struct Car {
  BOOST_HANA_DEFINE_STRUCT(Car,
    (std::string, brand),
    (std::string, model)
  );
};
struct Person {
  BOOST_HANA_DEFINE_STRUCT(Person,
    (std::string, name),
    (std::string, last_name),
    (int, age)
  );
};
Car bmw{"BMW", "Z3"}, audi{"Audi", "A4"};
Person john{"John", "Doe", 30};
auto tuple = hana::make_tuple(john, audi, bmw);
std::cout << to_json(tuple) << std::endl;