1. 定義

一個名為multi_index_container的類模板，它支持構建容器來維護一個或多個具有不同排序和訪問語義的索引。

每一個multi_index都相當于傳統數據庫的一個數據表（table），但將傳統數據庫的行與列的形式改為了單純的列。也就是說multi_index是一個線性排列的表，只有一列，每一行都只存儲一個對象。

1.1 Iterators（迭代器）

通過迭代器來操作數據表中的每個對象。

struct service_rec {uint64_t pkey; // 主鍵account_name customer; // 車主用戶名uint32_t service_date; // 維修保養時間uint32_t odometer; // 車輛里程};

1.2.

#include <algorithm> #include <iostream> #include <iterator> #include <string>#include <boost/multi_index_container.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/shared_ptr.hpp>using namespace std;//定義學生信息，同理可以使用結構定義 class student { public:student(int id, string name, int score, string remark) :id(id), name(name), score(score), remark(remark) {}void print() const {cout << "id:" << id << " name:" << name << " score:" << score << endl;}int id;string name;int score;string remark; };// 如果要把student某個屬性字段設置為搜索引擎，則需要定義用于排序的空結構體對象 struct _id {}; struct _name{}; struct _score {};// 定義一個multi_index_container（多索引容器） using student_table = boost::multi_index::multi_index_container<student,boost::multi_index::indexed_by<boost::multi_index::ordered_unique<boost::multi_index::tag<_id>, BOOST_MULTI_INDEX_MEMBER(student, int, id)>, // ID為唯一索引，類似主鍵boost::multi_index::ordered_non_unique<boost::multi_index::tag<_name>, BOOST_MULTI_INDEX_MEMBER(student, string, name)>, // 非唯一索引boost::multi_index::ordered_non_unique<boost::multi_index::tag<_score>, BOOST_MULTI_INDEX_MEMBER(student, int, score)>> >;int main() {// initialize data.student_table allStu;allStu.insert(student(1, "lili", 85, "hello"));allStu.insert(student(2, "liming", 90, "hello"));allStu.insert(student(3, "xiaoming", 65, "hello"));allStu.insert(student(4, "ergou", 80, "hello"));allStu.insert(student(5, "dagou", 60, "hello"));// sortstudent_table::index<_id>::type& sort_id = allStu.get<0>();cout << "sort by student id:" << endl;student_table::index<_id>::type::iterator iter_id = sort_id.begin();for (; iter_id != sort_id.end(); iter_id++) {iter_id->print();}cout << "\n" << endl;student_table::index<_name>::type& sort_name = allStu.get<1>();cout << "sort by student name:" << endl;student_table::index<_name>::type::iterator iter_name = sort_name.begin();for (; iter_name != sort_name.end(); iter_name++) {iter_name->print();}cout << "\n" << endl;student_table::index<_score>::type& sort_score = allStu.get<2>();cout << "sort by student score:" << endl;student_table::index<_score>::type::iterator iter_score = sort_score.begin();for (; iter_score != sort_score.end(); iter_score++) {iter_score->print();}cout << "\n" << endl;// findstudent_table::index<_name>::type& find_name = allStu.get<_name>();student_table::index<_name>::type::iterator iter_ergou = find_name.find("ergou");if (iter_ergou != find_name.end()) {cout << "find a student named ergou:" << endl;iter_ergou->print();// modify ergoustudent ergou = *iter_ergou;ergou.id = 6; // will be success. becasuse id 6 not in the table. otherwise failureergou.name = "ergou_v2";ergou.score = 91;ergou.remark = "hello ergou";bool isSuc = find_name.replace(iter_ergou, ergou);}// cout << "sort by student id after replace ergou:" << endl;student_table::index<_id>::type::iterator iter_id_v2 = sort_id.begin();for (; iter_id_v2 != sort_id.end(); iter_id_v2++) {iter_id_v2->print();}cout << "\n" << endl;system("pause"); }

輸出結果：

參考：

boost::multi_index多索引容器-使用說明

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