c++设计模式：模板方法模式(Template Method Pattern)

#include <iostream>
using namespace std;

class CaffeineBeverage
{
public:
    void prepareRecipe();
private:
    virtual void brew() = 0;
    virtual void addCondiments() = 0;
    void boilWater();
    void pourInCup();
    virtual bool customerWantsCondiments(); // 钩子
};

class Coffee : public CaffeineBeverage
{
private:
    void brew();
    void addCondiments();
    bool customerWantsCondiments();
};

class Tea : public CaffeineBeverage
{
private:
    void brew();
    void addCondiments();
    bool customerWantsCondiments();
};

void CaffeineBeverage::prepareRecipe()
{
    boilWater();
    brew();
    pourInCup();
    if (customerWantsCondiments())
    {
        addCondiments();
    }
}

void CaffeineBeverage::boilWater()
{
    printf("把水煮沸n");
}

void CaffeineBeverage::pourInCup()
{
    printf("倒入杯子中n");
}

bool CaffeineBeverage::customerWantsCondiments()
{
    return true;
}

void Coffee::brew()
{
    printf("用沸水冲泡咖啡粉n");
}

void Coffee::addCondiments()
{
    printf("加糖和牛奶n");
}

bool Coffee::customerWantsCondiments()
{
    char zAnswer;
    printf("您的咖啡中是否需要牛奶和糖：");
    fflush(stdin);
    zAnswer = getchar();
    zAnswer = toupper(zAnswer);
    if ('Y'==zAnswer)
    {
        return true;
    }
    else if ('N'==zAnswer)
    {
        return false;
    }
    else
    {
        printf("输入错误，默认不加调料n");
        return false;
    }
}

void Tea::brew()
{
    printf("用沸水浸泡茶叶n");
}
void Tea::addCondiments()
{
    printf("加柠檬n");
}

bool Tea::customerWantsCondiments()
{
    char zAnswer;
    printf("您的茶中是否需要柠檬：");
    fflush(stdin);
    zAnswer = getchar();
    zAnswer = toupper(zAnswer);
    if ('Y'==zAnswer)
    {
        return true;
    }
    else if ('N'==zAnswer)
    {
        return false;
    }
    else
    {
        printf("输入错误，默认不加调料n");
        return false;
    }
}

int main()
{
    Coffee coffee;
    Tea tea;
    coffee.prepareRecipe();
    tea.prepareRecipe();
    return 0;
}