策略模式(STRATEGY PATTERN )

strtegy.h 

#ifndef _STRTEGY_H_
#define _STRTEGY_H_

/**
* @brief 锦囊妙计（抽象类）
*/
class Strategy
{
public:
virtual void operate() = 0;
};

/**
* @brief 开后门（找乔国老帮忙，免杀刘备）
*/
class Backdoor : public Strategy
{
public:
void operate();
};

/**
* @brief 开绿灯（找吴国太帮忙，放行）
*/
class Greelight : public Strategy
{
public:
void operate();
};

/**
* @brief 断后（孙夫人断后）
*/
class BlockEnemy : public Strategy
{
public:
void operate();
};

/**
* 锦囊（存放妙计）
*/
class Content
{
public:
Content()
{

}
Content(Strategy * stra)
{
strat = stra;
}
~Content()
{
delete strat;
}
public:
void operate()
{
strat->operate();
}
private:
Strategy * strat;
};

#endif // _STRTEGY_H_

strtegy.cpp

#include "strtegy.h"
#include <iostream>
using namespace std;

void Backdoor::operate()
{
    cout << "找乔国老帮忙，开后门!" << endl;
}


void Greelight::operate()
{
    cout << "找吴国太开绿灯放行!" << endl;
}

void BlockEnemy::operate()
{
    cout << "孙夫人断后!" << endl;
}

main.cpp

#include <iostream>
#include "strtegy.h"

using namespace std;

/**
 * @brief 模板锦囊(放妙计)
 */
template <typename T>
class ContentT
{
public:
    void operate()
    {
       strat.operate();
    }
private:
    T strat;
};

int main()
{
#if 1
    Content * cont;     /// < 得到锦囊

    cont = new Content(new Backdoor());
    cont->operate();    /// < 开后门
    delete cont;

    cont = new Content(new Greelight());
    cont->operate();    /// < 开绿灯
    delete cont;

    cont = new Content(new BlockEnemy());
    cont->operate();    /// < 段后
    delete cont;
#endif