Is there a difference between using .begin() vs .end() for std::inserter for std::set?
问题 If there is any difference between it1 and it2? std::set<sometype> s; auto it1 = std::inserter(s, s.begin()); auto it2 = std::inserter(s, s.end()); 回答1: In practice, not much. If you're inserting a large number of already in order elements into an empty set , the second will be somewhat faster, but that's about it. std::insert_iterator calls insert with the iterator; std::set interprets it as a hint, and inserts in constant time (rather than lg n) if the insertion is immediately before the