• multi_index_container


    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;
    	}
     
     
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  • 原文地址:https://www.cnblogs.com/lehoho/p/9374624.html
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