Найти женщин-владельцев заданной марки автомобиля

#include <iostream>
#include <string>
 
struct Car {
  std::string make;
  std::string registration;
  size_t traveled;
  Car(const std::string &make_, const std::string &registration_,
    size_t traveled_) : make(make_), registration(registration_),
    traveled(traveled_) {}
};
 
enum Gender {
  MALE, FEMALE
};
 
struct Form {
  std::string name;
  Gender gender;
  Car car;
  Form(const std::string name_, const Gender &gender_, const Car &car_)
    : name(name_), gender(gender_), car(car_) {}
};
 
std::ostream &operator<<(std::ostream &stream, const Gender &gender) {
  if (gender == MALE) return stream << "male";
  if (gender == FEMALE) return stream << "female";
  return stream;
}
 
std::ostream &operator<<(std::ostream &stream, const Car &car) {
  return stream << car.make << ", registration number '" <<
    car.registration << "', traveled " << car.traveled << " km.";
}
 
std::ostream &operator<<(std::ostream &stream, const Form &form) {
  return stream << form.name << ", " << form.gender << ", car: " <<
    form.car;
}
 
int main(int argc, char *argv[]) {
  Form forms[] = {
    Form("Ivan", MALE, Car("Toyota", "a999aa", 10000)),
    Form("Petr", MALE, Car("Mercedes", "a998aa", 20021)),
    Form("Olga", FEMALE, Car("Shevrolet", "b192kk", 10021)),
    Form("Sergey", MALE, Car("VAZ", "k121tp", 100221)),
    Form("Elena", FEMALE, Car("Nissan", "e761ae", 61121)),
    Form("Daniil", MALE, Car("Toyota", "c423ce", 120121)),
    Form("Ivan", MALE, Car("Toyota", "h910kh", 100221)),
    Form("Roman", MALE, Car("Subaru", "k945ak", 2170021)),
    Form("Katerina", FEMALE, Car("Shkoda", "c112tc", 65412)),
    Form("Oleg", MALE, Car("Mercedes", "t627tt", 73413)),
    Form("Yana", FEMALE, Car("Skoda", "d791ad", 10021)),
    Form("Svetlana", FEMALE, Car("Nissan", "t231kk", 10021)),
    // тут мне стало лень.
    Form("Ivan", MALE, Car("Toyota", "a999aa", 10021)),
    Form("Ivan", MALE, Car("Toyota", "a999aa", 10021)),
    Form("Ivan", MALE, Car("Toyota", "a999aa", 10021)),
  };
  size_t numberOfForms = sizeof(forms) / sizeof(Form);
  for (size_t i = 0; i < numberOfForms; ++i)
    std::cout << forms[i] << std::endl;
    
  std::string make = "Nissan";
  std::cout << "Women's cars with make of " << make << " are:" << std::endl;
  for (size_t i = 0; i < numberOfForms; ++i) 
    if (forms[i].gender == FEMALE && forms[i].car.make == make)
      std::cout << forms[i] << std::endl;
  
}