LCOV - code coverage report
Current view: top level - /usr/include/c++/13/bits - random.tcc (source / functions) Coverage Total Hit
Test: coverage.info Lines: 100.0 % 40 40
Test Date: 2024-04-30 13:17:26 Functions: 100.0 % 3 3

            Line data    Source code
       1              : // random number generation (out of line) -*- C++ -*-
       2              : 
       3              : // Copyright (C) 2009-2023 Free Software Foundation, Inc.
       4              : //
       5              : // This file is part of the GNU ISO C++ Library.  This library is free
       6              : // software; you can redistribute it and/or modify it under the
       7              : // terms of the GNU General Public License as published by the
       8              : // Free Software Foundation; either version 3, or (at your option)
       9              : // any later version.
      10              : 
      11              : // This library is distributed in the hope that it will be useful,
      12              : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      13              : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14              : // GNU General Public License for more details.
      15              : 
      16              : // Under Section 7 of GPL version 3, you are granted additional
      17              : // permissions described in the GCC Runtime Library Exception, version
      18              : // 3.1, as published by the Free Software Foundation.
      19              : 
      20              : // You should have received a copy of the GNU General Public License and
      21              : // a copy of the GCC Runtime Library Exception along with this program;
      22              : // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23              : // <http://www.gnu.org/licenses/>.
      24              : 
      25              : /** @file bits/random.tcc
      26              :  *  This is an internal header file, included by other library headers.
      27              :  *  Do not attempt to use it directly. @headername{random}
      28              :  */
      29              : 
      30              : #ifndef _RANDOM_TCC
      31              : #define _RANDOM_TCC 1
      32              : 
      33              : #include <numeric> // std::accumulate and std::partial_sum
      34              : 
      35              : namespace std _GLIBCXX_VISIBILITY(default)
      36              : {
      37              : _GLIBCXX_BEGIN_NAMESPACE_VERSION
      38              : 
      39              :   /// @cond undocumented
      40              :   // (Further) implementation-space details.
      41              :   namespace __detail
      42              :   {
      43              :     // General case for x = (ax + c) mod m -- use Schrage's algorithm
      44              :     // to avoid integer overflow.
      45              :     //
      46              :     // Preconditions:  a > 0, m > 0.
      47              :     //
      48              :     // Note: only works correctly for __m % __a < __m / __a.
      49              :     template<typename _Tp, _Tp __m, _Tp __a, _Tp __c>
      50              :       _Tp
      51              :       _Mod<_Tp, __m, __a, __c, false, true>::
      52              :       __calc(_Tp __x)
      53              :       {
      54              :         if (__a == 1)
      55              :           __x %= __m;
      56              :         else
      57              :           {
      58              :             static const _Tp __q = __m / __a;
      59              :             static const _Tp __r = __m % __a;
      60              : 
      61              :             _Tp __t1 = __a * (__x % __q);
      62              :             _Tp __t2 = __r * (__x / __q);
      63              :             if (__t1 >= __t2)
      64              :               __x = __t1 - __t2;
      65              :             else
      66              :               __x = __m - __t2 + __t1;
      67              :           }
      68              : 
      69              :         if (__c != 0)
      70              :           {
      71              :             const _Tp __d = __m - __x;
      72              :             if (__d > __c)
      73              :               __x += __c;
      74              :             else
      75              :               __x = __c - __d;
      76              :           }
      77              :         return __x;
      78              :       }
      79              : 
      80              :     template<typename _InputIterator, typename _OutputIterator,
      81              :              typename _Tp>
      82              :       _OutputIterator
      83              :       __normalize(_InputIterator __first, _InputIterator __last,
      84              :                   _OutputIterator __result, const _Tp& __factor)
      85              :       {
      86              :         for (; __first != __last; ++__first, ++__result)
      87              :           *__result = *__first / __factor;
      88              :         return __result;
      89              :       }
      90              : 
      91              :   } // namespace __detail
      92              :   /// @endcond
      93              : 
      94              : #if ! __cpp_inline_variables
      95              :   template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
      96              :     constexpr _UIntType
      97              :     linear_congruential_engine<_UIntType, __a, __c, __m>::multiplier;
      98              : 
      99              :   template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
     100              :     constexpr _UIntType
     101              :     linear_congruential_engine<_UIntType, __a, __c, __m>::increment;
     102              : 
     103              :   template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
     104              :     constexpr _UIntType
     105              :     linear_congruential_engine<_UIntType, __a, __c, __m>::modulus;
     106              : 
     107              :   template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
     108              :     constexpr _UIntType
     109              :     linear_congruential_engine<_UIntType, __a, __c, __m>::default_seed;
     110              : #endif
     111              : 
     112              :   /**
     113              :    * Seeds the LCR with integral value @p __s, adjusted so that the
     114              :    * ring identity is never a member of the convergence set.
     115              :    */
     116              :   template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
     117              :     void
     118              :     linear_congruential_engine<_UIntType, __a, __c, __m>::
     119              :     seed(result_type __s)
     120              :     {
     121              :       if ((__detail::__mod<_UIntType, __m>(__c) == 0)
     122              :           && (__detail::__mod<_UIntType, __m>(__s) == 0))
     123              :         _M_x = 1;
     124              :       else
     125              :         _M_x = __detail::__mod<_UIntType, __m>(__s);
     126              :     }
     127              : 
     128              :   /**
     129              :    * Seeds the LCR engine with a value generated by @p __q.
     130              :    */
     131              :   template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
     132              :     template<typename _Sseq>
     133              :       auto
     134              :       linear_congruential_engine<_UIntType, __a, __c, __m>::
     135              :       seed(_Sseq& __q)
     136              :       -> _If_seed_seq<_Sseq>
     137              :       {
     138              :         const _UIntType __k0 = __m == 0 ? std::numeric_limits<_UIntType>::digits
     139              :                                         : std::__lg(__m);
     140              :         const _UIntType __k = (__k0 + 31) / 32;
     141              :         uint_least32_t __arr[__k + 3];
     142              :         __q.generate(__arr + 0, __arr + __k + 3);
     143              :         _UIntType __factor = 1u;
     144              :         _UIntType __sum = 0u;
     145              :         for (size_t __j = 0; __j < __k; ++__j)
     146              :           {
     147              :             __sum += __arr[__j + 3] * __factor;
     148              :             __factor *= __detail::_Shift<_UIntType, 32>::__value;
     149              :           }
     150              :         seed(__sum);
     151              :       }
     152              : 
     153              :   template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m,
     154              :            typename _CharT, typename _Traits>
     155              :     std::basic_ostream<_CharT, _Traits>&
     156              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
     157              :                const linear_congruential_engine<_UIntType,
     158              :                                                 __a, __c, __m>& __lcr)
     159              :     {
     160              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
     161              : 
     162              :       const typename __ios_base::fmtflags __flags = __os.flags();
     163              :       const _CharT __fill = __os.fill();
     164              :       __os.flags(__ios_base::dec | __ios_base::fixed | __ios_base::left);
     165              :       __os.fill(__os.widen(' '));
     166              : 
     167              :       __os << __lcr._M_x;
     168              : 
     169              :       __os.flags(__flags);
     170              :       __os.fill(__fill);
     171              :       return __os;
     172              :     }
     173              : 
     174              :   template<typename _UIntType, _UIntType __a, _UIntType __c, _UIntType __m,
     175              :            typename _CharT, typename _Traits>
     176              :     std::basic_istream<_CharT, _Traits>&
     177              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
     178              :                linear_congruential_engine<_UIntType, __a, __c, __m>& __lcr)
     179              :     {
     180              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
     181              : 
     182              :       const typename __ios_base::fmtflags __flags = __is.flags();
     183              :       __is.flags(__ios_base::dec);
     184              : 
     185              :       __is >> __lcr._M_x;
     186              : 
     187              :       __is.flags(__flags);
     188              :       return __is;
     189              :     }
     190              : 
     191              : #if ! __cpp_inline_variables
     192              :   template<typename _UIntType,
     193              :            size_t __w, size_t __n, size_t __m, size_t __r,
     194              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     195              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     196              :            _UIntType __f>
     197              :     constexpr size_t
     198              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     199              :                             __s, __b, __t, __c, __l, __f>::word_size;
     200              : 
     201              :   template<typename _UIntType,
     202              :            size_t __w, size_t __n, size_t __m, size_t __r,
     203              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     204              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     205              :            _UIntType __f>
     206              :     constexpr size_t
     207              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     208              :                             __s, __b, __t, __c, __l, __f>::state_size;
     209              : 
     210              :   template<typename _UIntType,
     211              :            size_t __w, size_t __n, size_t __m, size_t __r,
     212              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     213              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     214              :            _UIntType __f>
     215              :     constexpr size_t
     216              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     217              :                             __s, __b, __t, __c, __l, __f>::shift_size;
     218              : 
     219              :   template<typename _UIntType,
     220              :            size_t __w, size_t __n, size_t __m, size_t __r,
     221              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     222              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     223              :            _UIntType __f>
     224              :     constexpr size_t
     225              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     226              :                             __s, __b, __t, __c, __l, __f>::mask_bits;
     227              : 
     228              :   template<typename _UIntType,
     229              :            size_t __w, size_t __n, size_t __m, size_t __r,
     230              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     231              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     232              :            _UIntType __f>
     233              :     constexpr _UIntType
     234              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     235              :                             __s, __b, __t, __c, __l, __f>::xor_mask;
     236              : 
     237              :   template<typename _UIntType,
     238              :            size_t __w, size_t __n, size_t __m, size_t __r,
     239              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     240              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     241              :            _UIntType __f>
     242              :     constexpr size_t
     243              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     244              :                             __s, __b, __t, __c, __l, __f>::tempering_u;
     245              :    
     246              :   template<typename _UIntType,
     247              :            size_t __w, size_t __n, size_t __m, size_t __r,
     248              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     249              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     250              :            _UIntType __f>
     251              :     constexpr _UIntType
     252              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     253              :                             __s, __b, __t, __c, __l, __f>::tempering_d;
     254              : 
     255              :   template<typename _UIntType,
     256              :            size_t __w, size_t __n, size_t __m, size_t __r,
     257              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     258              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     259              :            _UIntType __f>
     260              :     constexpr size_t
     261              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     262              :                             __s, __b, __t, __c, __l, __f>::tempering_s;
     263              : 
     264              :   template<typename _UIntType,
     265              :            size_t __w, size_t __n, size_t __m, size_t __r,
     266              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     267              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     268              :            _UIntType __f>
     269              :     constexpr _UIntType
     270              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     271              :                             __s, __b, __t, __c, __l, __f>::tempering_b;
     272              : 
     273              :   template<typename _UIntType,
     274              :            size_t __w, size_t __n, size_t __m, size_t __r,
     275              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     276              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     277              :            _UIntType __f>
     278              :     constexpr size_t
     279              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     280              :                             __s, __b, __t, __c, __l, __f>::tempering_t;
     281              : 
     282              :   template<typename _UIntType,
     283              :            size_t __w, size_t __n, size_t __m, size_t __r,
     284              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     285              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     286              :            _UIntType __f>
     287              :     constexpr _UIntType
     288              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     289              :                             __s, __b, __t, __c, __l, __f>::tempering_c;
     290              : 
     291              :   template<typename _UIntType,
     292              :            size_t __w, size_t __n, size_t __m, size_t __r,
     293              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     294              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     295              :            _UIntType __f>
     296              :     constexpr size_t
     297              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     298              :                             __s, __b, __t, __c, __l, __f>::tempering_l;
     299              : 
     300              :   template<typename _UIntType,
     301              :            size_t __w, size_t __n, size_t __m, size_t __r,
     302              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     303              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     304              :            _UIntType __f>
     305              :     constexpr _UIntType
     306              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     307              :                             __s, __b, __t, __c, __l, __f>::
     308              :                                               initialization_multiplier;
     309              : 
     310              :   template<typename _UIntType,
     311              :            size_t __w, size_t __n, size_t __m, size_t __r,
     312              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     313              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     314              :            _UIntType __f>
     315              :     constexpr _UIntType
     316              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     317              :                             __s, __b, __t, __c, __l, __f>::default_seed;
     318              : #endif
     319              : 
     320              :   template<typename _UIntType,
     321              :            size_t __w, size_t __n, size_t __m, size_t __r,
     322              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     323              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     324              :            _UIntType __f>
     325              :     void
     326          542 :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     327              :                             __s, __b, __t, __c, __l, __f>::
     328              :     seed(result_type __sd)
     329              :     {
     330          542 :       _M_x[0] = __detail::__mod<_UIntType,
     331          542 :         __detail::_Shift<_UIntType, __w>::__value>(__sd);
     332              : 
     333       338208 :       for (size_t __i = 1; __i < state_size; ++__i)
     334              :         {
     335       337666 :           _UIntType __x = _M_x[__i - 1];
     336       337666 :           __x ^= __x >> (__w - 2);
     337       337666 :           __x *= __f;
     338       337666 :           __x += __detail::__mod<_UIntType, __n>(__i);
     339       337666 :           _M_x[__i] = __detail::__mod<_UIntType,
     340       337666 :             __detail::_Shift<_UIntType, __w>::__value>(__x);
     341              :         }
     342          542 :       _M_p = state_size;
     343          542 :     }
     344              : 
     345              :   template<typename _UIntType,
     346              :            size_t __w, size_t __n, size_t __m, size_t __r,
     347              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     348              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     349              :            _UIntType __f>
     350              :     template<typename _Sseq>
     351              :       auto
     352              :       mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     353              :                               __s, __b, __t, __c, __l, __f>::
     354              :       seed(_Sseq& __q)
     355              :       -> _If_seed_seq<_Sseq>
     356              :       {
     357              :         const _UIntType __upper_mask = (~_UIntType()) << __r;
     358              :         const size_t __k = (__w + 31) / 32;
     359              :         uint_least32_t __arr[__n * __k];
     360              :         __q.generate(__arr + 0, __arr + __n * __k);
     361              : 
     362              :         bool __zero = true;
     363              :         for (size_t __i = 0; __i < state_size; ++__i)
     364              :           {
     365              :             _UIntType __factor = 1u;
     366              :             _UIntType __sum = 0u;
     367              :             for (size_t __j = 0; __j < __k; ++__j)
     368              :               {
     369              :                 __sum += __arr[__k * __i + __j] * __factor;
     370              :                 __factor *= __detail::_Shift<_UIntType, 32>::__value;
     371              :               }
     372              :             _M_x[__i] = __detail::__mod<_UIntType,
     373              :               __detail::_Shift<_UIntType, __w>::__value>(__sum);
     374              : 
     375              :             if (__zero)
     376              :               {
     377              :                 if (__i == 0)
     378              :                   {
     379              :                     if ((_M_x[0] & __upper_mask) != 0u)
     380              :                       __zero = false;
     381              :                   }
     382              :                 else if (_M_x[__i] != 0u)
     383              :                   __zero = false;
     384              :               }
     385              :           }
     386              :         if (__zero)
     387              :           _M_x[0] = __detail::_Shift<_UIntType, __w - 1>::__value;
     388              :         _M_p = state_size;
     389              :       }
     390              : 
     391              :   template<typename _UIntType, size_t __w,
     392              :            size_t __n, size_t __m, size_t __r,
     393              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     394              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     395              :            _UIntType __f>
     396              :     void
     397          260 :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     398              :                             __s, __b, __t, __c, __l, __f>::
     399              :     _M_gen_rand(void)
     400              :     {
     401          260 :       const _UIntType __upper_mask = (~_UIntType()) << __r;
     402          260 :       const _UIntType __lower_mask = ~__upper_mask;
     403              : 
     404        59280 :       for (size_t __k = 0; __k < (__n - __m); ++__k)
     405              :         {
     406        59020 :           _UIntType __y = ((_M_x[__k] & __upper_mask)
     407        59020 :                            | (_M_x[__k + 1] & __lower_mask));
     408       118040 :           _M_x[__k] = (_M_x[__k + __m] ^ (__y >> 1)
     409        59020 :                        ^ ((__y & 0x01) ? __a : 0));
     410              :         }
     411              : 
     412       103220 :       for (size_t __k = (__n - __m); __k < (__n - 1); ++__k)
     413              :         {
     414       102960 :           _UIntType __y = ((_M_x[__k] & __upper_mask)
     415       102960 :                            | (_M_x[__k + 1] & __lower_mask));
     416       205920 :           _M_x[__k] = (_M_x[__k + (__m - __n)] ^ (__y >> 1)
     417       102960 :                        ^ ((__y & 0x01) ? __a : 0));
     418              :         }
     419              : 
     420          260 :       _UIntType __y = ((_M_x[__n - 1] & __upper_mask)
     421          260 :                        | (_M_x[0] & __lower_mask));
     422          520 :       _M_x[__n - 1] = (_M_x[__m - 1] ^ (__y >> 1)
     423          260 :                        ^ ((__y & 0x01) ? __a : 0));
     424          260 :       _M_p = 0;
     425          260 :     }
     426              : 
     427              :   template<typename _UIntType, size_t __w,
     428              :            size_t __n, size_t __m, size_t __r,
     429              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     430              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     431              :            _UIntType __f>
     432              :     void
     433              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     434              :                             __s, __b, __t, __c, __l, __f>::
     435              :     discard(unsigned long long __z)
     436              :     {
     437              :       while (__z > state_size - _M_p)
     438              :         {
     439              :           __z -= state_size - _M_p;
     440              :           _M_gen_rand();
     441              :         }
     442              :       _M_p += __z;
     443              :     }
     444              : 
     445              :   template<typename _UIntType, size_t __w,
     446              :            size_t __n, size_t __m, size_t __r,
     447              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     448              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     449              :            _UIntType __f>
     450              :     typename
     451              :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     452              :                             __s, __b, __t, __c, __l, __f>::result_type
     453        40674 :     mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d,
     454              :                             __s, __b, __t, __c, __l, __f>::
     455              :     operator()()
     456              :     {
     457              :       // Reload the vector - cost is O(n) amortized over n calls.
     458        40674 :       if (_M_p >= state_size)
     459          260 :         _M_gen_rand();
     460              : 
     461              :       // Calculate o(x(i)).
     462        40674 :       result_type __z = _M_x[_M_p++];
     463        40674 :       __z ^= (__z >> __u) & __d;
     464        40674 :       __z ^= (__z << __s) & __b;
     465        40674 :       __z ^= (__z << __t) & __c;
     466        40674 :       __z ^= (__z >> __l);
     467              : 
     468        40674 :       return __z;
     469              :     }
     470              : 
     471              :   template<typename _UIntType, size_t __w,
     472              :            size_t __n, size_t __m, size_t __r,
     473              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     474              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     475              :            _UIntType __f, typename _CharT, typename _Traits>
     476              :     std::basic_ostream<_CharT, _Traits>&
     477              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
     478              :                const mersenne_twister_engine<_UIntType, __w, __n, __m,
     479              :                __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>& __x)
     480              :     {
     481              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
     482              : 
     483              :       const typename __ios_base::fmtflags __flags = __os.flags();
     484              :       const _CharT __fill = __os.fill();
     485              :       const _CharT __space = __os.widen(' ');
     486              :       __os.flags(__ios_base::dec | __ios_base::fixed | __ios_base::left);
     487              :       __os.fill(__space);
     488              : 
     489              :       for (size_t __i = 0; __i < __n; ++__i)
     490              :         __os << __x._M_x[__i] << __space;
     491              :       __os << __x._M_p;
     492              : 
     493              :       __os.flags(__flags);
     494              :       __os.fill(__fill);
     495              :       return __os;
     496              :     }
     497              : 
     498              :   template<typename _UIntType, size_t __w,
     499              :            size_t __n, size_t __m, size_t __r,
     500              :            _UIntType __a, size_t __u, _UIntType __d, size_t __s,
     501              :            _UIntType __b, size_t __t, _UIntType __c, size_t __l,
     502              :            _UIntType __f, typename _CharT, typename _Traits>
     503              :     std::basic_istream<_CharT, _Traits>&
     504              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
     505              :                mersenne_twister_engine<_UIntType, __w, __n, __m,
     506              :                __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>& __x)
     507              :     {
     508              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
     509              : 
     510              :       const typename __ios_base::fmtflags __flags = __is.flags();
     511              :       __is.flags(__ios_base::dec | __ios_base::skipws);
     512              : 
     513              :       for (size_t __i = 0; __i < __n; ++__i)
     514              :         __is >> __x._M_x[__i];
     515              :       __is >> __x._M_p;
     516              : 
     517              :       __is.flags(__flags);
     518              :       return __is;
     519              :     }
     520              : 
     521              : #if ! __cpp_inline_variables
     522              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r>
     523              :     constexpr size_t
     524              :     subtract_with_carry_engine<_UIntType, __w, __s, __r>::word_size;
     525              : 
     526              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r>
     527              :     constexpr size_t
     528              :     subtract_with_carry_engine<_UIntType, __w, __s, __r>::short_lag;
     529              : 
     530              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r>
     531              :     constexpr size_t
     532              :     subtract_with_carry_engine<_UIntType, __w, __s, __r>::long_lag;
     533              : 
     534              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r>
     535              :     constexpr uint_least32_t
     536              :     subtract_with_carry_engine<_UIntType, __w, __s, __r>::default_seed;
     537              : #endif
     538              : 
     539              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r>
     540              :     void
     541              :     subtract_with_carry_engine<_UIntType, __w, __s, __r>::
     542              :     seed(result_type __value)
     543              :     {
     544              :       // _GLIBCXX_RESOLVE_LIB_DEFECTS
     545              :       // 3809. Is std::subtract_with_carry_engine<uint16_t> supposed to work?
     546              :       // 4014. LWG 3809 changes behavior of some existing code
     547              :       std::linear_congruential_engine<uint_least32_t, 40014u, 0u, 2147483563u>
     548              :         __lcg(__value == 0u ? default_seed : __value % 2147483563u);
     549              : 
     550              :       const size_t __n = (__w + 31) / 32;
     551              : 
     552              :       for (size_t __i = 0; __i < long_lag; ++__i)
     553              :         {
     554              :           _UIntType __sum = 0u;
     555              :           _UIntType __factor = 1u;
     556              :           for (size_t __j = 0; __j < __n; ++__j)
     557              :             {
     558              :               __sum += __detail::__mod<uint_least32_t,
     559              :                        __detail::_Shift<uint_least32_t, 32>::__value>
     560              :                          (__lcg()) * __factor;
     561              :               __factor *= __detail::_Shift<_UIntType, 32>::__value;
     562              :             }
     563              :           _M_x[__i] = __detail::__mod<_UIntType,
     564              :             __detail::_Shift<_UIntType, __w>::__value>(__sum);
     565              :         }
     566              :       _M_carry = (_M_x[long_lag - 1] == 0) ? 1 : 0;
     567              :       _M_p = 0;
     568              :     }
     569              : 
     570              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r>
     571              :     template<typename _Sseq>
     572              :       auto
     573              :       subtract_with_carry_engine<_UIntType, __w, __s, __r>::
     574              :       seed(_Sseq& __q)
     575              :       -> _If_seed_seq<_Sseq>
     576              :       {
     577              :         const size_t __k = (__w + 31) / 32;
     578              :         uint_least32_t __arr[__r * __k];
     579              :         __q.generate(__arr + 0, __arr + __r * __k);
     580              : 
     581              :         for (size_t __i = 0; __i < long_lag; ++__i)
     582              :           {
     583              :             _UIntType __sum = 0u;
     584              :             _UIntType __factor = 1u;
     585              :             for (size_t __j = 0; __j < __k; ++__j)
     586              :               {
     587              :                 __sum += __arr[__k * __i + __j] * __factor;
     588              :                 __factor *= __detail::_Shift<_UIntType, 32>::__value;
     589              :               }
     590              :             _M_x[__i] = __detail::__mod<_UIntType,
     591              :               __detail::_Shift<_UIntType, __w>::__value>(__sum);
     592              :           }
     593              :         _M_carry = (_M_x[long_lag - 1] == 0) ? 1 : 0;
     594              :         _M_p = 0;
     595              :       }
     596              : 
     597              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r>
     598              :     typename subtract_with_carry_engine<_UIntType, __w, __s, __r>::
     599              :              result_type
     600              :     subtract_with_carry_engine<_UIntType, __w, __s, __r>::
     601              :     operator()()
     602              :     {
     603              :       // Derive short lag index from current index.
     604              :       long __ps = _M_p - short_lag;
     605              :       if (__ps < 0)
     606              :         __ps += long_lag;
     607              : 
     608              :       // Calculate new x(i) without overflow or division.
     609              :       // NB: Thanks to the requirements for _UIntType, _M_x[_M_p] + _M_carry
     610              :       // cannot overflow.
     611              :       _UIntType __xi;
     612              :       if (_M_x[__ps] >= _M_x[_M_p] + _M_carry)
     613              :         {
     614              :           __xi = _M_x[__ps] - _M_x[_M_p] - _M_carry;
     615              :           _M_carry = 0;
     616              :         }
     617              :       else
     618              :         {
     619              :           __xi = (__detail::_Shift<_UIntType, __w>::__value
     620              :                   - _M_x[_M_p] - _M_carry + _M_x[__ps]);
     621              :           _M_carry = 1;
     622              :         }
     623              :       _M_x[_M_p] = __xi;
     624              : 
     625              :       // Adjust current index to loop around in ring buffer.
     626              :       if (++_M_p >= long_lag)
     627              :         _M_p = 0;
     628              : 
     629              :       return __xi;
     630              :     }
     631              : 
     632              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r,
     633              :            typename _CharT, typename _Traits>
     634              :     std::basic_ostream<_CharT, _Traits>&
     635              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
     636              :                const subtract_with_carry_engine<_UIntType,
     637              :                                                 __w, __s, __r>& __x)
     638              :     {
     639              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
     640              : 
     641              :       const typename __ios_base::fmtflags __flags = __os.flags();
     642              :       const _CharT __fill = __os.fill();
     643              :       const _CharT __space = __os.widen(' ');
     644              :       __os.flags(__ios_base::dec | __ios_base::fixed | __ios_base::left);
     645              :       __os.fill(__space);
     646              : 
     647              :       for (size_t __i = 0; __i < __r; ++__i)
     648              :         __os << __x._M_x[__i] << __space;
     649              :       __os << __x._M_carry << __space << __x._M_p;
     650              : 
     651              :       __os.flags(__flags);
     652              :       __os.fill(__fill);
     653              :       return __os;
     654              :     }
     655              : 
     656              :   template<typename _UIntType, size_t __w, size_t __s, size_t __r,
     657              :            typename _CharT, typename _Traits>
     658              :     std::basic_istream<_CharT, _Traits>&
     659              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
     660              :                subtract_with_carry_engine<_UIntType, __w, __s, __r>& __x)
     661              :     {
     662              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
     663              : 
     664              :       const typename __ios_base::fmtflags __flags = __is.flags();
     665              :       __is.flags(__ios_base::dec | __ios_base::skipws);
     666              : 
     667              :       for (size_t __i = 0; __i < __r; ++__i)
     668              :         __is >> __x._M_x[__i];
     669              :       __is >> __x._M_carry;
     670              :       __is >> __x._M_p;
     671              : 
     672              :       __is.flags(__flags);
     673              :       return __is;
     674              :     }
     675              : 
     676              : #if ! __cpp_inline_variables
     677              :   template<typename _RandomNumberEngine, size_t __p, size_t __r>
     678              :     constexpr size_t
     679              :     discard_block_engine<_RandomNumberEngine, __p, __r>::block_size;
     680              : 
     681              :   template<typename _RandomNumberEngine, size_t __p, size_t __r>
     682              :     constexpr size_t
     683              :     discard_block_engine<_RandomNumberEngine, __p, __r>::used_block;
     684              : #endif
     685              : 
     686              :   template<typename _RandomNumberEngine, size_t __p, size_t __r>
     687              :     typename discard_block_engine<_RandomNumberEngine,
     688              :                            __p, __r>::result_type
     689              :     discard_block_engine<_RandomNumberEngine, __p, __r>::
     690              :     operator()()
     691              :     {
     692              :       if (_M_n >= used_block)
     693              :         {
     694              :           _M_b.discard(block_size - _M_n);
     695              :           _M_n = 0;
     696              :         }
     697              :       ++_M_n;
     698              :       return _M_b();
     699              :     }
     700              : 
     701              :   template<typename _RandomNumberEngine, size_t __p, size_t __r,
     702              :            typename _CharT, typename _Traits>
     703              :     std::basic_ostream<_CharT, _Traits>&
     704              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
     705              :                const discard_block_engine<_RandomNumberEngine,
     706              :                __p, __r>& __x)
     707              :     {
     708              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
     709              : 
     710              :       const typename __ios_base::fmtflags __flags = __os.flags();
     711              :       const _CharT __fill = __os.fill();
     712              :       const _CharT __space = __os.widen(' ');
     713              :       __os.flags(__ios_base::dec | __ios_base::fixed | __ios_base::left);
     714              :       __os.fill(__space);
     715              : 
     716              :       __os << __x.base() << __space << __x._M_n;
     717              : 
     718              :       __os.flags(__flags);
     719              :       __os.fill(__fill);
     720              :       return __os;
     721              :     }
     722              : 
     723              :   template<typename _RandomNumberEngine, size_t __p, size_t __r,
     724              :            typename _CharT, typename _Traits>
     725              :     std::basic_istream<_CharT, _Traits>&
     726              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
     727              :                discard_block_engine<_RandomNumberEngine, __p, __r>& __x)
     728              :     {
     729              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
     730              : 
     731              :       const typename __ios_base::fmtflags __flags = __is.flags();
     732              :       __is.flags(__ios_base::dec | __ios_base::skipws);
     733              : 
     734              :       __is >> __x._M_b >> __x._M_n;
     735              : 
     736              :       __is.flags(__flags);
     737              :       return __is;
     738              :     }
     739              : 
     740              : 
     741              :   template<typename _RandomNumberEngine, size_t __w, typename _UIntType>
     742              :     typename independent_bits_engine<_RandomNumberEngine, __w, _UIntType>::
     743              :       result_type
     744              :     independent_bits_engine<_RandomNumberEngine, __w, _UIntType>::
     745              :     operator()()
     746              :     {
     747              :       typedef typename _RandomNumberEngine::result_type _Eresult_type;
     748              :       const _Eresult_type __r
     749              :         = (_M_b.max() - _M_b.min() < std::numeric_limits<_Eresult_type>::max()
     750              :            ? _M_b.max() - _M_b.min() + 1 : 0);
     751              :       const unsigned __edig = std::numeric_limits<_Eresult_type>::digits;
     752              :       const unsigned __m = __r ? std::__lg(__r) : __edig;
     753              : 
     754              :       typedef typename std::common_type<_Eresult_type, result_type>::type
     755              :         __ctype;
     756              :       const unsigned __cdig = std::numeric_limits<__ctype>::digits;
     757              : 
     758              :       unsigned __n, __n0;
     759              :       __ctype __s0, __s1, __y0, __y1;
     760              : 
     761              :       for (size_t __i = 0; __i < 2; ++__i)
     762              :         {
     763              :           __n = (__w + __m - 1) / __m + __i;
     764              :           __n0 = __n - __w % __n;
     765              :           const unsigned __w0 = __w / __n;  // __w0 <= __m
     766              : 
     767              :           __s0 = 0;
     768              :           __s1 = 0;
     769              :           if (__w0 < __cdig)
     770              :             {
     771              :               __s0 = __ctype(1) << __w0;
     772              :               __s1 = __s0 << 1;
     773              :             }
     774              : 
     775              :           __y0 = 0;
     776              :           __y1 = 0;
     777              :           if (__r)
     778              :             {
     779              :               __y0 = __s0 * (__r / __s0);
     780              :               if (__s1)
     781              :                 __y1 = __s1 * (__r / __s1);
     782              : 
     783              :               if (__r - __y0 <= __y0 / __n)
     784              :                 break;
     785              :             }
     786              :           else
     787              :             break;
     788              :         }
     789              : 
     790              :       result_type __sum = 0;
     791              :       for (size_t __k = 0; __k < __n0; ++__k)
     792              :         {
     793              :           __ctype __u;
     794              :           do
     795              :             __u = _M_b() - _M_b.min();
     796              :           while (__y0 && __u >= __y0);
     797              :           __sum = __s0 * __sum + (__s0 ? __u % __s0 : __u);
     798              :         }
     799              :       for (size_t __k = __n0; __k < __n; ++__k)
     800              :         {
     801              :           __ctype __u;
     802              :           do
     803              :             __u = _M_b() - _M_b.min();
     804              :           while (__y1 && __u >= __y1);
     805              :           __sum = __s1 * __sum + (__s1 ? __u % __s1 : __u);
     806              :         }
     807              :       return __sum;
     808              :     }
     809              : 
     810              : #if ! __cpp_inline_variables
     811              :   template<typename _RandomNumberEngine, size_t __k>
     812              :     constexpr size_t
     813              :     shuffle_order_engine<_RandomNumberEngine, __k>::table_size;
     814              : #endif
     815              : 
     816              :   namespace __detail
     817              :   {
     818              :     // Determine whether an integer is representable as double.
     819              :     template<typename _Tp>
     820              :       constexpr bool
     821              :       __representable_as_double(_Tp __x) noexcept
     822              :       {
     823              :         static_assert(numeric_limits<_Tp>::is_integer, "");
     824              :         static_assert(!numeric_limits<_Tp>::is_signed, "");
     825              :         // All integers <= 2^53 are representable.
     826              :         return (__x <= (1ull << __DBL_MANT_DIG__))
     827              :           // Between 2^53 and 2^54 only even numbers are representable.
     828              :           || (!(__x & 1) && __detail::__representable_as_double(__x >> 1));
     829              :       }
     830              : 
     831              :     // Determine whether x+1 is representable as double.
     832              :     template<typename _Tp>
     833              :       constexpr bool
     834              :       __p1_representable_as_double(_Tp __x) noexcept
     835              :       {
     836              :         static_assert(numeric_limits<_Tp>::is_integer, "");
     837              :         static_assert(!numeric_limits<_Tp>::is_signed, "");
     838              :         return numeric_limits<_Tp>::digits < __DBL_MANT_DIG__
     839              :           || (bool(__x + 1u) // return false if x+1 wraps around to zero
     840              :               && __detail::__representable_as_double(__x + 1u));
     841              :       }
     842              :   }
     843              : 
     844              :   template<typename _RandomNumberEngine, size_t __k>
     845              :     typename shuffle_order_engine<_RandomNumberEngine, __k>::result_type
     846              :     shuffle_order_engine<_RandomNumberEngine, __k>::
     847              :     operator()()
     848              :     {
     849              :       constexpr result_type __range = max() - min();
     850              :       size_t __j = __k;
     851              :       const result_type __y = _M_y - min();
     852              :       // Avoid using slower long double arithmetic if possible.
     853              :       if _GLIBCXX17_CONSTEXPR (__detail::__p1_representable_as_double(__range))
     854              :         __j *= __y / (__range + 1.0);
     855              :       else
     856              :         __j *= __y / (__range + 1.0L);
     857              :       _M_y = _M_v[__j];
     858              :       _M_v[__j] = _M_b();
     859              : 
     860              :       return _M_y;
     861              :     }
     862              : 
     863              :   template<typename _RandomNumberEngine, size_t __k,
     864              :            typename _CharT, typename _Traits>
     865              :     std::basic_ostream<_CharT, _Traits>&
     866              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
     867              :                const shuffle_order_engine<_RandomNumberEngine, __k>& __x)
     868              :     {
     869              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
     870              : 
     871              :       const typename __ios_base::fmtflags __flags = __os.flags();
     872              :       const _CharT __fill = __os.fill();
     873              :       const _CharT __space = __os.widen(' ');
     874              :       __os.flags(__ios_base::dec | __ios_base::fixed | __ios_base::left);
     875              :       __os.fill(__space);
     876              : 
     877              :       __os << __x.base();
     878              :       for (size_t __i = 0; __i < __k; ++__i)
     879              :         __os << __space << __x._M_v[__i];
     880              :       __os << __space << __x._M_y;
     881              : 
     882              :       __os.flags(__flags);
     883              :       __os.fill(__fill);
     884              :       return __os;
     885              :     }
     886              : 
     887              :   template<typename _RandomNumberEngine, size_t __k,
     888              :            typename _CharT, typename _Traits>
     889              :     std::basic_istream<_CharT, _Traits>&
     890              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
     891              :                shuffle_order_engine<_RandomNumberEngine, __k>& __x)
     892              :     {
     893              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
     894              : 
     895              :       const typename __ios_base::fmtflags __flags = __is.flags();
     896              :       __is.flags(__ios_base::dec | __ios_base::skipws);
     897              : 
     898              :       __is >> __x._M_b;
     899              :       for (size_t __i = 0; __i < __k; ++__i)
     900              :         __is >> __x._M_v[__i];
     901              :       __is >> __x._M_y;
     902              : 
     903              :       __is.flags(__flags);
     904              :       return __is;
     905              :     }
     906              : 
     907              : 
     908              :   template<typename _IntType, typename _CharT, typename _Traits>
     909              :     std::basic_ostream<_CharT, _Traits>&
     910              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
     911              :                const uniform_int_distribution<_IntType>& __x)
     912              :     {
     913              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
     914              : 
     915              :       const typename __ios_base::fmtflags __flags = __os.flags();
     916              :       const _CharT __fill = __os.fill();
     917              :       const _CharT __space = __os.widen(' ');
     918              :       __os.flags(__ios_base::scientific | __ios_base::left);
     919              :       __os.fill(__space);
     920              : 
     921              :       __os << __x.a() << __space << __x.b();
     922              : 
     923              :       __os.flags(__flags);
     924              :       __os.fill(__fill);
     925              :       return __os;
     926              :     }
     927              : 
     928              :   template<typename _IntType, typename _CharT, typename _Traits>
     929              :     std::basic_istream<_CharT, _Traits>&
     930              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
     931              :                uniform_int_distribution<_IntType>& __x)
     932              :     {
     933              :       using param_type
     934              :         = typename uniform_int_distribution<_IntType>::param_type;
     935              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
     936              : 
     937              :       const typename __ios_base::fmtflags __flags = __is.flags();
     938              :       __is.flags(__ios_base::dec | __ios_base::skipws);
     939              : 
     940              :       _IntType __a, __b;
     941              :       if (__is >> __a >> __b)
     942              :         __x.param(param_type(__a, __b));
     943              : 
     944              :       __is.flags(__flags);
     945              :       return __is;
     946              :     }
     947              : 
     948              : 
     949              :   template<typename _RealType>
     950              :     template<typename _ForwardIterator,
     951              :              typename _UniformRandomNumberGenerator>
     952              :       void
     953              :       uniform_real_distribution<_RealType>::
     954              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
     955              :                       _UniformRandomNumberGenerator& __urng,
     956              :                       const param_type& __p)
     957              :       {
     958              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
     959              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
     960              :           __aurng(__urng);
     961              :         auto __range = __p.b() - __p.a();
     962              :         while (__f != __t)
     963              :           *__f++ = __aurng() * __range + __p.a();
     964              :       }
     965              : 
     966              :   template<typename _RealType, typename _CharT, typename _Traits>
     967              :     std::basic_ostream<_CharT, _Traits>&
     968              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
     969              :                const uniform_real_distribution<_RealType>& __x)
     970              :     {
     971              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
     972              : 
     973              :       const typename __ios_base::fmtflags __flags = __os.flags();
     974              :       const _CharT __fill = __os.fill();
     975              :       const std::streamsize __precision = __os.precision();
     976              :       const _CharT __space = __os.widen(' ');
     977              :       __os.flags(__ios_base::scientific | __ios_base::left);
     978              :       __os.fill(__space);
     979              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
     980              : 
     981              :       __os << __x.a() << __space << __x.b();
     982              : 
     983              :       __os.flags(__flags);
     984              :       __os.fill(__fill);
     985              :       __os.precision(__precision);
     986              :       return __os;
     987              :     }
     988              : 
     989              :   template<typename _RealType, typename _CharT, typename _Traits>
     990              :     std::basic_istream<_CharT, _Traits>&
     991              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
     992              :                uniform_real_distribution<_RealType>& __x)
     993              :     {
     994              :       using param_type
     995              :         = typename uniform_real_distribution<_RealType>::param_type;
     996              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
     997              : 
     998              :       const typename __ios_base::fmtflags __flags = __is.flags();
     999              :       __is.flags(__ios_base::skipws);
    1000              : 
    1001              :       _RealType __a, __b;
    1002              :       if (__is >> __a >> __b)
    1003              :         __x.param(param_type(__a, __b));
    1004              : 
    1005              :       __is.flags(__flags);
    1006              :       return __is;
    1007              :     }
    1008              : 
    1009              : 
    1010              :   template<typename _ForwardIterator,
    1011              :            typename _UniformRandomNumberGenerator>
    1012              :     void
    1013              :     std::bernoulli_distribution::
    1014              :     __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1015              :                     _UniformRandomNumberGenerator& __urng,
    1016              :                     const param_type& __p)
    1017              :     {
    1018              :       __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1019              :       __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    1020              :         __aurng(__urng);
    1021              :       auto __limit = __p.p() * (__aurng.max() - __aurng.min());
    1022              : 
    1023              :       while (__f != __t)
    1024              :         *__f++ = (__aurng() - __aurng.min()) < __limit;
    1025              :     }
    1026              : 
    1027              :   template<typename _CharT, typename _Traits>
    1028              :     std::basic_ostream<_CharT, _Traits>&
    1029              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    1030              :                const bernoulli_distribution& __x)
    1031              :     {
    1032              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    1033              : 
    1034              :       const typename __ios_base::fmtflags __flags = __os.flags();
    1035              :       const _CharT __fill = __os.fill();
    1036              :       const std::streamsize __precision = __os.precision();
    1037              :       __os.flags(__ios_base::scientific | __ios_base::left);
    1038              :       __os.fill(__os.widen(' '));
    1039              :       __os.precision(std::numeric_limits<double>::max_digits10);
    1040              : 
    1041              :       __os << __x.p();
    1042              : 
    1043              :       __os.flags(__flags);
    1044              :       __os.fill(__fill);
    1045              :       __os.precision(__precision);
    1046              :       return __os;
    1047              :     }
    1048              : 
    1049              : 
    1050              :   template<typename _IntType>
    1051              :     template<typename _UniformRandomNumberGenerator>
    1052              :       typename geometric_distribution<_IntType>::result_type
    1053              :       geometric_distribution<_IntType>::
    1054              :       operator()(_UniformRandomNumberGenerator& __urng,
    1055              :                  const param_type& __param)
    1056              :       {
    1057              :         // About the epsilon thing see this thread:
    1058              :         // http://gcc.gnu.org/ml/gcc-patches/2006-10/msg00971.html
    1059              :         const double __naf =
    1060              :           (1 - std::numeric_limits<double>::epsilon()) / 2;
    1061              :         // The largest _RealType convertible to _IntType.
    1062              :         const double __thr =
    1063              :           std::numeric_limits<_IntType>::max() + __naf;
    1064              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    1065              :           __aurng(__urng);
    1066              : 
    1067              :         double __cand;
    1068              :         do
    1069              :           __cand = std::floor(std::log(1.0 - __aurng()) / __param._M_log_1_p);
    1070              :         while (__cand >= __thr);
    1071              : 
    1072              :         return result_type(__cand + __naf);
    1073              :       }
    1074              : 
    1075              :   template<typename _IntType>
    1076              :     template<typename _ForwardIterator,
    1077              :              typename _UniformRandomNumberGenerator>
    1078              :       void
    1079              :       geometric_distribution<_IntType>::
    1080              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1081              :                       _UniformRandomNumberGenerator& __urng,
    1082              :                       const param_type& __param)
    1083              :       {
    1084              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1085              :         // About the epsilon thing see this thread:
    1086              :         // http://gcc.gnu.org/ml/gcc-patches/2006-10/msg00971.html
    1087              :         const double __naf =
    1088              :           (1 - std::numeric_limits<double>::epsilon()) / 2;
    1089              :         // The largest _RealType convertible to _IntType.
    1090              :         const double __thr =
    1091              :           std::numeric_limits<_IntType>::max() + __naf;
    1092              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    1093              :           __aurng(__urng);
    1094              : 
    1095              :         while (__f != __t)
    1096              :           {
    1097              :             double __cand;
    1098              :             do
    1099              :               __cand = std::floor(std::log(1.0 - __aurng())
    1100              :                                   / __param._M_log_1_p);
    1101              :             while (__cand >= __thr);
    1102              : 
    1103              :             *__f++ = __cand + __naf;
    1104              :           }
    1105              :       }
    1106              : 
    1107              :   template<typename _IntType,
    1108              :            typename _CharT, typename _Traits>
    1109              :     std::basic_ostream<_CharT, _Traits>&
    1110              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    1111              :                const geometric_distribution<_IntType>& __x)
    1112              :     {
    1113              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    1114              : 
    1115              :       const typename __ios_base::fmtflags __flags = __os.flags();
    1116              :       const _CharT __fill = __os.fill();
    1117              :       const std::streamsize __precision = __os.precision();
    1118              :       __os.flags(__ios_base::scientific | __ios_base::left);
    1119              :       __os.fill(__os.widen(' '));
    1120              :       __os.precision(std::numeric_limits<double>::max_digits10);
    1121              : 
    1122              :       __os << __x.p();
    1123              : 
    1124              :       __os.flags(__flags);
    1125              :       __os.fill(__fill);
    1126              :       __os.precision(__precision);
    1127              :       return __os;
    1128              :     }
    1129              : 
    1130              :   template<typename _IntType,
    1131              :            typename _CharT, typename _Traits>
    1132              :     std::basic_istream<_CharT, _Traits>&
    1133              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    1134              :                geometric_distribution<_IntType>& __x)
    1135              :     {
    1136              :       using param_type = typename geometric_distribution<_IntType>::param_type;
    1137              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    1138              : 
    1139              :       const typename __ios_base::fmtflags __flags = __is.flags();
    1140              :       __is.flags(__ios_base::skipws);
    1141              : 
    1142              :       double __p;
    1143              :       if (__is >> __p)
    1144              :         __x.param(param_type(__p));
    1145              : 
    1146              :       __is.flags(__flags);
    1147              :       return __is;
    1148              :     }
    1149              : 
    1150              :   // This is Leger's algorithm, also in Devroye, Ch. X, Example 1.5.
    1151              :   template<typename _IntType>
    1152              :     template<typename _UniformRandomNumberGenerator>
    1153              :       typename negative_binomial_distribution<_IntType>::result_type
    1154              :       negative_binomial_distribution<_IntType>::
    1155              :       operator()(_UniformRandomNumberGenerator& __urng)
    1156              :       {
    1157              :         const double __y = _M_gd(__urng);
    1158              : 
    1159              :         // XXX Is the constructor too slow?
    1160              :         std::poisson_distribution<result_type> __poisson(__y);
    1161              :         return __poisson(__urng);
    1162              :       }
    1163              : 
    1164              :   template<typename _IntType>
    1165              :     template<typename _UniformRandomNumberGenerator>
    1166              :       typename negative_binomial_distribution<_IntType>::result_type
    1167              :       negative_binomial_distribution<_IntType>::
    1168              :       operator()(_UniformRandomNumberGenerator& __urng,
    1169              :                  const param_type& __p)
    1170              :       {
    1171              :         typedef typename std::gamma_distribution<double>::param_type
    1172              :           param_type;
    1173              :         
    1174              :         const double __y =
    1175              :           _M_gd(__urng, param_type(__p.k(), (1.0 - __p.p()) / __p.p()));
    1176              : 
    1177              :         std::poisson_distribution<result_type> __poisson(__y);
    1178              :         return __poisson(__urng);
    1179              :       }
    1180              : 
    1181              :   template<typename _IntType>
    1182              :     template<typename _ForwardIterator,
    1183              :              typename _UniformRandomNumberGenerator>
    1184              :       void
    1185              :       negative_binomial_distribution<_IntType>::
    1186              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1187              :                       _UniformRandomNumberGenerator& __urng)
    1188              :       {
    1189              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1190              :         while (__f != __t)
    1191              :           {
    1192              :             const double __y = _M_gd(__urng);
    1193              : 
    1194              :             // XXX Is the constructor too slow?
    1195              :             std::poisson_distribution<result_type> __poisson(__y);
    1196              :             *__f++ = __poisson(__urng);
    1197              :           }
    1198              :       }
    1199              : 
    1200              :   template<typename _IntType>
    1201              :     template<typename _ForwardIterator,
    1202              :              typename _UniformRandomNumberGenerator>
    1203              :       void
    1204              :       negative_binomial_distribution<_IntType>::
    1205              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1206              :                       _UniformRandomNumberGenerator& __urng,
    1207              :                       const param_type& __p)
    1208              :       {
    1209              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1210              :         typename std::gamma_distribution<result_type>::param_type
    1211              :           __p2(__p.k(), (1.0 - __p.p()) / __p.p());
    1212              : 
    1213              :         while (__f != __t)
    1214              :           {
    1215              :             const double __y = _M_gd(__urng, __p2);
    1216              : 
    1217              :             std::poisson_distribution<result_type> __poisson(__y);
    1218              :             *__f++ = __poisson(__urng);
    1219              :           }
    1220              :       }
    1221              : 
    1222              :   template<typename _IntType, typename _CharT, typename _Traits>
    1223              :     std::basic_ostream<_CharT, _Traits>&
    1224              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    1225              :                const negative_binomial_distribution<_IntType>& __x)
    1226              :     {
    1227              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    1228              : 
    1229              :       const typename __ios_base::fmtflags __flags = __os.flags();
    1230              :       const _CharT __fill = __os.fill();
    1231              :       const std::streamsize __precision = __os.precision();
    1232              :       const _CharT __space = __os.widen(' ');
    1233              :       __os.flags(__ios_base::scientific | __ios_base::left);
    1234              :       __os.fill(__os.widen(' '));
    1235              :       __os.precision(std::numeric_limits<double>::max_digits10);
    1236              : 
    1237              :       __os << __x.k() << __space << __x.p()
    1238              :            << __space << __x._M_gd;
    1239              : 
    1240              :       __os.flags(__flags);
    1241              :       __os.fill(__fill);
    1242              :       __os.precision(__precision);
    1243              :       return __os;
    1244              :     }
    1245              : 
    1246              :   template<typename _IntType, typename _CharT, typename _Traits>
    1247              :     std::basic_istream<_CharT, _Traits>&
    1248              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    1249              :                negative_binomial_distribution<_IntType>& __x)
    1250              :     {
    1251              :       using param_type
    1252              :         = typename negative_binomial_distribution<_IntType>::param_type;
    1253              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    1254              : 
    1255              :       const typename __ios_base::fmtflags __flags = __is.flags();
    1256              :       __is.flags(__ios_base::skipws);
    1257              : 
    1258              :       _IntType __k;
    1259              :       double __p;
    1260              :       if (__is >> __k >> __p >> __x._M_gd)
    1261              :         __x.param(param_type(__k, __p));
    1262              : 
    1263              :       __is.flags(__flags);
    1264              :       return __is;
    1265              :     }
    1266              : 
    1267              : 
    1268              :   template<typename _IntType>
    1269              :     void
    1270              :     poisson_distribution<_IntType>::param_type::
    1271              :     _M_initialize()
    1272              :     {
    1273              : #if _GLIBCXX_USE_C99_MATH_TR1
    1274              :       if (_M_mean >= 12)
    1275              :         {
    1276              :           const double __m = std::floor(_M_mean);
    1277              :           _M_lm_thr = std::log(_M_mean);
    1278              :           _M_lfm = std::lgamma(__m + 1);
    1279              :           _M_sm = std::sqrt(__m);
    1280              : 
    1281              :           const double __pi_4 = 0.7853981633974483096156608458198757L;
    1282              :           const double __dx = std::sqrt(2 * __m * std::log(32 * __m
    1283              :                                                               / __pi_4));
    1284              :           _M_d = std::round(std::max<double>(6.0, std::min(__m, __dx)));
    1285              :           const double __cx = 2 * __m + _M_d;
    1286              :           _M_scx = std::sqrt(__cx / 2);
    1287              :           _M_1cx = 1 / __cx;
    1288              : 
    1289              :           _M_c2b = std::sqrt(__pi_4 * __cx) * std::exp(_M_1cx);
    1290              :           _M_cb = 2 * __cx * std::exp(-_M_d * _M_1cx * (1 + _M_d / 2))
    1291              :                 / _M_d;
    1292              :         }
    1293              :       else
    1294              : #endif
    1295              :         _M_lm_thr = std::exp(-_M_mean);
    1296              :       }
    1297              : 
    1298              :   /**
    1299              :    * A rejection algorithm when mean >= 12 and a simple method based
    1300              :    * upon the multiplication of uniform random variates otherwise.
    1301              :    * NB: The former is available only if _GLIBCXX_USE_C99_MATH_TR1
    1302              :    * is defined.
    1303              :    *
    1304              :    * Reference:
    1305              :    * Devroye, L. Non-Uniform Random Variates Generation. Springer-Verlag,
    1306              :    * New York, 1986, Ch. X, Sects. 3.3 & 3.4 (+ Errata!).
    1307              :    */
    1308              :   template<typename _IntType>
    1309              :     template<typename _UniformRandomNumberGenerator>
    1310              :       typename poisson_distribution<_IntType>::result_type
    1311              :       poisson_distribution<_IntType>::
    1312              :       operator()(_UniformRandomNumberGenerator& __urng,
    1313              :                  const param_type& __param)
    1314              :       {
    1315              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    1316              :           __aurng(__urng);
    1317              : #if _GLIBCXX_USE_C99_MATH_TR1
    1318              :         if (__param.mean() >= 12)
    1319              :           {
    1320              :             double __x;
    1321              : 
    1322              :             // See comments above...
    1323              :             const double __naf =
    1324              :               (1 - std::numeric_limits<double>::epsilon()) / 2;
    1325              :             const double __thr =
    1326              :               std::numeric_limits<_IntType>::max() + __naf;
    1327              : 
    1328              :             const double __m = std::floor(__param.mean());
    1329              :             // sqrt(pi / 2)
    1330              :             const double __spi_2 = 1.2533141373155002512078826424055226L;
    1331              :             const double __c1 = __param._M_sm * __spi_2;
    1332              :             const double __c2 = __param._M_c2b + __c1;
    1333              :             const double __c3 = __c2 + 1;
    1334              :             const double __c4 = __c3 + 1;
    1335              :             // 1 / 78
    1336              :             const double __178 = 0.0128205128205128205128205128205128L;
    1337              :             // e^(1 / 78)
    1338              :             const double __e178 = 1.0129030479320018583185514777512983L;
    1339              :             const double __c5 = __c4 + __e178;
    1340              :             const double __c = __param._M_cb + __c5;
    1341              :             const double __2cx = 2 * (2 * __m + __param._M_d);
    1342              : 
    1343              :             bool __reject = true;
    1344              :             do
    1345              :               {
    1346              :                 const double __u = __c * __aurng();
    1347              :                 const double __e = -std::log(1.0 - __aurng());
    1348              : 
    1349              :                 double __w = 0.0;
    1350              : 
    1351              :                 if (__u <= __c1)
    1352              :                   {
    1353              :                     const double __n = _M_nd(__urng);
    1354              :                     const double __y = -std::abs(__n) * __param._M_sm - 1;
    1355              :                     __x = std::floor(__y);
    1356              :                     __w = -__n * __n / 2;
    1357              :                     if (__x < -__m)
    1358              :                       continue;
    1359              :                   }
    1360              :                 else if (__u <= __c2)
    1361              :                   {
    1362              :                     const double __n = _M_nd(__urng);
    1363              :                     const double __y = 1 + std::abs(__n) * __param._M_scx;
    1364              :                     __x = std::ceil(__y);
    1365              :                     __w = __y * (2 - __y) * __param._M_1cx;
    1366              :                     if (__x > __param._M_d)
    1367              :                       continue;
    1368              :                   }
    1369              :                 else if (__u <= __c3)
    1370              :                   // NB: This case not in the book, nor in the Errata,
    1371              :                   // but should be ok...
    1372              :                   __x = -1;
    1373              :                 else if (__u <= __c4)
    1374              :                   __x = 0;
    1375              :                 else if (__u <= __c5)
    1376              :                   {
    1377              :                     __x = 1;
    1378              :                     // Only in the Errata, see libstdc++/83237.
    1379              :                     __w = __178;
    1380              :                   }
    1381              :                 else
    1382              :                   {
    1383              :                     const double __v = -std::log(1.0 - __aurng());
    1384              :                     const double __y = __param._M_d
    1385              :                                      + __v * __2cx / __param._M_d;
    1386              :                     __x = std::ceil(__y);
    1387              :                     __w = -__param._M_d * __param._M_1cx * (1 + __y / 2);
    1388              :                   }
    1389              : 
    1390              :                 __reject = (__w - __e - __x * __param._M_lm_thr
    1391              :                             > __param._M_lfm - std::lgamma(__x + __m + 1));
    1392              : 
    1393              :                 __reject |= __x + __m >= __thr;
    1394              : 
    1395              :               } while (__reject);
    1396              : 
    1397              :             return result_type(__x + __m + __naf);
    1398              :           }
    1399              :         else
    1400              : #endif
    1401              :           {
    1402              :             _IntType     __x = 0;
    1403              :             double __prod = 1.0;
    1404              : 
    1405              :             do
    1406              :               {
    1407              :                 __prod *= __aurng();
    1408              :                 __x += 1;
    1409              :               }
    1410              :             while (__prod > __param._M_lm_thr);
    1411              : 
    1412              :             return __x - 1;
    1413              :           }
    1414              :       }
    1415              : 
    1416              :   template<typename _IntType>
    1417              :     template<typename _ForwardIterator,
    1418              :              typename _UniformRandomNumberGenerator>
    1419              :       void
    1420              :       poisson_distribution<_IntType>::
    1421              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1422              :                       _UniformRandomNumberGenerator& __urng,
    1423              :                       const param_type& __param)
    1424              :       {
    1425              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1426              :         // We could duplicate everything from operator()...
    1427              :         while (__f != __t)
    1428              :           *__f++ = this->operator()(__urng, __param);
    1429              :       }
    1430              : 
    1431              :   template<typename _IntType,
    1432              :            typename _CharT, typename _Traits>
    1433              :     std::basic_ostream<_CharT, _Traits>&
    1434              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    1435              :                const poisson_distribution<_IntType>& __x)
    1436              :     {
    1437              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    1438              : 
    1439              :       const typename __ios_base::fmtflags __flags = __os.flags();
    1440              :       const _CharT __fill = __os.fill();
    1441              :       const std::streamsize __precision = __os.precision();
    1442              :       const _CharT __space = __os.widen(' ');
    1443              :       __os.flags(__ios_base::scientific | __ios_base::left);
    1444              :       __os.fill(__space);
    1445              :       __os.precision(std::numeric_limits<double>::max_digits10);
    1446              : 
    1447              :       __os << __x.mean() << __space << __x._M_nd;
    1448              : 
    1449              :       __os.flags(__flags);
    1450              :       __os.fill(__fill);
    1451              :       __os.precision(__precision);
    1452              :       return __os;
    1453              :     }
    1454              : 
    1455              :   template<typename _IntType,
    1456              :            typename _CharT, typename _Traits>
    1457              :     std::basic_istream<_CharT, _Traits>&
    1458              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    1459              :                poisson_distribution<_IntType>& __x)
    1460              :     {
    1461              :       using param_type = typename poisson_distribution<_IntType>::param_type;
    1462              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    1463              : 
    1464              :       const typename __ios_base::fmtflags __flags = __is.flags();
    1465              :       __is.flags(__ios_base::skipws);
    1466              : 
    1467              :       double __mean;
    1468              :       if (__is >> __mean >> __x._M_nd)
    1469              :         __x.param(param_type(__mean));
    1470              : 
    1471              :       __is.flags(__flags);
    1472              :       return __is;
    1473              :     }
    1474              : 
    1475              : 
    1476              :   template<typename _IntType>
    1477              :     void
    1478              :     binomial_distribution<_IntType>::param_type::
    1479              :     _M_initialize()
    1480              :     {
    1481              :       const double __p12 = _M_p <= 0.5 ? _M_p : 1.0 - _M_p;
    1482              : 
    1483              :       _M_easy = true;
    1484              : 
    1485              : #if _GLIBCXX_USE_C99_MATH_TR1
    1486              :       if (_M_t * __p12 >= 8)
    1487              :         {
    1488              :           _M_easy = false;
    1489              :           const double __np = std::floor(_M_t * __p12);
    1490              :           const double __pa = __np / _M_t;
    1491              :           const double __1p = 1 - __pa;
    1492              : 
    1493              :           const double __pi_4 = 0.7853981633974483096156608458198757L;
    1494              :           const double __d1x =
    1495              :             std::sqrt(__np * __1p * std::log(32 * __np
    1496              :                                              / (81 * __pi_4 * __1p)));
    1497              :           _M_d1 = std::round(std::max<double>(1.0, __d1x));
    1498              :           const double __d2x =
    1499              :             std::sqrt(__np * __1p * std::log(32 * _M_t * __1p
    1500              :                                              / (__pi_4 * __pa)));
    1501              :           _M_d2 = std::round(std::max<double>(1.0, __d2x));
    1502              : 
    1503              :           // sqrt(pi / 2)
    1504              :           const double __spi_2 = 1.2533141373155002512078826424055226L;
    1505              :           _M_s1 = std::sqrt(__np * __1p) * (1 + _M_d1 / (4 * __np));
    1506              :           _M_s2 = std::sqrt(__np * __1p) * (1 + _M_d2 / (4 * _M_t * __1p));
    1507              :           _M_c = 2 * _M_d1 / __np;
    1508              :           _M_a1 = std::exp(_M_c) * _M_s1 * __spi_2;
    1509              :           const double __a12 = _M_a1 + _M_s2 * __spi_2;
    1510              :           const double __s1s = _M_s1 * _M_s1;
    1511              :           _M_a123 = __a12 + (std::exp(_M_d1 / (_M_t * __1p))
    1512              :                              * 2 * __s1s / _M_d1
    1513              :                              * std::exp(-_M_d1 * _M_d1 / (2 * __s1s)));
    1514              :           const double __s2s = _M_s2 * _M_s2;
    1515              :           _M_s = (_M_a123 + 2 * __s2s / _M_d2
    1516              :                   * std::exp(-_M_d2 * _M_d2 / (2 * __s2s)));
    1517              :           _M_lf = (std::lgamma(__np + 1)
    1518              :                    + std::lgamma(_M_t - __np + 1));
    1519              :           _M_lp1p = std::log(__pa / __1p);
    1520              : 
    1521              :           _M_q = -std::log(1 - (__p12 - __pa) / __1p);
    1522              :         }
    1523              :       else
    1524              : #endif
    1525              :         _M_q = -std::log(1 - __p12);
    1526              :     }
    1527              : 
    1528              :   template<typename _IntType>
    1529              :     template<typename _UniformRandomNumberGenerator>
    1530              :       typename binomial_distribution<_IntType>::result_type
    1531              :       binomial_distribution<_IntType>::
    1532              :       _M_waiting(_UniformRandomNumberGenerator& __urng,
    1533              :                  _IntType __t, double __q)
    1534              :       {
    1535              :         _IntType __x = 0;
    1536              :         double __sum = 0.0;
    1537              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    1538              :           __aurng(__urng);
    1539              : 
    1540              :         do
    1541              :           {
    1542              :             if (__t == __x)
    1543              :               return __x;
    1544              :             const double __e = -std::log(1.0 - __aurng());
    1545              :             __sum += __e / (__t - __x);
    1546              :             __x += 1;
    1547              :           }
    1548              :         while (__sum <= __q);
    1549              : 
    1550              :         return __x - 1;
    1551              :       }
    1552              : 
    1553              :   /**
    1554              :    * A rejection algorithm when t * p >= 8 and a simple waiting time
    1555              :    * method - the second in the referenced book - otherwise.
    1556              :    * NB: The former is available only if _GLIBCXX_USE_C99_MATH_TR1
    1557              :    * is defined.
    1558              :    *
    1559              :    * Reference:
    1560              :    * Devroye, L. Non-Uniform Random Variates Generation. Springer-Verlag,
    1561              :    * New York, 1986, Ch. X, Sect. 4 (+ Errata!).
    1562              :    */
    1563              :   template<typename _IntType>
    1564              :     template<typename _UniformRandomNumberGenerator>
    1565              :       typename binomial_distribution<_IntType>::result_type
    1566              :       binomial_distribution<_IntType>::
    1567              :       operator()(_UniformRandomNumberGenerator& __urng,
    1568              :                  const param_type& __param)
    1569              :       {
    1570              :         result_type __ret;
    1571              :         const _IntType __t = __param.t();
    1572              :         const double __p = __param.p();
    1573              :         const double __p12 = __p <= 0.5 ? __p : 1.0 - __p;
    1574              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    1575              :           __aurng(__urng);
    1576              : 
    1577              : #if _GLIBCXX_USE_C99_MATH_TR1
    1578              :         if (!__param._M_easy)
    1579              :           {
    1580              :             double __x;
    1581              : 
    1582              :             // See comments above...
    1583              :             const double __naf =
    1584              :               (1 - std::numeric_limits<double>::epsilon()) / 2;
    1585              :             const double __thr =
    1586              :               std::numeric_limits<_IntType>::max() + __naf;
    1587              : 
    1588              :             const double __np = std::floor(__t * __p12);
    1589              : 
    1590              :             // sqrt(pi / 2)
    1591              :             const double __spi_2 = 1.2533141373155002512078826424055226L;
    1592              :             const double __a1 = __param._M_a1;
    1593              :             const double __a12 = __a1 + __param._M_s2 * __spi_2;
    1594              :             const double __a123 = __param._M_a123;
    1595              :             const double __s1s = __param._M_s1 * __param._M_s1;
    1596              :             const double __s2s = __param._M_s2 * __param._M_s2;
    1597              : 
    1598              :             bool __reject;
    1599              :             do
    1600              :               {
    1601              :                 const double __u = __param._M_s * __aurng();
    1602              : 
    1603              :                 double __v;
    1604              : 
    1605              :                 if (__u <= __a1)
    1606              :                   {
    1607              :                     const double __n = _M_nd(__urng);
    1608              :                     const double __y = __param._M_s1 * std::abs(__n);
    1609              :                     __reject = __y >= __param._M_d1;
    1610              :                     if (!__reject)
    1611              :                       {
    1612              :                         const double __e = -std::log(1.0 - __aurng());
    1613              :                         __x = std::floor(__y);
    1614              :                         __v = -__e - __n * __n / 2 + __param._M_c;
    1615              :                       }
    1616              :                   }
    1617              :                 else if (__u <= __a12)
    1618              :                   {
    1619              :                     const double __n = _M_nd(__urng);
    1620              :                     const double __y = __param._M_s2 * std::abs(__n);
    1621              :                     __reject = __y >= __param._M_d2;
    1622              :                     if (!__reject)
    1623              :                       {
    1624              :                         const double __e = -std::log(1.0 - __aurng());
    1625              :                         __x = std::floor(-__y);
    1626              :                         __v = -__e - __n * __n / 2;
    1627              :                       }
    1628              :                   }
    1629              :                 else if (__u <= __a123)
    1630              :                   {
    1631              :                     const double __e1 = -std::log(1.0 - __aurng());
    1632              :                     const double __e2 = -std::log(1.0 - __aurng());
    1633              : 
    1634              :                     const double __y = __param._M_d1
    1635              :                                      + 2 * __s1s * __e1 / __param._M_d1;
    1636              :                     __x = std::floor(__y);
    1637              :                     __v = (-__e2 + __param._M_d1 * (1 / (__t - __np)
    1638              :                                                     -__y / (2 * __s1s)));
    1639              :                     __reject = false;
    1640              :                   }
    1641              :                 else
    1642              :                   {
    1643              :                     const double __e1 = -std::log(1.0 - __aurng());
    1644              :                     const double __e2 = -std::log(1.0 - __aurng());
    1645              : 
    1646              :                     const double __y = __param._M_d2
    1647              :                                      + 2 * __s2s * __e1 / __param._M_d2;
    1648              :                     __x = std::floor(-__y);
    1649              :                     __v = -__e2 - __param._M_d2 * __y / (2 * __s2s);
    1650              :                     __reject = false;
    1651              :                   }
    1652              : 
    1653              :                 __reject = __reject || __x < -__np || __x > __t - __np;
    1654              :                 if (!__reject)
    1655              :                   {
    1656              :                     const double __lfx =
    1657              :                       std::lgamma(__np + __x + 1)
    1658              :                       + std::lgamma(__t - (__np + __x) + 1);
    1659              :                     __reject = __v > __param._M_lf - __lfx
    1660              :                              + __x * __param._M_lp1p;
    1661              :                   }
    1662              : 
    1663              :                 __reject |= __x + __np >= __thr;
    1664              :               }
    1665              :             while (__reject);
    1666              : 
    1667              :             __x += __np + __naf;
    1668              : 
    1669              :             const _IntType __z = _M_waiting(__urng, __t - _IntType(__x),
    1670              :                                             __param._M_q);
    1671              :             __ret = _IntType(__x) + __z;
    1672              :           }
    1673              :         else
    1674              : #endif
    1675              :           __ret = _M_waiting(__urng, __t, __param._M_q);
    1676              : 
    1677              :         if (__p12 != __p)
    1678              :           __ret = __t - __ret;
    1679              :         return __ret;
    1680              :       }
    1681              : 
    1682              :   template<typename _IntType>
    1683              :     template<typename _ForwardIterator,
    1684              :              typename _UniformRandomNumberGenerator>
    1685              :       void
    1686              :       binomial_distribution<_IntType>::
    1687              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1688              :                       _UniformRandomNumberGenerator& __urng,
    1689              :                       const param_type& __param)
    1690              :       {
    1691              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1692              :         // We could duplicate everything from operator()...
    1693              :         while (__f != __t)
    1694              :           *__f++ = this->operator()(__urng, __param);
    1695              :       }
    1696              : 
    1697              :   template<typename _IntType,
    1698              :            typename _CharT, typename _Traits>
    1699              :     std::basic_ostream<_CharT, _Traits>&
    1700              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    1701              :                const binomial_distribution<_IntType>& __x)
    1702              :     {
    1703              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    1704              : 
    1705              :       const typename __ios_base::fmtflags __flags = __os.flags();
    1706              :       const _CharT __fill = __os.fill();
    1707              :       const std::streamsize __precision = __os.precision();
    1708              :       const _CharT __space = __os.widen(' ');
    1709              :       __os.flags(__ios_base::scientific | __ios_base::left);
    1710              :       __os.fill(__space);
    1711              :       __os.precision(std::numeric_limits<double>::max_digits10);
    1712              : 
    1713              :       __os << __x.t() << __space << __x.p()
    1714              :            << __space << __x._M_nd;
    1715              : 
    1716              :       __os.flags(__flags);
    1717              :       __os.fill(__fill);
    1718              :       __os.precision(__precision);
    1719              :       return __os;
    1720              :     }
    1721              : 
    1722              :   template<typename _IntType,
    1723              :            typename _CharT, typename _Traits>
    1724              :     std::basic_istream<_CharT, _Traits>&
    1725              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    1726              :                binomial_distribution<_IntType>& __x)
    1727              :     {
    1728              :       using param_type = typename binomial_distribution<_IntType>::param_type;
    1729              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    1730              : 
    1731              :       const typename __ios_base::fmtflags __flags = __is.flags();
    1732              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    1733              : 
    1734              :       _IntType __t;
    1735              :       double __p;
    1736              :       if (__is >> __t >> __p >> __x._M_nd)
    1737              :         __x.param(param_type(__t, __p));
    1738              : 
    1739              :       __is.flags(__flags);
    1740              :       return __is;
    1741              :     }
    1742              : 
    1743              : 
    1744              :   template<typename _RealType>
    1745              :     template<typename _ForwardIterator,
    1746              :              typename _UniformRandomNumberGenerator>
    1747              :       void
    1748              :       std::exponential_distribution<_RealType>::
    1749              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1750              :                       _UniformRandomNumberGenerator& __urng,
    1751              :                       const param_type& __p)
    1752              :       {
    1753              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1754              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    1755              :           __aurng(__urng);
    1756              :         while (__f != __t)
    1757              :           *__f++ = -std::log(result_type(1) - __aurng()) / __p.lambda();
    1758              :       }
    1759              : 
    1760              :   template<typename _RealType, typename _CharT, typename _Traits>
    1761              :     std::basic_ostream<_CharT, _Traits>&
    1762              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    1763              :                const exponential_distribution<_RealType>& __x)
    1764              :     {
    1765              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    1766              : 
    1767              :       const typename __ios_base::fmtflags __flags = __os.flags();
    1768              :       const _CharT __fill = __os.fill();
    1769              :       const std::streamsize __precision = __os.precision();
    1770              :       __os.flags(__ios_base::scientific | __ios_base::left);
    1771              :       __os.fill(__os.widen(' '));
    1772              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    1773              : 
    1774              :       __os << __x.lambda();
    1775              : 
    1776              :       __os.flags(__flags);
    1777              :       __os.fill(__fill);
    1778              :       __os.precision(__precision);
    1779              :       return __os;
    1780              :     }
    1781              : 
    1782              :   template<typename _RealType, typename _CharT, typename _Traits>
    1783              :     std::basic_istream<_CharT, _Traits>&
    1784              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    1785              :                exponential_distribution<_RealType>& __x)
    1786              :     {
    1787              :       using param_type
    1788              :         = typename exponential_distribution<_RealType>::param_type;
    1789              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    1790              : 
    1791              :       const typename __ios_base::fmtflags __flags = __is.flags();
    1792              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    1793              : 
    1794              :       _RealType __lambda;
    1795              :       if (__is >> __lambda)
    1796              :         __x.param(param_type(__lambda));
    1797              : 
    1798              :       __is.flags(__flags);
    1799              :       return __is;
    1800              :     }
    1801              : 
    1802              : 
    1803              :   /**
    1804              :    * Polar method due to Marsaglia.
    1805              :    *
    1806              :    * Devroye, L. Non-Uniform Random Variates Generation. Springer-Verlag,
    1807              :    * New York, 1986, Ch. V, Sect. 4.4.
    1808              :    */
    1809              :   template<typename _RealType>
    1810              :     template<typename _UniformRandomNumberGenerator>
    1811              :       typename normal_distribution<_RealType>::result_type
    1812              :       normal_distribution<_RealType>::
    1813              :       operator()(_UniformRandomNumberGenerator& __urng,
    1814              :                  const param_type& __param)
    1815              :       {
    1816              :         result_type __ret;
    1817              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    1818              :           __aurng(__urng);
    1819              : 
    1820              :         if (_M_saved_available)
    1821              :           {
    1822              :             _M_saved_available = false;
    1823              :             __ret = _M_saved;
    1824              :           }
    1825              :         else
    1826              :           {
    1827              :             result_type __x, __y, __r2;
    1828              :             do
    1829              :               {
    1830              :                 __x = result_type(2.0) * __aurng() - 1.0;
    1831              :                 __y = result_type(2.0) * __aurng() - 1.0;
    1832              :                 __r2 = __x * __x + __y * __y;
    1833              :               }
    1834              :             while (__r2 > 1.0 || __r2 == 0.0);
    1835              : 
    1836              :             const result_type __mult = std::sqrt(-2 * std::log(__r2) / __r2);
    1837              :             _M_saved = __x * __mult;
    1838              :             _M_saved_available = true;
    1839              :             __ret = __y * __mult;
    1840              :           }
    1841              : 
    1842              :         __ret = __ret * __param.stddev() + __param.mean();
    1843              :         return __ret;
    1844              :       }
    1845              : 
    1846              :   template<typename _RealType>
    1847              :     template<typename _ForwardIterator,
    1848              :              typename _UniformRandomNumberGenerator>
    1849              :       void
    1850              :       normal_distribution<_RealType>::
    1851              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1852              :                       _UniformRandomNumberGenerator& __urng,
    1853              :                       const param_type& __param)
    1854              :       {
    1855              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1856              : 
    1857              :         if (__f == __t)
    1858              :           return;
    1859              : 
    1860              :         if (_M_saved_available)
    1861              :           {
    1862              :             _M_saved_available = false;
    1863              :             *__f++ = _M_saved * __param.stddev() + __param.mean();
    1864              : 
    1865              :             if (__f == __t)
    1866              :               return;
    1867              :           }
    1868              : 
    1869              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    1870              :           __aurng(__urng);
    1871              : 
    1872              :         while (__f + 1 < __t)
    1873              :           {
    1874              :             result_type __x, __y, __r2;
    1875              :             do
    1876              :               {
    1877              :                 __x = result_type(2.0) * __aurng() - 1.0;
    1878              :                 __y = result_type(2.0) * __aurng() - 1.0;
    1879              :                 __r2 = __x * __x + __y * __y;
    1880              :               }
    1881              :             while (__r2 > 1.0 || __r2 == 0.0);
    1882              : 
    1883              :             const result_type __mult = std::sqrt(-2 * std::log(__r2) / __r2);
    1884              :             *__f++ = __y * __mult * __param.stddev() + __param.mean();
    1885              :             *__f++ = __x * __mult * __param.stddev() + __param.mean();
    1886              :           }
    1887              : 
    1888              :         if (__f != __t)
    1889              :           {
    1890              :             result_type __x, __y, __r2;
    1891              :             do
    1892              :               {
    1893              :                 __x = result_type(2.0) * __aurng() - 1.0;
    1894              :                 __y = result_type(2.0) * __aurng() - 1.0;
    1895              :                 __r2 = __x * __x + __y * __y;
    1896              :               }
    1897              :             while (__r2 > 1.0 || __r2 == 0.0);
    1898              : 
    1899              :             const result_type __mult = std::sqrt(-2 * std::log(__r2) / __r2);
    1900              :             _M_saved = __x * __mult;
    1901              :             _M_saved_available = true;
    1902              :             *__f = __y * __mult * __param.stddev() + __param.mean();
    1903              :           }
    1904              :       }
    1905              : 
    1906              :   template<typename _RealType>
    1907              :     bool
    1908              :     operator==(const std::normal_distribution<_RealType>& __d1,
    1909              :                const std::normal_distribution<_RealType>& __d2)
    1910              :     {
    1911              :       if (__d1._M_param == __d2._M_param
    1912              :           && __d1._M_saved_available == __d2._M_saved_available)
    1913              :         return __d1._M_saved_available ? __d1._M_saved == __d2._M_saved : true;
    1914              :       else
    1915              :         return false;
    1916              :     }
    1917              : 
    1918              :   template<typename _RealType, typename _CharT, typename _Traits>
    1919              :     std::basic_ostream<_CharT, _Traits>&
    1920              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    1921              :                const normal_distribution<_RealType>& __x)
    1922              :     {
    1923              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    1924              : 
    1925              :       const typename __ios_base::fmtflags __flags = __os.flags();
    1926              :       const _CharT __fill = __os.fill();
    1927              :       const std::streamsize __precision = __os.precision();
    1928              :       const _CharT __space = __os.widen(' ');
    1929              :       __os.flags(__ios_base::scientific | __ios_base::left);
    1930              :       __os.fill(__space);
    1931              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    1932              : 
    1933              :       __os << __x.mean() << __space << __x.stddev()
    1934              :            << __space << __x._M_saved_available;
    1935              :       if (__x._M_saved_available)
    1936              :         __os << __space << __x._M_saved;
    1937              : 
    1938              :       __os.flags(__flags);
    1939              :       __os.fill(__fill);
    1940              :       __os.precision(__precision);
    1941              :       return __os;
    1942              :     }
    1943              : 
    1944              :   template<typename _RealType, typename _CharT, typename _Traits>
    1945              :     std::basic_istream<_CharT, _Traits>&
    1946              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    1947              :                normal_distribution<_RealType>& __x)
    1948              :     {
    1949              :       using param_type = typename normal_distribution<_RealType>::param_type;
    1950              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    1951              : 
    1952              :       const typename __ios_base::fmtflags __flags = __is.flags();
    1953              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    1954              : 
    1955              :       double __mean, __stddev;
    1956              :       bool __saved_avail;
    1957              :       if (__is >> __mean >> __stddev >> __saved_avail)
    1958              :         {
    1959              :           if (!__saved_avail || (__is >> __x._M_saved))
    1960              :             {
    1961              :               __x._M_saved_available = __saved_avail;
    1962              :               __x.param(param_type(__mean, __stddev));
    1963              :             }
    1964              :         }
    1965              : 
    1966              :       __is.flags(__flags);
    1967              :       return __is;
    1968              :     }
    1969              : 
    1970              : 
    1971              :   template<typename _RealType>
    1972              :     template<typename _ForwardIterator,
    1973              :              typename _UniformRandomNumberGenerator>
    1974              :       void
    1975              :       lognormal_distribution<_RealType>::
    1976              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    1977              :                       _UniformRandomNumberGenerator& __urng,
    1978              :                       const param_type& __p)
    1979              :       {
    1980              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    1981              :           while (__f != __t)
    1982              :             *__f++ = std::exp(__p.s() * _M_nd(__urng) + __p.m());
    1983              :       }
    1984              : 
    1985              :   template<typename _RealType, typename _CharT, typename _Traits>
    1986              :     std::basic_ostream<_CharT, _Traits>&
    1987              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    1988              :                const lognormal_distribution<_RealType>& __x)
    1989              :     {
    1990              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    1991              : 
    1992              :       const typename __ios_base::fmtflags __flags = __os.flags();
    1993              :       const _CharT __fill = __os.fill();
    1994              :       const std::streamsize __precision = __os.precision();
    1995              :       const _CharT __space = __os.widen(' ');
    1996              :       __os.flags(__ios_base::scientific | __ios_base::left);
    1997              :       __os.fill(__space);
    1998              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    1999              : 
    2000              :       __os << __x.m() << __space << __x.s()
    2001              :            << __space << __x._M_nd;
    2002              : 
    2003              :       __os.flags(__flags);
    2004              :       __os.fill(__fill);
    2005              :       __os.precision(__precision);
    2006              :       return __os;
    2007              :     }
    2008              : 
    2009              :   template<typename _RealType, typename _CharT, typename _Traits>
    2010              :     std::basic_istream<_CharT, _Traits>&
    2011              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2012              :                lognormal_distribution<_RealType>& __x)
    2013              :     {
    2014              :       using param_type
    2015              :         = typename lognormal_distribution<_RealType>::param_type;
    2016              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2017              : 
    2018              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2019              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2020              : 
    2021              :       _RealType __m, __s;
    2022              :       if (__is >> __m >> __s >> __x._M_nd)
    2023              :         __x.param(param_type(__m, __s));
    2024              : 
    2025              :       __is.flags(__flags);
    2026              :       return __is;
    2027              :     }
    2028              : 
    2029              :   template<typename _RealType>
    2030              :     template<typename _ForwardIterator,
    2031              :              typename _UniformRandomNumberGenerator>
    2032              :       void
    2033              :       std::chi_squared_distribution<_RealType>::
    2034              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2035              :                       _UniformRandomNumberGenerator& __urng)
    2036              :       {
    2037              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2038              :         while (__f != __t)
    2039              :           *__f++ = 2 * _M_gd(__urng);
    2040              :       }
    2041              : 
    2042              :   template<typename _RealType>
    2043              :     template<typename _ForwardIterator,
    2044              :              typename _UniformRandomNumberGenerator>
    2045              :       void
    2046              :       std::chi_squared_distribution<_RealType>::
    2047              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2048              :                       _UniformRandomNumberGenerator& __urng,
    2049              :                       const typename
    2050              :                       std::gamma_distribution<result_type>::param_type& __p)
    2051              :       {
    2052              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2053              :         while (__f != __t)
    2054              :           *__f++ = 2 * _M_gd(__urng, __p);
    2055              :       }
    2056              : 
    2057              :   template<typename _RealType, typename _CharT, typename _Traits>
    2058              :     std::basic_ostream<_CharT, _Traits>&
    2059              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2060              :                const chi_squared_distribution<_RealType>& __x)
    2061              :     {
    2062              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2063              : 
    2064              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2065              :       const _CharT __fill = __os.fill();
    2066              :       const std::streamsize __precision = __os.precision();
    2067              :       const _CharT __space = __os.widen(' ');
    2068              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2069              :       __os.fill(__space);
    2070              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    2071              : 
    2072              :       __os << __x.n() << __space << __x._M_gd;
    2073              : 
    2074              :       __os.flags(__flags);
    2075              :       __os.fill(__fill);
    2076              :       __os.precision(__precision);
    2077              :       return __os;
    2078              :     }
    2079              : 
    2080              :   template<typename _RealType, typename _CharT, typename _Traits>
    2081              :     std::basic_istream<_CharT, _Traits>&
    2082              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2083              :                chi_squared_distribution<_RealType>& __x)
    2084              :     {
    2085              :       using param_type
    2086              :         = typename chi_squared_distribution<_RealType>::param_type;
    2087              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2088              : 
    2089              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2090              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2091              : 
    2092              :       _RealType __n;
    2093              :       if (__is >> __n >> __x._M_gd)
    2094              :         __x.param(param_type(__n));
    2095              : 
    2096              :       __is.flags(__flags);
    2097              :       return __is;
    2098              :     }
    2099              : 
    2100              : 
    2101              :   template<typename _RealType>
    2102              :     template<typename _UniformRandomNumberGenerator>
    2103              :       typename cauchy_distribution<_RealType>::result_type
    2104              :       cauchy_distribution<_RealType>::
    2105              :       operator()(_UniformRandomNumberGenerator& __urng,
    2106              :                  const param_type& __p)
    2107              :       {
    2108              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    2109              :           __aurng(__urng);
    2110              :         _RealType __u;
    2111              :         do
    2112              :           __u = __aurng();
    2113              :         while (__u == 0.5);
    2114              : 
    2115              :         const _RealType __pi = 3.1415926535897932384626433832795029L;
    2116              :         return __p.a() + __p.b() * std::tan(__pi * __u);
    2117              :       }
    2118              : 
    2119              :   template<typename _RealType>
    2120              :     template<typename _ForwardIterator,
    2121              :              typename _UniformRandomNumberGenerator>
    2122              :       void
    2123              :       cauchy_distribution<_RealType>::
    2124              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2125              :                       _UniformRandomNumberGenerator& __urng,
    2126              :                       const param_type& __p)
    2127              :       {
    2128              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2129              :         const _RealType __pi = 3.1415926535897932384626433832795029L;
    2130              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    2131              :           __aurng(__urng);
    2132              :         while (__f != __t)
    2133              :           {
    2134              :             _RealType __u;
    2135              :             do
    2136              :               __u = __aurng();
    2137              :             while (__u == 0.5);
    2138              : 
    2139              :             *__f++ = __p.a() + __p.b() * std::tan(__pi * __u);
    2140              :           }
    2141              :       }
    2142              : 
    2143              :   template<typename _RealType, typename _CharT, typename _Traits>
    2144              :     std::basic_ostream<_CharT, _Traits>&
    2145              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2146              :                const cauchy_distribution<_RealType>& __x)
    2147              :     {
    2148              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2149              : 
    2150              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2151              :       const _CharT __fill = __os.fill();
    2152              :       const std::streamsize __precision = __os.precision();
    2153              :       const _CharT __space = __os.widen(' ');
    2154              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2155              :       __os.fill(__space);
    2156              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    2157              : 
    2158              :       __os << __x.a() << __space << __x.b();
    2159              : 
    2160              :       __os.flags(__flags);
    2161              :       __os.fill(__fill);
    2162              :       __os.precision(__precision);
    2163              :       return __os;
    2164              :     }
    2165              : 
    2166              :   template<typename _RealType, typename _CharT, typename _Traits>
    2167              :     std::basic_istream<_CharT, _Traits>&
    2168              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2169              :                cauchy_distribution<_RealType>& __x)
    2170              :     {
    2171              :       using param_type = typename cauchy_distribution<_RealType>::param_type;
    2172              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2173              : 
    2174              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2175              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2176              : 
    2177              :       _RealType __a, __b;
    2178              :       if (__is >> __a >> __b)
    2179              :         __x.param(param_type(__a, __b));
    2180              : 
    2181              :       __is.flags(__flags);
    2182              :       return __is;
    2183              :     }
    2184              : 
    2185              : 
    2186              :   template<typename _RealType>
    2187              :     template<typename _ForwardIterator,
    2188              :              typename _UniformRandomNumberGenerator>
    2189              :       void
    2190              :       std::fisher_f_distribution<_RealType>::
    2191              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2192              :                       _UniformRandomNumberGenerator& __urng)
    2193              :       {
    2194              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2195              :         while (__f != __t)
    2196              :           *__f++ = ((_M_gd_x(__urng) * n()) / (_M_gd_y(__urng) * m()));
    2197              :       }
    2198              : 
    2199              :   template<typename _RealType>
    2200              :     template<typename _ForwardIterator,
    2201              :              typename _UniformRandomNumberGenerator>
    2202              :       void
    2203              :       std::fisher_f_distribution<_RealType>::
    2204              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2205              :                       _UniformRandomNumberGenerator& __urng,
    2206              :                       const param_type& __p)
    2207              :       {
    2208              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2209              :         typedef typename std::gamma_distribution<result_type>::param_type
    2210              :           param_type;
    2211              :         param_type __p1(__p.m() / 2);
    2212              :         param_type __p2(__p.n() / 2);
    2213              :         while (__f != __t)
    2214              :           *__f++ = ((_M_gd_x(__urng, __p1) * n())
    2215              :                     / (_M_gd_y(__urng, __p2) * m()));
    2216              :       }
    2217              : 
    2218              :   template<typename _RealType, typename _CharT, typename _Traits>
    2219              :     std::basic_ostream<_CharT, _Traits>&
    2220              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2221              :                const fisher_f_distribution<_RealType>& __x)
    2222              :     {
    2223              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2224              : 
    2225              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2226              :       const _CharT __fill = __os.fill();
    2227              :       const std::streamsize __precision = __os.precision();
    2228              :       const _CharT __space = __os.widen(' ');
    2229              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2230              :       __os.fill(__space);
    2231              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    2232              : 
    2233              :       __os << __x.m() << __space << __x.n()
    2234              :            << __space << __x._M_gd_x << __space << __x._M_gd_y;
    2235              : 
    2236              :       __os.flags(__flags);
    2237              :       __os.fill(__fill);
    2238              :       __os.precision(__precision);
    2239              :       return __os;
    2240              :     }
    2241              : 
    2242              :   template<typename _RealType, typename _CharT, typename _Traits>
    2243              :     std::basic_istream<_CharT, _Traits>&
    2244              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2245              :                fisher_f_distribution<_RealType>& __x)
    2246              :     {
    2247              :       using param_type
    2248              :         = typename fisher_f_distribution<_RealType>::param_type;
    2249              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2250              : 
    2251              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2252              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2253              : 
    2254              :       _RealType __m, __n;
    2255              :       if (__is >> __m >> __n >> __x._M_gd_x >> __x._M_gd_y)
    2256              :         __x.param(param_type(__m, __n));
    2257              : 
    2258              :       __is.flags(__flags);
    2259              :       return __is;
    2260              :     }
    2261              : 
    2262              : 
    2263              :   template<typename _RealType>
    2264              :     template<typename _ForwardIterator,
    2265              :              typename _UniformRandomNumberGenerator>
    2266              :       void
    2267              :       std::student_t_distribution<_RealType>::
    2268              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2269              :                       _UniformRandomNumberGenerator& __urng)
    2270              :       {
    2271              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2272              :         while (__f != __t)
    2273              :           *__f++ = _M_nd(__urng) * std::sqrt(n() / _M_gd(__urng));
    2274              :       }
    2275              : 
    2276              :   template<typename _RealType>
    2277              :     template<typename _ForwardIterator,
    2278              :              typename _UniformRandomNumberGenerator>
    2279              :       void
    2280              :       std::student_t_distribution<_RealType>::
    2281              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2282              :                       _UniformRandomNumberGenerator& __urng,
    2283              :                       const param_type& __p)
    2284              :       {
    2285              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2286              :         typename std::gamma_distribution<result_type>::param_type
    2287              :           __p2(__p.n() / 2, 2);
    2288              :         while (__f != __t)
    2289              :           *__f++ =  _M_nd(__urng) * std::sqrt(__p.n() / _M_gd(__urng, __p2));
    2290              :       }
    2291              : 
    2292              :   template<typename _RealType, typename _CharT, typename _Traits>
    2293              :     std::basic_ostream<_CharT, _Traits>&
    2294              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2295              :                const student_t_distribution<_RealType>& __x)
    2296              :     {
    2297              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2298              : 
    2299              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2300              :       const _CharT __fill = __os.fill();
    2301              :       const std::streamsize __precision = __os.precision();
    2302              :       const _CharT __space = __os.widen(' ');
    2303              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2304              :       __os.fill(__space);
    2305              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    2306              : 
    2307              :       __os << __x.n() << __space << __x._M_nd << __space << __x._M_gd;
    2308              : 
    2309              :       __os.flags(__flags);
    2310              :       __os.fill(__fill);
    2311              :       __os.precision(__precision);
    2312              :       return __os;
    2313              :     }
    2314              : 
    2315              :   template<typename _RealType, typename _CharT, typename _Traits>
    2316              :     std::basic_istream<_CharT, _Traits>&
    2317              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2318              :                student_t_distribution<_RealType>& __x)
    2319              :     {
    2320              :       using param_type
    2321              :         = typename student_t_distribution<_RealType>::param_type;
    2322              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2323              : 
    2324              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2325              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2326              : 
    2327              :       _RealType __n;
    2328              :       if (__is >> __n >> __x._M_nd >> __x._M_gd)
    2329              :         __x.param(param_type(__n));
    2330              : 
    2331              :       __is.flags(__flags);
    2332              :       return __is;
    2333              :     }
    2334              : 
    2335              : 
    2336              :   template<typename _RealType>
    2337              :     void
    2338              :     gamma_distribution<_RealType>::param_type::
    2339              :     _M_initialize()
    2340              :     {
    2341              :       _M_malpha = _M_alpha < 1.0 ? _M_alpha + _RealType(1.0) : _M_alpha;
    2342              : 
    2343              :       const _RealType __a1 = _M_malpha - _RealType(1.0) / _RealType(3.0);
    2344              :       _M_a2 = _RealType(1.0) / std::sqrt(_RealType(9.0) * __a1);
    2345              :     }
    2346              : 
    2347              :   /**
    2348              :    * Marsaglia, G. and Tsang, W. W.
    2349              :    * "A Simple Method for Generating Gamma Variables"
    2350              :    * ACM Transactions on Mathematical Software, 26, 3, 363-372, 2000.
    2351              :    */
    2352              :   template<typename _RealType>
    2353              :     template<typename _UniformRandomNumberGenerator>
    2354              :       typename gamma_distribution<_RealType>::result_type
    2355              :       gamma_distribution<_RealType>::
    2356              :       operator()(_UniformRandomNumberGenerator& __urng,
    2357              :                  const param_type& __param)
    2358              :       {
    2359              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    2360              :           __aurng(__urng);
    2361              : 
    2362              :         result_type __u, __v, __n;
    2363              :         const result_type __a1 = (__param._M_malpha
    2364              :                                   - _RealType(1.0) / _RealType(3.0));
    2365              : 
    2366              :         do
    2367              :           {
    2368              :             do
    2369              :               {
    2370              :                 __n = _M_nd(__urng);
    2371              :                 __v = result_type(1.0) + __param._M_a2 * __n; 
    2372              :               }
    2373              :             while (__v <= 0.0);
    2374              : 
    2375              :             __v = __v * __v * __v;
    2376              :             __u = __aurng();
    2377              :           }
    2378              :         while (__u > result_type(1.0) - 0.0331 * __n * __n * __n * __n
    2379              :                && (std::log(__u) > (0.5 * __n * __n + __a1
    2380              :                                     * (1.0 - __v + std::log(__v)))));
    2381              : 
    2382              :         if (__param.alpha() == __param._M_malpha)
    2383              :           return __a1 * __v * __param.beta();
    2384              :         else
    2385              :           {
    2386              :             do
    2387              :               __u = __aurng();
    2388              :             while (__u == 0.0);
    2389              :             
    2390              :             return (std::pow(__u, result_type(1.0) / __param.alpha())
    2391              :                     * __a1 * __v * __param.beta());
    2392              :           }
    2393              :       }
    2394              : 
    2395              :   template<typename _RealType>
    2396              :     template<typename _ForwardIterator,
    2397              :              typename _UniformRandomNumberGenerator>
    2398              :       void
    2399              :       gamma_distribution<_RealType>::
    2400              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2401              :                       _UniformRandomNumberGenerator& __urng,
    2402              :                       const param_type& __param)
    2403              :       {
    2404              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2405              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    2406              :           __aurng(__urng);
    2407              : 
    2408              :         result_type __u, __v, __n;
    2409              :         const result_type __a1 = (__param._M_malpha
    2410              :                                   - _RealType(1.0) / _RealType(3.0));
    2411              : 
    2412              :         if (__param.alpha() == __param._M_malpha)
    2413              :           while (__f != __t)
    2414              :             {
    2415              :               do
    2416              :                 {
    2417              :                   do
    2418              :                     {
    2419              :                       __n = _M_nd(__urng);
    2420              :                       __v = result_type(1.0) + __param._M_a2 * __n;
    2421              :                     }
    2422              :                   while (__v <= 0.0);
    2423              : 
    2424              :                   __v = __v * __v * __v;
    2425              :                   __u = __aurng();
    2426              :                 }
    2427              :               while (__u > result_type(1.0) - 0.0331 * __n * __n * __n * __n
    2428              :                      && (std::log(__u) > (0.5 * __n * __n + __a1
    2429              :                                           * (1.0 - __v + std::log(__v)))));
    2430              : 
    2431              :               *__f++ = __a1 * __v * __param.beta();
    2432              :             }
    2433              :         else
    2434              :           while (__f != __t)
    2435              :             {
    2436              :               do
    2437              :                 {
    2438              :                   do
    2439              :                     {
    2440              :                       __n = _M_nd(__urng);
    2441              :                       __v = result_type(1.0) + __param._M_a2 * __n;
    2442              :                     }
    2443              :                   while (__v <= 0.0);
    2444              : 
    2445              :                   __v = __v * __v * __v;
    2446              :                   __u = __aurng();
    2447              :                 }
    2448              :               while (__u > result_type(1.0) - 0.0331 * __n * __n * __n * __n
    2449              :                      && (std::log(__u) > (0.5 * __n * __n + __a1
    2450              :                                           * (1.0 - __v + std::log(__v)))));
    2451              : 
    2452              :               do
    2453              :                 __u = __aurng();
    2454              :               while (__u == 0.0);
    2455              : 
    2456              :               *__f++ = (std::pow(__u, result_type(1.0) / __param.alpha())
    2457              :                         * __a1 * __v * __param.beta());
    2458              :             }
    2459              :       }
    2460              : 
    2461              :   template<typename _RealType, typename _CharT, typename _Traits>
    2462              :     std::basic_ostream<_CharT, _Traits>&
    2463              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2464              :                const gamma_distribution<_RealType>& __x)
    2465              :     {
    2466              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2467              : 
    2468              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2469              :       const _CharT __fill = __os.fill();
    2470              :       const std::streamsize __precision = __os.precision();
    2471              :       const _CharT __space = __os.widen(' ');
    2472              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2473              :       __os.fill(__space);
    2474              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    2475              : 
    2476              :       __os << __x.alpha() << __space << __x.beta()
    2477              :            << __space << __x._M_nd;
    2478              : 
    2479              :       __os.flags(__flags);
    2480              :       __os.fill(__fill);
    2481              :       __os.precision(__precision);
    2482              :       return __os;
    2483              :     }
    2484              : 
    2485              :   template<typename _RealType, typename _CharT, typename _Traits>
    2486              :     std::basic_istream<_CharT, _Traits>&
    2487              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2488              :                gamma_distribution<_RealType>& __x)
    2489              :     {
    2490              :       using param_type = typename gamma_distribution<_RealType>::param_type;
    2491              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2492              : 
    2493              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2494              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2495              : 
    2496              :       _RealType __alpha_val, __beta_val;
    2497              :       if (__is >> __alpha_val >> __beta_val >> __x._M_nd)
    2498              :         __x.param(param_type(__alpha_val, __beta_val));
    2499              : 
    2500              :       __is.flags(__flags);
    2501              :       return __is;
    2502              :     }
    2503              : 
    2504              : 
    2505              :   template<typename _RealType>
    2506              :     template<typename _UniformRandomNumberGenerator>
    2507              :       typename weibull_distribution<_RealType>::result_type
    2508              :       weibull_distribution<_RealType>::
    2509              :       operator()(_UniformRandomNumberGenerator& __urng,
    2510              :                  const param_type& __p)
    2511              :       {
    2512              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    2513              :           __aurng(__urng);
    2514              :         return __p.b() * std::pow(-std::log(result_type(1) - __aurng()),
    2515              :                                   result_type(1) / __p.a());
    2516              :       }
    2517              : 
    2518              :   template<typename _RealType>
    2519              :     template<typename _ForwardIterator,
    2520              :              typename _UniformRandomNumberGenerator>
    2521              :       void
    2522              :       weibull_distribution<_RealType>::
    2523              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2524              :                       _UniformRandomNumberGenerator& __urng,
    2525              :                       const param_type& __p)
    2526              :       {
    2527              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2528              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    2529              :           __aurng(__urng);
    2530              :         auto __inv_a = result_type(1) / __p.a();
    2531              : 
    2532              :         while (__f != __t)
    2533              :           *__f++ = __p.b() * std::pow(-std::log(result_type(1) - __aurng()),
    2534              :                                       __inv_a);
    2535              :       }
    2536              : 
    2537              :   template<typename _RealType, typename _CharT, typename _Traits>
    2538              :     std::basic_ostream<_CharT, _Traits>&
    2539              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2540              :                const weibull_distribution<_RealType>& __x)
    2541              :     {
    2542              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2543              : 
    2544              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2545              :       const _CharT __fill = __os.fill();
    2546              :       const std::streamsize __precision = __os.precision();
    2547              :       const _CharT __space = __os.widen(' ');
    2548              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2549              :       __os.fill(__space);
    2550              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    2551              : 
    2552              :       __os << __x.a() << __space << __x.b();
    2553              : 
    2554              :       __os.flags(__flags);
    2555              :       __os.fill(__fill);
    2556              :       __os.precision(__precision);
    2557              :       return __os;
    2558              :     }
    2559              : 
    2560              :   template<typename _RealType, typename _CharT, typename _Traits>
    2561              :     std::basic_istream<_CharT, _Traits>&
    2562              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2563              :                weibull_distribution<_RealType>& __x)
    2564              :     {
    2565              :       using param_type = typename weibull_distribution<_RealType>::param_type;
    2566              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2567              : 
    2568              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2569              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2570              : 
    2571              :       _RealType __a, __b;
    2572              :       if (__is >> __a >> __b)
    2573              :         __x.param(param_type(__a, __b));
    2574              : 
    2575              :       __is.flags(__flags);
    2576              :       return __is;
    2577              :     }
    2578              : 
    2579              : 
    2580              :   template<typename _RealType>
    2581              :     template<typename _UniformRandomNumberGenerator>
    2582              :       typename extreme_value_distribution<_RealType>::result_type
    2583              :       extreme_value_distribution<_RealType>::
    2584              :       operator()(_UniformRandomNumberGenerator& __urng,
    2585              :                  const param_type& __p)
    2586              :       {
    2587              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    2588              :           __aurng(__urng);
    2589              :         return __p.a() - __p.b() * std::log(-std::log(result_type(1)
    2590              :                                                       - __aurng()));
    2591              :       }
    2592              : 
    2593              :   template<typename _RealType>
    2594              :     template<typename _ForwardIterator,
    2595              :              typename _UniformRandomNumberGenerator>
    2596              :       void
    2597              :       extreme_value_distribution<_RealType>::
    2598              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2599              :                       _UniformRandomNumberGenerator& __urng,
    2600              :                       const param_type& __p)
    2601              :       {
    2602              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2603              :         __detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
    2604              :           __aurng(__urng);
    2605              : 
    2606              :         while (__f != __t)
    2607              :           *__f++ = __p.a() - __p.b() * std::log(-std::log(result_type(1)
    2608              :                                                           - __aurng()));
    2609              :       }
    2610              : 
    2611              :   template<typename _RealType, typename _CharT, typename _Traits>
    2612              :     std::basic_ostream<_CharT, _Traits>&
    2613              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2614              :                const extreme_value_distribution<_RealType>& __x)
    2615              :     {
    2616              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2617              : 
    2618              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2619              :       const _CharT __fill = __os.fill();
    2620              :       const std::streamsize __precision = __os.precision();
    2621              :       const _CharT __space = __os.widen(' ');
    2622              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2623              :       __os.fill(__space);
    2624              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    2625              : 
    2626              :       __os << __x.a() << __space << __x.b();
    2627              : 
    2628              :       __os.flags(__flags);
    2629              :       __os.fill(__fill);
    2630              :       __os.precision(__precision);
    2631              :       return __os;
    2632              :     }
    2633              : 
    2634              :   template<typename _RealType, typename _CharT, typename _Traits>
    2635              :     std::basic_istream<_CharT, _Traits>&
    2636              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2637              :                extreme_value_distribution<_RealType>& __x)
    2638              :     {
    2639              :       using param_type
    2640              :         = typename extreme_value_distribution<_RealType>::param_type;
    2641              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2642              : 
    2643              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2644              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2645              : 
    2646              :       _RealType __a, __b;
    2647              :       if (__is >> __a >> __b)
    2648              :         __x.param(param_type(__a, __b));
    2649              : 
    2650              :       __is.flags(__flags);
    2651              :       return __is;
    2652              :     }
    2653              : 
    2654              : 
    2655              :   template<typename _IntType>
    2656              :     void
    2657              :     discrete_distribution<_IntType>::param_type::
    2658              :     _M_initialize()
    2659              :     {
    2660              :       if (_M_prob.size() < 2)
    2661              :         {
    2662              :           _M_prob.clear();
    2663              :           return;
    2664              :         }
    2665              : 
    2666              :       const double __sum = std::accumulate(_M_prob.begin(),
    2667              :                                            _M_prob.end(), 0.0);
    2668              :       __glibcxx_assert(__sum > 0);
    2669              :       // Now normalize the probabilites.
    2670              :       __detail::__normalize(_M_prob.begin(), _M_prob.end(), _M_prob.begin(),
    2671              :                             __sum);
    2672              :       // Accumulate partial sums.
    2673              :       _M_cp.reserve(_M_prob.size());
    2674              :       std::partial_sum(_M_prob.begin(), _M_prob.end(),
    2675              :                        std::back_inserter(_M_cp));
    2676              :       // Make sure the last cumulative probability is one.
    2677              :       _M_cp[_M_cp.size() - 1] = 1.0;
    2678              :     }
    2679              : 
    2680              :   template<typename _IntType>
    2681              :     template<typename _Func>
    2682              :       discrete_distribution<_IntType>::param_type::
    2683              :       param_type(size_t __nw, double __xmin, double __xmax, _Func __fw)
    2684              :       : _M_prob(), _M_cp()
    2685              :       {
    2686              :         const size_t __n = __nw == 0 ? 1 : __nw;
    2687              :         const double __delta = (__xmax - __xmin) / __n;
    2688              : 
    2689              :         _M_prob.reserve(__n);
    2690              :         for (size_t __k = 0; __k < __nw; ++__k)
    2691              :           _M_prob.push_back(__fw(__xmin + __k * __delta + 0.5 * __delta));
    2692              : 
    2693              :         _M_initialize();
    2694              :       }
    2695              : 
    2696              :   template<typename _IntType>
    2697              :     template<typename _UniformRandomNumberGenerator>
    2698              :       typename discrete_distribution<_IntType>::result_type
    2699              :       discrete_distribution<_IntType>::
    2700              :       operator()(_UniformRandomNumberGenerator& __urng,
    2701              :                  const param_type& __param)
    2702              :       {
    2703              :         if (__param._M_cp.empty())
    2704              :           return result_type(0);
    2705              : 
    2706              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    2707              :           __aurng(__urng);
    2708              : 
    2709              :         const double __p = __aurng();
    2710              :         auto __pos = std::lower_bound(__param._M_cp.begin(),
    2711              :                                       __param._M_cp.end(), __p);
    2712              : 
    2713              :         return __pos - __param._M_cp.begin();
    2714              :       }
    2715              : 
    2716              :   template<typename _IntType>
    2717              :     template<typename _ForwardIterator,
    2718              :              typename _UniformRandomNumberGenerator>
    2719              :       void
    2720              :       discrete_distribution<_IntType>::
    2721              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2722              :                       _UniformRandomNumberGenerator& __urng,
    2723              :                       const param_type& __param)
    2724              :       {
    2725              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2726              : 
    2727              :         if (__param._M_cp.empty())
    2728              :           {
    2729              :             while (__f != __t)
    2730              :               *__f++ = result_type(0);
    2731              :             return;
    2732              :           }
    2733              : 
    2734              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    2735              :           __aurng(__urng);
    2736              : 
    2737              :         while (__f != __t)
    2738              :           {
    2739              :             const double __p = __aurng();
    2740              :             auto __pos = std::lower_bound(__param._M_cp.begin(),
    2741              :                                           __param._M_cp.end(), __p);
    2742              : 
    2743              :             *__f++ = __pos - __param._M_cp.begin();
    2744              :           }
    2745              :       }
    2746              : 
    2747              :   template<typename _IntType, typename _CharT, typename _Traits>
    2748              :     std::basic_ostream<_CharT, _Traits>&
    2749              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2750              :                const discrete_distribution<_IntType>& __x)
    2751              :     {
    2752              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2753              : 
    2754              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2755              :       const _CharT __fill = __os.fill();
    2756              :       const std::streamsize __precision = __os.precision();
    2757              :       const _CharT __space = __os.widen(' ');
    2758              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2759              :       __os.fill(__space);
    2760              :       __os.precision(std::numeric_limits<double>::max_digits10);
    2761              : 
    2762              :       std::vector<double> __prob = __x.probabilities();
    2763              :       __os << __prob.size();
    2764              :       for (auto __dit = __prob.begin(); __dit != __prob.end(); ++__dit)
    2765              :         __os << __space << *__dit;
    2766              : 
    2767              :       __os.flags(__flags);
    2768              :       __os.fill(__fill);
    2769              :       __os.precision(__precision);
    2770              :       return __os;
    2771              :     }
    2772              : 
    2773              : namespace __detail
    2774              : {
    2775              :   template<typename _ValT, typename _CharT, typename _Traits>
    2776              :     basic_istream<_CharT, _Traits>&
    2777              :     __extract_params(basic_istream<_CharT, _Traits>& __is,
    2778              :                      vector<_ValT>& __vals, size_t __n)
    2779              :     {
    2780              :       __vals.reserve(__n);
    2781              :       while (__n--)
    2782              :         {
    2783              :           _ValT __val;
    2784              :           if (__is >> __val)
    2785              :             __vals.push_back(__val);
    2786              :           else
    2787              :             break;
    2788              :         }
    2789              :       return __is;
    2790              :     }
    2791              : } // namespace __detail
    2792              : 
    2793              :   template<typename _IntType, typename _CharT, typename _Traits>
    2794              :     std::basic_istream<_CharT, _Traits>&
    2795              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    2796              :                discrete_distribution<_IntType>& __x)
    2797              :     {
    2798              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    2799              : 
    2800              :       const typename __ios_base::fmtflags __flags = __is.flags();
    2801              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    2802              : 
    2803              :       size_t __n;
    2804              :       if (__is >> __n)
    2805              :         {
    2806              :           std::vector<double> __prob_vec;
    2807              :           if (__detail::__extract_params(__is, __prob_vec, __n))
    2808              :             __x.param({__prob_vec.begin(), __prob_vec.end()});
    2809              :         }
    2810              : 
    2811              :       __is.flags(__flags);
    2812              :       return __is;
    2813              :     }
    2814              : 
    2815              : 
    2816              :   template<typename _RealType>
    2817              :     void
    2818              :     piecewise_constant_distribution<_RealType>::param_type::
    2819              :     _M_initialize()
    2820              :     {
    2821              :       if (_M_int.size() < 2
    2822              :           || (_M_int.size() == 2
    2823              :               && _M_int[0] == _RealType(0)
    2824              :               && _M_int[1] == _RealType(1)))
    2825              :         {
    2826              :           _M_int.clear();
    2827              :           _M_den.clear();
    2828              :           return;
    2829              :         }
    2830              : 
    2831              :       const double __sum = std::accumulate(_M_den.begin(),
    2832              :                                            _M_den.end(), 0.0);
    2833              :       __glibcxx_assert(__sum > 0);
    2834              : 
    2835              :       __detail::__normalize(_M_den.begin(), _M_den.end(), _M_den.begin(),
    2836              :                             __sum);
    2837              : 
    2838              :       _M_cp.reserve(_M_den.size());
    2839              :       std::partial_sum(_M_den.begin(), _M_den.end(),
    2840              :                        std::back_inserter(_M_cp));
    2841              : 
    2842              :       // Make sure the last cumulative probability is one.
    2843              :       _M_cp[_M_cp.size() - 1] = 1.0;
    2844              : 
    2845              :       for (size_t __k = 0; __k < _M_den.size(); ++__k)
    2846              :         _M_den[__k] /= _M_int[__k + 1] - _M_int[__k];
    2847              :     }
    2848              : 
    2849              :   template<typename _RealType>
    2850              :     template<typename _InputIteratorB, typename _InputIteratorW>
    2851              :       piecewise_constant_distribution<_RealType>::param_type::
    2852              :       param_type(_InputIteratorB __bbegin,
    2853              :                  _InputIteratorB __bend,
    2854              :                  _InputIteratorW __wbegin)
    2855              :       : _M_int(), _M_den(), _M_cp()
    2856              :       {
    2857              :         if (__bbegin != __bend)
    2858              :           {
    2859              :             for (;;)
    2860              :               {
    2861              :                 _M_int.push_back(*__bbegin);
    2862              :                 ++__bbegin;
    2863              :                 if (__bbegin == __bend)
    2864              :                   break;
    2865              : 
    2866              :                 _M_den.push_back(*__wbegin);
    2867              :                 ++__wbegin;
    2868              :               }
    2869              :           }
    2870              : 
    2871              :         _M_initialize();
    2872              :       }
    2873              : 
    2874              :   template<typename _RealType>
    2875              :     template<typename _Func>
    2876              :       piecewise_constant_distribution<_RealType>::param_type::
    2877              :       param_type(initializer_list<_RealType> __bl, _Func __fw)
    2878              :       : _M_int(), _M_den(), _M_cp()
    2879              :       {
    2880              :         _M_int.reserve(__bl.size());
    2881              :         for (auto __biter = __bl.begin(); __biter != __bl.end(); ++__biter)
    2882              :           _M_int.push_back(*__biter);
    2883              : 
    2884              :         _M_den.reserve(_M_int.size() - 1);
    2885              :         for (size_t __k = 0; __k < _M_int.size() - 1; ++__k)
    2886              :           _M_den.push_back(__fw(0.5 * (_M_int[__k + 1] + _M_int[__k])));
    2887              : 
    2888              :         _M_initialize();
    2889              :       }
    2890              : 
    2891              :   template<typename _RealType>
    2892              :     template<typename _Func>
    2893              :       piecewise_constant_distribution<_RealType>::param_type::
    2894              :       param_type(size_t __nw, _RealType __xmin, _RealType __xmax, _Func __fw)
    2895              :       : _M_int(), _M_den(), _M_cp()
    2896              :       {
    2897              :         const size_t __n = __nw == 0 ? 1 : __nw;
    2898              :         const _RealType __delta = (__xmax - __xmin) / __n;
    2899              : 
    2900              :         _M_int.reserve(__n + 1);
    2901              :         for (size_t __k = 0; __k <= __nw; ++__k)
    2902              :           _M_int.push_back(__xmin + __k * __delta);
    2903              : 
    2904              :         _M_den.reserve(__n);
    2905              :         for (size_t __k = 0; __k < __nw; ++__k)
    2906              :           _M_den.push_back(__fw(_M_int[__k] + 0.5 * __delta));
    2907              : 
    2908              :         _M_initialize();
    2909              :       }
    2910              : 
    2911              :   template<typename _RealType>
    2912              :     template<typename _UniformRandomNumberGenerator>
    2913              :       typename piecewise_constant_distribution<_RealType>::result_type
    2914              :       piecewise_constant_distribution<_RealType>::
    2915              :       operator()(_UniformRandomNumberGenerator& __urng,
    2916              :                  const param_type& __param)
    2917              :       {
    2918              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    2919              :           __aurng(__urng);
    2920              : 
    2921              :         const double __p = __aurng();
    2922              :         if (__param._M_cp.empty())
    2923              :           return __p;
    2924              : 
    2925              :         auto __pos = std::lower_bound(__param._M_cp.begin(),
    2926              :                                       __param._M_cp.end(), __p);
    2927              :         const size_t __i = __pos - __param._M_cp.begin();
    2928              : 
    2929              :         const double __pref = __i > 0 ? __param._M_cp[__i - 1] : 0.0;
    2930              : 
    2931              :         return __param._M_int[__i] + (__p - __pref) / __param._M_den[__i];
    2932              :       }
    2933              : 
    2934              :   template<typename _RealType>
    2935              :     template<typename _ForwardIterator,
    2936              :              typename _UniformRandomNumberGenerator>
    2937              :       void
    2938              :       piecewise_constant_distribution<_RealType>::
    2939              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    2940              :                       _UniformRandomNumberGenerator& __urng,
    2941              :                       const param_type& __param)
    2942              :       {
    2943              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    2944              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    2945              :           __aurng(__urng);
    2946              : 
    2947              :         if (__param._M_cp.empty())
    2948              :           {
    2949              :             while (__f != __t)
    2950              :               *__f++ = __aurng();
    2951              :             return;
    2952              :           }
    2953              : 
    2954              :         while (__f != __t)
    2955              :           {
    2956              :             const double __p = __aurng();
    2957              : 
    2958              :             auto __pos = std::lower_bound(__param._M_cp.begin(),
    2959              :                                           __param._M_cp.end(), __p);
    2960              :             const size_t __i = __pos - __param._M_cp.begin();
    2961              : 
    2962              :             const double __pref = __i > 0 ? __param._M_cp[__i - 1] : 0.0;
    2963              : 
    2964              :             *__f++ = (__param._M_int[__i]
    2965              :                       + (__p - __pref) / __param._M_den[__i]);
    2966              :           }
    2967              :       }
    2968              : 
    2969              :   template<typename _RealType, typename _CharT, typename _Traits>
    2970              :     std::basic_ostream<_CharT, _Traits>&
    2971              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    2972              :                const piecewise_constant_distribution<_RealType>& __x)
    2973              :     {
    2974              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    2975              : 
    2976              :       const typename __ios_base::fmtflags __flags = __os.flags();
    2977              :       const _CharT __fill = __os.fill();
    2978              :       const std::streamsize __precision = __os.precision();
    2979              :       const _CharT __space = __os.widen(' ');
    2980              :       __os.flags(__ios_base::scientific | __ios_base::left);
    2981              :       __os.fill(__space);
    2982              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    2983              : 
    2984              :       std::vector<_RealType> __int = __x.intervals();
    2985              :       __os << __int.size() - 1;
    2986              : 
    2987              :       for (auto __xit = __int.begin(); __xit != __int.end(); ++__xit)
    2988              :         __os << __space << *__xit;
    2989              : 
    2990              :       std::vector<double> __den = __x.densities();
    2991              :       for (auto __dit = __den.begin(); __dit != __den.end(); ++__dit)
    2992              :         __os << __space << *__dit;
    2993              : 
    2994              :       __os.flags(__flags);
    2995              :       __os.fill(__fill);
    2996              :       __os.precision(__precision);
    2997              :       return __os;
    2998              :     }
    2999              : 
    3000              :   template<typename _RealType, typename _CharT, typename _Traits>
    3001              :     std::basic_istream<_CharT, _Traits>&
    3002              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    3003              :                piecewise_constant_distribution<_RealType>& __x)
    3004              :     {
    3005              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    3006              : 
    3007              :       const typename __ios_base::fmtflags __flags = __is.flags();
    3008              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    3009              : 
    3010              :       size_t __n;
    3011              :       if (__is >> __n)
    3012              :         {
    3013              :           std::vector<_RealType> __int_vec;
    3014              :           if (__detail::__extract_params(__is, __int_vec, __n + 1))
    3015              :             {
    3016              :               std::vector<double> __den_vec;
    3017              :               if (__detail::__extract_params(__is, __den_vec, __n))
    3018              :                 {
    3019              :                   __x.param({ __int_vec.begin(), __int_vec.end(),
    3020              :                               __den_vec.begin() });
    3021              :                 }
    3022              :             }
    3023              :         }
    3024              : 
    3025              :       __is.flags(__flags);
    3026              :       return __is;
    3027              :     }
    3028              : 
    3029              : 
    3030              :   template<typename _RealType>
    3031              :     void
    3032              :     piecewise_linear_distribution<_RealType>::param_type::
    3033              :     _M_initialize()
    3034              :     {
    3035              :       if (_M_int.size() < 2
    3036              :           || (_M_int.size() == 2
    3037              :               && _M_int[0] == _RealType(0)
    3038              :               && _M_int[1] == _RealType(1)
    3039              :               && _M_den[0] == _M_den[1]))
    3040              :         {
    3041              :           _M_int.clear();
    3042              :           _M_den.clear();
    3043              :           return;
    3044              :         }
    3045              : 
    3046              :       double __sum = 0.0;
    3047              :       _M_cp.reserve(_M_int.size() - 1);
    3048              :       _M_m.reserve(_M_int.size() - 1);
    3049              :       for (size_t __k = 0; __k < _M_int.size() - 1; ++__k)
    3050              :         {
    3051              :           const _RealType __delta = _M_int[__k + 1] - _M_int[__k];
    3052              :           __sum += 0.5 * (_M_den[__k + 1] + _M_den[__k]) * __delta;
    3053              :           _M_cp.push_back(__sum);
    3054              :           _M_m.push_back((_M_den[__k + 1] - _M_den[__k]) / __delta);
    3055              :         }
    3056              :       __glibcxx_assert(__sum > 0);
    3057              : 
    3058              :       //  Now normalize the densities...
    3059              :       __detail::__normalize(_M_den.begin(), _M_den.end(), _M_den.begin(),
    3060              :                             __sum);
    3061              :       //  ... and partial sums... 
    3062              :       __detail::__normalize(_M_cp.begin(), _M_cp.end(), _M_cp.begin(), __sum);
    3063              :       //  ... and slopes.
    3064              :       __detail::__normalize(_M_m.begin(), _M_m.end(), _M_m.begin(), __sum);
    3065              : 
    3066              :       //  Make sure the last cumulative probablility is one.
    3067              :       _M_cp[_M_cp.size() - 1] = 1.0;
    3068              :      }
    3069              : 
    3070              :   template<typename _RealType>
    3071              :     template<typename _InputIteratorB, typename _InputIteratorW>
    3072              :       piecewise_linear_distribution<_RealType>::param_type::
    3073              :       param_type(_InputIteratorB __bbegin,
    3074              :                  _InputIteratorB __bend,
    3075              :                  _InputIteratorW __wbegin)
    3076              :       : _M_int(), _M_den(), _M_cp(), _M_m()
    3077              :       {
    3078              :         for (; __bbegin != __bend; ++__bbegin, ++__wbegin)
    3079              :           {
    3080              :             _M_int.push_back(*__bbegin);
    3081              :             _M_den.push_back(*__wbegin);
    3082              :           }
    3083              : 
    3084              :         _M_initialize();
    3085              :       }
    3086              : 
    3087              :   template<typename _RealType>
    3088              :     template<typename _Func>
    3089              :       piecewise_linear_distribution<_RealType>::param_type::
    3090              :       param_type(initializer_list<_RealType> __bl, _Func __fw)
    3091              :       : _M_int(), _M_den(), _M_cp(), _M_m()
    3092              :       {
    3093              :         _M_int.reserve(__bl.size());
    3094              :         _M_den.reserve(__bl.size());
    3095              :         for (auto __biter = __bl.begin(); __biter != __bl.end(); ++__biter)
    3096              :           {
    3097              :             _M_int.push_back(*__biter);
    3098              :             _M_den.push_back(__fw(*__biter));
    3099              :           }
    3100              : 
    3101              :         _M_initialize();
    3102              :       }
    3103              : 
    3104              :   template<typename _RealType>
    3105              :     template<typename _Func>
    3106              :       piecewise_linear_distribution<_RealType>::param_type::
    3107              :       param_type(size_t __nw, _RealType __xmin, _RealType __xmax, _Func __fw)
    3108              :       : _M_int(), _M_den(), _M_cp(), _M_m()
    3109              :       {
    3110              :         const size_t __n = __nw == 0 ? 1 : __nw;
    3111              :         const _RealType __delta = (__xmax - __xmin) / __n;
    3112              : 
    3113              :         _M_int.reserve(__n + 1);
    3114              :         _M_den.reserve(__n + 1);
    3115              :         for (size_t __k = 0; __k <= __nw; ++__k)
    3116              :           {
    3117              :             _M_int.push_back(__xmin + __k * __delta);
    3118              :             _M_den.push_back(__fw(_M_int[__k] + __delta));
    3119              :           }
    3120              : 
    3121              :         _M_initialize();
    3122              :       }
    3123              : 
    3124              :   template<typename _RealType>
    3125              :     template<typename _UniformRandomNumberGenerator>
    3126              :       typename piecewise_linear_distribution<_RealType>::result_type
    3127              :       piecewise_linear_distribution<_RealType>::
    3128              :       operator()(_UniformRandomNumberGenerator& __urng,
    3129              :                  const param_type& __param)
    3130              :       {
    3131              :         __detail::_Adaptor<_UniformRandomNumberGenerator, double>
    3132              :           __aurng(__urng);
    3133              : 
    3134              :         const double __p = __aurng();
    3135              :         if (__param._M_cp.empty())
    3136              :           return __p;
    3137              : 
    3138              :         auto __pos = std::lower_bound(__param._M_cp.begin(),
    3139              :                                       __param._M_cp.end(), __p);
    3140              :         const size_t __i = __pos - __param._M_cp.begin();
    3141              : 
    3142              :         const double __pref = __i > 0 ? __param._M_cp[__i - 1] : 0.0;
    3143              : 
    3144              :         const double __a = 0.5 * __param._M_m[__i];
    3145              :         const double __b = __param._M_den[__i];
    3146              :         const double __cm = __p - __pref;
    3147              : 
    3148              :         _RealType __x = __param._M_int[__i];
    3149              :         if (__a == 0)
    3150              :           __x += __cm / __b;
    3151              :         else
    3152              :           {
    3153              :             const double __d = __b * __b + 4.0 * __a * __cm;
    3154              :             __x += 0.5 * (std::sqrt(__d) - __b) / __a;
    3155              :           }
    3156              : 
    3157              :         return __x;
    3158              :       }
    3159              : 
    3160              :   template<typename _RealType>
    3161              :     template<typename _ForwardIterator,
    3162              :              typename _UniformRandomNumberGenerator>
    3163              :       void
    3164              :       piecewise_linear_distribution<_RealType>::
    3165              :       __generate_impl(_ForwardIterator __f, _ForwardIterator __t,
    3166              :                       _UniformRandomNumberGenerator& __urng,
    3167              :                       const param_type& __param)
    3168              :       {
    3169              :         __glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
    3170              :         // We could duplicate everything from operator()...
    3171              :         while (__f != __t)
    3172              :           *__f++ = this->operator()(__urng, __param);
    3173              :       }
    3174              : 
    3175              :   template<typename _RealType, typename _CharT, typename _Traits>
    3176              :     std::basic_ostream<_CharT, _Traits>&
    3177              :     operator<<(std::basic_ostream<_CharT, _Traits>& __os,
    3178              :                const piecewise_linear_distribution<_RealType>& __x)
    3179              :     {
    3180              :       using __ios_base = typename basic_ostream<_CharT, _Traits>::ios_base;
    3181              : 
    3182              :       const typename __ios_base::fmtflags __flags = __os.flags();
    3183              :       const _CharT __fill = __os.fill();
    3184              :       const std::streamsize __precision = __os.precision();
    3185              :       const _CharT __space = __os.widen(' ');
    3186              :       __os.flags(__ios_base::scientific | __ios_base::left);
    3187              :       __os.fill(__space);
    3188              :       __os.precision(std::numeric_limits<_RealType>::max_digits10);
    3189              : 
    3190              :       std::vector<_RealType> __int = __x.intervals();
    3191              :       __os << __int.size() - 1;
    3192              : 
    3193              :       for (auto __xit = __int.begin(); __xit != __int.end(); ++__xit)
    3194              :         __os << __space << *__xit;
    3195              : 
    3196              :       std::vector<double> __den = __x.densities();
    3197              :       for (auto __dit = __den.begin(); __dit != __den.end(); ++__dit)
    3198              :         __os << __space << *__dit;
    3199              : 
    3200              :       __os.flags(__flags);
    3201              :       __os.fill(__fill);
    3202              :       __os.precision(__precision);
    3203              :       return __os;
    3204              :     }
    3205              : 
    3206              :   template<typename _RealType, typename _CharT, typename _Traits>
    3207              :     std::basic_istream<_CharT, _Traits>&
    3208              :     operator>>(std::basic_istream<_CharT, _Traits>& __is,
    3209              :                piecewise_linear_distribution<_RealType>& __x)
    3210              :     {
    3211              :       using __ios_base = typename basic_istream<_CharT, _Traits>::ios_base;
    3212              : 
    3213              :       const typename __ios_base::fmtflags __flags = __is.flags();
    3214              :       __is.flags(__ios_base::dec | __ios_base::skipws);
    3215              : 
    3216              :       size_t __n;
    3217              :       if (__is >> __n)
    3218              :         {
    3219              :           vector<_RealType> __int_vec;
    3220              :           if (__detail::__extract_params(__is, __int_vec, __n + 1))
    3221              :             {
    3222              :               vector<double> __den_vec;
    3223              :               if (__detail::__extract_params(__is, __den_vec, __n + 1))
    3224              :                 {
    3225              :                   __x.param({ __int_vec.begin(), __int_vec.end(),
    3226              :                               __den_vec.begin() });
    3227              :                 }
    3228              :             }
    3229              :         }
    3230              :       __is.flags(__flags);
    3231              :       return __is;
    3232              :     }
    3233              : 
    3234              : 
    3235              :   template<typename _IntType, typename>
    3236              :     seed_seq::seed_seq(std::initializer_list<_IntType> __il)
    3237              :     {
    3238              :       _M_v.reserve(__il.size());
    3239              :       for (auto __iter = __il.begin(); __iter != __il.end(); ++__iter)
    3240              :         _M_v.push_back(__detail::__mod<result_type,
    3241              :                        __detail::_Shift<result_type, 32>::__value>(*__iter));
    3242              :     }
    3243              : 
    3244              :   template<typename _InputIterator>
    3245              :     seed_seq::seed_seq(_InputIterator __begin, _InputIterator __end)
    3246              :     {
    3247              :       if _GLIBCXX17_CONSTEXPR (__is_random_access_iter<_InputIterator>::value)
    3248              :         _M_v.reserve(std::distance(__begin, __end));
    3249              : 
    3250              :       for (_InputIterator __iter = __begin; __iter != __end; ++__iter)
    3251              :         _M_v.push_back(__detail::__mod<result_type,
    3252              :                        __detail::_Shift<result_type, 32>::__value>(*__iter));
    3253              :     }
    3254              : 
    3255              :   template<typename _RandomAccessIterator>
    3256              :     void
    3257              :     seed_seq::generate(_RandomAccessIterator __begin,
    3258              :                        _RandomAccessIterator __end)
    3259              :     {
    3260              :       typedef typename iterator_traits<_RandomAccessIterator>::value_type
    3261              :         _Type;
    3262              : 
    3263              :       if (__begin == __end)
    3264              :         return;
    3265              : 
    3266              :       std::fill(__begin, __end, _Type(0x8b8b8b8bu));
    3267              : 
    3268              :       const size_t __n = __end - __begin;
    3269              :       const size_t __s = _M_v.size();
    3270              :       const size_t __t = (__n >= 623) ? 11
    3271              :                        : (__n >=  68) ? 7
    3272              :                        : (__n >=  39) ? 5
    3273              :                        : (__n >=   7) ? 3
    3274              :                        : (__n - 1) / 2;
    3275              :       const size_t __p = (__n - __t) / 2;
    3276              :       const size_t __q = __p + __t;
    3277              :       const size_t __m = std::max(size_t(__s + 1), __n);
    3278              : 
    3279              : #ifndef __UINT32_TYPE__
    3280              :       struct _Up
    3281              :       {
    3282              :         _Up(uint_least32_t v) : _M_v(v & 0xffffffffu) { }
    3283              : 
    3284              :         operator uint_least32_t() const { return _M_v; }
    3285              : 
    3286              :         uint_least32_t _M_v;
    3287              :       };
    3288              :       using uint32_t = _Up;
    3289              : #endif
    3290              : 
    3291              :       // k == 0, every element in [begin,end) equals 0x8b8b8b8bu
    3292              :         {
    3293              :           uint32_t __r1 = 1371501266u;
    3294              :           uint32_t __r2 = __r1 + __s;
    3295              :           __begin[__p] += __r1;
    3296              :           __begin[__q] = (uint32_t)__begin[__q] + __r2;
    3297              :           __begin[0] = __r2;
    3298              :         }
    3299              : 
    3300              :       for (size_t __k = 1; __k <= __s; ++__k)
    3301              :         {
    3302              :           const size_t __kn = __k % __n;
    3303              :           const size_t __kpn = (__k + __p) % __n;
    3304              :           const size_t __kqn = (__k + __q) % __n;
    3305              :           uint32_t __arg = (__begin[__kn]
    3306              :                             ^ __begin[__kpn]
    3307              :                             ^ __begin[(__k - 1) % __n]);
    3308              :           uint32_t __r1 = 1664525u * (__arg ^ (__arg >> 27));
    3309              :           uint32_t __r2 = __r1 + (uint32_t)__kn + _M_v[__k - 1];
    3310              :           __begin[__kpn] = (uint32_t)__begin[__kpn] + __r1;
    3311              :           __begin[__kqn] = (uint32_t)__begin[__kqn] + __r2;
    3312              :           __begin[__kn] = __r2;
    3313              :         }
    3314              : 
    3315              :       for (size_t __k = __s + 1; __k < __m; ++__k)
    3316              :         {
    3317              :           const size_t __kn = __k % __n;
    3318              :           const size_t __kpn = (__k + __p) % __n;
    3319              :           const size_t __kqn = (__k + __q) % __n;
    3320              :           uint32_t __arg = (__begin[__kn]
    3321              :                                  ^ __begin[__kpn]
    3322              :                                  ^ __begin[(__k - 1) % __n]);
    3323              :           uint32_t __r1 = 1664525u * (__arg ^ (__arg >> 27));
    3324              :           uint32_t __r2 = __r1 + (uint32_t)__kn;
    3325              :           __begin[__kpn] = (uint32_t)__begin[__kpn] + __r1;
    3326              :           __begin[__kqn] = (uint32_t)__begin[__kqn] + __r2;
    3327              :           __begin[__kn] = __r2;
    3328              :         }
    3329              : 
    3330              :       for (size_t __k = __m; __k < __m + __n; ++__k)
    3331              :         {
    3332              :           const size_t __kn = __k % __n;
    3333              :           const size_t __kpn = (__k + __p) % __n;
    3334              :           const size_t __kqn = (__k + __q) % __n;
    3335              :           uint32_t __arg = (__begin[__kn]
    3336              :                             + __begin[__kpn]
    3337              :                             + __begin[(__k - 1) % __n]);
    3338              :           uint32_t __r3 = 1566083941u * (__arg ^ (__arg >> 27));
    3339              :           uint32_t __r4 = __r3 - __kn;
    3340              :           __begin[__kpn] ^= __r3;
    3341              :           __begin[__kqn] ^= __r4;
    3342              :           __begin[__kn] = __r4;
    3343              :         }
    3344              :     }
    3345              : 
    3346              :   template<typename _RealType, size_t __bits,
    3347              :            typename _UniformRandomNumberGenerator>
    3348              :     _RealType
    3349              :     generate_canonical(_UniformRandomNumberGenerator& __urng)
    3350              :     {
    3351              :       static_assert(std::is_floating_point<_RealType>::value,
    3352              :                     "template argument must be a floating point type");
    3353              : 
    3354              :       const size_t __b
    3355              :         = std::min(static_cast<size_t>(std::numeric_limits<_RealType>::digits),
    3356              :                    __bits);
    3357              :       const long double __r = static_cast<long double>(__urng.max())
    3358              :                             - static_cast<long double>(__urng.min()) + 1.0L;
    3359              :       const size_t __log2r = std::log(__r) / std::log(2.0L);
    3360              :       const size_t __m = std::max<size_t>(1UL,
    3361              :                                           (__b + __log2r - 1UL) / __log2r);
    3362              :       _RealType __ret;
    3363              :       _RealType __sum = _RealType(0);
    3364              :       _RealType __tmp = _RealType(1);
    3365              :       for (size_t __k = __m; __k != 0; --__k)
    3366              :         {
    3367              :           __sum += _RealType(__urng() - __urng.min()) * __tmp;
    3368              :           __tmp *= __r;
    3369              :         }
    3370              :       __ret = __sum / __tmp;
    3371              :       if (__builtin_expect(__ret >= _RealType(1), 0))
    3372              :         {
    3373              : #if _GLIBCXX_USE_C99_MATH_TR1
    3374              :           __ret = std::nextafter(_RealType(1), _RealType(0));
    3375              : #else
    3376              :           __ret = _RealType(1)
    3377              :             - std::numeric_limits<_RealType>::epsilon() / _RealType(2);
    3378              : #endif
    3379              :         }
    3380              :       return __ret;
    3381              :     }
    3382              : 
    3383              : _GLIBCXX_END_NAMESPACE_VERSION
    3384              : } // namespace
    3385              : 
    3386              : #endif
        

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