[C++知识库]量化交易之设计模式篇 - 备忘录模式

//
// Created by win10 on 2021/11/16.
//

#include <thread>
#include <iostream>
#include <vector>
using namespace std;

/*
 * 备忘录模式
 * 在不破坏封装性的前提下, 捕获一个对象的内部状态, 并在该对象之外保存这个状态, 这样就可以将以后的对象状态恢复到先前保存的状态
 */
class Memo;

class Originator {
public:
    Memo* createMemo();
    void setMemo(Memo* memo);

    void show() {
        std::cout << "state: " << state << std::endl;
    }

    string state;
};

// 备忘录类
class Memo {
public:
    Memo(string state) {
        this->state = state;
    }

    string state;
};

Memo* Originator::createMemo() {
    return new Memo(this->state);
}
void Originator::setMemo(Memo* memo) {
    this->state = memo->state;
}

class Caretaker {
public:
    Memo* memo;
};

int main() {

    Originator* originator=new Originator();
    originator->state = "originator";
    originator->show();
    Caretaker* caretaker = new Caretaker();
    caretaker->memo = originator->createMemo();
    originator->state = "off";
    originator->show();
    originator->setMemo(caretaker->memo);
    originator->show();

    return 0;
}