Editor/operator_usages_highlight.cpp

// Find all usages of overloaded << operator using Alt+F7
//Try semantic highlighting by switching it on in Settings/Preferences, Editor | Colors & Fonts | Language Defaults

#include <iostream>

//TODO: check operators
class Fraction {
    int gcd(int a , int b)
    {
        return b == 0 ? a : gcd(b , a % b);
    }

    int n , d;
public:
    Fraction(int n , int d = 1) : n(n / gcd(n , d)) , d(d / gcd(n , d))
    {}

    int num() const
    { return n; }

    int den() const
    { return d; }

    Fraction &operator*=(const Fraction &rhs)
    {
        int new_n = n * rhs.n / gcd(n * rhs.n , d * rhs.d);
        d = d * rhs.d / gcd(n * rhs.n , d * rhs.d);
        n = new_n;
        return *this;
    }
};


bool operator==(const Fraction& lhs, const Fraction& rhs)
{
    return lhs.num() == rhs.num() && lhs.den() == rhs.den();
}

bool operator!=(const Fraction& lhs, const Fraction& rhs)
{
    return !(lhs == rhs);
}

Fraction operator*(Fraction lhs, const Fraction& rhs)
{
    return lhs *= rhs;
}

std::ostream& operator<<(std::ostream& out, const Fraction& f) {
    return out << f.num() << '/' << f.den();
}

void fraction_sample() {
    Fraction f1(3, 8), f2(1, 2);

    std::cout << f1 << " * " << f2 << " = " << f1 * f2 << '\n';
}