s2ga/s2ga.hpp

#include <array>
#include <bit>
#include <random>
#include <regex>

namespace s2ga
{
    template<class... T>
    struct always_false: std::false_type
    {
    };

    class lehmer64
    {
    public:
        lehmer64(__uint128_t seed = 0)
        {
            this->seed(seed);
        }

        void seed(__uint128_t z)
        {
            if(z == 0)
            {
                z = 0xC0FFEE;
            }

            s = z;
        }

        uint64_t operator()() noexcept
        {
            s *= 0xda942042e4dd58b5;
            return s >> 64;
        }

        static constexpr uint64_t min()
        {
            return 0;
        }

        static constexpr uint64_t max()
        {
            return UINT64_MAX;
        }

        template<typename T>
        T random(T min, T max)
        {
            if constexpr(std::is_integral_v<T>)
            {
                return std::uniform_int_distribution<T>(min, max)(*this);
            }
            else if constexpr(std::is_floating_point_v<T>)
            {
                return std::uniform_real_distribution<T>(min, max)(*this);
            }
            else
            {
                static_assert(always_false<T>::value,
                              "unsupported distribution type");
            }
        }

    private:
        __uint128_t s;
    };

    static_assert(std::uniform_random_bit_generator<lehmer64>);
}; // namespace s2ga

inline void foo()
{
}