Basic.h

Go to the documentation of this file.

 
#ifndef EIGENRAND_DISTS_BASIC_H
#define EIGENRAND_DISTS_BASIC_H
 
namespace Eigen
{
    namespace Rand
    {
        namespace constant
        {
            static constexpr double pi = 3.1415926535897932;
            static constexpr double e = 2.7182818284590452;
        }
 
        template<typename DerivedGen, typename Scalar>
        class GenBase
        {
        public:
            DerivedGen &derived() { return static_cast<DerivedGen &>(*this); }
 
            template<typename Derived, typename Urng>
            inline const CwiseNullaryOp<internal::scalar_rng_adaptor<DerivedGen&, Scalar, Urng>, const Derived>
                generate(Index rows, Index cols, Urng&& urng)
            {
                return {
                    rows, cols, { std::forward<Urng>(urng), derived() }
                };
            }
 
            template<typename Derived, typename Urng>
            inline const CwiseNullaryOp<internal::scalar_rng_adaptor<DerivedGen&, Scalar, Urng>, const Derived>
                generateLike(const Derived& o, Urng&& urng)
            {
                return {
                    o.rows(), o.cols(), { std::forward<Urng>(urng), derived() }
                };
            }
        };
 
        template<typename DerivedGen, typename Scalar, typename ScalarA>
        class UnaryGenBase
        {
        public:
            DerivedGen &derived() { return static_cast<DerivedGen &>(*this); }
 
            template<typename Lhs, typename Urng>
            inline CwiseUnaryOp<
                internal::scalar_unary_rng_adaptor<DerivedGen&, Scalar, typename Lhs::Scalar, Urng>,
                const Lhs
            > generate(Urng&& urng, const ArrayBase<Lhs>& a)
            {
                return {
                    a, { std::forward<Urng>(urng), derived() }
                };
            }
        };
 
        template<typename DerivedGen, typename Scalar, typename ScalarA, typename ScalarB>
        class BinaryGenBase
        {
        public:
            DerivedGen &derived() { return static_cast<DerivedGen &>(*this); }
 
            template<typename Lhs, typename Rhs, typename Urng>
            inline CwiseBinaryOp<
                internal::scalar_binary_rng_adaptor<DerivedGen&, Scalar, typename Lhs::Scalar, typename Rhs::Scalar, Urng>,
                const Lhs, const Rhs
            > generate(Urng&& urng, const ArrayBase<Lhs>& a, const ArrayBase<Rhs>& b)
            {
                return {
                    a, b, { std::forward<Urng>(urng), derived() }
                };
            }
 
            template<typename Lhs, typename Rhs, typename Urng>
            inline CwiseBinaryOp<
                internal::scalar_binary_rng_adaptor<DerivedGen&, Scalar, typename Lhs::Scalar, Rhs, Urng>,
                const Lhs, CwiseNullaryOp<internal::scalar_constant_op<Rhs>, const Lhs>
            > generate(Urng&& urng, const ArrayBase<Lhs>& a, Rhs b)
            {
                return {
                    a, { a.rows(), a.cols(), internal::scalar_constant_op<Rhs>{ b } },
                    { std::forward<Urng>(urng), derived() }
                };
            }
 
            template<typename Lhs, typename Rhs, typename Urng>
            inline CwiseBinaryOp<
                internal::scalar_binary_rng_adaptor<DerivedGen&, Scalar, Lhs, typename Rhs::Scalar, Urng>,
                CwiseNullaryOp<internal::scalar_constant_op<Lhs>, const Rhs>, const Rhs
            > generate(Urng&& urng, Lhs a, const ArrayBase<Rhs>& b)
            {
                return {
                    { b.rows(), b.cols(), internal::scalar_constant_op<Lhs>{ a } }, b,
                    { std::forward<Urng>(urng), derived() }
                };
            }
        };
 
        template<typename DerivedGen, typename _Scalar, Index Dim>
        class MvVecGenBase
        {
        public:
            DerivedGen &derived() { return static_cast<DerivedGen &>(*this); }
 
            Index dims() const { return derived().dims(); }
 
            template<typename Urng>
            inline Matrix<_Scalar, Dim, -1> generate(Urng&& urng, Index samples)
            {
                return derived().generate(std::forward<Urng>(urng), samples);
            }
 
            template<typename Urng>
            inline Matrix<_Scalar, Dim, 1> generate(Urng&& urng)
            {
                return derived().generate(std::forward<Urng>(urng));
            }
        };
 
        template<typename DerivedGen, typename _Scalar, Index Dim>
        class MvMatGenBase
        {
        public:
            DerivedGen &derived() { return static_cast<DerivedGen &>(*this); }
 
            Index dims() const { return derived().dims(); }
 
            template<typename Urng>
            inline Matrix<_Scalar, Dim, -1> generate(Urng&& urng, Index samples)
            {
                return derived().generate(std::forward<Urng>(urng), samples);
            }
 
            template<typename Urng>
            inline Matrix<_Scalar, Dim, Dim> generate(Urng&& urng)
            {
                return derived().generate(std::forward<Urng>(urng));
            }
        };
 
        template<Index _alignment=0>
        class CacheStore
        {
        protected:
            enum { max_size = sizeof(internal::find_best_packet<float, -1>::type) };
            int8_t raw_data[max_size + _alignment - 1] = { 0, };
            void* aligned_ptr;
 
        public:
            CacheStore()
            {
                aligned_ptr = (void*)((((size_t)raw_data + _alignment - 1) / _alignment) * _alignment);
            }
 
            CacheStore(const CacheStore& c)
            {
                std::copy(c.raw_data, c.raw_data + max_size, raw_data);
                aligned_ptr = (void*)((((size_t)raw_data + _alignment - 1) / _alignment) * _alignment);
            }
 
            CacheStore(CacheStore&& c)
            {
                std::copy(c.raw_data, c.raw_data + max_size, raw_data);
                aligned_ptr = (void*)((((size_t)raw_data + _alignment - 1) / _alignment) * _alignment);
            }
 
            template<typename Ty>
            Ty& get()
            {
                return *(Ty*)aligned_ptr;
            }
 
            template<typename Ty>
            const Ty& get() const
            {
                return *(const Ty*)aligned_ptr;
            }
        };
 
        template<>
        class CacheStore<0>
        {
        protected:
            enum { max_size = sizeof(internal::find_best_packet<float, -1>::type) };
            int8_t raw_data[max_size] = { 0, };
 
        public:
            CacheStore()
            {
            }
 
            CacheStore(const CacheStore& c)
            {
                std::copy(c.raw_data, c.raw_data + max_size, raw_data);
            }
 
            CacheStore(CacheStore&& c)
            {
                std::copy(c.raw_data, c.raw_data + max_size, raw_data);
            }
 
            template<typename Ty>
            Ty& get()
            {
                return *(Ty*)raw_data;
            }
 
            template<typename Ty>
            const Ty& get() const
            {
                return *(const Ty*)raw_data;
            }
        };
 
        using OptCacheStore = CacheStore<EIGEN_MAX_ALIGN_BYTES>;
 
        template<typename _Scalar>
        struct ExtractFirstUint;
 
        template<>
        struct ExtractFirstUint<float>
        {
            template<typename Packet>
            auto operator()(Packet v) -> decltype(Eigen::internal::pfirst(v))
            {
                return Eigen::internal::pfirst(v);
            }
        };
 
        template<>
        struct ExtractFirstUint<double>
        {
            template<typename Packet>
            auto operator()(Packet v) -> uint64_t
            {
#ifdef EIGEN_VECTORIZE_AVX512
                return Eigen::internal::pfirst(v);
#else
                uint64_t arr[sizeof(Packet) / 8];
                Eigen::internal::pstoreu((Packet*)arr, v);
                return arr[0];
#endif
            }
        };
 
        template<typename _Scalar>
        class RandbitsGen : public GenBase<RandbitsGen<_Scalar>, _Scalar>
        {
            static_assert(std::is_integral<_Scalar>::value, "randBits needs integral types.");
        
        public:
            using Scalar = _Scalar;
 
            template<typename Rng>
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng)
            {
                using namespace Eigen::internal;
                return pfirst(std::forward<Rng>(rng)());
            }
 
            template<typename Packet, typename Rng>
            EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng)
            {
                using namespace Eigen::internal;
                using RUtils = RawbitsMaker<Packet, Rng>;
                return RUtils{}.rawbits(std::forward<Rng>(rng));
            }
        };
 
        template<typename _Scalar>
        class BalancedGen : public GenBase<BalancedGen<_Scalar>, _Scalar>
        {
            static_assert(std::is_floating_point<_Scalar>::value, "balanced needs floating point types.");
 
        public:
            using Scalar = _Scalar;
 
            template<typename Rng>
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng)
            {
                using namespace Eigen::internal;
                return ((_Scalar)((int32_t)pfirst(std::forward<Rng>(rng)()) & 0x7FFFFFFF) / 0x7FFFFFFF) * 2 - 1;
            }
 
            template<typename Packet, typename Rng>
            EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng)
            {
                using namespace Eigen::internal;
                using RUtils = RandUtils<Packet, Rng>;
                return RUtils{}.balanced(std::forward<Rng>(rng));
            }
        };
 
        template<typename _Scalar>
        class Balanced2Gen : public GenBase<Balanced2Gen<_Scalar>, _Scalar>
        {
            static_assert(std::is_floating_point<_Scalar>::value, "balanced needs floating point types.");
            _Scalar slope = 2, bias = -1;
        public:
            using Scalar = _Scalar;
 
            Balanced2Gen(_Scalar _a = -1, _Scalar _b = 1)
                : slope{ _b - _a }, bias{ _a }
            {
            }
 
            template<typename Rng>
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng)
            {
                using namespace Eigen::internal;
                return ((_Scalar)((int32_t)pfirst(std::forward<Rng>(rng)()) & 0x7FFFFFFF) / 0x7FFFFFFF) * slope + bias;
            }
 
            template<typename Packet, typename Rng>
            EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng)
            {
                using namespace Eigen::internal;
                using RUtils = RandUtils<Packet, Rng>;
                return RUtils{}.balanced(std::forward<Rng>(rng), slope, bias);
            }
        };
 
        template<typename _Scalar>
        class BalancedVGen : public BinaryGenBase<BalancedVGen<_Scalar>, _Scalar, _Scalar, _Scalar>
        {
            static_assert(std::is_floating_point<_Scalar>::value, "balanced needs floating point types.");
 
        public:
            using Scalar = _Scalar;
 
            template<typename Rng>
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng, _Scalar a, _Scalar b)
            {
                using namespace Eigen::internal;
                return ((_Scalar)((int32_t)pfirst(std::forward<Rng>(rng)()) & 0x7FFFFFFF) / 0x7FFFFFFF) * (b - a) + a;
            }
 
            template<typename Packet, typename Rng>
            EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng, const Packet& a, const Packet& b)
            {
                using namespace Eigen::internal;
                using RUtils = RandUtils<Packet, Rng>;
                return padd(pmul(RUtils{}.zero_to_one(std::forward<Rng>(rng)), psub(b, a)), a);
            }
        };
 
        namespace detail
        {
            template<size_t v>
            struct BitWidth
            {
                static constexpr size_t value = BitWidth<v / 2>::value + 1;
            };
 
            template<>
            struct BitWidth<0>
            {
                static constexpr size_t value = 0;
            };
 
            template<class Rng>
            struct RngBitSize
            {
                static constexpr size_t _min = Rng::min();
                static constexpr size_t _max = Rng::max();
 
                static constexpr bool _fullbit_rng = _min == 0 && (_max & (_max + 1)) == 0;
                static constexpr size_t value = IsPacketRandomEngine<Rng>::value ? sizeof(typename Rng::result_type) * 8 : (_fullbit_rng ? BitWidth<_max>::value : 0);
            };
        }
 
        template<typename _Scalar>
        class StdUniformRealGen : public GenBase<StdUniformRealGen<_Scalar>, _Scalar>
        {
            static_assert(std::is_floating_point<_Scalar>::value, "uniformReal needs floating point types.");
 
        public:
            using Scalar = _Scalar;
 
            template<typename Rng, 
                typename std::enable_if<sizeof(Scalar) * 8 <= detail::RngBitSize<typename std::remove_const<typename std::remove_reference<Rng>::type>::type>::value, int>::type = 0
            >
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng)
            {
                using namespace Eigen::internal;
                return BitScalar<_Scalar>{}.to_ur(ExtractFirstUint<_Scalar>{}(std::forward<Rng>(rng)()));
            }
 
            template<typename Rng,
                typename std::enable_if<detail::RngBitSize<typename std::remove_const<typename std::remove_reference<Rng>::type>::type>::value < sizeof(Scalar) * 8, int>::type = 0
            >
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng)
            {
                using RRng = typename std::remove_const<typename std::remove_reference<Rng>::type>::type;
                static_assert(detail::RngBitSize<RRng>::value > 0,
                    "BaseRng must be a kind of mersenne_twister_engine.");
                using ResultType = typename std::conditional<detail::RngBitSize<RRng>::value == 32, uint32_t, uint64_t>::type;
                using namespace Eigen::internal;
                ResultType arr[sizeof(Scalar) / sizeof(ResultType)];
                for (size_t i = 0; i < sizeof(Scalar) / sizeof(ResultType); ++i)
                {
                    arr[i] = rng();
                }
                return BitScalar<_Scalar>{}.to_ur(*(uint64_t*)arr);
            }
 
            template<typename Rng,
                typename std::enable_if<sizeof(Scalar) <= sizeof(typename std::remove_const<typename std::remove_reference<Rng>::type>::type::result_type), int>::type = 0
            >
            EIGEN_STRONG_INLINE const _Scalar nzur_scalar(Rng&& rng)
            {
                using namespace Eigen::internal;
                return BitScalar<_Scalar>{}.to_nzur(ExtractFirstUint<_Scalar>{}(std::forward<Rng>(rng)()));
            }
 
            template<typename Rng,
                typename std::enable_if<sizeof(typename std::remove_const<typename std::remove_reference<Rng>::type>::type::result_type) < sizeof(Scalar), int > ::type = 0
            >
            EIGEN_STRONG_INLINE const _Scalar nzur_scalar(Rng&& rng)
            {
                using namespace Eigen::internal;
                using RngResult = typename std::remove_const<typename std::remove_reference<Rng>::type>::type::result_type;
                RngResult arr[sizeof(Scalar) / sizeof(RngResult)];
                for (size_t i = 0; i < sizeof(Scalar) / sizeof(RngResult); ++i)
                {
                    arr[i] = rng();
                }
                return BitScalar<_Scalar>{}.to_nzur(*(Scalar*)arr);
            }
 
            template<typename Packet, typename Rng>
            EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng)
            {
                using namespace Eigen::internal;
                using RUtils = RandUtils<Packet, Rng>;
                return RUtils{}.uniform_real(std::forward<Rng>(rng));
            }
        };
 
        template<typename _Scalar>
        class UniformRealGen : public GenBase<UniformRealGen<_Scalar>, _Scalar>
        {
            static_assert(std::is_floating_point<_Scalar>::value, "uniformReal needs floating point types.");
            _Scalar bias, slope;
 
        public:
            using Scalar = _Scalar;
 
            UniformRealGen(_Scalar _min = 0, _Scalar _max = 1)
                : bias{ _min }, slope{ _max - _min }
            {
            }
 
            UniformRealGen(const UniformRealGen&) = default;
            UniformRealGen(UniformRealGen&&) = default;
 
            UniformRealGen& operator=(const UniformRealGen&) = default;
            UniformRealGen& operator=(UniformRealGen&&) = default;
 
            template<typename Rng>
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng)
            {
                using namespace Eigen::internal;
                return bias + BitScalar<_Scalar>{}.to_ur(pfirst(std::forward<Rng>(rng)())) * slope;
            }
 
            template<typename Packet, typename Rng>
            EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng)
            {
                using namespace Eigen::internal;
                using RUtils = RandUtils<Packet, Rng>;
                return padd(pmul(
                    RUtils{}.uniform_real(std::forward<Rng>(rng)), pset1<Packet>(slope)
                ), pset1<Packet>(bias));
            }
        };
 
        template<typename _Scalar>
        class UniformRealVGen : public BinaryGenBase<UniformRealVGen<_Scalar>, _Scalar, _Scalar, _Scalar>
        {
            static_assert(std::is_floating_point<_Scalar>::value, "uniformReal needs floating point types.");
 
        public:
            using Scalar = _Scalar;
 
            template<typename Rng>
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng, _Scalar a, _Scalar b)
            {
                using namespace Eigen::internal;
                return a + BitScalar<_Scalar>{}.to_ur(pfirst(std::forward<Rng>(rng)())) * (b - a);
            }
 
            template<typename Packet, typename Rng>
            EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng, const Packet& a, const Packet& b)
            {
                using namespace Eigen::internal;
                using RUtils = RandUtils<Packet, Rng>;
                return padd(pmul(
                    RUtils{}.uniform_real(std::forward<Rng>(rng)), psub(b, a)
                ), a);
            }
        };
 
 
        template<typename _Scalar>
        class BernoulliGen : public GenBase<BernoulliGen<_Scalar>, _Scalar>
        {
            uint32_t p;
        public:
            using Scalar = _Scalar;
 
            BernoulliGen(double _p = 0.5)
            {
                eigen_assert(0 <= _p && _p <= 1 );
                p = (uint32_t)(_p * 0x80000000);
            }
 
            BernoulliGen(const BernoulliGen&) = default;
            BernoulliGen(BernoulliGen&&) = default;
 
            BernoulliGen& operator=(const BernoulliGen&) = default;
            BernoulliGen& operator=(BernoulliGen&&) = default;
 
            template<typename Rng>
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng)
            {
                using namespace Eigen::internal;
                return (((uint32_t)pfirst(std::forward<Rng>(rng)()) & 0x7FFFFFFF) < p) ? 1 : 0;
            }
 
            template<typename Packet, typename Rng>
            EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng)
            {
                using namespace Eigen::internal;
                using IPacket = decltype(reinterpret_to_int(std::declval<Packet>()));
                using RUtils = RawbitsMaker<IPacket, Rng>;
                auto one = pset1<Packet>(1);
                auto zero = pset1<Packet>(0);
                auto r = RUtils{}.rawbits(std::forward<Rng>(rng));
                r = pand(r, pset1<IPacket>(0x7FFFFFFF));
                return pblendv(pcmplt(r, pset1<IPacket>(p)), one, zero);
            }
        };
 
        template<typename _Scalar>
        class BernoulliVGen : public UnaryGenBase<BernoulliVGen<_Scalar>, _Scalar, _Scalar>
        {
            static_assert(std::is_floating_point<_Scalar>::value, "vectorized `bernoulli` needs a float type.");
        public:
            using Scalar = _Scalar;
 
            template<typename Rng>
            EIGEN_STRONG_INLINE const _Scalar operator() (Rng&& rng, _Scalar a)
            {
                using namespace Eigen::internal;
                uint32_t p = (uint32_t)(a * 0x80000000);
                return (((uint32_t)pfirst(std::forward<Rng>(rng)()) & 0x7FFFFFFF) < p) ? 1 : 0;
            }
 
            template<typename Packet, typename Rng>
            EIGEN_STRONG_INLINE const Packet packetOp(Rng&& rng, const Packet& a)
            {
                using namespace Eigen::internal;
                using IPacket = decltype(reinterpret_to_int(std::declval<Packet>()));
                using RUtils = RawbitsMaker<IPacket, Rng>;
                auto one = pset1<Packet>(1);
                auto zero = pset1<Packet>(0);
                auto p = pcast<Packet, IPacket>(pmul(a, pset1<Packet>(0x80000000)));
                auto r = RUtils{}.rawbits(std::forward<Rng>(rng));
                r = pand(r, pset1<IPacket>(0x7FFFFFFF));
                return pblendv(pcmplt(r, p), one, zero);
            }
        };
 
        template<typename Derived, typename Urng>
        using RandBitsType = CwiseNullaryOp<internal::scalar_rng_adaptor<RandbitsGen<typename Derived::Scalar>, typename Derived::Scalar, Urng, true>, const Derived>;
 
        template<typename Derived, typename Urng>
        inline const RandBitsType<Derived, Urng>
            randBits(Index rows, Index cols, Urng&& urng)
        {
            return {
                rows, cols, { std::forward<Urng>(urng) }
            };
        }
 
        template<typename Derived, typename Urng>
        inline const RandBitsType<Derived, Urng>
            randBitsLike(Derived& o, Urng&& urng)
        {
            return {
                o.rows(), o.cols(), { std::forward<Urng>(urng) }
            };
        }
 
        template<typename Derived, typename Urng>
        using BalancedType = CwiseNullaryOp<internal::scalar_rng_adaptor<BalancedGen<typename Derived::Scalar>, typename Derived::Scalar, Urng, true>, const Derived>;
 
        template<typename Derived, typename Urng>
        inline const BalancedType<Derived, Urng>
            balanced(Index rows, Index cols, Urng&& urng)
        {
            return {
                rows, cols, { std::forward<Urng>(urng) }
            };
        }
 
        template<typename Derived, typename Urng>
        inline const BalancedType<Derived, Urng>
            balancedLike(const Derived& o, Urng&& urng)
        {
            return {
                o.rows(), o.cols(), { std::forward<Urng>(urng) }
            };
        }
 
        template<typename Derived, typename Urng>
        using Balanced2Type = CwiseNullaryOp<internal::scalar_rng_adaptor<Balanced2Gen<typename Derived::Scalar>, typename Derived::Scalar, Urng, true>, const Derived>;
 
        template<typename Derived, typename Urng>
        inline const Balanced2Type<Derived, Urng>
            balanced(Index rows, Index cols, Urng&& urng, typename Derived::Scalar a, typename Derived::Scalar b)
        {
            return {
                rows, cols, { std::forward<Urng>(urng), Balanced2Gen<typename Derived::Scalar>{a, b} }
            };
        }
 
        template<typename Derived, typename Urng>
        inline const Balanced2Type<Derived, Urng>
            balancedLike(const Derived& o, Urng&& urng, typename Derived::Scalar a, typename Derived::Scalar b)
        {
            return {
                o.rows(), o.cols(), { std::forward<Urng>(urng), Balanced2Gen<typename Derived::Scalar>{a, b} }
            };
        }
 
        template<typename Derived, typename Urng>
        using BalancedVVType = CwiseBinaryOp<
            internal::scalar_binary_rng_adaptor<BalancedVGen<typename Derived::Scalar>, typename Derived::Scalar, typename Derived::Scalar, typename Derived::Scalar, Urng, true>,
            const Derived, const Derived
        >;
 
        template<typename Lhs, typename Rhs, typename Urng>
        inline const BalancedVVType<Lhs, Urng>
            balanced(Urng&& urng, const ArrayBase<Lhs>& a, const ArrayBase<Rhs>& b)
        {
            static_assert(std::is_same<typename Lhs::Scalar, typename Rhs::Scalar>::value, "`Lhs::Scalar` must be equal to `Rhs::Scalar`");
            return {
                static_cast<const Lhs&>(a), static_cast<const Rhs&>(b), 
                { std::forward<Urng>(urng), BalancedVGen<typename Lhs::Scalar>{} }
            };
        }
 
        template<typename Derived, typename Urng>
        using BalancedVSType = CwiseBinaryOp<
            internal::scalar_binary_rng_adaptor<BalancedVGen<typename Derived::Scalar>, typename Derived::Scalar, typename Derived::Scalar, typename Derived::Scalar, Urng, true>,
            const Derived, CwiseNullaryOp<internal::scalar_constant_op<typename Derived::Scalar>, const Derived>
        >;
 
        template<typename Lhs, typename Urng>
        inline const BalancedVSType<Lhs, Urng>
            balanced(Urng&& urng, const ArrayBase<Lhs>& a, typename Lhs::Scalar b)
        {
            return {
                static_cast<const Lhs&>(a), { a.rows(), a.cols(), internal::scalar_constant_op<typename Lhs::Scalar>{ b } },
                { std::forward<Urng>(urng), BalancedVGen<typename Lhs::Scalar>{} }
            };
        }
 
        template<typename Derived, typename Urng>
        using BalancedSVType = CwiseBinaryOp<
            internal::scalar_binary_rng_adaptor<BalancedVGen<typename Derived::Scalar>, typename Derived::Scalar, typename Derived::Scalar, typename Derived::Scalar, Urng, true>,
            CwiseNullaryOp<internal::scalar_constant_op<typename Derived::Scalar>, const Derived>, const Derived
        >;
 
        template<typename Rhs, typename Urng>
        inline const BalancedSVType<Rhs, Urng>
            balanced(Urng&& urng, typename Rhs::Scalar a, const ArrayBase<Rhs>& b)
        {
            return {
                { b.rows(), b.cols(), internal::scalar_constant_op<typename Rhs::Scalar>{ a } }, static_cast<const Rhs&>(b),
                { std::forward<Urng>(urng), BalancedVGen<typename Rhs::Scalar>{} }
            };
        }
 
        template<typename Derived, typename Urng>
        using StdUniformRealType = CwiseNullaryOp<internal::scalar_rng_adaptor<StdUniformRealGen<typename Derived::Scalar>, typename Derived::Scalar, Urng, true>, const Derived>;
 
        template<typename Derived, typename Urng>
        inline const StdUniformRealType<Derived, Urng>
            uniformReal(Index rows, Index cols, Urng&& urng)
        {
            return {
                rows, cols, { std::forward<Urng>(urng) }
            };
        }
 
        template<typename Derived, typename Urng>
        inline const StdUniformRealType<Derived, Urng>
            uniformRealLike(Derived& o, Urng&& urng)
        {
            return {
                o.rows(), o.cols(), { std::forward<Urng>(urng) }
            };
        }
 
        template<typename Derived, typename Urng>
        using UniformRealType = CwiseNullaryOp<internal::scalar_rng_adaptor<UniformRealGen<typename Derived::Scalar>, typename Derived::Scalar, Urng, true>, const Derived>;
 
        template<typename Derived, typename Urng>
        inline const UniformRealType<Derived, Urng>
            uniformReal(Index rows, Index cols, Urng&& urng, typename Derived::Scalar min, typename Derived::Scalar max)
        {
            return {
                rows, cols, { std::forward<Urng>(urng), UniformRealGen<typename Derived::Scalar>{ min, max } }
            };
        }
 
        template<typename Derived, typename Urng>
        inline const UniformRealType<Derived, Urng>
            uniformRealLike(Derived& o, Urng&& urng, typename Derived::Scalar min, typename Derived::Scalar max)
        {
            return {
                o.rows(), o.cols(), { std::forward<Urng>(urng), UniformRealGen<typename Derived::Scalar>{ min, max } }
            };
        }
 
        template<typename Derived, typename Urng>
        using UniformRealVVType = CwiseBinaryOp<
            internal::scalar_binary_rng_adaptor<UniformRealVGen<typename Derived::Scalar>, typename Derived::Scalar, typename Derived::Scalar, typename Derived::Scalar, Urng, true>,
            const Derived, const Derived
        >;
 
        template<typename Lhs, typename Rhs, typename Urng>
        inline const UniformRealVVType<Lhs, Urng>
            uniformReal(Urng&& urng, const ArrayBase<Lhs>& a, const ArrayBase<Rhs>& b)
        {
            static_assert(std::is_same<typename Lhs::Scalar, typename Rhs::Scalar>::value, "`Lhs::Scalar` must be equal to `Rhs::Scalar`");
            return {
                static_cast<const Lhs&>(a), static_cast<const Rhs&>(b), 
                { std::forward<Urng>(urng), UniformRealVGen<typename Lhs::Scalar>{} }
            };
        }
 
        template<typename Derived, typename Urng>
        using UniformRealVSType = CwiseBinaryOp<
            internal::scalar_binary_rng_adaptor<UniformRealVGen<typename Derived::Scalar>, typename Derived::Scalar, typename Derived::Scalar, typename Derived::Scalar, Urng, true>,
            const Derived, CwiseNullaryOp<internal::scalar_constant_op<typename Derived::Scalar>, const Derived>
        >;
 
        template<typename Lhs, typename Urng>
        inline const UniformRealVSType<Lhs, Urng>
            uniformReal(Urng&& urng, const ArrayBase<Lhs>& a, typename Lhs::Scalar b)
        {
            return {
                static_cast<const Lhs&>(a), { a.rows(), a.cols(), internal::scalar_constant_op<typename Lhs::Scalar>{ b } },
                { std::forward<Urng>(urng), UniformRealVGen<typename Lhs::Scalar>{} }
            };
        }
 
 
        template<typename Derived, typename Urng>
        using UniformRealSVType = CwiseBinaryOp<
            internal::scalar_binary_rng_adaptor<UniformRealVGen<typename Derived::Scalar>, typename Derived::Scalar, typename Derived::Scalar, typename Derived::Scalar, Urng, true>,
            CwiseNullaryOp<internal::scalar_constant_op<typename Derived::Scalar>, const Derived>, const Derived
        >;
 
        template<typename Rhs, typename Urng>
        inline const UniformRealSVType<Rhs, Urng>
            uniformReal(Urng&& urng, typename Rhs::Scalar a, const ArrayBase<Rhs>& b)
        {
            return {
                { b.rows(), b.cols(), internal::scalar_constant_op<typename Rhs::Scalar>{ a } }, static_cast<const Rhs&>(b),
                { std::forward<Urng>(urng), UniformRealVGen<typename Rhs::Scalar>{} }
            };
        }
 
        template<typename Derived, typename Urng>
        using BernoulliType = CwiseNullaryOp<internal::scalar_rng_adaptor<BernoulliGen<typename Derived::Scalar>, typename Derived::Scalar, Urng, true>, const Derived>;
 
        template<typename Derived, typename Urng>
        inline const BernoulliType<Derived, Urng>
            bernoulli(Index rows, Index cols, Urng&& urng, double p = 0.5)
        {
            return {
                rows, cols, { std::forward<Urng>(urng), BernoulliGen<typename Derived::Scalar>{ p } }
            };
        }
 
        template<typename Derived, typename Urng>
        inline const BernoulliType<Derived, Urng>
            bernoulli(Derived& o, Urng&& urng, double p = 0.5)
        {
            return {
                o.rows(), o.cols(), { std::forward<Urng>(urng), BernoulliGen<typename Derived::Scalar>{ p } }
            };
        }
 
        template<typename Derived, typename Urng>
        using BernoulliVType = CwiseUnaryOp<
            internal::scalar_unary_rng_adaptor<BernoulliVGen<typename Derived::Scalar>, typename Derived::Scalar, typename Derived::Scalar, Urng, true>, 
            const Derived
        >;
 
        template<typename Lhs, typename Urng>
        inline const BernoulliVType<Lhs, Urng>
            bernoulli(Urng&& urng, const ArrayBase<Lhs>& p)
        {
            return BernoulliVType<Lhs, Urng>{
                static_cast<const Lhs&>(p), { std::forward<Urng>(urng), BernoulliVGen<typename Lhs::Scalar>{} }
            };
        }
    }
}
 
#endif