Правильное считывание с файла

class person {
private:
    std::string first_name;
    std::string last_name;
    int age;
 
public:
    person(std::string first_name = "N/A", std::string last_name = "N/A", int age = 0):
        first_name(first_name), last_name(last_name), age(age) {}
 
    void showData() {
        std::cout << "Имя: " << first_name << "\n";
        std::cout << "Фамилия: " << last_name << "\n";
        std::cout << "Возраст: " << age << "\n";
    }
    friend std::ostream& operator<<(std::ostream&, person&);
    friend std::istream& operator>>(std::istream&, person&);
};
 
std::ostream& operator<<(std::ostream& os, person& prs) {
    if (typeid(os) == typeid(std::ofstream)) {
        os << "Name: " << std::setw(30) << prs.first_name <<
            " | Last name: " << std::setw(30) << prs.last_name <<
            " | Age: " << prs.age << " |";
 
        return os;
    }
    prs.showData();
    return os;
}
std::istream& operator>>(std::istream& is, person& prs) {
    if (typeid(is) == typeid(std::ifstream)) {
        int counter = 0;
        while (is.get() != ':')
            counter++;
        is.seekg(counter + 1, std::ios::beg);
        is >> prs.first_name;
 
        while (is.get() != ':')
            counter++;
        is.seekg(counter + 1, std::ios::beg);
        is >> prs.last_name;
 
        while (is.get() != ':')
            counter++;
        is.seekg(counter + 1, std::ios::beg);
        is >> prs.age;
 
        return is;
    }
    is >> prs.first_name >> prs.last_name >> prs.age;
    return is;
}

string s;
 
getline(is, s, ':');
is >> prs.first_name;
getline(is, s, ':');
is >> prs.last_name;
getline(is, s, ':');
is >> prs.age;
getline(is, s);