设计模式 策略模式2 c++11

根据需求的不同 选择不同的策略算法

之前是保存的各种策略类的指针

这里直接使用 function  bind 选择对应的算法

代码

// 005.cpp: 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <functional>
#include <iostream>

using namespace std;




int MyAdd(int a, int b) { return a + b; }

class MyMinus {
public:
    int operator()(int a, int b) {
        return a - b;
    }
};

class binary_operators {
public:
    typedef std::function<int(int, int)> FUNC;
    binary_operators(FUNC f,int a, int b) :func_(f),left(a), right(b),result(0) {}
    int GetResult() { return func_(left, right); }
private:
    std::function<int(int, int)> func_;
    int left;
    int right;
    int result;
};

int main()
{
    binary_operators addOperation(std::function<int(int, int)>(MyAdd),1,2);
    binary_operators minusOperation(std::function<int(int, int)>(MyMinus()), 5, 7);
    
    std::cout << "addOperation(1,2) result: " << addOperation.GetResult() << std::endl;
    std::cout << "minusOperation(5,7) result: " << minusOperation.GetResult() << std::endl;
    return 0;
}