#include <compare>
#include <cassert>

struct rational
{
    int d = 0, n = 1;
    auto operator<=>(const rational& b) const { return d * b.n <=> n * b.d; }
    bool operator== (const rational& b) const { return d * b.n ==  n * b.d; }
    auto operator<=>(int number) const { return d <=> n * number; }
    bool operator== (int number) const { return d ==  n * number; }
};

int main()
{
    rational a, b{1, 2};
    assert( a != b && 1 > b );
}