СПРИНТ № 4 | Перегрузка операторов | Урок 2: Перегрузка операторов ввода-вывода

#include <numeric>
#include <iostream>

using namespace std;

class Rational {
public:
    Rational() = default;

    Rational(int numerator)
        : numerator_(numerator)
        , denominator_(1) {
    }

    Rational(int numerator, int denominator)
        : numerator_(numerator)
        , denominator_(denominator) {
        Normalize();
    }

    int Numerator() const {
        return numerator_;
    }

    int Denominator() const {
        return denominator_;
    }

    friend std::ostream& operator<<(std::ostream& os, Rational& rat);
    friend std::istream& operator>>(std::istream& in, Rational& rat);


private:
    void Normalize() {
        if (denominator_ < 0) {
            numerator_ = -numerator_;
            denominator_ = -denominator_;
        }
        const int divisor = gcd(numerator_, denominator_);
        numerator_ /= divisor;
        denominator_ /= divisor;
    }

    int numerator_ = 0;
    int denominator_ = 1;
};

std::ostream& operator<<(std::ostream& os, Rational& rat){
    os << rat.Numerator() << "/" << rat.Denominator();
    return os;
}

std::istream& operator>>(std::istream& is, Rational& rat){
    char b;
    is >> rat.numerator_ >> b >> rat.denominator_;
    return is;
}

int main(){
    Rational rational;
    Rational rational1;

    std::cout << rational1;
}