cppFractionBaseClass

#include <iostream>

class Fraction
{
    int numerator;
    int denominator;
    int gcd(int a, int b);
    void reduce();
public:
    Fraction(int num, int denom)
        : numerator{ num }, denominator{ denom ? denom : 1 }
    {
        reduce();
        std::cout << "Fraction constructed for " << this << '\n';
    };
    Fraction() : Fraction(1, 1) {};
    ~Fraction() { std::cout << "Fraction destructed for " << this << '\n'; };
    void setNumerator(int num) { numerator = num; reduce(); };
    int getNumerator() const { return numerator; };
    void setDenominator(int denom) { denominator = denom ? denom : 1; reduce(); };
    int getDenominator() const { return denominator; };
    void print() const;
    Fraction& add(const Fraction& fract);
    Fraction& sub(const Fraction& fract);
    Fraction& mul(const Fraction& fract);
    Fraction& div(const Fraction& fract);

};

int Fraction::gcd(int a, int b)
{
    while (b)
    {
        a %= b;
        std::swap(a, b);
    }
    return a;
}

void Fraction::reduce()
{
    int gcdVal{ gcd(numerator, denominator) };
    numerator /= gcdVal;
    denominator /= gcdVal;

    if (denominator < 0 and numerator < 0)
    {
        denominator *= -1;
        numerator *= -1;
    }
}

Fraction& Fraction::add(const Fraction& fract)
{
    numerator *= fract.denominator + fract.numerator * denominator;
    denominator *= fract.denominator;
    reduce();
    return *this;
}

Fraction& Fraction::sub(const Fraction& fract)
{
    numerator *= fract.denominator - fract.numerator * denominator;
    denominator *= fract.denominator;
    reduce();
    return *this;
}

Fraction& Fraction::mul(const Fraction& fract)
{
    numerator *= fract.numerator;
    denominator *= fract.denominator;
    reduce();
    return *this;
}

Fraction& Fraction::div(const Fraction& fract)
{
    numerator *= fract.denominator;
    denominator *= fract.numerator;
    reduce();
    return *this;
}

void Fraction::print() const
{
    std::cout << '(' << numerator << " / " << denominator << ")";
}

int main()
{
    Fraction a{ 1,2 };
    Fraction b{ 1,3 };

    std::cout << " a + b = "; a.add(b).print(); std::cout << '\n';

    a.setNumerator(1); a.setDenominator(2);
    std::cout << " a - b = "; a.sub(b).print(); std::cout << '\n';

    a.setNumerator(1); a.setDenominator(2);
    std::cout << " a * b = "; a.mul(b).print(); std::cout << '\n';

    a.setNumerator(1); a.setDenominator(2);
    std::cout << " a / b = "; a.div(b).print(); std::cout << '\n';

    return 0;
}