C++工厂方法模式

#include 
#include 

// 产品接口
class Product
{
public:
    virtual ~Product() {}
    virtual std::string Operation() = 0;
};

// 具体的产品
class ConcreteProduct1 : public Product
{
public:
    std::string Operation() override
    {
        return "result of the concrete product 1.";
    }
};

class ConcreteProduct2 : public Product
{
public:
    std::string Operation() override
    {
        return "result of the concrete product 2.";
    }
};

// 创建者接口
class Creator
{
public:
    virtual ~Creator() {}
    
    // 返回产品对象的工厂方法
    virtual Product *FactoryMethod() const = 0;

    std::string SomeOperation() const
    {
        // 调用工厂方法，创建一个产品对象
        Product *product = this->FactoryMethod();

        // 使用产品对象
        std::string result = "create a product with : " + product->Operation();
        
        // 删除对象
        delete product;
        
        return result;
    }
};

// 具体的创建者，会重写工厂方法
class ConcreteCreator1 : public Creator
{
public:
    Product* FactoryMethod() const override
    {
        // 创建对象
        return new ConcreteProduct1();
    }
};

class ConcreteCreator2 : public Creator
{
public:
    Product* FactoryMethod() const override
    {
        return new ConcreteProduct2();
    }
};

int main()
{
    Creator *creator1 = new ConcreteCreator1();
    std::cout << creator1->SomeOperation() << std::endl;

    Creator *creator2 = new ConcreteCreator2();
    std::cout << creator2->SomeOperation() << std::endl;
}