Агрегирование

#include <iostream>
#include <string>
#include <ctime>
#include <set>
struct Console {
    static void cyrillic() {
        system("chcp 1251 > nul");
    }
    static void clear() {
        system("cls");
    }
    static void pause() {
        system("pause > nul");
    }
    static void flush(std::istream& stream = std::cin) {
        stream.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
    }
};
using namespace std;
struct Address {
    string country;
    string city;
    string street;
    string house;
    friend bool operator<(const Address& a, const Address& b) {
        if (a.country < b.country) return true;
        else if (a.country == b.country) {
            if (a.city < b.city) return true;
            else if (a.city == b.city) {
                if (a.street < b.street) return true;
                else if (a.street == b.street) {
                    return a.house < b.house;
                }
            }
        }
        return false;
    }
    friend bool operator==(const Address& a, const Address& b) {
        return a.country == b.country
            && a.city == b.city
            && a.street == b.street
            && a.house == b.house;
    }
};
struct Birthday {
    Birthday() : year(1900), month(1), day(1) {}
    int year;
    int month;
    int day;
    string show()const {
        auto dd = to_string(day);
        auto mm = to_string(month);
        auto date = day < 10 ? "0"s + dd : dd;
        date += month < 10 ? ".0"s + mm : "."s + mm;
        date += "."s + to_string(year);
        return date;
    }
    friend bool operator<(const Birthday& a, const Birthday& b) {
        if (a.year < b.year) return true;
        else if (a.year == b.year) {
            if (a.month < b.month) return true;
            else if (a.year < b.year) {
                return a.day < b.day;
            }
        }
        return false;
    }
    friend bool operator==(const Birthday& a, const Birthday& b) {
        return a.year == b.year
            && a.month == b.month
            && a.day == b.day;
    }
};
struct Anthropometry {
    Anthropometry() : weight(.0), growth(.0) {}
    string hair_color;
    string sex;
    double weight;
    double growth;
    friend bool operator<(const Anthropometry& a, const Anthropometry& b) {
        return a.growth < b.growth;
    }
    friend bool operator==(const Anthropometry& a, const Anthropometry& b) {
        return a.growth == b.growth;
    }
};
struct Person {
    string name;
    Address address;
    Anthropometry anthropometry;
    Birthday birthday;
    int age()const {
        tm sys_time;
        __time64_t time;
        _time64(&time);
        _localtime64_s(&sys_time, &time);
        auto year = sys_time.tm_year + 1900;
        auto month = sys_time.tm_mon + 1;
        auto day = sys_time.tm_mday;
        auto diff = year - birthday.year;
        if (month < birthday.month || (month == birthday.month && day < birthday.day)) --diff;
        return diff;
    }
    friend bool operator<(const Person& a, const Person& b) {
        if (a.name < b.name) return true;
        else if (a.name == b.name) {
            if (a.birthday < b.birthday) return true;
            else if (a.birthday == b.birthday) {
                if (a.address < b.address) return true;
                else if (a.address == b.address) {
                    return a.anthropometry < b.anthropometry;
                }
            }
        }
        return false;
    }
};
Person input_person() {
    Person person;
    cout << "Ф.И.О.: ";
    getline(cin, person.name);
    cout << "Год рождения в формате YYYY: ";
    cin >> person.birthday.year;
    cout << "Месяц рождения в формате (1-12): ";
    cin >> person.birthday.month;
    cout << "Число рождения в формате (1-31): ";
    cin >> person.birthday.day;
    Console::flush();
    cout << "Страна: ";
    getline(cin, person.address.country);
    cout << "Населённый пункт: ";
    getline(cin, person.address.city);
    cout << "Улица: ";
    getline(cin, person.address.street);
    cout << "Дом-квартира: ";
    getline(cin, person.address.house);
    cout << "Рост (в сантиметрах): ";
    cin >> person.anthropometry.growth;
    cout << "Вес (в килограммах): ";
    cin >> person.anthropometry.weight;
    Console::flush();
    cout << "Пол: ";
    cin >> person.anthropometry.sex;
    cout << "Цвет волос: ";
    cin >> person.anthropometry.hair_color;
    Console::clear();
    Console::flush();
    return person;
}
void output_person(const Person& person) {
    cout << person.name << '\n'
        << " - Дата рождения: " << person.birthday.show() << '\n'
        << " - Возраст: " << person.age() << '\n'
        << " - Адрес:\n"
        << "\t- Страна: " << person.address.country << '\n'
        << "\t- Населённый пункт: " << person.address.city << '\n'
        << "\t- Улица: " << person.address.street << '\n'
        << "\t- Дом-квартира: " << person.address.house << '\n'
        << " - Антропологические данные:\n"
        << "\t- Пол: " << person.anthropometry.sex << '\n'
        << "\t- Рост: " << person.anthropometry.growth << '\n'
        << "\t- Вес: " << person.anthropometry.weight << '\n'
        << "\t- Цвет волос: " << person.anthropometry.hair_color << '\n';
}
int main() {
    Console::cyrillic();
    set<Person> persons;
    for (auto i = 0; i < 2; ++i) {
        auto person = input_person();
        persons.insert(person);
    }
    for (const auto& person : persons) {
        output_person(person);
        cout.put('\n');
    }
    Console::pause();
}