如何在C++中实现建造者设计模式？

class Pizza {
public:
  std::string dough;
  std::string sauce;
  std::vector<std::string> toppings;

  Pizza(const std::string& dough, const std::string& sauce) :
    dough(dough), sauce(sauce) {}
};

class PizzaBuilder {
public:
  virtual void setDough(const std::string& dough) = 0;
  virtual void setSauce(const std::string& sauce) = 0;
  virtual void addTopping(const std::string& topping) = 0;
  virtual Pizza* buildPizza() = 0;
};

class MargheritaBuilder : public PizzaBuilder {
public:
  Pizza* buildPizza() override {
    Pizza* pizza = new Pizza("Thin", "Marinara");
    pizza->addTopping("Mozzarella");
    pizza->addTopping("Basil");
    return pizza;
  }
  void setDough(const std::string& dough) override {
    // Игнорировать, тесто уже определено.
  }
  void setSauce(const std::string& sauce) override {
    // Игнорировать, соус уже определен.
  }
  void addTopping(const std::string& topping) override {
    // Добавьте начинку.
  }
};

class PepperoniBuilder : public PizzaBuilder {
public:
  Pizza* buildPizza() override {
    Pizza* pizza = new Pizza("Thick", "BBQ Sauce");
    pizza->addTopping("Pepperoni");
    pizza->addTopping("Mozzarella");
    pizza->addTopping("Pepper Flakes");
    return pizza;
  }
  void setDough(const std::string& dough) override {
    // Определите тесто.
  }
  void setSauce(const std::string& sauce) override {
    // Определите соус.
  }
  void addTopping(const std::string& topping) override {
    // Добавьте начинку.
  }
};

class Director {
public:
  Pizza* makePizza(PizzaBuilder* builder) {
    builder->setDough("Thin");
    builder->setSauce("Marinara");
    builder->addTopping("Mozzarella");
    return builder->buildPizza();
  }
};

int main() {
  // Создать строителей пиццы.
  MargheritaBuilder margheritaBuilder;
  PepperoniBuilder pepperoniBuilder;

  // Создайте директора и инициируйте процесс сборки.
  Director director;
  Pizza* margherita = director.makePizza(&margheritaBuilder);
  Pizza* pepperoni = director.makePizza(&pepperoniBuilder);

  // Печать информации о пицце.
  std::cout << "Маргарита:" << std::endl;
  std::cout << " - Тесто: " << margherita->dough << std::endl;
  std::cout << " - Соус " << margherita->sauce << std::endl;
  std::cout << " - Начинка: " << margherita.toppings.join(", ") << std::endl;

  std::cout << "Пепперони:" << std::endl;
  std::cout << " - Тесто: " << pepperoni->dough << std::endl;
  std::cout << " - Соус " << pepperoni->sauce << std::endl;
  std::cout << " - Начинка: " << pepperoni->toppings.join(", ") << std::endl;

  return 0;
}