c++ - C++ std::set 的排序输出

Question

我想按字母顺序列出我的集合的输出。下面是对此的尝试，但它似乎很慢/效率低下，我什至还没有完成。

void ordered(ostream &os) {
    bool inserted = false;
    for (objects::iterator i = begin(); i != end(); ) {
        for (objects::iterator x = begin(); x != end(); ++x) {
            if((**i) < (**x)) { //overloaded and works
                os << **i << endl;
                inserted = true;
                break;
            }
        }
        if(inserted) {
            ++i;
        }
    }
}

很明显，这只会输出按字母顺序排列在第一个对象之后的对象。

我也考虑过将对象从一个集合移动到另一个容器中，但它似乎仍然效率低下。

Answer 1

std::set 是一个有序容器，参见引用资料:
http://en.cppreference.com/w/cpp/container/set

std::set is an associative container that contains a sorted set of unique objects of type Key. Sorting is done using the key comparison function Compare. Search, removal, and insertion operations have logarithmic complexity. Sets are usually implemented as red-black trees.