std::ratio_power

ratio_power.cpp

template<typename R, int p>
struct ratio_power {
private:
        using S = typename std::ratio_multiply<R, R>::type;
public:
        using type = typename std::ratio_multiply<
                typename ratio_power<R, p%2>::type,
                typename ratio_power<S, p/2>::type
        >::type;
        constexpr static intmax_t num = type::num;
        constexpr static intmax_t den = type::den;
};

template<typename R>
struct ratio_power<R, 0> {
        using type = std::ratio<1>;
        constexpr static intmax_t num = type::num;
        constexpr static intmax_t den = type::den;
};

template<typename R>
struct ratio_power<R, 1> {
        using type = R;
        constexpr static intmax_t num = type::num;
        constexpr static intmax_t den = type::den;
};

template<typename R>
struct ratio_power<R, -1> {
        using type = typename std::ratio_divide<std::ratio<1>, R>::type;
        constexpr static intmax_t num = type::num;
        constexpr static intmax_t den = type::den;
};