//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___RANDOM_MERSENNE_TWISTER_ENGINE_H
#define _LIBCPP___RANDOM_MERSENNE_TWISTER_ENGINE_H

#include <__algorithm/equal.h>
#include <__algorithm/min.h>
#include <__config>
#include <__random/is_seed_sequence.h>
#include <cstddef>
#include <cstdint>
#include <iosfwd>
#include <limits>
#include <type_traits>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_PUSH_MACROS
#include <__undef_macros>

_LIBCPP_BEGIN_NAMESPACE_STD

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine;

template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
bool
operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);

template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
_LIBCPP_INLINE_VISIBILITY
bool
operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);

template <class _CharT, class _Traits,
          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os,
           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x);

template <class _CharT, class _Traits,
          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
basic_istream<_CharT, _Traits>&
operator>>(basic_istream<_CharT, _Traits>& __is,
           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x);

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine
{
public:
    // types
    typedef _UIntType result_type;

private:
    result_type __x_[__n];
    size_t      __i_;

    static_assert(  0 <  __m, "mersenne_twister_engine invalid parameters");
    static_assert(__m <= __n, "mersenne_twister_engine invalid parameters");
    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
    static_assert(__w <= _Dt, "mersenne_twister_engine invalid parameters");
    static_assert(  2 <= __w, "mersenne_twister_engine invalid parameters");
    static_assert(__r <= __w, "mersenne_twister_engine invalid parameters");
    static_assert(__u <= __w, "mersenne_twister_engine invalid parameters");
    static_assert(__s <= __w, "mersenne_twister_engine invalid parameters");
    static_assert(__t <= __w, "mersenne_twister_engine invalid parameters");
    static_assert(__l <= __w, "mersenne_twister_engine invalid parameters");
public:
    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
                                                      (result_type(1) << __w) - result_type(1);
    static_assert(_Min < _Max, "mersenne_twister_engine invalid parameters");
    static_assert(__a <= _Max, "mersenne_twister_engine invalid parameters");
    static_assert(__b <= _Max, "mersenne_twister_engine invalid parameters");
    static_assert(__c <= _Max, "mersenne_twister_engine invalid parameters");
    static_assert(__d <= _Max, "mersenne_twister_engine invalid parameters");
    static_assert(__f <= _Max, "mersenne_twister_engine invalid parameters");

    // engine characteristics
    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
    static _LIBCPP_CONSTEXPR const size_t state_size = __n;
    static _LIBCPP_CONSTEXPR const size_t shift_size = __m;
    static _LIBCPP_CONSTEXPR const size_t mask_bits = __r;
    static _LIBCPP_CONSTEXPR const result_type xor_mask = __a;
    static _LIBCPP_CONSTEXPR const size_t tempering_u = __u;
    static _LIBCPP_CONSTEXPR const result_type tempering_d = __d;
    static _LIBCPP_CONSTEXPR const size_t tempering_s = __s;
    static _LIBCPP_CONSTEXPR const result_type tempering_b = __b;
    static _LIBCPP_CONSTEXPR const size_t tempering_t = __t;
    static _LIBCPP_CONSTEXPR const result_type tempering_c = __c;
    static _LIBCPP_CONSTEXPR const size_t tempering_l = __l;
    static _LIBCPP_CONSTEXPR const result_type initialization_multiplier = __f;
    _LIBCPP_INLINE_VISIBILITY
    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
    _LIBCPP_INLINE_VISIBILITY
    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
    static _LIBCPP_CONSTEXPR const result_type default_seed = 5489u;

    // constructors and seeding functions
#ifndef _LIBCPP_CXX03_LANG
    _LIBCPP_INLINE_VISIBILITY
    mersenne_twister_engine() : mersenne_twister_engine(default_seed) {}
    _LIBCPP_INLINE_VISIBILITY
    explicit mersenne_twister_engine(result_type __sd) { seed(__sd); }
#else
    _LIBCPP_INLINE_VISIBILITY
    explicit mersenne_twister_engine(result_type __sd = default_seed) {
      seed(__sd);
    }
#endif
    template<class _Sseq>
        _LIBCPP_INLINE_VISIBILITY
        explicit mersenne_twister_engine(_Sseq& __q,
        typename enable_if<__is_seed_sequence<_Sseq, mersenne_twister_engine>::value>::type* = 0)
        {seed(__q);}
    void seed(result_type __sd = default_seed);
    template<class _Sseq>
        _LIBCPP_INLINE_VISIBILITY
        typename enable_if
        <
            __is_seed_sequence<_Sseq, mersenne_twister_engine>::value,
            void
        >::type
        seed(_Sseq& __q)
            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}

    // generating functions
    result_type operator()();
    _LIBCPP_INLINE_VISIBILITY
    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}

    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
    friend
    bool
    operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);

    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
    friend
    bool
    operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);

    template <class _CharT, class _Traits,
              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
    friend
    basic_ostream<_CharT, _Traits>&
    operator<<(basic_ostream<_CharT, _Traits>& __os,
               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x);

    template <class _CharT, class _Traits,
              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
    friend
    basic_istream<_CharT, _Traits>&
    operator>>(basic_istream<_CharT, _Traits>& __is,
               mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                       _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
private:

    template<class _Sseq>
        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
    template<class _Sseq>
        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);

    template <size_t __count>
        _LIBCPP_INLINE_VISIBILITY
        static
        typename enable_if
        <
            __count < __w,
            result_type
        >::type
        __lshift(result_type __x) {return (__x << __count) & _Max;}

    template <size_t __count>
        _LIBCPP_INLINE_VISIBILITY
        static
        typename enable_if
        <
            (__count >= __w),
            result_type
        >::type
        __lshift(result_type) {return result_type(0);}

    template <size_t __count>
        _LIBCPP_INLINE_VISIBILITY
        static
        typename enable_if
        <
            __count < _Dt,
            result_type
        >::type
        __rshift(result_type __x) {return __x >> __count;}

    template <size_t __count>
        _LIBCPP_INLINE_VISIBILITY
        static
        typename enable_if
        <
            (__count >= _Dt),
            result_type
        >::type
        __rshift(result_type) {return result_type(0);}
};

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const size_t
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::word_size;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const size_t
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::state_size;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const size_t
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::shift_size;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const size_t
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::mask_bits;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::xor_mask;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const size_t
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_u;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_d;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const size_t
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_s;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_b;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const size_t
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_t;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_c;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const size_t
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_l;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::initialization_multiplier;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::default_seed;

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
void
mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
    __t, __c, __l, __f>::seed(result_type __sd)
    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
{   // __w >= 2
    __x_[0] = __sd & _Max;
    for (size_t __i = 1; __i < __n; ++__i)
        __x_[__i] = (__f * (__x_[__i-1] ^ __rshift<__w - 2>(__x_[__i-1])) + __i) & _Max;
    __i_ = 0;
}

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
template<class _Sseq>
void
mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 1>)
{
    const unsigned __k = 1;
    uint32_t __ar[__n * __k];
    __q.generate(__ar, __ar + __n * __k);
    for (size_t __i = 0; __i < __n; ++__i)
        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
    const result_type __mask = __r == _Dt ? result_type(~0) :
                                       (result_type(1) << __r) - result_type(1);
    __i_ = 0;
    if ((__x_[0] & ~__mask) == 0)
    {
        for (size_t __i = 1; __i < __n; ++__i)
            if (__x_[__i] != 0)
                return;
        __x_[0] = result_type(1) << (__w - 1);
    }
}

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
template<class _Sseq>
void
mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 2>)
{
    const unsigned __k = 2;
    uint32_t __ar[__n * __k];
    __q.generate(__ar, __ar + __n * __k);
    for (size_t __i = 0; __i < __n; ++__i)
        __x_[__i] = static_cast<result_type>(
            (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
    const result_type __mask = __r == _Dt ? result_type(~0) :
                                       (result_type(1) << __r) - result_type(1);
    __i_ = 0;
    if ((__x_[0] & ~__mask) == 0)
    {
        for (size_t __i = 1; __i < __n; ++__i)
            if (__x_[__i] != 0)
                return;
        __x_[0] = result_type(1) << (__w - 1);
    }
}

template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
_UIntType
mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
    __t, __c, __l, __f>::operator()()
{
    const size_t __j = (__i_ + 1) % __n;
    const result_type __mask = __r == _Dt ? result_type(~0) :
                                       (result_type(1) << __r) - result_type(1);
    const result_type _Yp = (__x_[__i_] & ~__mask) | (__x_[__j] & __mask);
    const size_t __k = (__i_ + __m) % __n;
    __x_[__i_] = __x_[__k] ^ __rshift<1>(_Yp) ^ (__a * (_Yp & 1));
    result_type __z = __x_[__i_] ^ (__rshift<__u>(__x_[__i_]) & __d);
    __i_ = __j;
    __z ^= __lshift<__s>(__z) & __b;
    __z ^= __lshift<__t>(__z) & __c;
    return __z ^ __rshift<__l>(__z);
}

template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
bool
operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
{
    if (__x.__i_ == __y.__i_)
        return _VSTD::equal(__x.__x_, __x.__x_ + _Np, __y.__x_);
    if (__x.__i_ == 0 || __y.__i_ == 0)
    {
        size_t __j = _VSTD::min(_Np - __x.__i_, _Np - __y.__i_);
        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
                         __y.__x_ + __y.__i_))
            return false;
        if (__x.__i_ == 0)
            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Np, __y.__x_);
        return _VSTD::equal(__x.__x_, __x.__x_ + (_Np - __j), __y.__x_ + __j);
    }
    if (__x.__i_ < __y.__i_)
    {
        size_t __j = _Np - __y.__i_;
        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
                         __y.__x_ + __y.__i_))
            return false;
        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Np,
                         __y.__x_))
            return false;
        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
                           __y.__x_ + (_Np - (__x.__i_ + __j)));
    }
    size_t __j = _Np - __x.__i_;
    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
                     __x.__x_ + __x.__i_))
        return false;
    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Np,
                     __x.__x_))
        return false;
    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
                       __x.__x_ + (_Np - (__y.__i_ + __j)));
}

template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
{
    return !(__x == __y);
}

template <class _CharT, class _Traits,
          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os,
           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
{
    __save_flags<_CharT, _Traits> __lx(__os);
    typedef basic_ostream<_CharT, _Traits> _Ostream;
    __os.flags(_Ostream::dec | _Ostream::left);
    _CharT __sp = __os.widen(' ');
    __os.fill(__sp);
    __os << __x.__x_[__x.__i_];
    for (size_t __j = __x.__i_ + 1; __j < _Np; ++__j)
        __os << __sp << __x.__x_[__j];
    for (size_t __j = 0; __j < __x.__i_; ++__j)
        __os << __sp << __x.__x_[__j];
    return __os;
}

template <class _CharT, class _Traits,
          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
basic_istream<_CharT, _Traits>&
operator>>(basic_istream<_CharT, _Traits>& __is,
           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
{
    __save_flags<_CharT, _Traits> __lx(__is);
    typedef basic_istream<_CharT, _Traits> _Istream;
    __is.flags(_Istream::dec | _Istream::skipws);
    _UInt __t[_Np];
    for (size_t __i = 0; __i < _Np; ++__i)
        __is >> __t[__i];
    if (!__is.fail())
    {
        for (size_t __i = 0; __i < _Np; ++__i)
            __x.__x_[__i] = __t[__i];
        __x.__i_ = 0;
    }
    return __is;
}

typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
                                0x9908b0df, 11, 0xffffffff,
                                7,  0x9d2c5680,
                                15, 0xefc60000,
                                18, 1812433253>                         mt19937;
typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
                                0xb5026f5aa96619e9ULL, 29, 0x5555555555555555ULL,
                                17, 0x71d67fffeda60000ULL,
                                37, 0xfff7eee000000000ULL,
                                43, 6364136223846793005ULL>          mt19937_64;

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#endif // _LIBCPP___RANDOM_MERSENNE_TWISTER_ENGINE_H