maps, Sets & Algorithms

The Standard Template Library is C++'s toolbox of ready-made, fast, generic components: • containers — vector, list, deque, map, set, unordered_map, stack, queue, • iterators — a common way to walk any container, • algorithms — sort, find, count, accumulate, transform, and dozens more.

Because algorithms work on iterators, the same std::sort or std::count_if works on many containers. Reach for the STL before writing your own loops and data structures.