C++如何实现工厂方法 C++工厂方法的实现变体

#include <iostream>
#include <string>

// 抽象产品类
class Product {
public:
    virtual std::string operation() const = 0;
    virtual ~Product() {}
};

// 具体产品类A
class ConcreteProductA : public Product {
public:
    std::string operation() const override {
        return "ConcreteProductA";
    }
};

// 具体产品类B
class ConcreteProductB : public Product {
public:
    std::string operation() const override {
        return "ConcreteProductB";
    }
};

// 抽象工厂类
class Factory {
public:
    virtual Product* createProduct() const = 0;
    virtual ~Factory() {}
};

// 具体工厂类A
class ConcreteFactoryA : public Factory {
public:
    Product* createProduct() const override {
        return new ConcreteProductA();
    }
};

// 具体工厂类B
class ConcreteFactoryB : public Factory {
public:
    Product* createProduct() const override {
        return new ConcreteProductB();
    }
};

// 客户端代码
int main() {
    Factory* factoryA = new ConcreteFactoryA();
    Product* productA = factoryA->createProduct();
    std::cout << productA->operation() << std::endl; // 输出：ConcreteProductA
    delete productA;
    delete factoryA;

    Factory* factoryB = new ConcreteFactoryB();
    Product* productB = factoryB->createProduct();
    std::cout << productB->operation() << std::endl; // 输出：ConcreteProductB
    delete productB;
    delete factoryB;

    return 0;
}