boost pointer container

1. boost::ptr_vector

#include <boost/ptr_container/ptr_vector.hpp>
#include <iostream>

int main() {
  boost::ptr_vector<int> v;
  v.push_back(new int());
  v.push_back(new int());
  std::cout << v.back() << std::endl;
  return ;
}

boost::ptr_vector knows that it stores dynamically allocated objects, member functions like back() return a reference to a dynamically allocated object and not a pointer. Thus, the example writes 2 to standard output.

2. boost:ptr_set 有顺序的容器

#include <boost/ptr_container/ptr_set.hpp>
#include <iostream>

int main() {
  boost::ptr_set<int> s;
  s.insert(new int());
  s.insert(new int());
  std::cout << *s.begin() << std::endl;
  return ;
}

输出： 1

3. additional containers include boost::ptr_deque, boost::ptr_list, boost::ptr_map, boost::ptr_unordered_set, boost::ptr_unordered_map