转自：https://blog.csdn.net/buptman1/article/details/38657807

multi_index_container：

Boost Multi-index Containers Library定义了multi_index_container模板类，可以从不同的维度建索引、排序和存取。

如上图，容器multi_index_container分别从shape,number和sequenced(默认插入的顺序)三个维度对元素进行管理。

#include <string>

#include <iostream>

#include <boost/multi_index_container.hpp>

#include <boost/multi_index/member.hpp>

#include <boost/multi_index/ordered_index.hpp>

using namespace boost;

using namespace boost::multi_index;

using namespace std;

struct Employee{

  int id;

  string name;

  int age;

  Employee(int id_,std::string name_,int age_):id(id_),name(name_),age(age_){}

  friend std::ostream& operator<<(std::ostream& os,const Employee& e)

  {

    os<<e.id<<" "<<e.name<<" "<<e.age<<std::endl;

    return os;

  }

};

typedef multi_index_container<

  Employee,

  indexed_by<

    ordered_unique<member<Employee, int, &Employee::id> >,

    ordered_non_unique<member<Employee, string, &Employee::name> >,

    ordered_non_unique<member<Employee, int, &Employee::age> >

  >

> EmployeeContainer;

typedef EmployeeContainer::nth_index<0>::type IdIndex;

typedef EmployeeContainer::nth_index<1>::type NameIndex;

typedef EmployeeContainer::nth_index<2>::type AgeIndex;

int main(){

  EmployeeContainer con;

  con.insert(Employee(0,"Joe",31));

  con.insert(Employee(1,"Robert",27));

  con.insert(Employee(2,"John",40));

  IdIndex& ids = con.get<0>();

  copy(ids.begin(),ids.end(), ostream_iterator<Employee>(cout));

  cout << endl;

  NameIndex& names = con.get<1>();

  copy(names.begin(), names.end(), ostream_iterator<Employee>(cout));

  cout << endl;

  names.erase(names.begin());

  AgeIndex& ages = con.get<2>();

  copy(ages.begin(), ages.end(), ostream_iterator<Employee>(cout));

  cout << endl;

  return 0;

}

#include "boost/multi_index_container.hpp"

#include "boost/multi_index/member.hpp"

#include "boost/multi_index/ordered_index.hpp"

using boost::multi_index_container;

using namespace boost::multi_index;

struct stu_num{};	// 索引-学号

struct stu_name{};  // 索引-姓名

struct stu_age{};	// 索引-年龄

typedef

boost::multi_index_container<

	Student,

	indexed_by<

		ordered_unique<

                  // 学号是唯一值的索引

		tag<stu_num>,  BOOST_MULTI_INDEX_MEMBER(Student,unsigned int,stu_num)>,

    		// 姓名是非唯一值的索引

                     ordered_non_unique<

		tag<stu_name>,BOOST_MULTI_INDEX_MEMBER(Student,std::string,stu_name)>,

                  // 年龄是非唯一值的索引

		ordered_non_unique<

		tag<stu_age>, BOOST_MULTI_INDEX_MEMBER(Student,unsigned int,stu_age)>

	>

> StudentContainer;

	// 用名字作为索引

	StudentContainer::index<stu_name>::type& indexOfName = studentsets.get<stu_name>();

	// 查找名叫李四的人

	StudentContainer::index<stu_name>::type::iterator it = indexOfName.find("李四");

	// 找到了？

	if( it != indexOfName.end() )

	{

               // it就是一个Student序列的迭代器，现在你可以

                 // 像普通迭代器一样操作它了，比如cout << *it

	}

	// 用名字作为索引

	StudentContainer::index<stu_name>::type& indexOfName = studentsets.get<stu_name>();

	// 查找名叫张三的人的下界

	StudentContainer::index<stu_name>::type::iterator itL = indexOfName.lower_bound("张三");

	// 查找名叫张三的人的上界

	StudentContainer::index<stu_name>::type::iterator itU = indexOfName.upper_bound("张三");

         // 遍历输出所有名叫“张三”的学生信息

	while(itL != itU)

	{

		std::cout << *itL;

		++itL;

	}