proxy-cardealership.cpp

class Car
{
  string brand_;
  string model_;

public:
  auto &brand() { return brand_; }
  auto &model() { return model_; }
};

class CarDealership
{
  string      name_;
  vector<Car> showroom_;

public:
  auto &name()     { return name_; }
  auto &showroom() { return showroom_; }
};