c/c++工厂模式

简单工厂模式不符合开放关闭原则，扩展功能时候需要修改之前的代码。所以尽量少用。
结构：
由一个工厂父类（抽象工厂），多个工厂子类（具体工厂），一个产品父类（抽象产品），多个产品子类（具体产品）构成。

C实现方式

typedef struct people
{
	int age;
	char name[20];
};

typedef struct student
{
	people p;
	//add other
}student, *pstudent;
people*  get_student(int age)
{
	student *p = (student *)malloc(sizeof(student));
	((people *)p)->age = age;
	strcpy_s((((people *)p)->name), "student");
	return  (people*)p;
}


typedef struct teacher
{
	people p;
	//add other
}teacher, *pteacher;
people*  get_teacher(int age)
{
	teacher *p = (teacher *)malloc(sizeof(teacher));
	((people *)p)->age = age;
	strcpy_s((((people *)p)->name), "teacher");
	return  (people*)p;
}

typedef  people *(*virtual_)(int age);
typedef struct  factory
{
	virtual_ v;
}factory;

typedef struct  factory_student
{
	factory fa = {get_student};
}factory_student;

typedef struct  factory_teacher
{
	factory fa = { get_teacher };
}factory_teacher;

void get_date(people *p)
{
	printf("name:%s  age: %d\n", p->name, p->age);
}
int main()
{
	factory_student fa_student;
	people * student=fa_student.fa.v(20);

	factory_teacher fa_teacher;
	people *teacher=fa_teacher.fa.v(50);
	get_date(student);
	get_date(teacher);
	system("pause");
}

c++实现方式

class people
{
public:
	virtual void get_date() = 0;
protected:
	int age;
	std::string name;
};

class student :public people
{
public:
	student(int age) { name = { "student" }, people::age = age; };
	~student() {};
	void get_date()
	{
		std::cout << "name:" << name.c_str() << "age: " << age << std::endl;
	}
};

class teacher :public people
{
public:
	teacher(int age) { name = { "teacher" }, people::age = age; };
	~teacher() {};
	void get_date()
	{
		std::cout << "name:" << name.c_str() << "age: " << age << std::endl;
	}
};


class factory
{
public:
	virtual people * creat(int age)=0;
};

class factory_teacher  :public factory
{
public:
	people * creat(int age)
	{
		return new teacher(age);
	}
};

class factory_student :public factory
{
public:
	people * creat(int age)
	{
		return new student(age);
	}
};


int main()
{
	factory_teacher *fa_teacher = new factory_teacher();
	factory_student *fa_student = new factory_student();
	people *student= fa_student->creat(20);
	student->get_date();
	people *teacher = fa_teacher->creat(50);
	teacher->get_date();
	system("pause");
	return 0;
}