xref: /llvm-project-15.0.7/libcxx/include/random (revision e0d01294)
1// -*- C++ -*-
2//===--------------------------- random -----------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_RANDOM
11#define _LIBCPP_RANDOM
12
13/*
14    random synopsis
15
16#include <initializer_list>
17
18namespace std
19{
20
21// Engines
22
23template <class UIntType, UIntType a, UIntType c, UIntType m>
24class linear_congruential_engine
25{
26public:
27    // types
28    typedef UIntType result_type;
29
30    // engine characteristics
31    static constexpr result_type multiplier = a;
32    static constexpr result_type increment = c;
33    static constexpr result_type modulus = m;
34    static constexpr result_type min() { return c == 0u ? 1u: 0u;}
35    static constexpr result_type max() { return m - 1u;}
36    static constexpr result_type default_seed = 1u;
37
38    // constructors and seeding functions
39    explicit linear_congruential_engine(result_type s = default_seed);
40    template<class Sseq> explicit linear_congruential_engine(Sseq& q);
41    void seed(result_type s = default_seed);
42    template<class Sseq> void seed(Sseq& q);
43
44    // generating functions
45    result_type operator()();
46    void discard(unsigned long long z);
47};
48
49template <class UIntType, UIntType a, UIntType c, UIntType m>
50bool
51operator==(const linear_congruential_engine<UIntType, a, c, m>& x,
52           const linear_congruential_engine<UIntType, a, c, m>& y);
53
54template <class UIntType, UIntType a, UIntType c, UIntType m>
55bool
56operator!=(const linear_congruential_engine<UIntType, a, c, m>& x,
57           const linear_congruential_engine<UIntType, a, c, m>& y);
58
59template <class charT, class traits,
60          class UIntType, UIntType a, UIntType c, UIntType m>
61basic_ostream<charT, traits>&
62operator<<(basic_ostream<charT, traits>& os,
63           const linear_congruential_engine<UIntType, a, c, m>& x);
64
65template <class charT, class traits,
66          class UIntType, UIntType a, UIntType c, UIntType m>
67basic_istream<charT, traits>&
68operator>>(basic_istream<charT, traits>& is,
69           linear_congruential_engine<UIntType, a, c, m>& x);
70
71template <class UIntType, size_t w, size_t n, size_t m, size_t r,
72          UIntType a, size_t u, UIntType d, size_t s,
73          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
74class mersenne_twister_engine
75{
76public:
77    // types
78    typedef UIntType result_type;
79
80    // engine characteristics
81    static constexpr size_t word_size = w;
82    static constexpr size_t state_size = n;
83    static constexpr size_t shift_size = m;
84    static constexpr size_t mask_bits = r;
85    static constexpr result_type xor_mask = a;
86    static constexpr size_t tempering_u = u;
87    static constexpr result_type tempering_d = d;
88    static constexpr size_t tempering_s = s;
89    static constexpr result_type tempering_b = b;
90    static constexpr size_t tempering_t = t;
91    static constexpr result_type tempering_c = c;
92    static constexpr size_t tempering_l = l;
93    static constexpr result_type initialization_multiplier = f;
94    static constexpr result_type min () { return 0; }
95    static constexpr result_type max() { return 2^w - 1; }
96    static constexpr result_type default_seed = 5489u;
97
98    // constructors and seeding functions
99    explicit mersenne_twister_engine(result_type value = default_seed);
100    template<class Sseq> explicit mersenne_twister_engine(Sseq& q);
101    void seed(result_type value = default_seed);
102    template<class Sseq> void seed(Sseq& q);
103
104    // generating functions
105    result_type operator()();
106    void discard(unsigned long long z);
107};
108
109template <class UIntType, size_t w, size_t n, size_t m, size_t r,
110          UIntType a, size_t u, UIntType d, size_t s,
111          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
112bool
113operator==(
114    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x,
115    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& y);
116
117template <class UIntType, size_t w, size_t n, size_t m, size_t r,
118          UIntType a, size_t u, UIntType d, size_t s,
119          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
120bool
121operator!=(
122    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x,
123    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& y);
124
125template <class charT, class traits,
126          class UIntType, size_t w, size_t n, size_t m, size_t r,
127          UIntType a, size_t u, UIntType d, size_t s,
128          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
129basic_ostream<charT, traits>&
130operator<<(basic_ostream<charT, traits>& os,
131           const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x);
132
133template <class charT, class traits,
134          class UIntType, size_t w, size_t n, size_t m, size_t r,
135          UIntType a, size_t u, UIntType d, size_t s,
136          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
137basic_istream<charT, traits>&
138operator>>(basic_istream<charT, traits>& is,
139           mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x);
140
141template<class UIntType, size_t w, size_t s, size_t r>
142class subtract_with_carry_engine
143{
144public:
145    // types
146    typedef UIntType result_type;
147
148    // engine characteristics
149    static constexpr size_t word_size = w;
150    static constexpr size_t short_lag = s;
151    static constexpr size_t long_lag = r;
152    static constexpr result_type min() { return 0; }
153    static constexpr result_type max() { return m-1; }
154    static constexpr result_type default_seed = 19780503u;
155
156    // constructors and seeding functions
157    explicit subtract_with_carry_engine(result_type value = default_seed);
158    template<class Sseq> explicit subtract_with_carry_engine(Sseq& q);
159    void seed(result_type value = default_seed);
160    template<class Sseq> void seed(Sseq& q);
161
162    // generating functions
163    result_type operator()();
164    void discard(unsigned long long z);
165};
166
167template<class UIntType, size_t w, size_t s, size_t r>
168bool
169operator==(
170    const subtract_with_carry_engine<UIntType, w, s, r>& x,
171    const subtract_with_carry_engine<UIntType, w, s, r>& y);
172
173template<class UIntType, size_t w, size_t s, size_t r>
174bool
175operator!=(
176    const subtract_with_carry_engine<UIntType, w, s, r>& x,
177    const subtract_with_carry_engine<UIntType, w, s, r>& y);
178
179template <class charT, class traits,
180          class UIntType, size_t w, size_t s, size_t r>
181basic_ostream<charT, traits>&
182operator<<(basic_ostream<charT, traits>& os,
183           const subtract_with_carry_engine<UIntType, w, s, r>& x);
184
185template <class charT, class traits,
186          class UIntType, size_t w, size_t s, size_t r>
187basic_istream<charT, traits>&
188operator>>(basic_istream<charT, traits>& is,
189           subtract_with_carry_engine<UIntType, w, s, r>& x);
190
191template<class Engine, size_t p, size_t r>
192class discard_block_engine
193{
194public:
195    // types
196    typedef typename Engine::result_type result_type;
197
198    // engine characteristics
199    static constexpr size_t block_size = p;
200    static constexpr size_t used_block = r;
201    static constexpr result_type min() { return Engine::min(); }
202    static constexpr result_type max() { return Engine::max(); }
203
204    // constructors and seeding functions
205    discard_block_engine();
206    explicit discard_block_engine(const Engine& e);
207    explicit discard_block_engine(Engine&& e);
208    explicit discard_block_engine(result_type s);
209    template<class Sseq> explicit discard_block_engine(Sseq& q);
210    void seed();
211    void seed(result_type s);
212    template<class Sseq> void seed(Sseq& q);
213
214    // generating functions
215    result_type operator()();
216    void discard(unsigned long long z);
217
218    // property functions
219    const Engine& base() const noexcept;
220};
221
222template<class Engine, size_t p, size_t r>
223bool
224operator==(
225    const discard_block_engine<Engine, p, r>& x,
226    const discard_block_engine<Engine, p, r>& y);
227
228template<class Engine, size_t p, size_t r>
229bool
230operator!=(
231    const discard_block_engine<Engine, p, r>& x,
232    const discard_block_engine<Engine, p, r>& y);
233
234template <class charT, class traits,
235          class Engine, size_t p, size_t r>
236basic_ostream<charT, traits>&
237operator<<(basic_ostream<charT, traits>& os,
238           const discard_block_engine<Engine, p, r>& x);
239
240template <class charT, class traits,
241          class Engine, size_t p, size_t r>
242basic_istream<charT, traits>&
243operator>>(basic_istream<charT, traits>& is,
244           discard_block_engine<Engine, p, r>& x);
245
246template<class Engine, size_t w, class UIntType>
247class independent_bits_engine
248{
249public:
250    // types
251    typedef UIntType result_type;
252
253    // engine characteristics
254    static constexpr result_type min() { return 0; }
255    static constexpr result_type max() { return 2^w - 1; }
256
257    // constructors and seeding functions
258    independent_bits_engine();
259    explicit independent_bits_engine(const Engine& e);
260    explicit independent_bits_engine(Engine&& e);
261    explicit independent_bits_engine(result_type s);
262    template<class Sseq> explicit independent_bits_engine(Sseq& q);
263    void seed();
264    void seed(result_type s);
265    template<class Sseq> void seed(Sseq& q);
266
267    // generating functions
268    result_type operator()(); void discard(unsigned long long z);
269
270    // property functions
271    const Engine& base() const noexcept;
272};
273
274template<class Engine, size_t w, class UIntType>
275bool
276operator==(
277    const independent_bits_engine<Engine, w, UIntType>& x,
278    const independent_bits_engine<Engine, w, UIntType>& y);
279
280template<class Engine, size_t w, class UIntType>
281bool
282operator!=(
283    const independent_bits_engine<Engine, w, UIntType>& x,
284    const independent_bits_engine<Engine, w, UIntType>& y);
285
286template <class charT, class traits,
287          class Engine, size_t w, class UIntType>
288basic_ostream<charT, traits>&
289operator<<(basic_ostream<charT, traits>& os,
290           const independent_bits_engine<Engine, w, UIntType>& x);
291
292template <class charT, class traits,
293          class Engine, size_t w, class UIntType>
294basic_istream<charT, traits>&
295operator>>(basic_istream<charT, traits>& is,
296           independent_bits_engine<Engine, w, UIntType>& x);
297
298template<class Engine, size_t k>
299class shuffle_order_engine
300{
301public:
302    // types
303    typedef typename Engine::result_type result_type;
304
305    // engine characteristics
306    static constexpr size_t table_size = k;
307    static constexpr result_type min() { return Engine::min; }
308    static constexpr result_type max() { return Engine::max; }
309
310    // constructors and seeding functions
311    shuffle_order_engine();
312    explicit shuffle_order_engine(const Engine& e);
313    explicit shuffle_order_engine(Engine&& e);
314    explicit shuffle_order_engine(result_type s);
315    template<class Sseq> explicit shuffle_order_engine(Sseq& q);
316    void seed();
317    void seed(result_type s);
318    template<class Sseq> void seed(Sseq& q);
319
320    // generating functions
321    result_type operator()();
322    void discard(unsigned long long z);
323
324    // property functions
325    const Engine& base() const noexcept;
326};
327
328template<class Engine, size_t k>
329bool
330operator==(
331    const shuffle_order_engine<Engine, k>& x,
332    const shuffle_order_engine<Engine, k>& y);
333
334template<class Engine, size_t k>
335bool
336operator!=(
337    const shuffle_order_engine<Engine, k>& x,
338    const shuffle_order_engine<Engine, k>& y);
339
340template <class charT, class traits,
341          class Engine, size_t k>
342basic_ostream<charT, traits>&
343operator<<(basic_ostream<charT, traits>& os,
344           const shuffle_order_engine<Engine, k>& x);
345
346template <class charT, class traits,
347          class Engine, size_t k>
348basic_istream<charT, traits>&
349operator>>(basic_istream<charT, traits>& is,
350           shuffle_order_engine<Engine, k>& x);
351
352typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
353                                                                   minstd_rand0;
354typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
355                                                                    minstd_rand;
356typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
357                                0x9908b0df,
358                                11, 0xffffffff,
359                                7,  0x9d2c5680,
360                                15, 0xefc60000,
361                                18, 1812433253>                         mt19937;
362typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
363                                0xb5026f5aa96619e9,
364                                29, 0x5555555555555555,
365                                17, 0x71d67fffeda60000,
366                                37, 0xfff7eee000000000,
367                                43, 6364136223846793005>             mt19937_64;
368typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
369typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
370typedef discard_block_engine<ranlux24_base, 223, 23>                   ranlux24;
371typedef discard_block_engine<ranlux48_base, 389, 11>                   ranlux48;
372typedef shuffle_order_engine<minstd_rand0, 256>                         knuth_b;
373typedef minstd_rand                                       default_random_engine;
374
375// Generators
376
377class random_device
378{
379public:
380    // types
381    typedef unsigned int result_type;
382
383    // generator characteristics
384    static constexpr result_type min() { return numeric_limits<result_type>::min(); }
385    static constexpr result_type max() { return numeric_limits<result_type>::max(); }
386
387    // constructors
388    explicit random_device(const string& token = "/dev/urandom");
389
390    // generating functions
391    result_type operator()();
392
393    // property functions
394    double entropy() const noexcept;
395
396    // no copy functions
397    random_device(const random_device& ) = delete;
398    void operator=(const random_device& ) = delete;
399};
400
401// Utilities
402
403class seed_seq
404{
405public:
406    // types
407    typedef uint_least32_t result_type;
408
409    // constructors
410    seed_seq();
411    template<class T>
412        seed_seq(initializer_list<T> il);
413    template<class InputIterator>
414        seed_seq(InputIterator begin, InputIterator end);
415
416    // generating functions
417    template<class RandomAccessIterator>
418        void generate(RandomAccessIterator begin, RandomAccessIterator end);
419
420    // property functions
421    size_t size() const;
422    template<class OutputIterator>
423        void param(OutputIterator dest) const;
424
425    // no copy functions
426    seed_seq(const seed_seq&) = delete;
427    void operator=(const seed_seq& ) = delete;
428};
429
430template<class RealType, size_t bits, class URNG>
431    RealType generate_canonical(URNG& g);
432
433// Distributions
434
435template<class IntType = int>
436class uniform_int_distribution
437{
438public:
439    // types
440    typedef IntType result_type;
441
442    class param_type
443    {
444    public:
445        typedef uniform_int_distribution distribution_type;
446
447        explicit param_type(IntType a = 0,
448                                    IntType b = numeric_limits<IntType>::max());
449
450        result_type a() const;
451        result_type b() const;
452
453        friend bool operator==(const param_type& x, const param_type& y);
454        friend bool operator!=(const param_type& x, const param_type& y);
455    };
456
457    // constructors and reset functions
458    explicit uniform_int_distribution(IntType a = 0,
459                                    IntType b = numeric_limits<IntType>::max());
460    explicit uniform_int_distribution(const param_type& parm);
461    void reset();
462
463    // generating functions
464    template<class URNG> result_type operator()(URNG& g);
465    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
466
467    // property functions
468    result_type a() const;
469    result_type b() const;
470
471    param_type param() const;
472    void param(const param_type& parm);
473
474    result_type min() const;
475    result_type max() const;
476
477    friend bool operator==(const uniform_int_distribution& x,
478                           const uniform_int_distribution& y);
479    friend bool operator!=(const uniform_int_distribution& x,
480                           const uniform_int_distribution& y);
481
482    template <class charT, class traits>
483    friend
484    basic_ostream<charT, traits>&
485    operator<<(basic_ostream<charT, traits>& os,
486               const uniform_int_distribution& x);
487
488    template <class charT, class traits>
489    friend
490    basic_istream<charT, traits>&
491    operator>>(basic_istream<charT, traits>& is,
492               uniform_int_distribution& x);
493};
494
495template<class RealType = double>
496class uniform_real_distribution
497{
498public:
499    // types
500    typedef RealType result_type;
501
502    class param_type
503    {
504    public:
505        typedef uniform_real_distribution distribution_type;
506
507        explicit param_type(RealType a = 0,
508                            RealType b = 1);
509
510        result_type a() const;
511        result_type b() const;
512
513        friend bool operator==(const param_type& x, const param_type& y);
514        friend bool operator!=(const param_type& x, const param_type& y);
515    };
516
517    // constructors and reset functions
518    explicit uniform_real_distribution(RealType a = 0.0, RealType b = 1.0);
519    explicit uniform_real_distribution(const param_type& parm);
520    void reset();
521
522    // generating functions
523    template<class URNG> result_type operator()(URNG& g);
524    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
525
526    // property functions
527    result_type a() const;
528    result_type b() const;
529
530    param_type param() const;
531    void param(const param_type& parm);
532
533    result_type min() const;
534    result_type max() const;
535
536    friend bool operator==(const uniform_real_distribution& x,
537                           const uniform_real_distribution& y);
538    friend bool operator!=(const uniform_real_distribution& x,
539                           const uniform_real_distribution& y);
540
541    template <class charT, class traits>
542    friend
543    basic_ostream<charT, traits>&
544    operator<<(basic_ostream<charT, traits>& os,
545               const uniform_real_distribution& x);
546
547    template <class charT, class traits>
548    friend
549    basic_istream<charT, traits>&
550    operator>>(basic_istream<charT, traits>& is,
551               uniform_real_distribution& x);
552};
553
554class bernoulli_distribution
555{
556public:
557    // types
558    typedef bool result_type;
559
560    class param_type
561    {
562    public:
563        typedef bernoulli_distribution distribution_type;
564
565        explicit param_type(double p = 0.5);
566
567        double p() const;
568
569        friend bool operator==(const param_type& x, const param_type& y);
570        friend bool operator!=(const param_type& x, const param_type& y);
571    };
572
573    // constructors and reset functions
574    explicit bernoulli_distribution(double p = 0.5);
575    explicit bernoulli_distribution(const param_type& parm);
576    void reset();
577
578    // generating functions
579    template<class URNG> result_type operator()(URNG& g);
580    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
581
582    // property functions
583    double p() const;
584
585    param_type param() const;
586    void param(const param_type& parm);
587
588    result_type min() const;
589    result_type max() const;
590
591    friend bool operator==(const bernoulli_distribution& x,
592                           const bernoulli_distribution& y);
593    friend bool operator!=(const bernoulli_distribution& x,
594                           const bernoulli_distribution& y);
595
596    template <class charT, class traits>
597    friend
598    basic_ostream<charT, traits>&
599    operator<<(basic_ostream<charT, traits>& os,
600               const bernoulli_distribution& x);
601
602    template <class charT, class traits>
603    friend
604    basic_istream<charT, traits>&
605    operator>>(basic_istream<charT, traits>& is,
606               bernoulli_distribution& x);
607};
608
609template<class IntType = int>
610class binomial_distribution
611{
612public:
613    // types
614    typedef IntType result_type;
615
616    class param_type
617    {
618    public:
619        typedef binomial_distribution distribution_type;
620
621        explicit param_type(IntType t = 1, double p = 0.5);
622
623        IntType t() const;
624        double p() const;
625
626        friend bool operator==(const param_type& x, const param_type& y);
627        friend bool operator!=(const param_type& x, const param_type& y);
628    };
629
630    // constructors and reset functions
631    explicit binomial_distribution(IntType t = 1, double p = 0.5);
632    explicit binomial_distribution(const param_type& parm);
633    void reset();
634
635    // generating functions
636    template<class URNG> result_type operator()(URNG& g);
637    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
638
639    // property functions
640    IntType t() const;
641    double p() const;
642
643    param_type param() const;
644    void param(const param_type& parm);
645
646    result_type min() const;
647    result_type max() const;
648
649    friend bool operator==(const binomial_distribution& x,
650                           const binomial_distribution& y);
651    friend bool operator!=(const binomial_distribution& x,
652                           const binomial_distribution& y);
653
654    template <class charT, class traits>
655    friend
656    basic_ostream<charT, traits>&
657    operator<<(basic_ostream<charT, traits>& os,
658               const binomial_distribution& x);
659
660    template <class charT, class traits>
661    friend
662    basic_istream<charT, traits>&
663    operator>>(basic_istream<charT, traits>& is,
664               binomial_distribution& x);
665};
666
667template<class IntType = int>
668class geometric_distribution
669{
670public:
671    // types
672    typedef IntType result_type;
673
674    class param_type
675    {
676    public:
677        typedef geometric_distribution distribution_type;
678
679        explicit param_type(double p = 0.5);
680
681        double p() const;
682
683        friend bool operator==(const param_type& x, const param_type& y);
684        friend bool operator!=(const param_type& x, const param_type& y);
685    };
686
687    // constructors and reset functions
688    explicit geometric_distribution(double p = 0.5);
689    explicit geometric_distribution(const param_type& parm);
690    void reset();
691
692    // generating functions
693    template<class URNG> result_type operator()(URNG& g);
694    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
695
696    // property functions
697    double p() const;
698
699    param_type param() const;
700    void param(const param_type& parm);
701
702    result_type min() const;
703    result_type max() const;
704
705    friend bool operator==(const geometric_distribution& x,
706                           const geometric_distribution& y);
707    friend bool operator!=(const geometric_distribution& x,
708                           const geometric_distribution& y);
709
710    template <class charT, class traits>
711    friend
712    basic_ostream<charT, traits>&
713    operator<<(basic_ostream<charT, traits>& os,
714               const geometric_distribution& x);
715
716    template <class charT, class traits>
717    friend
718    basic_istream<charT, traits>&
719    operator>>(basic_istream<charT, traits>& is,
720               geometric_distribution& x);
721};
722
723template<class IntType = int>
724class negative_binomial_distribution
725{
726public:
727    // types
728    typedef IntType result_type;
729
730    class param_type
731    {
732    public:
733        typedef negative_binomial_distribution distribution_type;
734
735        explicit param_type(result_type k = 1, double p = 0.5);
736
737        result_type k() const;
738        double p() const;
739
740        friend bool operator==(const param_type& x, const param_type& y);
741        friend bool operator!=(const param_type& x, const param_type& y);
742    };
743
744    // constructor and reset functions
745    explicit negative_binomial_distribution(result_type k = 1, double p = 0.5);
746    explicit negative_binomial_distribution(const param_type& parm);
747    void reset();
748
749    // generating functions
750    template<class URNG> result_type operator()(URNG& g);
751    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
752
753    // property functions
754    result_type k() const;
755    double p() const;
756
757    param_type param() const;
758    void param(const param_type& parm);
759
760    result_type min() const;
761    result_type max() const;
762
763    friend bool operator==(const negative_binomial_distribution& x,
764                           const negative_binomial_distribution& y);
765    friend bool operator!=(const negative_binomial_distribution& x,
766                           const negative_binomial_distribution& y);
767
768    template <class charT, class traits>
769    friend
770    basic_ostream<charT, traits>&
771    operator<<(basic_ostream<charT, traits>& os,
772               const negative_binomial_distribution& x);
773
774    template <class charT, class traits>
775    friend
776    basic_istream<charT, traits>&
777    operator>>(basic_istream<charT, traits>& is,
778               negative_binomial_distribution& x);
779};
780
781template<class IntType = int>
782class poisson_distribution
783{
784public:
785    // types
786    typedef IntType result_type;
787
788    class param_type
789    {
790    public:
791        typedef poisson_distribution distribution_type;
792
793        explicit param_type(double mean = 1.0);
794
795        double mean() const;
796
797        friend bool operator==(const param_type& x, const param_type& y);
798        friend bool operator!=(const param_type& x, const param_type& y);
799    };
800
801    // constructors and reset functions
802    explicit poisson_distribution(double mean = 1.0);
803    explicit poisson_distribution(const param_type& parm);
804    void reset();
805
806    // generating functions
807    template<class URNG> result_type operator()(URNG& g);
808    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
809
810    // property functions
811    double mean() const;
812
813    param_type param() const;
814    void param(const param_type& parm);
815
816    result_type min() const;
817    result_type max() const;
818
819    friend bool operator==(const poisson_distribution& x,
820                           const poisson_distribution& y);
821    friend bool operator!=(const poisson_distribution& x,
822                           const poisson_distribution& y);
823
824    template <class charT, class traits>
825    friend
826    basic_ostream<charT, traits>&
827    operator<<(basic_ostream<charT, traits>& os,
828               const poisson_distribution& x);
829
830    template <class charT, class traits>
831    friend
832    basic_istream<charT, traits>&
833    operator>>(basic_istream<charT, traits>& is,
834               poisson_distribution& x);
835};
836
837template<class RealType = double>
838class exponential_distribution
839{
840public:
841    // types
842    typedef RealType result_type;
843
844    class param_type
845    {
846    public:
847        typedef exponential_distribution distribution_type;
848
849        explicit param_type(result_type lambda = 1.0);
850
851        result_type lambda() const;
852
853        friend bool operator==(const param_type& x, const param_type& y);
854        friend bool operator!=(const param_type& x, const param_type& y);
855    };
856
857    // constructors and reset functions
858    explicit exponential_distribution(result_type lambda = 1.0);
859    explicit exponential_distribution(const param_type& parm);
860    void reset();
861
862    // generating functions
863    template<class URNG> result_type operator()(URNG& g);
864    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
865
866    // property functions
867    result_type lambda() const;
868
869    param_type param() const;
870    void param(const param_type& parm);
871
872    result_type min() const;
873    result_type max() const;
874
875    friend bool operator==(const exponential_distribution& x,
876                           const exponential_distribution& y);
877    friend bool operator!=(const exponential_distribution& x,
878                           const exponential_distribution& y);
879
880    template <class charT, class traits>
881    friend
882    basic_ostream<charT, traits>&
883    operator<<(basic_ostream<charT, traits>& os,
884               const exponential_distribution& x);
885
886    template <class charT, class traits>
887    friend
888    basic_istream<charT, traits>&
889    operator>>(basic_istream<charT, traits>& is,
890               exponential_distribution& x);
891};
892
893template<class RealType = double>
894class gamma_distribution
895{
896public:
897    // types
898    typedef RealType result_type;
899
900    class param_type
901    {
902    public:
903        typedef gamma_distribution distribution_type;
904
905        explicit param_type(result_type alpha = 1, result_type beta = 1);
906
907        result_type alpha() const;
908        result_type beta() const;
909
910        friend bool operator==(const param_type& x, const param_type& y);
911        friend bool operator!=(const param_type& x, const param_type& y);
912    };
913
914    // constructors and reset functions
915    explicit gamma_distribution(result_type alpha = 1, result_type beta = 1);
916    explicit gamma_distribution(const param_type& parm);
917    void reset();
918
919    // generating functions
920    template<class URNG> result_type operator()(URNG& g);
921    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
922
923    // property functions
924    result_type alpha() const;
925    result_type beta() const;
926
927    param_type param() const;
928    void param(const param_type& parm);
929
930    result_type min() const;
931    result_type max() const;
932
933    friend bool operator==(const gamma_distribution& x,
934                           const gamma_distribution& y);
935    friend bool operator!=(const gamma_distribution& x,
936                           const gamma_distribution& y);
937
938    template <class charT, class traits>
939    friend
940    basic_ostream<charT, traits>&
941    operator<<(basic_ostream<charT, traits>& os,
942               const gamma_distribution& x);
943
944    template <class charT, class traits>
945    friend
946    basic_istream<charT, traits>&
947    operator>>(basic_istream<charT, traits>& is,
948               gamma_distribution& x);
949};
950
951template<class RealType = double>
952class weibull_distribution
953{
954public:
955    // types
956    typedef RealType result_type;
957
958    class param_type
959    {
960    public:
961        typedef weibull_distribution distribution_type;
962
963        explicit param_type(result_type alpha = 1, result_type beta = 1);
964
965        result_type a() const;
966        result_type b() const;
967
968        friend bool operator==(const param_type& x, const param_type& y);
969        friend bool operator!=(const param_type& x, const param_type& y);
970    };
971
972    // constructor and reset functions
973    explicit weibull_distribution(result_type a = 1, result_type b = 1);
974    explicit weibull_distribution(const param_type& parm);
975    void reset();
976
977    // generating functions
978    template<class URNG> result_type operator()(URNG& g);
979    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
980
981    // property functions
982    result_type a() const;
983    result_type b() const;
984
985    param_type param() const;
986    void param(const param_type& parm);
987
988    result_type min() const;
989    result_type max() const;
990
991    friend bool operator==(const weibull_distribution& x,
992                           const weibull_distribution& y);
993    friend bool operator!=(const weibull_distribution& x,
994                           const weibull_distribution& y);
995
996    template <class charT, class traits>
997    friend
998    basic_ostream<charT, traits>&
999    operator<<(basic_ostream<charT, traits>& os,
1000               const weibull_distribution& x);
1001
1002    template <class charT, class traits>
1003    friend
1004    basic_istream<charT, traits>&
1005    operator>>(basic_istream<charT, traits>& is,
1006               weibull_distribution& x);
1007};
1008
1009template<class RealType = double>
1010class extreme_value_distribution
1011{
1012public:
1013    // types
1014    typedef RealType result_type;
1015
1016    class param_type
1017    {
1018    public:
1019        typedef extreme_value_distribution distribution_type;
1020
1021        explicit param_type(result_type a = 0, result_type b = 1);
1022
1023        result_type a() const;
1024        result_type b() const;
1025
1026        friend bool operator==(const param_type& x, const param_type& y);
1027        friend bool operator!=(const param_type& x, const param_type& y);
1028    };
1029
1030    // constructor and reset functions
1031    explicit extreme_value_distribution(result_type a = 0, result_type b = 1);
1032    explicit extreme_value_distribution(const param_type& parm);
1033    void reset();
1034
1035    // generating functions
1036    template<class URNG> result_type operator()(URNG& g);
1037    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1038
1039    // property functions
1040    result_type a() const;
1041    result_type b() const;
1042
1043    param_type param() const;
1044    void param(const param_type& parm);
1045
1046    result_type min() const;
1047    result_type max() const;
1048
1049    friend bool operator==(const extreme_value_distribution& x,
1050                           const extreme_value_distribution& y);
1051    friend bool operator!=(const extreme_value_distribution& x,
1052                           const extreme_value_distribution& y);
1053
1054    template <class charT, class traits>
1055    friend
1056    basic_ostream<charT, traits>&
1057    operator<<(basic_ostream<charT, traits>& os,
1058               const extreme_value_distribution& x);
1059
1060    template <class charT, class traits>
1061    friend
1062    basic_istream<charT, traits>&
1063    operator>>(basic_istream<charT, traits>& is,
1064               extreme_value_distribution& x);
1065};
1066
1067template<class RealType = double>
1068class normal_distribution
1069{
1070public:
1071    // types
1072    typedef RealType result_type;
1073
1074    class param_type
1075    {
1076    public:
1077        typedef normal_distribution distribution_type;
1078
1079        explicit param_type(result_type mean = 0, result_type stddev = 1);
1080
1081        result_type mean() const;
1082        result_type stddev() const;
1083
1084        friend bool operator==(const param_type& x, const param_type& y);
1085        friend bool operator!=(const param_type& x, const param_type& y);
1086    };
1087
1088    // constructors and reset functions
1089    explicit normal_distribution(result_type mean = 0, result_type stddev = 1);
1090    explicit normal_distribution(const param_type& parm);
1091    void reset();
1092
1093    // generating functions
1094    template<class URNG> result_type operator()(URNG& g);
1095    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1096
1097    // property functions
1098    result_type mean() const;
1099    result_type stddev() const;
1100
1101    param_type param() const;
1102    void param(const param_type& parm);
1103
1104    result_type min() const;
1105    result_type max() const;
1106
1107    friend bool operator==(const normal_distribution& x,
1108                           const normal_distribution& y);
1109    friend bool operator!=(const normal_distribution& x,
1110                           const normal_distribution& y);
1111
1112    template <class charT, class traits>
1113    friend
1114    basic_ostream<charT, traits>&
1115    operator<<(basic_ostream<charT, traits>& os,
1116               const normal_distribution& x);
1117
1118    template <class charT, class traits>
1119    friend
1120    basic_istream<charT, traits>&
1121    operator>>(basic_istream<charT, traits>& is,
1122               normal_distribution& x);
1123};
1124
1125template<class RealType = double>
1126class lognormal_distribution
1127{
1128public:
1129    // types
1130    typedef RealType result_type;
1131
1132    class param_type
1133    {
1134    public:
1135        typedef lognormal_distribution distribution_type;
1136
1137        explicit param_type(result_type m = 0, result_type s = 1);
1138
1139        result_type m() const;
1140        result_type s() const;
1141
1142        friend bool operator==(const param_type& x, const param_type& y);
1143        friend bool operator!=(const param_type& x, const param_type& y);
1144    };
1145
1146    // constructor and reset functions
1147    explicit lognormal_distribution(result_type m = 0, result_type s = 1);
1148    explicit lognormal_distribution(const param_type& parm);
1149    void reset();
1150
1151    // generating functions
1152    template<class URNG> result_type operator()(URNG& g);
1153    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1154
1155    // property functions
1156    result_type m() const;
1157    result_type s() const;
1158
1159    param_type param() const;
1160    void param(const param_type& parm);
1161
1162    result_type min() const;
1163    result_type max() const;
1164
1165    friend bool operator==(const lognormal_distribution& x,
1166                           const lognormal_distribution& y);
1167    friend bool operator!=(const lognormal_distribution& x,
1168                           const lognormal_distribution& y);
1169
1170    template <class charT, class traits>
1171    friend
1172    basic_ostream<charT, traits>&
1173    operator<<(basic_ostream<charT, traits>& os,
1174               const lognormal_distribution& x);
1175
1176    template <class charT, class traits>
1177    friend
1178    basic_istream<charT, traits>&
1179    operator>>(basic_istream<charT, traits>& is,
1180               lognormal_distribution& x);
1181};
1182
1183template<class RealType = double>
1184class chi_squared_distribution
1185{
1186public:
1187    // types
1188    typedef RealType result_type;
1189
1190    class param_type
1191    {
1192    public:
1193        typedef chi_squared_distribution distribution_type;
1194
1195        explicit param_type(result_type n = 1);
1196
1197        result_type n() const;
1198
1199        friend bool operator==(const param_type& x, const param_type& y);
1200        friend bool operator!=(const param_type& x, const param_type& y);
1201    };
1202
1203    // constructor and reset functions
1204    explicit chi_squared_distribution(result_type n = 1);
1205    explicit chi_squared_distribution(const param_type& parm);
1206    void reset();
1207
1208    // generating functions
1209    template<class URNG> result_type operator()(URNG& g);
1210    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1211
1212    // property functions
1213    result_type n() const;
1214
1215    param_type param() const;
1216    void param(const param_type& parm);
1217
1218    result_type min() const;
1219    result_type max() const;
1220
1221    friend bool operator==(const chi_squared_distribution& x,
1222                           const chi_squared_distribution& y);
1223    friend bool operator!=(const chi_squared_distribution& x,
1224                           const chi_squared_distribution& y);
1225
1226    template <class charT, class traits>
1227    friend
1228    basic_ostream<charT, traits>&
1229    operator<<(basic_ostream<charT, traits>& os,
1230               const chi_squared_distribution& x);
1231
1232    template <class charT, class traits>
1233    friend
1234    basic_istream<charT, traits>&
1235    operator>>(basic_istream<charT, traits>& is,
1236               chi_squared_distribution& x);
1237};
1238
1239template<class RealType = double>
1240class cauchy_distribution
1241{
1242public:
1243    // types
1244    typedef RealType result_type;
1245
1246    class param_type
1247    {
1248    public:
1249        typedef cauchy_distribution distribution_type;
1250
1251        explicit param_type(result_type a = 0, result_type b = 1);
1252
1253        result_type a() const;
1254        result_type b() const;
1255
1256        friend bool operator==(const param_type& x, const param_type& y);
1257        friend bool operator!=(const param_type& x, const param_type& y);
1258    };
1259
1260    // constructor and reset functions
1261    explicit cauchy_distribution(result_type a = 0, result_type b = 1);
1262    explicit cauchy_distribution(const param_type& parm);
1263    void reset();
1264
1265    // generating functions
1266    template<class URNG> result_type operator()(URNG& g);
1267    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1268
1269    // property functions
1270    result_type a() const;
1271    result_type b() const;
1272
1273    param_type param() const;
1274    void param(const param_type& parm);
1275
1276    result_type min() const;
1277    result_type max() const;
1278
1279    friend bool operator==(const cauchy_distribution& x,
1280                           const cauchy_distribution& y);
1281    friend bool operator!=(const cauchy_distribution& x,
1282                           const cauchy_distribution& y);
1283
1284    template <class charT, class traits>
1285    friend
1286    basic_ostream<charT, traits>&
1287    operator<<(basic_ostream<charT, traits>& os,
1288               const cauchy_distribution& x);
1289
1290    template <class charT, class traits>
1291    friend
1292    basic_istream<charT, traits>&
1293    operator>>(basic_istream<charT, traits>& is,
1294               cauchy_distribution& x);
1295};
1296
1297template<class RealType = double>
1298class fisher_f_distribution
1299{
1300public:
1301    // types
1302    typedef RealType result_type;
1303
1304    class param_type
1305    {
1306    public:
1307        typedef fisher_f_distribution distribution_type;
1308
1309        explicit param_type(result_type m = 1, result_type n = 1);
1310
1311        result_type m() const;
1312        result_type n() const;
1313
1314        friend bool operator==(const param_type& x, const param_type& y);
1315        friend bool operator!=(const param_type& x, const param_type& y);
1316    };
1317
1318    // constructor and reset functions
1319    explicit fisher_f_distribution(result_type m = 1, result_type n = 1);
1320    explicit fisher_f_distribution(const param_type& parm);
1321    void reset();
1322
1323    // generating functions
1324    template<class URNG> result_type operator()(URNG& g);
1325    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1326
1327    // property functions
1328    result_type m() const;
1329    result_type n() const;
1330
1331    param_type param() const;
1332    void param(const param_type& parm);
1333
1334    result_type min() const;
1335    result_type max() const;
1336
1337    friend bool operator==(const fisher_f_distribution& x,
1338                           const fisher_f_distribution& y);
1339    friend bool operator!=(const fisher_f_distribution& x,
1340                           const fisher_f_distribution& y);
1341
1342    template <class charT, class traits>
1343    friend
1344    basic_ostream<charT, traits>&
1345    operator<<(basic_ostream<charT, traits>& os,
1346               const fisher_f_distribution& x);
1347
1348    template <class charT, class traits>
1349    friend
1350    basic_istream<charT, traits>&
1351    operator>>(basic_istream<charT, traits>& is,
1352               fisher_f_distribution& x);
1353};
1354
1355template<class RealType = double>
1356class student_t_distribution
1357{
1358public:
1359    // types
1360    typedef RealType result_type;
1361
1362    class param_type
1363    {
1364    public:
1365        typedef student_t_distribution distribution_type;
1366
1367        explicit param_type(result_type n = 1);
1368
1369        result_type n() const;
1370
1371        friend bool operator==(const param_type& x, const param_type& y);
1372        friend bool operator!=(const param_type& x, const param_type& y);
1373    };
1374
1375    // constructor and reset functions
1376    explicit student_t_distribution(result_type n = 1);
1377    explicit student_t_distribution(const param_type& parm);
1378    void reset();
1379
1380    // generating functions
1381    template<class URNG> result_type operator()(URNG& g);
1382    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1383
1384    // property functions
1385    result_type n() const;
1386
1387    param_type param() const;
1388    void param(const param_type& parm);
1389
1390    result_type min() const;
1391    result_type max() const;
1392
1393    friend bool operator==(const student_t_distribution& x,
1394                           const student_t_distribution& y);
1395    friend bool operator!=(const student_t_distribution& x,
1396                           const student_t_distribution& y);
1397
1398    template <class charT, class traits>
1399    friend
1400    basic_ostream<charT, traits>&
1401    operator<<(basic_ostream<charT, traits>& os,
1402               const student_t_distribution& x);
1403
1404    template <class charT, class traits>
1405    friend
1406    basic_istream<charT, traits>&
1407    operator>>(basic_istream<charT, traits>& is,
1408               student_t_distribution& x);
1409};
1410
1411template<class IntType = int>
1412class discrete_distribution
1413{
1414public:
1415    // types
1416    typedef IntType result_type;
1417
1418    class param_type
1419    {
1420    public:
1421        typedef discrete_distribution distribution_type;
1422
1423        param_type();
1424        template<class InputIterator>
1425            param_type(InputIterator firstW, InputIterator lastW);
1426        param_type(initializer_list<double> wl);
1427        template<class UnaryOperation>
1428            param_type(size_t nw, double xmin, double xmax, UnaryOperation fw);
1429
1430        vector<double> probabilities() const;
1431
1432        friend bool operator==(const param_type& x, const param_type& y);
1433        friend bool operator!=(const param_type& x, const param_type& y);
1434    };
1435
1436    // constructor and reset functions
1437    discrete_distribution();
1438    template<class InputIterator>
1439        discrete_distribution(InputIterator firstW, InputIterator lastW);
1440    discrete_distribution(initializer_list<double> wl);
1441    template<class UnaryOperation>
1442        discrete_distribution(size_t nw, double xmin, double xmax,
1443                              UnaryOperation fw);
1444    explicit discrete_distribution(const param_type& parm);
1445    void reset();
1446
1447    // generating functions
1448    template<class URNG> result_type operator()(URNG& g);
1449    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1450
1451    // property functions
1452    vector<double> probabilities() const;
1453
1454    param_type param() const;
1455    void param(const param_type& parm);
1456
1457    result_type min() const;
1458    result_type max() const;
1459
1460    friend bool operator==(const discrete_distribution& x,
1461                           const discrete_distribution& y);
1462    friend bool operator!=(const discrete_distribution& x,
1463                           const discrete_distribution& y);
1464
1465    template <class charT, class traits>
1466    friend
1467    basic_ostream<charT, traits>&
1468    operator<<(basic_ostream<charT, traits>& os,
1469               const discrete_distribution& x);
1470
1471    template <class charT, class traits>
1472    friend
1473    basic_istream<charT, traits>&
1474    operator>>(basic_istream<charT, traits>& is,
1475               discrete_distribution& x);
1476};
1477
1478template<class RealType = double>
1479class piecewise_constant_distribution
1480{
1481    // types
1482    typedef RealType result_type;
1483
1484    class param_type
1485    {
1486    public:
1487        typedef piecewise_constant_distribution distribution_type;
1488
1489        param_type();
1490        template<class InputIteratorB, class InputIteratorW>
1491            param_type(InputIteratorB firstB, InputIteratorB lastB,
1492                       InputIteratorW firstW);
1493        template<class UnaryOperation>
1494            param_type(initializer_list<result_type> bl, UnaryOperation fw);
1495        template<class UnaryOperation>
1496            param_type(size_t nw, result_type xmin, result_type xmax,
1497                       UnaryOperation fw);
1498
1499        vector<result_type> intervals() const;
1500        vector<result_type> densities() const;
1501
1502        friend bool operator==(const param_type& x, const param_type& y);
1503        friend bool operator!=(const param_type& x, const param_type& y);
1504    };
1505
1506    // constructor and reset functions
1507    piecewise_constant_distribution();
1508    template<class InputIteratorB, class InputIteratorW>
1509        piecewise_constant_distribution(InputIteratorB firstB,
1510                                        InputIteratorB lastB,
1511                                        InputIteratorW firstW);
1512    template<class UnaryOperation>
1513        piecewise_constant_distribution(initializer_list<result_type> bl,
1514                                        UnaryOperation fw);
1515    template<class UnaryOperation>
1516        piecewise_constant_distribution(size_t nw, result_type xmin,
1517                                        result_type xmax, UnaryOperation fw);
1518    explicit piecewise_constant_distribution(const param_type& parm);
1519    void reset();
1520
1521    // generating functions
1522    template<class URNG> result_type operator()(URNG& g);
1523    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1524
1525    // property functions
1526    vector<result_type> intervals() const;
1527    vector<result_type> densities() const;
1528
1529    param_type param() const;
1530    void param(const param_type& parm);
1531
1532    result_type min() const;
1533    result_type max() const;
1534
1535    friend bool operator==(const piecewise_constant_distribution& x,
1536                           const piecewise_constant_distribution& y);
1537    friend bool operator!=(const piecewise_constant_distribution& x,
1538                           const piecewise_constant_distribution& y);
1539
1540    template <class charT, class traits>
1541    friend
1542    basic_ostream<charT, traits>&
1543    operator<<(basic_ostream<charT, traits>& os,
1544               const piecewise_constant_distribution& x);
1545
1546    template <class charT, class traits>
1547    friend
1548    basic_istream<charT, traits>&
1549    operator>>(basic_istream<charT, traits>& is,
1550               piecewise_constant_distribution& x);
1551};
1552
1553template<class RealType = double>
1554class piecewise_linear_distribution
1555{
1556    // types
1557    typedef RealType result_type;
1558
1559    class param_type
1560    {
1561    public:
1562        typedef piecewise_linear_distribution distribution_type;
1563
1564        param_type();
1565        template<class InputIteratorB, class InputIteratorW>
1566            param_type(InputIteratorB firstB, InputIteratorB lastB,
1567                       InputIteratorW firstW);
1568        template<class UnaryOperation>
1569            param_type(initializer_list<result_type> bl, UnaryOperation fw);
1570        template<class UnaryOperation>
1571            param_type(size_t nw, result_type xmin, result_type xmax,
1572                       UnaryOperation fw);
1573
1574        vector<result_type> intervals() const;
1575        vector<result_type> densities() const;
1576
1577        friend bool operator==(const param_type& x, const param_type& y);
1578        friend bool operator!=(const param_type& x, const param_type& y);
1579    };
1580
1581    // constructor and reset functions
1582    piecewise_linear_distribution();
1583    template<class InputIteratorB, class InputIteratorW>
1584        piecewise_linear_distribution(InputIteratorB firstB,
1585                                      InputIteratorB lastB,
1586                                      InputIteratorW firstW);
1587
1588    template<class UnaryOperation>
1589        piecewise_linear_distribution(initializer_list<result_type> bl,
1590                                      UnaryOperation fw);
1591
1592    template<class UnaryOperation>
1593        piecewise_linear_distribution(size_t nw, result_type xmin,
1594                                      result_type xmax, UnaryOperation fw);
1595
1596    explicit piecewise_linear_distribution(const param_type& parm);
1597    void reset();
1598
1599    // generating functions
1600    template<class URNG> result_type operator()(URNG& g);
1601    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1602
1603    // property functions
1604    vector<result_type> intervals() const;
1605    vector<result_type> densities() const;
1606
1607    param_type param() const;
1608    void param(const param_type& parm);
1609
1610    result_type min() const;
1611    result_type max() const;
1612
1613    friend bool operator==(const piecewise_linear_distribution& x,
1614                           const piecewise_linear_distribution& y);
1615    friend bool operator!=(const piecewise_linear_distribution& x,
1616                           const piecewise_linear_distribution& y);
1617
1618    template <class charT, class traits>
1619    friend
1620    basic_ostream<charT, traits>&
1621    operator<<(basic_ostream<charT, traits>& os,
1622               const piecewise_linear_distribution& x);
1623
1624    template <class charT, class traits>
1625    friend
1626    basic_istream<charT, traits>&
1627    operator>>(basic_istream<charT, traits>& is,
1628               piecewise_linear_distribution& x);
1629};
1630
1631} // std
1632*/
1633
1634#include <__config>
1635#include <cstddef>
1636#include <cstdint>
1637#include <cmath>
1638#include <type_traits>
1639#include <initializer_list>
1640#include <limits>
1641#include <algorithm>
1642#include <numeric>
1643#include <vector>
1644#include <string>
1645#include <istream>
1646#include <ostream>
1647
1648#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1649#pragma GCC system_header
1650#endif
1651
1652_LIBCPP_PUSH_MACROS
1653#include <__undef_macros>
1654
1655
1656_LIBCPP_BEGIN_NAMESPACE_STD
1657
1658// __is_seed_sequence
1659
1660template <class _Sseq, class _Engine>
1661struct __is_seed_sequence
1662{
1663    static _LIBCPP_CONSTEXPR const bool value =
1664              !is_convertible<_Sseq, typename _Engine::result_type>::value &&
1665              !is_same<typename remove_cv<_Sseq>::type, _Engine>::value;
1666};
1667
1668// linear_congruential_engine
1669
1670template <unsigned long long __a, unsigned long long __c,
1671          unsigned long long __m, unsigned long long _Mp,
1672          bool _MightOverflow = (__a != 0 && __m != 0 && __m-1 > (_Mp-__c)/__a)>
1673struct __lce_ta;
1674
1675// 64
1676
1677template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
1678struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), true>
1679{
1680    typedef unsigned long long result_type;
1681    _LIBCPP_INLINE_VISIBILITY
1682    static result_type next(result_type __x)
1683    {
1684        // Schrage's algorithm
1685        const result_type __q = __m / __a;
1686        const result_type __r = __m % __a;
1687        const result_type __t0 = __a * (__x % __q);
1688        const result_type __t1 = __r * (__x / __q);
1689        __x = __t0 + (__t0 < __t1) * __m - __t1;
1690        __x += __c - (__x >= __m - __c) * __m;
1691        return __x;
1692    }
1693};
1694
1695template <unsigned long long __a, unsigned long long __m>
1696struct __lce_ta<__a, 0, __m, (unsigned long long)(~0), true>
1697{
1698    typedef unsigned long long result_type;
1699    _LIBCPP_INLINE_VISIBILITY
1700    static result_type next(result_type __x)
1701    {
1702        // Schrage's algorithm
1703        const result_type __q = __m / __a;
1704        const result_type __r = __m % __a;
1705        const result_type __t0 = __a * (__x % __q);
1706        const result_type __t1 = __r * (__x / __q);
1707        __x = __t0 + (__t0 < __t1) * __m - __t1;
1708        return __x;
1709    }
1710};
1711
1712template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
1713struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), false>
1714{
1715    typedef unsigned long long result_type;
1716    _LIBCPP_INLINE_VISIBILITY
1717    static result_type next(result_type __x)
1718    {
1719        return (__a * __x + __c) % __m;
1720    }
1721};
1722
1723template <unsigned long long __a, unsigned long long __c>
1724struct __lce_ta<__a, __c, 0, (unsigned long long)(~0), false>
1725{
1726    typedef unsigned long long result_type;
1727    _LIBCPP_INLINE_VISIBILITY
1728    static result_type next(result_type __x)
1729    {
1730        return __a * __x + __c;
1731    }
1732};
1733
1734// 32
1735
1736template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
1737struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), true>
1738{
1739    typedef unsigned result_type;
1740    _LIBCPP_INLINE_VISIBILITY
1741    static result_type next(result_type __x)
1742    {
1743        const result_type __a = static_cast<result_type>(_Ap);
1744        const result_type __c = static_cast<result_type>(_Cp);
1745        const result_type __m = static_cast<result_type>(_Mp);
1746        // Schrage's algorithm
1747        const result_type __q = __m / __a;
1748        const result_type __r = __m % __a;
1749        const result_type __t0 = __a * (__x % __q);
1750        const result_type __t1 = __r * (__x / __q);
1751        __x = __t0 + (__t0 < __t1) * __m - __t1;
1752        __x += __c - (__x >= __m - __c) * __m;
1753        return __x;
1754    }
1755};
1756
1757template <unsigned long long _Ap, unsigned long long _Mp>
1758struct __lce_ta<_Ap, 0, _Mp, unsigned(~0), true>
1759{
1760    typedef unsigned result_type;
1761    _LIBCPP_INLINE_VISIBILITY
1762    static result_type next(result_type __x)
1763    {
1764        const result_type __a = static_cast<result_type>(_Ap);
1765        const result_type __m = static_cast<result_type>(_Mp);
1766        // Schrage's algorithm
1767        const result_type __q = __m / __a;
1768        const result_type __r = __m % __a;
1769        const result_type __t0 = __a * (__x % __q);
1770        const result_type __t1 = __r * (__x / __q);
1771        __x = __t0 + (__t0 < __t1) * __m - __t1;
1772        return __x;
1773    }
1774};
1775
1776template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
1777struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), false>
1778{
1779    typedef unsigned result_type;
1780    _LIBCPP_INLINE_VISIBILITY
1781    static result_type next(result_type __x)
1782    {
1783        const result_type __a = static_cast<result_type>(_Ap);
1784        const result_type __c = static_cast<result_type>(_Cp);
1785        const result_type __m = static_cast<result_type>(_Mp);
1786        return (__a * __x + __c) % __m;
1787    }
1788};
1789
1790template <unsigned long long _Ap, unsigned long long _Cp>
1791struct __lce_ta<_Ap, _Cp, 0, unsigned(~0), false>
1792{
1793    typedef unsigned result_type;
1794    _LIBCPP_INLINE_VISIBILITY
1795    static result_type next(result_type __x)
1796    {
1797        const result_type __a = static_cast<result_type>(_Ap);
1798        const result_type __c = static_cast<result_type>(_Cp);
1799        return __a * __x + __c;
1800    }
1801};
1802
1803// 16
1804
1805template <unsigned long long __a, unsigned long long __c, unsigned long long __m, bool __b>
1806struct __lce_ta<__a, __c, __m, (unsigned short)(~0), __b>
1807{
1808    typedef unsigned short result_type;
1809    _LIBCPP_INLINE_VISIBILITY
1810    static result_type next(result_type __x)
1811    {
1812        return static_cast<result_type>(__lce_ta<__a, __c, __m, unsigned(~0)>::next(__x));
1813    }
1814};
1815
1816template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1817class _LIBCPP_TEMPLATE_VIS linear_congruential_engine;
1818
1819template <class _CharT, class _Traits,
1820          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1821_LIBCPP_INLINE_VISIBILITY
1822basic_ostream<_CharT, _Traits>&
1823operator<<(basic_ostream<_CharT, _Traits>& __os,
1824           const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
1825
1826template <class _CharT, class _Traits,
1827          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1828basic_istream<_CharT, _Traits>&
1829operator>>(basic_istream<_CharT, _Traits>& __is,
1830           linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
1831
1832template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1833class _LIBCPP_TEMPLATE_VIS linear_congruential_engine
1834{
1835public:
1836    // types
1837    typedef _UIntType result_type;
1838
1839private:
1840    result_type __x_;
1841
1842    static _LIBCPP_CONSTEXPR const result_type _Mp = result_type(~0);
1843
1844    static_assert(__m == 0 || __a < __m, "linear_congruential_engine invalid parameters");
1845    static_assert(__m == 0 || __c < __m, "linear_congruential_engine invalid parameters");
1846public:
1847    static _LIBCPP_CONSTEXPR const result_type _Min = __c == 0u ? 1u: 0u;
1848    static _LIBCPP_CONSTEXPR const result_type _Max = __m - 1u;
1849    static_assert(_Min < _Max,           "linear_congruential_engine invalid parameters");
1850
1851    // engine characteristics
1852    static _LIBCPP_CONSTEXPR const result_type multiplier = __a;
1853    static _LIBCPP_CONSTEXPR const result_type increment = __c;
1854    static _LIBCPP_CONSTEXPR const result_type modulus = __m;
1855    _LIBCPP_INLINE_VISIBILITY
1856    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
1857    _LIBCPP_INLINE_VISIBILITY
1858    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
1859    static _LIBCPP_CONSTEXPR const result_type default_seed = 1u;
1860
1861    // constructors and seeding functions
1862    _LIBCPP_INLINE_VISIBILITY
1863    explicit linear_congruential_engine(result_type __s = default_seed)
1864        {seed(__s);}
1865    template<class _Sseq>
1866        _LIBCPP_INLINE_VISIBILITY
1867        explicit linear_congruential_engine(_Sseq& __q,
1868        typename enable_if<__is_seed_sequence<_Sseq, linear_congruential_engine>::value>::type* = 0)
1869        {seed(__q);}
1870    _LIBCPP_INLINE_VISIBILITY
1871    void seed(result_type __s = default_seed)
1872        {seed(integral_constant<bool, __m == 0>(),
1873              integral_constant<bool, __c == 0>(), __s);}
1874    template<class _Sseq>
1875        _LIBCPP_INLINE_VISIBILITY
1876        typename enable_if
1877        <
1878            __is_seed_sequence<_Sseq, linear_congruential_engine>::value,
1879            void
1880        >::type
1881        seed(_Sseq& __q)
1882            {__seed(__q, integral_constant<unsigned,
1883                1 + (__m == 0 ? (sizeof(result_type) * __CHAR_BIT__ - 1)/32
1884                             :  (__m > 0x100000000ull))>());}
1885
1886    // generating functions
1887    _LIBCPP_INLINE_VISIBILITY
1888    result_type operator()()
1889        {return __x_ = static_cast<result_type>(__lce_ta<__a, __c, __m, _Mp>::next(__x_));}
1890    _LIBCPP_INLINE_VISIBILITY
1891    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
1892
1893    friend _LIBCPP_INLINE_VISIBILITY
1894    bool operator==(const linear_congruential_engine& __x,
1895                    const linear_congruential_engine& __y)
1896        {return __x.__x_ == __y.__x_;}
1897    friend _LIBCPP_INLINE_VISIBILITY
1898    bool operator!=(const linear_congruential_engine& __x,
1899                    const linear_congruential_engine& __y)
1900        {return !(__x == __y);}
1901
1902private:
1903
1904    _LIBCPP_INLINE_VISIBILITY
1905    void seed(true_type, true_type, result_type __s) {__x_ = __s == 0 ? 1 : __s;}
1906    _LIBCPP_INLINE_VISIBILITY
1907    void seed(true_type, false_type, result_type __s) {__x_ = __s;}
1908    _LIBCPP_INLINE_VISIBILITY
1909    void seed(false_type, true_type, result_type __s) {__x_ = __s % __m == 0 ?
1910                                                                 1 : __s % __m;}
1911    _LIBCPP_INLINE_VISIBILITY
1912    void seed(false_type, false_type, result_type __s) {__x_ = __s % __m;}
1913
1914    template<class _Sseq>
1915        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
1916    template<class _Sseq>
1917        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
1918
1919    template <class _CharT, class _Traits,
1920              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1921    friend
1922    basic_ostream<_CharT, _Traits>&
1923    operator<<(basic_ostream<_CharT, _Traits>& __os,
1924               const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
1925
1926    template <class _CharT, class _Traits,
1927              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1928    friend
1929    basic_istream<_CharT, _Traits>&
1930    operator>>(basic_istream<_CharT, _Traits>& __is,
1931               linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
1932};
1933
1934template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1935    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1936    linear_congruential_engine<_UIntType, __a, __c, __m>::multiplier;
1937
1938template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1939    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1940    linear_congruential_engine<_UIntType, __a, __c, __m>::increment;
1941
1942template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1943    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1944    linear_congruential_engine<_UIntType, __a, __c, __m>::modulus;
1945
1946template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1947    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1948    linear_congruential_engine<_UIntType, __a, __c, __m>::default_seed;
1949
1950template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1951template<class _Sseq>
1952void
1953linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
1954                                                 integral_constant<unsigned, 1>)
1955{
1956    const unsigned __k = 1;
1957    uint32_t __ar[__k+3];
1958    __q.generate(__ar, __ar + __k + 3);
1959    result_type __s = static_cast<result_type>(__ar[3] % __m);
1960    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
1961}
1962
1963template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1964template<class _Sseq>
1965void
1966linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
1967                                                 integral_constant<unsigned, 2>)
1968{
1969    const unsigned __k = 2;
1970    uint32_t __ar[__k+3];
1971    __q.generate(__ar, __ar + __k + 3);
1972    result_type __s = static_cast<result_type>((__ar[3] +
1973                                              ((uint64_t)__ar[4] << 32)) % __m);
1974    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
1975}
1976
1977template <class _CharT, class _Traits,
1978          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1979inline _LIBCPP_INLINE_VISIBILITY
1980basic_ostream<_CharT, _Traits>&
1981operator<<(basic_ostream<_CharT, _Traits>& __os,
1982           const linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
1983{
1984    __save_flags<_CharT, _Traits> __lx(__os);
1985    __os.flags(ios_base::dec | ios_base::left);
1986    __os.fill(__os.widen(' '));
1987    return __os << __x.__x_;
1988}
1989
1990template <class _CharT, class _Traits,
1991          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1992basic_istream<_CharT, _Traits>&
1993operator>>(basic_istream<_CharT, _Traits>& __is,
1994           linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
1995{
1996    __save_flags<_CharT, _Traits> __lx(__is);
1997    __is.flags(ios_base::dec | ios_base::skipws);
1998    _UIntType __t;
1999    __is >> __t;
2000    if (!__is.fail())
2001        __x.__x_ = __t;
2002    return __is;
2003}
2004
2005typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
2006                                                                   minstd_rand0;
2007typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
2008                                                                    minstd_rand;
2009typedef minstd_rand                                       default_random_engine;
2010// mersenne_twister_engine
2011
2012template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2013          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2014          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2015class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine;
2016
2017template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2018          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2019          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2020bool
2021operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2022                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2023           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2024                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2025
2026template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2027          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2028          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2029_LIBCPP_INLINE_VISIBILITY
2030bool
2031operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2032                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2033           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2034                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2035
2036template <class _CharT, class _Traits,
2037          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2038          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2039          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2040basic_ostream<_CharT, _Traits>&
2041operator<<(basic_ostream<_CharT, _Traits>& __os,
2042           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2043                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2044
2045template <class _CharT, class _Traits,
2046          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2047          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2048          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2049basic_istream<_CharT, _Traits>&
2050operator>>(basic_istream<_CharT, _Traits>& __is,
2051           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2052                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2053
2054template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2055          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2056          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2057class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine
2058{
2059public:
2060    // types
2061    typedef _UIntType result_type;
2062
2063private:
2064    result_type __x_[__n];
2065    size_t      __i_;
2066
2067    static_assert(  0 <  __m, "mersenne_twister_engine invalid parameters");
2068    static_assert(__m <= __n, "mersenne_twister_engine invalid parameters");
2069    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
2070    static_assert(__w <= _Dt, "mersenne_twister_engine invalid parameters");
2071    static_assert(  2 <= __w, "mersenne_twister_engine invalid parameters");
2072    static_assert(__r <= __w, "mersenne_twister_engine invalid parameters");
2073    static_assert(__u <= __w, "mersenne_twister_engine invalid parameters");
2074    static_assert(__s <= __w, "mersenne_twister_engine invalid parameters");
2075    static_assert(__t <= __w, "mersenne_twister_engine invalid parameters");
2076    static_assert(__l <= __w, "mersenne_twister_engine invalid parameters");
2077public:
2078    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
2079    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
2080                                                      (result_type(1) << __w) - result_type(1);
2081    static_assert(_Min < _Max, "mersenne_twister_engine invalid parameters");
2082    static_assert(__a <= _Max, "mersenne_twister_engine invalid parameters");
2083    static_assert(__b <= _Max, "mersenne_twister_engine invalid parameters");
2084    static_assert(__c <= _Max, "mersenne_twister_engine invalid parameters");
2085    static_assert(__d <= _Max, "mersenne_twister_engine invalid parameters");
2086    static_assert(__f <= _Max, "mersenne_twister_engine invalid parameters");
2087
2088    // engine characteristics
2089    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
2090    static _LIBCPP_CONSTEXPR const size_t state_size = __n;
2091    static _LIBCPP_CONSTEXPR const size_t shift_size = __m;
2092    static _LIBCPP_CONSTEXPR const size_t mask_bits = __r;
2093    static _LIBCPP_CONSTEXPR const result_type xor_mask = __a;
2094    static _LIBCPP_CONSTEXPR const size_t tempering_u = __u;
2095    static _LIBCPP_CONSTEXPR const result_type tempering_d = __d;
2096    static _LIBCPP_CONSTEXPR const size_t tempering_s = __s;
2097    static _LIBCPP_CONSTEXPR const result_type tempering_b = __b;
2098    static _LIBCPP_CONSTEXPR const size_t tempering_t = __t;
2099    static _LIBCPP_CONSTEXPR const result_type tempering_c = __c;
2100    static _LIBCPP_CONSTEXPR const size_t tempering_l = __l;
2101    static _LIBCPP_CONSTEXPR const result_type initialization_multiplier = __f;
2102    _LIBCPP_INLINE_VISIBILITY
2103    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
2104    _LIBCPP_INLINE_VISIBILITY
2105    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
2106    static _LIBCPP_CONSTEXPR const result_type default_seed = 5489u;
2107
2108    // constructors and seeding functions
2109    _LIBCPP_INLINE_VISIBILITY
2110    explicit mersenne_twister_engine(result_type __sd = default_seed)
2111        {seed(__sd);}
2112    template<class _Sseq>
2113        _LIBCPP_INLINE_VISIBILITY
2114        explicit mersenne_twister_engine(_Sseq& __q,
2115        typename enable_if<__is_seed_sequence<_Sseq, mersenne_twister_engine>::value>::type* = 0)
2116        {seed(__q);}
2117    void seed(result_type __sd = default_seed);
2118    template<class _Sseq>
2119        _LIBCPP_INLINE_VISIBILITY
2120        typename enable_if
2121        <
2122            __is_seed_sequence<_Sseq, mersenne_twister_engine>::value,
2123            void
2124        >::type
2125        seed(_Sseq& __q)
2126            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2127
2128    // generating functions
2129    result_type operator()();
2130    _LIBCPP_INLINE_VISIBILITY
2131    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2132
2133    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2134              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2135              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2136    friend
2137    bool
2138    operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2139                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2140               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2141                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2142
2143    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2144              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2145              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2146    friend
2147    bool
2148    operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2149                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2150               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2151                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2152
2153    template <class _CharT, class _Traits,
2154              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2155              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2156              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2157    friend
2158    basic_ostream<_CharT, _Traits>&
2159    operator<<(basic_ostream<_CharT, _Traits>& __os,
2160               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2161                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2162
2163    template <class _CharT, class _Traits,
2164              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2165              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2166              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2167    friend
2168    basic_istream<_CharT, _Traits>&
2169    operator>>(basic_istream<_CharT, _Traits>& __is,
2170               mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2171                                       _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2172private:
2173
2174    template<class _Sseq>
2175        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
2176    template<class _Sseq>
2177        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
2178
2179    template <size_t __count>
2180        _LIBCPP_INLINE_VISIBILITY
2181        static
2182        typename enable_if
2183        <
2184            __count < __w,
2185            result_type
2186        >::type
2187        __lshift(result_type __x) {return (__x << __count) & _Max;}
2188
2189    template <size_t __count>
2190        _LIBCPP_INLINE_VISIBILITY
2191        static
2192        typename enable_if
2193        <
2194            (__count >= __w),
2195            result_type
2196        >::type
2197        __lshift(result_type) {return result_type(0);}
2198
2199    template <size_t __count>
2200        _LIBCPP_INLINE_VISIBILITY
2201        static
2202        typename enable_if
2203        <
2204            __count < _Dt,
2205            result_type
2206        >::type
2207        __rshift(result_type __x) {return __x >> __count;}
2208
2209    template <size_t __count>
2210        _LIBCPP_INLINE_VISIBILITY
2211        static
2212        typename enable_if
2213        <
2214            (__count >= _Dt),
2215            result_type
2216        >::type
2217        __rshift(result_type) {return result_type(0);}
2218};
2219
2220template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2221          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2222          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2223    _LIBCPP_CONSTEXPR const size_t
2224    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::word_size;
2225
2226template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2227          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2228          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2229    _LIBCPP_CONSTEXPR const size_t
2230    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::state_size;
2231
2232template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2233          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2234          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2235    _LIBCPP_CONSTEXPR const size_t
2236    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::shift_size;
2237
2238template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2239          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2240          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2241    _LIBCPP_CONSTEXPR const size_t
2242    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::mask_bits;
2243
2244template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2245          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2246          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2247    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2248    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::xor_mask;
2249
2250template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2251          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2252          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2253    _LIBCPP_CONSTEXPR const size_t
2254    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_u;
2255
2256template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2257          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2258          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2259    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2260    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_d;
2261
2262template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2263          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2264          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2265    _LIBCPP_CONSTEXPR const size_t
2266    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_s;
2267
2268template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2269          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2270          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2271    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2272    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_b;
2273
2274template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2275          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2276          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2277    _LIBCPP_CONSTEXPR const size_t
2278    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_t;
2279
2280template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2281          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2282          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2283    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2284    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_c;
2285
2286template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2287          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2288          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2289    _LIBCPP_CONSTEXPR const size_t
2290    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_l;
2291
2292template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2293          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2294          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2295    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2296    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::initialization_multiplier;
2297
2298template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2299          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2300          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2301    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2302    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::default_seed;
2303
2304template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2305          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2306          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2307void
2308mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2309    __t, __c, __l, __f>::seed(result_type __sd)
2310    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
2311{   // __w >= 2
2312    __x_[0] = __sd & _Max;
2313    for (size_t __i = 1; __i < __n; ++__i)
2314        __x_[__i] = (__f * (__x_[__i-1] ^ __rshift<__w - 2>(__x_[__i-1])) + __i) & _Max;
2315    __i_ = 0;
2316}
2317
2318template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2319          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2320          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2321template<class _Sseq>
2322void
2323mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2324    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 1>)
2325{
2326    const unsigned __k = 1;
2327    uint32_t __ar[__n * __k];
2328    __q.generate(__ar, __ar + __n * __k);
2329    for (size_t __i = 0; __i < __n; ++__i)
2330        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
2331    const result_type __mask = __r == _Dt ? result_type(~0) :
2332                                       (result_type(1) << __r) - result_type(1);
2333    __i_ = 0;
2334    if ((__x_[0] & ~__mask) == 0)
2335    {
2336        for (size_t __i = 1; __i < __n; ++__i)
2337            if (__x_[__i] != 0)
2338                return;
2339        __x_[0] = result_type(1) << (__w - 1);
2340    }
2341}
2342
2343template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2344          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2345          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2346template<class _Sseq>
2347void
2348mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2349    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 2>)
2350{
2351    const unsigned __k = 2;
2352    uint32_t __ar[__n * __k];
2353    __q.generate(__ar, __ar + __n * __k);
2354    for (size_t __i = 0; __i < __n; ++__i)
2355        __x_[__i] = static_cast<result_type>(
2356            (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
2357    const result_type __mask = __r == _Dt ? result_type(~0) :
2358                                       (result_type(1) << __r) - result_type(1);
2359    __i_ = 0;
2360    if ((__x_[0] & ~__mask) == 0)
2361    {
2362        for (size_t __i = 1; __i < __n; ++__i)
2363            if (__x_[__i] != 0)
2364                return;
2365        __x_[0] = result_type(1) << (__w - 1);
2366    }
2367}
2368
2369template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2370          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2371          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2372_UIntType
2373mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2374    __t, __c, __l, __f>::operator()()
2375{
2376    const size_t __j = (__i_ + 1) % __n;
2377    const result_type __mask = __r == _Dt ? result_type(~0) :
2378                                       (result_type(1) << __r) - result_type(1);
2379    const result_type _Yp = (__x_[__i_] & ~__mask) | (__x_[__j] & __mask);
2380    const size_t __k = (__i_ + __m) % __n;
2381    __x_[__i_] = __x_[__k] ^ __rshift<1>(_Yp) ^ (__a * (_Yp & 1));
2382    result_type __z = __x_[__i_] ^ (__rshift<__u>(__x_[__i_]) & __d);
2383    __i_ = __j;
2384    __z ^= __lshift<__s>(__z) & __b;
2385    __z ^= __lshift<__t>(__z) & __c;
2386    return __z ^ __rshift<__l>(__z);
2387}
2388
2389template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2390          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2391          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2392bool
2393operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2394                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2395           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2396                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
2397{
2398    if (__x.__i_ == __y.__i_)
2399        return _VSTD::equal(__x.__x_, __x.__x_ + _Np, __y.__x_);
2400    if (__x.__i_ == 0 || __y.__i_ == 0)
2401    {
2402        size_t __j = _VSTD::min(_Np - __x.__i_, _Np - __y.__i_);
2403        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
2404                         __y.__x_ + __y.__i_))
2405            return false;
2406        if (__x.__i_ == 0)
2407            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Np, __y.__x_);
2408        return _VSTD::equal(__x.__x_, __x.__x_ + (_Np - __j), __y.__x_ + __j);
2409    }
2410    if (__x.__i_ < __y.__i_)
2411    {
2412        size_t __j = _Np - __y.__i_;
2413        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
2414                         __y.__x_ + __y.__i_))
2415            return false;
2416        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Np,
2417                         __y.__x_))
2418            return false;
2419        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
2420                           __y.__x_ + (_Np - (__x.__i_ + __j)));
2421    }
2422    size_t __j = _Np - __x.__i_;
2423    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
2424                     __x.__x_ + __x.__i_))
2425        return false;
2426    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Np,
2427                     __x.__x_))
2428        return false;
2429    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
2430                       __x.__x_ + (_Np - (__y.__i_ + __j)));
2431}
2432
2433template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2434          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2435          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2436inline _LIBCPP_INLINE_VISIBILITY
2437bool
2438operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2439                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2440           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2441                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
2442{
2443    return !(__x == __y);
2444}
2445
2446template <class _CharT, class _Traits,
2447          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2448          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2449          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2450basic_ostream<_CharT, _Traits>&
2451operator<<(basic_ostream<_CharT, _Traits>& __os,
2452           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2453                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
2454{
2455    __save_flags<_CharT, _Traits> __lx(__os);
2456    __os.flags(ios_base::dec | ios_base::left);
2457    _CharT __sp = __os.widen(' ');
2458    __os.fill(__sp);
2459    __os << __x.__x_[__x.__i_];
2460    for (size_t __j = __x.__i_ + 1; __j < _Np; ++__j)
2461        __os << __sp << __x.__x_[__j];
2462    for (size_t __j = 0; __j < __x.__i_; ++__j)
2463        __os << __sp << __x.__x_[__j];
2464    return __os;
2465}
2466
2467template <class _CharT, class _Traits,
2468          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2469          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2470          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2471basic_istream<_CharT, _Traits>&
2472operator>>(basic_istream<_CharT, _Traits>& __is,
2473           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2474                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
2475{
2476    __save_flags<_CharT, _Traits> __lx(__is);
2477    __is.flags(ios_base::dec | ios_base::skipws);
2478    _UInt __t[_Np];
2479    for (size_t __i = 0; __i < _Np; ++__i)
2480        __is >> __t[__i];
2481    if (!__is.fail())
2482    {
2483        for (size_t __i = 0; __i < _Np; ++__i)
2484            __x.__x_[__i] = __t[__i];
2485        __x.__i_ = 0;
2486    }
2487    return __is;
2488}
2489
2490typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
2491                                0x9908b0df, 11, 0xffffffff,
2492                                7,  0x9d2c5680,
2493                                15, 0xefc60000,
2494                                18, 1812433253>                         mt19937;
2495typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
2496                                0xb5026f5aa96619e9ULL, 29, 0x5555555555555555ULL,
2497                                17, 0x71d67fffeda60000ULL,
2498                                37, 0xfff7eee000000000ULL,
2499                                43, 6364136223846793005ULL>          mt19937_64;
2500
2501// subtract_with_carry_engine
2502
2503template<class _UIntType, size_t __w, size_t __s, size_t __r>
2504class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine;
2505
2506template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2507bool
2508operator==(
2509    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2510    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2511
2512template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2513_LIBCPP_INLINE_VISIBILITY
2514bool
2515operator!=(
2516    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2517    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2518
2519template <class _CharT, class _Traits,
2520          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2521basic_ostream<_CharT, _Traits>&
2522operator<<(basic_ostream<_CharT, _Traits>& __os,
2523           const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2524
2525template <class _CharT, class _Traits,
2526          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2527basic_istream<_CharT, _Traits>&
2528operator>>(basic_istream<_CharT, _Traits>& __is,
2529           subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2530
2531template<class _UIntType, size_t __w, size_t __s, size_t __r>
2532class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine
2533{
2534public:
2535    // types
2536    typedef _UIntType result_type;
2537
2538private:
2539    result_type __x_[__r];
2540    result_type  __c_;
2541    size_t      __i_;
2542
2543    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
2544    static_assert(  0 <  __w, "subtract_with_carry_engine invalid parameters");
2545    static_assert(__w <= _Dt, "subtract_with_carry_engine invalid parameters");
2546    static_assert(  0 <  __s, "subtract_with_carry_engine invalid parameters");
2547    static_assert(__s <  __r, "subtract_with_carry_engine invalid parameters");
2548public:
2549    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
2550    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
2551                                                      (result_type(1) << __w) - result_type(1);
2552    static_assert(_Min < _Max, "subtract_with_carry_engine invalid parameters");
2553
2554    // engine characteristics
2555    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
2556    static _LIBCPP_CONSTEXPR const size_t short_lag = __s;
2557    static _LIBCPP_CONSTEXPR const size_t long_lag = __r;
2558    _LIBCPP_INLINE_VISIBILITY
2559    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
2560    _LIBCPP_INLINE_VISIBILITY
2561    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
2562    static _LIBCPP_CONSTEXPR const result_type default_seed = 19780503u;
2563
2564    // constructors and seeding functions
2565    _LIBCPP_INLINE_VISIBILITY
2566    explicit subtract_with_carry_engine(result_type __sd = default_seed)
2567        {seed(__sd);}
2568    template<class _Sseq>
2569        _LIBCPP_INLINE_VISIBILITY
2570        explicit subtract_with_carry_engine(_Sseq& __q,
2571        typename enable_if<__is_seed_sequence<_Sseq, subtract_with_carry_engine>::value>::type* = 0)
2572        {seed(__q);}
2573    _LIBCPP_INLINE_VISIBILITY
2574    void seed(result_type __sd = default_seed)
2575        {seed(__sd, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2576    template<class _Sseq>
2577        _LIBCPP_INLINE_VISIBILITY
2578        typename enable_if
2579        <
2580            __is_seed_sequence<_Sseq, subtract_with_carry_engine>::value,
2581            void
2582        >::type
2583        seed(_Sseq& __q)
2584            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2585
2586    // generating functions
2587    result_type operator()();
2588    _LIBCPP_INLINE_VISIBILITY
2589    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2590
2591    template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2592    friend
2593    bool
2594    operator==(
2595        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2596        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2597
2598    template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2599    friend
2600    bool
2601    operator!=(
2602        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2603        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2604
2605    template <class _CharT, class _Traits,
2606              class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2607    friend
2608    basic_ostream<_CharT, _Traits>&
2609    operator<<(basic_ostream<_CharT, _Traits>& __os,
2610               const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2611
2612    template <class _CharT, class _Traits,
2613              class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2614    friend
2615    basic_istream<_CharT, _Traits>&
2616    operator>>(basic_istream<_CharT, _Traits>& __is,
2617               subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2618
2619private:
2620
2621    void seed(result_type __sd, integral_constant<unsigned, 1>);
2622    void seed(result_type __sd, integral_constant<unsigned, 2>);
2623    template<class _Sseq>
2624        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
2625    template<class _Sseq>
2626        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
2627};
2628
2629template<class _UIntType, size_t __w, size_t __s, size_t __r>
2630    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::word_size;
2631
2632template<class _UIntType, size_t __w, size_t __s, size_t __r>
2633    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::short_lag;
2634
2635template<class _UIntType, size_t __w, size_t __s, size_t __r>
2636    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::long_lag;
2637
2638template<class _UIntType, size_t __w, size_t __s, size_t __r>
2639    _LIBCPP_CONSTEXPR const typename subtract_with_carry_engine<_UIntType, __w, __s, __r>::result_type
2640    subtract_with_carry_engine<_UIntType, __w, __s, __r>::default_seed;
2641
2642template<class _UIntType, size_t __w, size_t __s, size_t __r>
2643void
2644subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
2645        integral_constant<unsigned, 1>)
2646{
2647    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
2648        __e(__sd == 0u ? default_seed : __sd);
2649    for (size_t __i = 0; __i < __r; ++__i)
2650        __x_[__i] = static_cast<result_type>(__e() & _Max);
2651    __c_ = __x_[__r-1] == 0;
2652    __i_ = 0;
2653}
2654
2655template<class _UIntType, size_t __w, size_t __s, size_t __r>
2656void
2657subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
2658        integral_constant<unsigned, 2>)
2659{
2660    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
2661        __e(__sd == 0u ? default_seed : __sd);
2662    for (size_t __i = 0; __i < __r; ++__i)
2663    {
2664        result_type __e0 = __e();
2665        __x_[__i] = static_cast<result_type>(
2666                                    (__e0 + ((uint64_t)__e() << 32)) & _Max);
2667    }
2668    __c_ = __x_[__r-1] == 0;
2669    __i_ = 0;
2670}
2671
2672template<class _UIntType, size_t __w, size_t __s, size_t __r>
2673template<class _Sseq>
2674void
2675subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
2676        integral_constant<unsigned, 1>)
2677{
2678    const unsigned __k = 1;
2679    uint32_t __ar[__r * __k];
2680    __q.generate(__ar, __ar + __r * __k);
2681    for (size_t __i = 0; __i < __r; ++__i)
2682        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
2683    __c_ = __x_[__r-1] == 0;
2684    __i_ = 0;
2685}
2686
2687template<class _UIntType, size_t __w, size_t __s, size_t __r>
2688template<class _Sseq>
2689void
2690subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
2691        integral_constant<unsigned, 2>)
2692{
2693    const unsigned __k = 2;
2694    uint32_t __ar[__r * __k];
2695    __q.generate(__ar, __ar + __r * __k);
2696    for (size_t __i = 0; __i < __r; ++__i)
2697        __x_[__i] = static_cast<result_type>(
2698                  (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
2699    __c_ = __x_[__r-1] == 0;
2700    __i_ = 0;
2701}
2702
2703template<class _UIntType, size_t __w, size_t __s, size_t __r>
2704_UIntType
2705subtract_with_carry_engine<_UIntType, __w, __s, __r>::operator()()
2706{
2707    const result_type& __xs = __x_[(__i_ + (__r - __s)) % __r];
2708    result_type& __xr = __x_[__i_];
2709    result_type __new_c = __c_ == 0 ? __xs < __xr : __xs != 0 ? __xs <= __xr : 1;
2710    __xr = (__xs - __xr - __c_) & _Max;
2711    __c_ = __new_c;
2712    __i_ = (__i_ + 1) % __r;
2713    return __xr;
2714}
2715
2716template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2717bool
2718operator==(
2719    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2720    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
2721{
2722    if (__x.__c_ != __y.__c_)
2723        return false;
2724    if (__x.__i_ == __y.__i_)
2725        return _VSTD::equal(__x.__x_, __x.__x_ + _Rp, __y.__x_);
2726    if (__x.__i_ == 0 || __y.__i_ == 0)
2727    {
2728        size_t __j = _VSTD::min(_Rp - __x.__i_, _Rp - __y.__i_);
2729        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
2730                         __y.__x_ + __y.__i_))
2731            return false;
2732        if (__x.__i_ == 0)
2733            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Rp, __y.__x_);
2734        return _VSTD::equal(__x.__x_, __x.__x_ + (_Rp - __j), __y.__x_ + __j);
2735    }
2736    if (__x.__i_ < __y.__i_)
2737    {
2738        size_t __j = _Rp - __y.__i_;
2739        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
2740                         __y.__x_ + __y.__i_))
2741            return false;
2742        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Rp,
2743                         __y.__x_))
2744            return false;
2745        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
2746                           __y.__x_ + (_Rp - (__x.__i_ + __j)));
2747    }
2748    size_t __j = _Rp - __x.__i_;
2749    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
2750                     __x.__x_ + __x.__i_))
2751        return false;
2752    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Rp,
2753                     __x.__x_))
2754        return false;
2755    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
2756                       __x.__x_ + (_Rp - (__y.__i_ + __j)));
2757}
2758
2759template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2760inline _LIBCPP_INLINE_VISIBILITY
2761bool
2762operator!=(
2763    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2764    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
2765{
2766    return !(__x == __y);
2767}
2768
2769template <class _CharT, class _Traits,
2770          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2771basic_ostream<_CharT, _Traits>&
2772operator<<(basic_ostream<_CharT, _Traits>& __os,
2773           const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
2774{
2775    __save_flags<_CharT, _Traits> __lx(__os);
2776    __os.flags(ios_base::dec | ios_base::left);
2777    _CharT __sp = __os.widen(' ');
2778    __os.fill(__sp);
2779    __os << __x.__x_[__x.__i_];
2780    for (size_t __j = __x.__i_ + 1; __j < _Rp; ++__j)
2781        __os << __sp << __x.__x_[__j];
2782    for (size_t __j = 0; __j < __x.__i_; ++__j)
2783        __os << __sp << __x.__x_[__j];
2784    __os << __sp << __x.__c_;
2785    return __os;
2786}
2787
2788template <class _CharT, class _Traits,
2789          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2790basic_istream<_CharT, _Traits>&
2791operator>>(basic_istream<_CharT, _Traits>& __is,
2792           subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
2793{
2794    __save_flags<_CharT, _Traits> __lx(__is);
2795    __is.flags(ios_base::dec | ios_base::skipws);
2796    _UInt __t[_Rp+1];
2797    for (size_t __i = 0; __i < _Rp+1; ++__i)
2798        __is >> __t[__i];
2799    if (!__is.fail())
2800    {
2801        for (size_t __i = 0; __i < _Rp; ++__i)
2802            __x.__x_[__i] = __t[__i];
2803        __x.__c_ = __t[_Rp];
2804        __x.__i_ = 0;
2805    }
2806    return __is;
2807}
2808
2809typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
2810typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
2811
2812// discard_block_engine
2813
2814template<class _Engine, size_t __p, size_t __r>
2815class _LIBCPP_TEMPLATE_VIS discard_block_engine
2816{
2817    _Engine __e_;
2818    int     __n_;
2819
2820    static_assert(  0 <  __r, "discard_block_engine invalid parameters");
2821    static_assert(__r <= __p, "discard_block_engine invalid parameters");
2822    static_assert(__r <= INT_MAX, "discard_block_engine invalid parameters");
2823public:
2824    // types
2825    typedef typename _Engine::result_type result_type;
2826
2827    // engine characteristics
2828    static _LIBCPP_CONSTEXPR const size_t block_size = __p;
2829    static _LIBCPP_CONSTEXPR const size_t used_block = __r;
2830
2831#ifdef _LIBCPP_CXX03_LANG
2832    static const result_type _Min = _Engine::_Min;
2833    static const result_type _Max = _Engine::_Max;
2834#else
2835    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
2836    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
2837#endif
2838
2839    _LIBCPP_INLINE_VISIBILITY
2840    static _LIBCPP_CONSTEXPR result_type min() { return _Engine::min(); }
2841    _LIBCPP_INLINE_VISIBILITY
2842    static _LIBCPP_CONSTEXPR result_type max() { return _Engine::max(); }
2843
2844    // constructors and seeding functions
2845    _LIBCPP_INLINE_VISIBILITY
2846    discard_block_engine() : __n_(0) {}
2847    _LIBCPP_INLINE_VISIBILITY
2848    explicit discard_block_engine(const _Engine& __e)
2849        : __e_(__e), __n_(0) {}
2850#ifndef _LIBCPP_CXX03_LANG
2851    _LIBCPP_INLINE_VISIBILITY
2852    explicit discard_block_engine(_Engine&& __e)
2853        : __e_(_VSTD::move(__e)), __n_(0) {}
2854#endif  // _LIBCPP_CXX03_LANG
2855    _LIBCPP_INLINE_VISIBILITY
2856    explicit discard_block_engine(result_type __sd) : __e_(__sd), __n_(0) {}
2857    template<class _Sseq>
2858        _LIBCPP_INLINE_VISIBILITY
2859        explicit discard_block_engine(_Sseq& __q,
2860        typename enable_if<__is_seed_sequence<_Sseq, discard_block_engine>::value &&
2861                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
2862        : __e_(__q), __n_(0) {}
2863    _LIBCPP_INLINE_VISIBILITY
2864    void seed() {__e_.seed(); __n_ = 0;}
2865    _LIBCPP_INLINE_VISIBILITY
2866    void seed(result_type __sd) {__e_.seed(__sd); __n_ = 0;}
2867    template<class _Sseq>
2868        _LIBCPP_INLINE_VISIBILITY
2869        typename enable_if
2870        <
2871            __is_seed_sequence<_Sseq, discard_block_engine>::value,
2872            void
2873        >::type
2874        seed(_Sseq& __q) {__e_.seed(__q); __n_ = 0;}
2875
2876    // generating functions
2877    result_type operator()();
2878    _LIBCPP_INLINE_VISIBILITY
2879    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2880
2881    // property functions
2882    _LIBCPP_INLINE_VISIBILITY
2883    const _Engine& base() const _NOEXCEPT {return __e_;}
2884
2885    template<class _Eng, size_t _Pp, size_t _Rp>
2886    friend
2887    bool
2888    operator==(
2889        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2890        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
2891
2892    template<class _Eng, size_t _Pp, size_t _Rp>
2893    friend
2894    bool
2895    operator!=(
2896        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2897        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
2898
2899    template <class _CharT, class _Traits,
2900              class _Eng, size_t _Pp, size_t _Rp>
2901    friend
2902    basic_ostream<_CharT, _Traits>&
2903    operator<<(basic_ostream<_CharT, _Traits>& __os,
2904               const discard_block_engine<_Eng, _Pp, _Rp>& __x);
2905
2906    template <class _CharT, class _Traits,
2907              class _Eng, size_t _Pp, size_t _Rp>
2908    friend
2909    basic_istream<_CharT, _Traits>&
2910    operator>>(basic_istream<_CharT, _Traits>& __is,
2911               discard_block_engine<_Eng, _Pp, _Rp>& __x);
2912};
2913
2914template<class _Engine, size_t __p, size_t __r>
2915    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::block_size;
2916
2917template<class _Engine, size_t __p, size_t __r>
2918    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::used_block;
2919
2920template<class _Engine, size_t __p, size_t __r>
2921typename discard_block_engine<_Engine, __p, __r>::result_type
2922discard_block_engine<_Engine, __p, __r>::operator()()
2923{
2924    if (__n_ >= static_cast<int>(__r))
2925    {
2926        __e_.discard(__p - __r);
2927        __n_ = 0;
2928    }
2929    ++__n_;
2930    return __e_();
2931}
2932
2933template<class _Eng, size_t _Pp, size_t _Rp>
2934inline _LIBCPP_INLINE_VISIBILITY
2935bool
2936operator==(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2937           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
2938{
2939    return __x.__n_ == __y.__n_ && __x.__e_ == __y.__e_;
2940}
2941
2942template<class _Eng, size_t _Pp, size_t _Rp>
2943inline _LIBCPP_INLINE_VISIBILITY
2944bool
2945operator!=(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2946           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
2947{
2948    return !(__x == __y);
2949}
2950
2951template <class _CharT, class _Traits,
2952          class _Eng, size_t _Pp, size_t _Rp>
2953basic_ostream<_CharT, _Traits>&
2954operator<<(basic_ostream<_CharT, _Traits>& __os,
2955           const discard_block_engine<_Eng, _Pp, _Rp>& __x)
2956{
2957    __save_flags<_CharT, _Traits> __lx(__os);
2958    __os.flags(ios_base::dec | ios_base::left);
2959    _CharT __sp = __os.widen(' ');
2960    __os.fill(__sp);
2961    return __os << __x.__e_ << __sp << __x.__n_;
2962}
2963
2964template <class _CharT, class _Traits,
2965          class _Eng, size_t _Pp, size_t _Rp>
2966basic_istream<_CharT, _Traits>&
2967operator>>(basic_istream<_CharT, _Traits>& __is,
2968           discard_block_engine<_Eng, _Pp, _Rp>& __x)
2969{
2970    __save_flags<_CharT, _Traits> __lx(__is);
2971    __is.flags(ios_base::dec | ios_base::skipws);
2972    _Eng __e;
2973    int __n;
2974    __is >> __e >> __n;
2975    if (!__is.fail())
2976    {
2977        __x.__e_ = __e;
2978        __x.__n_ = __n;
2979    }
2980    return __is;
2981}
2982
2983typedef discard_block_engine<ranlux24_base, 223, 23> ranlux24;
2984typedef discard_block_engine<ranlux48_base, 389, 11> ranlux48;
2985
2986// independent_bits_engine
2987
2988template<class _Engine, size_t __w, class _UIntType>
2989class _LIBCPP_TEMPLATE_VIS independent_bits_engine
2990{
2991    template <class _UInt, _UInt _R0, size_t _Wp, size_t _Mp>
2992    class __get_n
2993    {
2994        static _LIBCPP_CONSTEXPR const size_t _Dt = numeric_limits<_UInt>::digits;
2995        static _LIBCPP_CONSTEXPR const size_t _Np = _Wp / _Mp + (_Wp % _Mp != 0);
2996        static _LIBCPP_CONSTEXPR const size_t _W0 = _Wp / _Np;
2997        static _LIBCPP_CONSTEXPR const _UInt _Y0 = _W0 >= _Dt ? 0 : (_R0 >> _W0) << _W0;
2998    public:
2999        static _LIBCPP_CONSTEXPR const size_t value = _R0 - _Y0 > _Y0 / _Np ? _Np + 1 : _Np;
3000    };
3001public:
3002    // types
3003    typedef _UIntType result_type;
3004
3005private:
3006    _Engine __e_;
3007
3008    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
3009    static_assert(  0 <  __w, "independent_bits_engine invalid parameters");
3010    static_assert(__w <= _Dt, "independent_bits_engine invalid parameters");
3011
3012    typedef typename _Engine::result_type _Engine_result_type;
3013    typedef typename conditional
3014        <
3015            sizeof(_Engine_result_type) <= sizeof(result_type),
3016                result_type,
3017                _Engine_result_type
3018        >::type _Working_result_type;
3019#ifdef _LIBCPP_CXX03_LANG
3020    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
3021                                          + _Working_result_type(1);
3022#else
3023    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
3024                                                            + _Working_result_type(1);
3025#endif
3026    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
3027    static _LIBCPP_CONSTEXPR const size_t __n = __get_n<_Working_result_type, _Rp, __w, __m>::value;
3028    static _LIBCPP_CONSTEXPR const size_t __w0 = __w / __n;
3029    static _LIBCPP_CONSTEXPR const size_t __n0 = __n - __w % __n;
3030    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
3031    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
3032    static _LIBCPP_CONSTEXPR const _Working_result_type __y0 = __w0 >= _WDt ? 0 :
3033                                                               (_Rp >> __w0) << __w0;
3034    static _LIBCPP_CONSTEXPR const _Working_result_type __y1 = __w0 >= _WDt - 1 ? 0 :
3035                                                               (_Rp >> (__w0+1)) << (__w0+1);
3036    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask0 = __w0 > 0 ?
3037                                _Engine_result_type(~0) >> (_EDt - __w0) :
3038                                _Engine_result_type(0);
3039    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask1 = __w0 < _EDt - 1 ?
3040                                _Engine_result_type(~0) >> (_EDt - (__w0 + 1)) :
3041                                _Engine_result_type(~0);
3042public:
3043    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
3044    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
3045                                                      (result_type(1) << __w) - result_type(1);
3046    static_assert(_Min < _Max, "independent_bits_engine invalid parameters");
3047
3048    // engine characteristics
3049    _LIBCPP_INLINE_VISIBILITY
3050    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
3051    _LIBCPP_INLINE_VISIBILITY
3052    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
3053
3054    // constructors and seeding functions
3055    _LIBCPP_INLINE_VISIBILITY
3056    independent_bits_engine() {}
3057    _LIBCPP_INLINE_VISIBILITY
3058    explicit independent_bits_engine(const _Engine& __e)
3059        : __e_(__e) {}
3060#ifndef _LIBCPP_CXX03_LANG
3061    _LIBCPP_INLINE_VISIBILITY
3062    explicit independent_bits_engine(_Engine&& __e)
3063        : __e_(_VSTD::move(__e)) {}
3064#endif  // _LIBCPP_CXX03_LANG
3065    _LIBCPP_INLINE_VISIBILITY
3066    explicit independent_bits_engine(result_type __sd) : __e_(__sd) {}
3067    template<class _Sseq>
3068        _LIBCPP_INLINE_VISIBILITY
3069        explicit independent_bits_engine(_Sseq& __q,
3070        typename enable_if<__is_seed_sequence<_Sseq, independent_bits_engine>::value &&
3071                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
3072         : __e_(__q) {}
3073    _LIBCPP_INLINE_VISIBILITY
3074    void seed() {__e_.seed();}
3075    _LIBCPP_INLINE_VISIBILITY
3076    void seed(result_type __sd) {__e_.seed(__sd);}
3077    template<class _Sseq>
3078        _LIBCPP_INLINE_VISIBILITY
3079        typename enable_if
3080        <
3081            __is_seed_sequence<_Sseq, independent_bits_engine>::value,
3082            void
3083        >::type
3084        seed(_Sseq& __q) {__e_.seed(__q);}
3085
3086    // generating functions
3087    _LIBCPP_INLINE_VISIBILITY
3088    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
3089    _LIBCPP_INLINE_VISIBILITY
3090    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
3091
3092    // property functions
3093    _LIBCPP_INLINE_VISIBILITY
3094    const _Engine& base() const _NOEXCEPT {return __e_;}
3095
3096    template<class _Eng, size_t _Wp, class _UInt>
3097    friend
3098    bool
3099    operator==(
3100        const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3101        const independent_bits_engine<_Eng, _Wp, _UInt>& __y);
3102
3103    template<class _Eng, size_t _Wp, class _UInt>
3104    friend
3105    bool
3106    operator!=(
3107        const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3108        const independent_bits_engine<_Eng, _Wp, _UInt>& __y);
3109
3110    template <class _CharT, class _Traits,
3111              class _Eng, size_t _Wp, class _UInt>
3112    friend
3113    basic_ostream<_CharT, _Traits>&
3114    operator<<(basic_ostream<_CharT, _Traits>& __os,
3115               const independent_bits_engine<_Eng, _Wp, _UInt>& __x);
3116
3117    template <class _CharT, class _Traits,
3118              class _Eng, size_t _Wp, class _UInt>
3119    friend
3120    basic_istream<_CharT, _Traits>&
3121    operator>>(basic_istream<_CharT, _Traits>& __is,
3122               independent_bits_engine<_Eng, _Wp, _UInt>& __x);
3123
3124private:
3125    _LIBCPP_INLINE_VISIBILITY
3126    result_type __eval(false_type);
3127    result_type __eval(true_type);
3128
3129    template <size_t __count>
3130        _LIBCPP_INLINE_VISIBILITY
3131        static
3132        typename enable_if
3133        <
3134            __count < _Dt,
3135            result_type
3136        >::type
3137        __lshift(result_type __x) {return __x << __count;}
3138
3139    template <size_t __count>
3140        _LIBCPP_INLINE_VISIBILITY
3141        static
3142        typename enable_if
3143        <
3144            (__count >= _Dt),
3145            result_type
3146        >::type
3147        __lshift(result_type) {return result_type(0);}
3148};
3149
3150template<class _Engine, size_t __w, class _UIntType>
3151inline
3152_UIntType
3153independent_bits_engine<_Engine, __w, _UIntType>::__eval(false_type)
3154{
3155    return static_cast<result_type>(__e_() & __mask0);
3156}
3157
3158template<class _Engine, size_t __w, class _UIntType>
3159_UIntType
3160independent_bits_engine<_Engine, __w, _UIntType>::__eval(true_type)
3161{
3162    result_type _Sp = 0;
3163    for (size_t __k = 0; __k < __n0; ++__k)
3164    {
3165        _Engine_result_type __u;
3166        do
3167        {
3168            __u = __e_() - _Engine::min();
3169        } while (__u >= __y0);
3170        _Sp = static_cast<result_type>(__lshift<__w0>(_Sp) + (__u & __mask0));
3171    }
3172    for (size_t __k = __n0; __k < __n; ++__k)
3173    {
3174        _Engine_result_type __u;
3175        do
3176        {
3177            __u = __e_() - _Engine::min();
3178        } while (__u >= __y1);
3179        _Sp = static_cast<result_type>(__lshift<__w0+1>(_Sp) + (__u & __mask1));
3180    }
3181    return _Sp;
3182}
3183
3184template<class _Eng, size_t _Wp, class _UInt>
3185inline _LIBCPP_INLINE_VISIBILITY
3186bool
3187operator==(
3188    const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3189    const independent_bits_engine<_Eng, _Wp, _UInt>& __y)
3190{
3191    return __x.base() == __y.base();
3192}
3193
3194template<class _Eng, size_t _Wp, class _UInt>
3195inline _LIBCPP_INLINE_VISIBILITY
3196bool
3197operator!=(
3198    const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3199    const independent_bits_engine<_Eng, _Wp, _UInt>& __y)
3200{
3201    return !(__x == __y);
3202}
3203
3204template <class _CharT, class _Traits,
3205          class _Eng, size_t _Wp, class _UInt>
3206basic_ostream<_CharT, _Traits>&
3207operator<<(basic_ostream<_CharT, _Traits>& __os,
3208           const independent_bits_engine<_Eng, _Wp, _UInt>& __x)
3209{
3210    return __os << __x.base();
3211}
3212
3213template <class _CharT, class _Traits,
3214          class _Eng, size_t _Wp, class _UInt>
3215basic_istream<_CharT, _Traits>&
3216operator>>(basic_istream<_CharT, _Traits>& __is,
3217           independent_bits_engine<_Eng, _Wp, _UInt>& __x)
3218{
3219    _Eng __e;
3220    __is >> __e;
3221    if (!__is.fail())
3222        __x.__e_ = __e;
3223    return __is;
3224}
3225
3226// shuffle_order_engine
3227
3228template <uint64_t _Xp, uint64_t _Yp>
3229struct __ugcd
3230{
3231    static _LIBCPP_CONSTEXPR const uint64_t value = __ugcd<_Yp, _Xp % _Yp>::value;
3232};
3233
3234template <uint64_t _Xp>
3235struct __ugcd<_Xp, 0>
3236{
3237    static _LIBCPP_CONSTEXPR const uint64_t value = _Xp;
3238};
3239
3240template <uint64_t _Np, uint64_t _Dp>
3241class __uratio
3242{
3243    static_assert(_Dp != 0, "__uratio divide by 0");
3244    static _LIBCPP_CONSTEXPR const uint64_t __gcd = __ugcd<_Np, _Dp>::value;
3245public:
3246    static _LIBCPP_CONSTEXPR const uint64_t num = _Np / __gcd;
3247    static _LIBCPP_CONSTEXPR const uint64_t den = _Dp / __gcd;
3248
3249    typedef __uratio<num, den> type;
3250};
3251
3252template<class _Engine, size_t __k>
3253class _LIBCPP_TEMPLATE_VIS shuffle_order_engine
3254{
3255    static_assert(0 < __k, "shuffle_order_engine invalid parameters");
3256public:
3257    // types
3258    typedef typename _Engine::result_type result_type;
3259
3260private:
3261    _Engine __e_;
3262    result_type _V_[__k];
3263    result_type _Y_;
3264
3265public:
3266    // engine characteristics
3267    static _LIBCPP_CONSTEXPR const size_t table_size = __k;
3268
3269#ifdef _LIBCPP_CXX03_LANG
3270    static const result_type _Min = _Engine::_Min;
3271    static const result_type _Max = _Engine::_Max;
3272#else
3273    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
3274    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
3275#endif
3276    static_assert(_Min < _Max, "shuffle_order_engine invalid parameters");
3277    _LIBCPP_INLINE_VISIBILITY
3278    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
3279    _LIBCPP_INLINE_VISIBILITY
3280    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
3281
3282    static _LIBCPP_CONSTEXPR const unsigned long long _Rp = _Max - _Min + 1ull;
3283
3284    // constructors and seeding functions
3285    _LIBCPP_INLINE_VISIBILITY
3286    shuffle_order_engine() {__init();}
3287    _LIBCPP_INLINE_VISIBILITY
3288    explicit shuffle_order_engine(const _Engine& __e)
3289        : __e_(__e) {__init();}
3290#ifndef _LIBCPP_CXX03_LANG
3291    _LIBCPP_INLINE_VISIBILITY
3292    explicit shuffle_order_engine(_Engine&& __e)
3293        : __e_(_VSTD::move(__e)) {__init();}
3294#endif  // _LIBCPP_CXX03_LANG
3295    _LIBCPP_INLINE_VISIBILITY
3296    explicit shuffle_order_engine(result_type __sd) : __e_(__sd) {__init();}
3297    template<class _Sseq>
3298        _LIBCPP_INLINE_VISIBILITY
3299        explicit shuffle_order_engine(_Sseq& __q,
3300        typename enable_if<__is_seed_sequence<_Sseq, shuffle_order_engine>::value &&
3301                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
3302         : __e_(__q) {__init();}
3303    _LIBCPP_INLINE_VISIBILITY
3304    void seed() {__e_.seed(); __init();}
3305    _LIBCPP_INLINE_VISIBILITY
3306    void seed(result_type __sd) {__e_.seed(__sd); __init();}
3307    template<class _Sseq>
3308        _LIBCPP_INLINE_VISIBILITY
3309        typename enable_if
3310        <
3311            __is_seed_sequence<_Sseq, shuffle_order_engine>::value,
3312            void
3313        >::type
3314        seed(_Sseq& __q) {__e_.seed(__q); __init();}
3315
3316    // generating functions
3317    _LIBCPP_INLINE_VISIBILITY
3318    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
3319    _LIBCPP_INLINE_VISIBILITY
3320    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
3321
3322    // property functions
3323    _LIBCPP_INLINE_VISIBILITY
3324    const _Engine& base() const _NOEXCEPT {return __e_;}
3325
3326private:
3327    template<class _Eng, size_t _Kp>
3328    friend
3329    bool
3330    operator==(
3331        const shuffle_order_engine<_Eng, _Kp>& __x,
3332        const shuffle_order_engine<_Eng, _Kp>& __y);
3333
3334    template<class _Eng, size_t _Kp>
3335    friend
3336    bool
3337    operator!=(
3338        const shuffle_order_engine<_Eng, _Kp>& __x,
3339        const shuffle_order_engine<_Eng, _Kp>& __y);
3340
3341    template <class _CharT, class _Traits,
3342              class _Eng, size_t _Kp>
3343    friend
3344    basic_ostream<_CharT, _Traits>&
3345    operator<<(basic_ostream<_CharT, _Traits>& __os,
3346               const shuffle_order_engine<_Eng, _Kp>& __x);
3347
3348    template <class _CharT, class _Traits,
3349              class _Eng, size_t _Kp>
3350    friend
3351    basic_istream<_CharT, _Traits>&
3352    operator>>(basic_istream<_CharT, _Traits>& __is,
3353               shuffle_order_engine<_Eng, _Kp>& __x);
3354
3355    _LIBCPP_INLINE_VISIBILITY
3356    void __init()
3357    {
3358        for (size_t __i = 0; __i < __k; ++__i)
3359            _V_[__i] = __e_();
3360        _Y_ = __e_();
3361    }
3362
3363    _LIBCPP_INLINE_VISIBILITY
3364    result_type __eval(false_type) {return __eval2(integral_constant<bool, __k & 1>());}
3365    _LIBCPP_INLINE_VISIBILITY
3366    result_type __eval(true_type) {return __eval(__uratio<__k, _Rp>());}
3367
3368    _LIBCPP_INLINE_VISIBILITY
3369    result_type __eval2(false_type) {return __eval(__uratio<__k/2, 0x8000000000000000ull>());}
3370    _LIBCPP_INLINE_VISIBILITY
3371    result_type __eval2(true_type) {return __evalf<__k, 0>();}
3372
3373    template <uint64_t _Np, uint64_t _Dp>
3374        _LIBCPP_INLINE_VISIBILITY
3375        typename enable_if
3376        <
3377            (__uratio<_Np, _Dp>::num > 0xFFFFFFFFFFFFFFFFull / (_Max - _Min)),
3378            result_type
3379        >::type
3380        __eval(__uratio<_Np, _Dp>)
3381            {return __evalf<__uratio<_Np, _Dp>::num, __uratio<_Np, _Dp>::den>();}
3382
3383    template <uint64_t _Np, uint64_t _Dp>
3384        _LIBCPP_INLINE_VISIBILITY
3385        typename enable_if
3386        <
3387            __uratio<_Np, _Dp>::num <= 0xFFFFFFFFFFFFFFFFull / (_Max - _Min),
3388            result_type
3389        >::type
3390        __eval(__uratio<_Np, _Dp>)
3391        {
3392            const size_t __j = static_cast<size_t>(__uratio<_Np, _Dp>::num * (_Y_ - _Min)
3393                                                   / __uratio<_Np, _Dp>::den);
3394            _Y_ = _V_[__j];
3395            _V_[__j] = __e_();
3396            return _Y_;
3397        }
3398
3399    template <uint64_t __n, uint64_t __d>
3400        _LIBCPP_INLINE_VISIBILITY
3401        result_type __evalf()
3402        {
3403            const double _Fp = __d == 0 ?
3404                __n / (2. * 0x8000000000000000ull) :
3405                __n / (double)__d;
3406            const size_t __j = static_cast<size_t>(_Fp * (_Y_ - _Min));
3407            _Y_ = _V_[__j];
3408            _V_[__j] = __e_();
3409            return _Y_;
3410        }
3411};
3412
3413template<class _Engine, size_t __k>
3414    _LIBCPP_CONSTEXPR const size_t shuffle_order_engine<_Engine, __k>::table_size;
3415
3416template<class _Eng, size_t _Kp>
3417bool
3418operator==(
3419    const shuffle_order_engine<_Eng, _Kp>& __x,
3420    const shuffle_order_engine<_Eng, _Kp>& __y)
3421{
3422    return __x._Y_ == __y._Y_ && _VSTD::equal(__x._V_, __x._V_ + _Kp, __y._V_) &&
3423           __x.__e_ == __y.__e_;
3424}
3425
3426template<class _Eng, size_t _Kp>
3427inline _LIBCPP_INLINE_VISIBILITY
3428bool
3429operator!=(
3430    const shuffle_order_engine<_Eng, _Kp>& __x,
3431    const shuffle_order_engine<_Eng, _Kp>& __y)
3432{
3433    return !(__x == __y);
3434}
3435
3436template <class _CharT, class _Traits,
3437          class _Eng, size_t _Kp>
3438basic_ostream<_CharT, _Traits>&
3439operator<<(basic_ostream<_CharT, _Traits>& __os,
3440           const shuffle_order_engine<_Eng, _Kp>& __x)
3441{
3442    __save_flags<_CharT, _Traits> __lx(__os);
3443    __os.flags(ios_base::dec | ios_base::left);
3444    _CharT __sp = __os.widen(' ');
3445    __os.fill(__sp);
3446    __os << __x.__e_ << __sp << __x._V_[0];
3447    for (size_t __i = 1; __i < _Kp; ++__i)
3448        __os << __sp << __x._V_[__i];
3449    return __os << __sp << __x._Y_;
3450}
3451
3452template <class _CharT, class _Traits,
3453          class _Eng, size_t _Kp>
3454basic_istream<_CharT, _Traits>&
3455operator>>(basic_istream<_CharT, _Traits>& __is,
3456           shuffle_order_engine<_Eng, _Kp>& __x)
3457{
3458    typedef typename shuffle_order_engine<_Eng, _Kp>::result_type result_type;
3459    __save_flags<_CharT, _Traits> __lx(__is);
3460    __is.flags(ios_base::dec | ios_base::skipws);
3461    _Eng __e;
3462    result_type _Vp[_Kp+1];
3463    __is >> __e;
3464    for (size_t __i = 0; __i < _Kp+1; ++__i)
3465        __is >> _Vp[__i];
3466    if (!__is.fail())
3467    {
3468        __x.__e_ = __e;
3469        for (size_t __i = 0; __i < _Kp; ++__i)
3470            __x._V_[__i] = _Vp[__i];
3471        __x._Y_ = _Vp[_Kp];
3472    }
3473    return __is;
3474}
3475
3476typedef shuffle_order_engine<minstd_rand0, 256>                         knuth_b;
3477
3478// random_device
3479
3480#if !defined(_LIBCPP_HAS_NO_RANDOM_DEVICE)
3481
3482class _LIBCPP_TYPE_VIS random_device
3483{
3484#ifdef _LIBCPP_USING_DEV_RANDOM
3485    int __f_;
3486#endif // defined(_LIBCPP_USING_DEV_RANDOM)
3487public:
3488    // types
3489    typedef unsigned result_type;
3490
3491    // generator characteristics
3492    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
3493    static _LIBCPP_CONSTEXPR const result_type _Max = 0xFFFFFFFFu;
3494
3495    _LIBCPP_INLINE_VISIBILITY
3496    static _LIBCPP_CONSTEXPR result_type min() { return _Min;}
3497    _LIBCPP_INLINE_VISIBILITY
3498    static _LIBCPP_CONSTEXPR result_type max() { return _Max;}
3499
3500    // constructors
3501    explicit random_device(const string& __token = "/dev/urandom");
3502    ~random_device();
3503
3504    // generating functions
3505    result_type operator()();
3506
3507    // property functions
3508    double entropy() const _NOEXCEPT;
3509
3510private:
3511    // no copy functions
3512    random_device(const random_device&); // = delete;
3513    random_device& operator=(const random_device&); // = delete;
3514};
3515
3516#endif // !_LIBCPP_HAS_NO_RANDOM_DEVICE
3517
3518// seed_seq
3519
3520class _LIBCPP_TEMPLATE_VIS seed_seq
3521{
3522public:
3523    // types
3524    typedef uint32_t result_type;
3525
3526private:
3527    vector<result_type> __v_;
3528
3529    template<class _InputIterator>
3530        void init(_InputIterator __first, _InputIterator __last);
3531public:
3532    // constructors
3533    _LIBCPP_INLINE_VISIBILITY
3534    seed_seq() _NOEXCEPT {}
3535#ifndef _LIBCPP_CXX03_LANG
3536    template<class _Tp>
3537        _LIBCPP_INLINE_VISIBILITY
3538        seed_seq(initializer_list<_Tp> __il) {init(__il.begin(), __il.end());}
3539#endif  // _LIBCPP_CXX03_LANG
3540
3541    template<class _InputIterator>
3542        _LIBCPP_INLINE_VISIBILITY
3543        seed_seq(_InputIterator __first, _InputIterator __last)
3544             {init(__first, __last);}
3545
3546    // generating functions
3547    template<class _RandomAccessIterator>
3548        void generate(_RandomAccessIterator __first, _RandomAccessIterator __last);
3549
3550    // property functions
3551    _LIBCPP_INLINE_VISIBILITY
3552    size_t size() const _NOEXCEPT {return __v_.size();}
3553    template<class _OutputIterator>
3554        _LIBCPP_INLINE_VISIBILITY
3555        void param(_OutputIterator __dest) const
3556            {_VSTD::copy(__v_.begin(), __v_.end(), __dest);}
3557
3558private:
3559    // no copy functions
3560    seed_seq(const seed_seq&); // = delete;
3561    void operator=(const seed_seq&); // = delete;
3562
3563    _LIBCPP_INLINE_VISIBILITY
3564    static result_type _Tp(result_type __x) {return __x ^ (__x >> 27);}
3565};
3566
3567template<class _InputIterator>
3568void
3569seed_seq::init(_InputIterator __first, _InputIterator __last)
3570{
3571    for (_InputIterator __s = __first; __s != __last; ++__s)
3572        __v_.push_back(*__s & 0xFFFFFFFF);
3573}
3574
3575template<class _RandomAccessIterator>
3576void
3577seed_seq::generate(_RandomAccessIterator __first, _RandomAccessIterator __last)
3578{
3579    if (__first != __last)
3580    {
3581        _VSTD::fill(__first, __last, 0x8b8b8b8b);
3582        const size_t __n = static_cast<size_t>(__last - __first);
3583        const size_t __s = __v_.size();
3584        const size_t __t = (__n >= 623) ? 11
3585                         : (__n >= 68) ? 7
3586                         : (__n >= 39) ? 5
3587                         : (__n >= 7)  ? 3
3588                         : (__n - 1) / 2;
3589        const size_t __p = (__n - __t) / 2;
3590        const size_t __q = __p + __t;
3591        const size_t __m = _VSTD::max(__s + 1, __n);
3592        // __k = 0;
3593        {
3594            result_type __r = 1664525 * _Tp(__first[0] ^ __first[__p]
3595                                                      ^  __first[__n - 1]);
3596            __first[__p] += __r;
3597            __r += __s;
3598            __first[__q] += __r;
3599            __first[0] = __r;
3600        }
3601        for (size_t __k = 1; __k <= __s; ++__k)
3602        {
3603            const size_t __kmodn = __k % __n;
3604            const size_t __kpmodn = (__k + __p) % __n;
3605            result_type __r = 1664525 * _Tp(__first[__kmodn] ^ __first[__kpmodn]
3606                                           ^ __first[(__k - 1) % __n]);
3607            __first[__kpmodn] += __r;
3608            __r +=  __kmodn + __v_[__k-1];
3609            __first[(__k + __q) % __n] += __r;
3610            __first[__kmodn] = __r;
3611        }
3612        for (size_t __k = __s + 1; __k < __m; ++__k)
3613        {
3614            const size_t __kmodn = __k % __n;
3615            const size_t __kpmodn = (__k + __p) % __n;
3616            result_type __r = 1664525 * _Tp(__first[__kmodn] ^ __first[__kpmodn]
3617                                           ^ __first[(__k - 1) % __n]);
3618            __first[__kpmodn] += __r;
3619            __r +=  __kmodn;
3620            __first[(__k + __q) % __n] += __r;
3621            __first[__kmodn] = __r;
3622        }
3623        for (size_t __k = __m; __k < __m + __n; ++__k)
3624        {
3625            const size_t __kmodn = __k % __n;
3626            const size_t __kpmodn = (__k + __p) % __n;
3627            result_type __r = 1566083941 * _Tp(__first[__kmodn] +
3628                                              __first[__kpmodn] +
3629                                              __first[(__k - 1) % __n]);
3630            __first[__kpmodn] ^= __r;
3631            __r -= __kmodn;
3632            __first[(__k + __q) % __n] ^= __r;
3633            __first[__kmodn] = __r;
3634        }
3635    }
3636}
3637
3638// generate_canonical
3639
3640template<class _RealType, size_t __bits, class _URNG>
3641_RealType
3642generate_canonical(_URNG& __g)
3643{
3644    const size_t _Dt = numeric_limits<_RealType>::digits;
3645    const size_t __b = _Dt < __bits ? _Dt : __bits;
3646#ifdef _LIBCPP_CXX03_LANG
3647    const size_t __logR = __log2<uint64_t, _URNG::_Max - _URNG::_Min + uint64_t(1)>::value;
3648#else
3649    const size_t __logR = __log2<uint64_t, _URNG::max() - _URNG::min() + uint64_t(1)>::value;
3650#endif
3651    const size_t __k = __b / __logR + (__b % __logR != 0) + (__b == 0);
3652    const _RealType _Rp = static_cast<_RealType>(_URNG::max() - _URNG::min()) + _RealType(1);
3653    _RealType __base = _Rp;
3654    _RealType _Sp = __g() - _URNG::min();
3655    for (size_t __i = 1; __i < __k; ++__i, __base *= _Rp)
3656        _Sp += (__g() - _URNG::min()) * __base;
3657    return _Sp / __base;
3658}
3659
3660// uniform_int_distribution
3661
3662// in <algorithm>
3663
3664template <class _CharT, class _Traits, class _IT>
3665basic_ostream<_CharT, _Traits>&
3666operator<<(basic_ostream<_CharT, _Traits>& __os,
3667           const uniform_int_distribution<_IT>& __x)
3668{
3669    __save_flags<_CharT, _Traits> __lx(__os);
3670    __os.flags(ios_base::dec | ios_base::left);
3671    _CharT __sp = __os.widen(' ');
3672    __os.fill(__sp);
3673    return __os << __x.a() << __sp << __x.b();
3674}
3675
3676template <class _CharT, class _Traits, class _IT>
3677basic_istream<_CharT, _Traits>&
3678operator>>(basic_istream<_CharT, _Traits>& __is,
3679           uniform_int_distribution<_IT>& __x)
3680{
3681    typedef uniform_int_distribution<_IT> _Eng;
3682    typedef typename _Eng::result_type result_type;
3683    typedef typename _Eng::param_type param_type;
3684    __save_flags<_CharT, _Traits> __lx(__is);
3685    __is.flags(ios_base::dec | ios_base::skipws);
3686    result_type __a;
3687    result_type __b;
3688    __is >> __a >> __b;
3689    if (!__is.fail())
3690        __x.param(param_type(__a, __b));
3691    return __is;
3692}
3693
3694// uniform_real_distribution
3695
3696template<class _RealType = double>
3697class _LIBCPP_TEMPLATE_VIS uniform_real_distribution
3698{
3699public:
3700    // types
3701    typedef _RealType result_type;
3702
3703    class _LIBCPP_TEMPLATE_VIS param_type
3704    {
3705        result_type __a_;
3706        result_type __b_;
3707    public:
3708        typedef uniform_real_distribution distribution_type;
3709
3710        _LIBCPP_INLINE_VISIBILITY
3711        explicit param_type(result_type __a = 0,
3712                            result_type __b = 1)
3713            : __a_(__a), __b_(__b) {}
3714
3715        _LIBCPP_INLINE_VISIBILITY
3716        result_type a() const {return __a_;}
3717        _LIBCPP_INLINE_VISIBILITY
3718        result_type b() const {return __b_;}
3719
3720        friend _LIBCPP_INLINE_VISIBILITY
3721        bool operator==(const param_type& __x, const param_type& __y)
3722            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
3723        friend _LIBCPP_INLINE_VISIBILITY
3724        bool operator!=(const param_type& __x, const param_type& __y)
3725            {return !(__x == __y);}
3726    };
3727
3728private:
3729    param_type __p_;
3730
3731public:
3732    // constructors and reset functions
3733    _LIBCPP_INLINE_VISIBILITY
3734    explicit uniform_real_distribution(result_type __a = 0, result_type __b = 1)
3735        : __p_(param_type(__a, __b)) {}
3736    _LIBCPP_INLINE_VISIBILITY
3737    explicit uniform_real_distribution(const param_type& __p) : __p_(__p) {}
3738    _LIBCPP_INLINE_VISIBILITY
3739    void reset() {}
3740
3741    // generating functions
3742    template<class _URNG>
3743        _LIBCPP_INLINE_VISIBILITY
3744        result_type operator()(_URNG& __g)
3745        {return (*this)(__g, __p_);}
3746    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
3747
3748    // property functions
3749    _LIBCPP_INLINE_VISIBILITY
3750    result_type a() const {return __p_.a();}
3751    _LIBCPP_INLINE_VISIBILITY
3752    result_type b() const {return __p_.b();}
3753
3754    _LIBCPP_INLINE_VISIBILITY
3755    param_type param() const {return __p_;}
3756    _LIBCPP_INLINE_VISIBILITY
3757    void param(const param_type& __p) {__p_ = __p;}
3758
3759    _LIBCPP_INLINE_VISIBILITY
3760    result_type min() const {return a();}
3761    _LIBCPP_INLINE_VISIBILITY
3762    result_type max() const {return b();}
3763
3764    friend _LIBCPP_INLINE_VISIBILITY
3765        bool operator==(const uniform_real_distribution& __x,
3766                        const uniform_real_distribution& __y)
3767        {return __x.__p_ == __y.__p_;}
3768    friend _LIBCPP_INLINE_VISIBILITY
3769        bool operator!=(const uniform_real_distribution& __x,
3770                        const uniform_real_distribution& __y)
3771        {return !(__x == __y);}
3772};
3773
3774template<class _RealType>
3775template<class _URNG>
3776inline
3777typename uniform_real_distribution<_RealType>::result_type
3778uniform_real_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
3779{
3780    return (__p.b() - __p.a())
3781        * _VSTD::generate_canonical<_RealType, numeric_limits<_RealType>::digits>(__g)
3782        + __p.a();
3783}
3784
3785template <class _CharT, class _Traits, class _RT>
3786basic_ostream<_CharT, _Traits>&
3787operator<<(basic_ostream<_CharT, _Traits>& __os,
3788           const uniform_real_distribution<_RT>& __x)
3789{
3790    __save_flags<_CharT, _Traits> __lx(__os);
3791    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
3792               ios_base::scientific);
3793    _CharT __sp = __os.widen(' ');
3794    __os.fill(__sp);
3795    return __os << __x.a() << __sp << __x.b();
3796}
3797
3798template <class _CharT, class _Traits, class _RT>
3799basic_istream<_CharT, _Traits>&
3800operator>>(basic_istream<_CharT, _Traits>& __is,
3801           uniform_real_distribution<_RT>& __x)
3802{
3803    typedef uniform_real_distribution<_RT> _Eng;
3804    typedef typename _Eng::result_type result_type;
3805    typedef typename _Eng::param_type param_type;
3806    __save_flags<_CharT, _Traits> __lx(__is);
3807    __is.flags(ios_base::dec | ios_base::skipws);
3808    result_type __a;
3809    result_type __b;
3810    __is >> __a >> __b;
3811    if (!__is.fail())
3812        __x.param(param_type(__a, __b));
3813    return __is;
3814}
3815
3816// bernoulli_distribution
3817
3818class _LIBCPP_TEMPLATE_VIS bernoulli_distribution
3819{
3820public:
3821    // types
3822    typedef bool result_type;
3823
3824    class _LIBCPP_TEMPLATE_VIS param_type
3825    {
3826        double __p_;
3827    public:
3828        typedef bernoulli_distribution distribution_type;
3829
3830        _LIBCPP_INLINE_VISIBILITY
3831        explicit param_type(double __p = 0.5) : __p_(__p) {}
3832
3833        _LIBCPP_INLINE_VISIBILITY
3834        double p() const {return __p_;}
3835
3836        friend _LIBCPP_INLINE_VISIBILITY
3837            bool operator==(const param_type& __x, const param_type& __y)
3838            {return __x.__p_ == __y.__p_;}
3839        friend _LIBCPP_INLINE_VISIBILITY
3840            bool operator!=(const param_type& __x, const param_type& __y)
3841            {return !(__x == __y);}
3842    };
3843
3844private:
3845    param_type __p_;
3846
3847public:
3848    // constructors and reset functions
3849    _LIBCPP_INLINE_VISIBILITY
3850    explicit bernoulli_distribution(double __p = 0.5)
3851        : __p_(param_type(__p)) {}
3852    _LIBCPP_INLINE_VISIBILITY
3853    explicit bernoulli_distribution(const param_type& __p) : __p_(__p) {}
3854    _LIBCPP_INLINE_VISIBILITY
3855    void reset() {}
3856
3857    // generating functions
3858    template<class _URNG>
3859        _LIBCPP_INLINE_VISIBILITY
3860        result_type operator()(_URNG& __g)
3861        {return (*this)(__g, __p_);}
3862    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
3863
3864    // property functions
3865    _LIBCPP_INLINE_VISIBILITY
3866    double p() const {return __p_.p();}
3867
3868    _LIBCPP_INLINE_VISIBILITY
3869    param_type param() const {return __p_;}
3870    _LIBCPP_INLINE_VISIBILITY
3871    void param(const param_type& __p) {__p_ = __p;}
3872
3873    _LIBCPP_INLINE_VISIBILITY
3874    result_type min() const {return false;}
3875    _LIBCPP_INLINE_VISIBILITY
3876    result_type max() const {return true;}
3877
3878    friend _LIBCPP_INLINE_VISIBILITY
3879        bool operator==(const bernoulli_distribution& __x,
3880                        const bernoulli_distribution& __y)
3881        {return __x.__p_ == __y.__p_;}
3882    friend _LIBCPP_INLINE_VISIBILITY
3883        bool operator!=(const bernoulli_distribution& __x,
3884                        const bernoulli_distribution& __y)
3885        {return !(__x == __y);}
3886};
3887
3888template<class _URNG>
3889inline
3890bernoulli_distribution::result_type
3891bernoulli_distribution::operator()(_URNG& __g, const param_type& __p)
3892{
3893    uniform_real_distribution<double> __gen;
3894    return __gen(__g) < __p.p();
3895}
3896
3897template <class _CharT, class _Traits>
3898basic_ostream<_CharT, _Traits>&
3899operator<<(basic_ostream<_CharT, _Traits>& __os, const bernoulli_distribution& __x)
3900{
3901    __save_flags<_CharT, _Traits> __lx(__os);
3902    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
3903               ios_base::scientific);
3904    _CharT __sp = __os.widen(' ');
3905    __os.fill(__sp);
3906    return __os << __x.p();
3907}
3908
3909template <class _CharT, class _Traits>
3910basic_istream<_CharT, _Traits>&
3911operator>>(basic_istream<_CharT, _Traits>& __is, bernoulli_distribution& __x)
3912{
3913    typedef bernoulli_distribution _Eng;
3914    typedef typename _Eng::param_type param_type;
3915    __save_flags<_CharT, _Traits> __lx(__is);
3916    __is.flags(ios_base::dec | ios_base::skipws);
3917    double __p;
3918    __is >> __p;
3919    if (!__is.fail())
3920        __x.param(param_type(__p));
3921    return __is;
3922}
3923
3924// binomial_distribution
3925
3926template<class _IntType = int>
3927class _LIBCPP_TEMPLATE_VIS binomial_distribution
3928{
3929public:
3930    // types
3931    typedef _IntType result_type;
3932
3933    class _LIBCPP_TEMPLATE_VIS param_type
3934    {
3935        result_type __t_;
3936        double __p_;
3937        double __pr_;
3938        double __odds_ratio_;
3939        result_type __r0_;
3940    public:
3941        typedef binomial_distribution distribution_type;
3942
3943        explicit param_type(result_type __t = 1, double __p = 0.5);
3944
3945        _LIBCPP_INLINE_VISIBILITY
3946        result_type t() const {return __t_;}
3947        _LIBCPP_INLINE_VISIBILITY
3948        double p() const {return __p_;}
3949
3950        friend _LIBCPP_INLINE_VISIBILITY
3951            bool operator==(const param_type& __x, const param_type& __y)
3952            {return __x.__t_ == __y.__t_ && __x.__p_ == __y.__p_;}
3953        friend _LIBCPP_INLINE_VISIBILITY
3954            bool operator!=(const param_type& __x, const param_type& __y)
3955            {return !(__x == __y);}
3956
3957        friend class binomial_distribution;
3958    };
3959
3960private:
3961    param_type __p_;
3962
3963public:
3964    // constructors and reset functions
3965    _LIBCPP_INLINE_VISIBILITY
3966    explicit binomial_distribution(result_type __t = 1, double __p = 0.5)
3967        : __p_(param_type(__t, __p)) {}
3968    _LIBCPP_INLINE_VISIBILITY
3969    explicit binomial_distribution(const param_type& __p) : __p_(__p) {}
3970    _LIBCPP_INLINE_VISIBILITY
3971    void reset() {}
3972
3973    // generating functions
3974    template<class _URNG>
3975        _LIBCPP_INLINE_VISIBILITY
3976        result_type operator()(_URNG& __g)
3977        {return (*this)(__g, __p_);}
3978    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
3979
3980    // property functions
3981    _LIBCPP_INLINE_VISIBILITY
3982    result_type t() const {return __p_.t();}
3983    _LIBCPP_INLINE_VISIBILITY
3984    double p() const {return __p_.p();}
3985
3986    _LIBCPP_INLINE_VISIBILITY
3987    param_type param() const {return __p_;}
3988    _LIBCPP_INLINE_VISIBILITY
3989    void param(const param_type& __p) {__p_ = __p;}
3990
3991    _LIBCPP_INLINE_VISIBILITY
3992    result_type min() const {return 0;}
3993    _LIBCPP_INLINE_VISIBILITY
3994    result_type max() const {return t();}
3995
3996    friend _LIBCPP_INLINE_VISIBILITY
3997        bool operator==(const binomial_distribution& __x,
3998                        const binomial_distribution& __y)
3999        {return __x.__p_ == __y.__p_;}
4000    friend _LIBCPP_INLINE_VISIBILITY
4001        bool operator!=(const binomial_distribution& __x,
4002                        const binomial_distribution& __y)
4003        {return !(__x == __y);}
4004};
4005
4006#ifndef _LIBCPP_MSVCRT
4007extern "C" double lgamma_r(double, int *);
4008#endif
4009
4010inline _LIBCPP_INLINE_VISIBILITY double __libcpp_lgamma(double __d) {
4011#if defined(_LIBCPP_MSVCRT)
4012  return lgamma(__d);
4013#else
4014  int __sign;
4015  return lgamma_r(__d, &__sign);
4016#endif
4017}
4018
4019template<class _IntType>
4020binomial_distribution<_IntType>::param_type::param_type(const result_type __t, const double __p)
4021    : __t_(__t), __p_(__p)
4022{
4023    if (0 < __p_ && __p_ < 1)
4024    {
4025        __r0_ = static_cast<result_type>((__t_ + 1) * __p_);
4026        __pr_ = _VSTD::exp(__libcpp_lgamma(__t_ + 1.) -
4027                           __libcpp_lgamma(__r0_ + 1.) -
4028                           __libcpp_lgamma(__t_ - __r0_ + 1.) + __r0_ * _VSTD::log(__p_) +
4029                           (__t_ - __r0_) * _VSTD::log(1 - __p_));
4030        __odds_ratio_ = __p_ / (1 - __p_);
4031    }
4032}
4033
4034// Reference: Kemp, C.D. (1986). `A modal method for generating binomial
4035//           variables', Commun. Statist. - Theor. Meth. 15(3), 805-813.
4036template<class _IntType>
4037template<class _URNG>
4038_IntType
4039binomial_distribution<_IntType>::operator()(_URNG& __g, const param_type& __pr)
4040{
4041    if (__pr.__t_ == 0 || __pr.__p_ == 0)
4042        return 0;
4043    if (__pr.__p_ == 1)
4044        return __pr.__t_;
4045    uniform_real_distribution<double> __gen;
4046    double __u = __gen(__g) - __pr.__pr_;
4047    if (__u < 0)
4048        return __pr.__r0_;
4049    double __pu = __pr.__pr_;
4050    double __pd = __pu;
4051    result_type __ru = __pr.__r0_;
4052    result_type __rd = __ru;
4053    while (true)
4054    {
4055        bool __break = true;
4056        if (__rd >= 1)
4057        {
4058            __pd *= __rd / (__pr.__odds_ratio_ * (__pr.__t_ - __rd + 1));
4059            __u -= __pd;
4060            __break = false;
4061            if (__u < 0)
4062                return __rd - 1;
4063        }
4064        if ( __rd != 0 )
4065            --__rd;
4066        ++__ru;
4067        if (__ru <= __pr.__t_)
4068        {
4069            __pu *= (__pr.__t_ - __ru + 1) * __pr.__odds_ratio_ / __ru;
4070            __u -= __pu;
4071            __break = false;
4072            if (__u < 0)
4073                return __ru;
4074        }
4075        if (__break)
4076            return 0;
4077    }
4078}
4079
4080template <class _CharT, class _Traits, class _IntType>
4081basic_ostream<_CharT, _Traits>&
4082operator<<(basic_ostream<_CharT, _Traits>& __os,
4083           const binomial_distribution<_IntType>& __x)
4084{
4085    __save_flags<_CharT, _Traits> __lx(__os);
4086    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4087               ios_base::scientific);
4088    _CharT __sp = __os.widen(' ');
4089    __os.fill(__sp);
4090    return __os << __x.t() << __sp << __x.p();
4091}
4092
4093template <class _CharT, class _Traits, class _IntType>
4094basic_istream<_CharT, _Traits>&
4095operator>>(basic_istream<_CharT, _Traits>& __is,
4096           binomial_distribution<_IntType>& __x)
4097{
4098    typedef binomial_distribution<_IntType> _Eng;
4099    typedef typename _Eng::result_type result_type;
4100    typedef typename _Eng::param_type param_type;
4101    __save_flags<_CharT, _Traits> __lx(__is);
4102    __is.flags(ios_base::dec | ios_base::skipws);
4103    result_type __t;
4104    double __p;
4105    __is >> __t >> __p;
4106    if (!__is.fail())
4107        __x.param(param_type(__t, __p));
4108    return __is;
4109}
4110
4111// exponential_distribution
4112
4113template<class _RealType = double>
4114class _LIBCPP_TEMPLATE_VIS exponential_distribution
4115{
4116public:
4117    // types
4118    typedef _RealType result_type;
4119
4120    class _LIBCPP_TEMPLATE_VIS param_type
4121    {
4122        result_type __lambda_;
4123    public:
4124        typedef exponential_distribution distribution_type;
4125
4126        _LIBCPP_INLINE_VISIBILITY
4127        explicit param_type(result_type __lambda = 1) : __lambda_(__lambda) {}
4128
4129        _LIBCPP_INLINE_VISIBILITY
4130        result_type lambda() const {return __lambda_;}
4131
4132        friend _LIBCPP_INLINE_VISIBILITY
4133            bool operator==(const param_type& __x, const param_type& __y)
4134            {return __x.__lambda_ == __y.__lambda_;}
4135        friend _LIBCPP_INLINE_VISIBILITY
4136            bool operator!=(const param_type& __x, const param_type& __y)
4137            {return !(__x == __y);}
4138    };
4139
4140private:
4141    param_type __p_;
4142
4143public:
4144    // constructors and reset functions
4145    _LIBCPP_INLINE_VISIBILITY
4146    explicit exponential_distribution(result_type __lambda = 1)
4147        : __p_(param_type(__lambda)) {}
4148    _LIBCPP_INLINE_VISIBILITY
4149    explicit exponential_distribution(const param_type& __p) : __p_(__p) {}
4150    _LIBCPP_INLINE_VISIBILITY
4151    void reset() {}
4152
4153    // generating functions
4154    template<class _URNG>
4155        _LIBCPP_INLINE_VISIBILITY
4156        result_type operator()(_URNG& __g)
4157        {return (*this)(__g, __p_);}
4158    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4159
4160    // property functions
4161    _LIBCPP_INLINE_VISIBILITY
4162    result_type lambda() const {return __p_.lambda();}
4163
4164    _LIBCPP_INLINE_VISIBILITY
4165    param_type param() const {return __p_;}
4166    _LIBCPP_INLINE_VISIBILITY
4167    void param(const param_type& __p) {__p_ = __p;}
4168
4169    _LIBCPP_INLINE_VISIBILITY
4170    result_type min() const {return 0;}
4171    _LIBCPP_INLINE_VISIBILITY
4172    result_type max() const {return numeric_limits<result_type>::infinity();}
4173
4174    friend _LIBCPP_INLINE_VISIBILITY
4175        bool operator==(const exponential_distribution& __x,
4176                        const exponential_distribution& __y)
4177        {return __x.__p_ == __y.__p_;}
4178    friend _LIBCPP_INLINE_VISIBILITY
4179        bool operator!=(const exponential_distribution& __x,
4180                        const exponential_distribution& __y)
4181        {return !(__x == __y);}
4182};
4183
4184template <class _RealType>
4185template<class _URNG>
4186_RealType
4187exponential_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4188{
4189    return -_VSTD::log
4190                  (
4191                      result_type(1) -
4192                      _VSTD::generate_canonical<result_type,
4193                                       numeric_limits<result_type>::digits>(__g)
4194                  )
4195                  / __p.lambda();
4196}
4197
4198template <class _CharT, class _Traits, class _RealType>
4199basic_ostream<_CharT, _Traits>&
4200operator<<(basic_ostream<_CharT, _Traits>& __os,
4201           const exponential_distribution<_RealType>& __x)
4202{
4203    __save_flags<_CharT, _Traits> __lx(__os);
4204    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4205               ios_base::scientific);
4206    return __os << __x.lambda();
4207}
4208
4209template <class _CharT, class _Traits, class _RealType>
4210basic_istream<_CharT, _Traits>&
4211operator>>(basic_istream<_CharT, _Traits>& __is,
4212           exponential_distribution<_RealType>& __x)
4213{
4214    typedef exponential_distribution<_RealType> _Eng;
4215    typedef typename _Eng::result_type result_type;
4216    typedef typename _Eng::param_type param_type;
4217    __save_flags<_CharT, _Traits> __lx(__is);
4218    __is.flags(ios_base::dec | ios_base::skipws);
4219    result_type __lambda;
4220    __is >> __lambda;
4221    if (!__is.fail())
4222        __x.param(param_type(__lambda));
4223    return __is;
4224}
4225
4226// normal_distribution
4227
4228template<class _RealType = double>
4229class _LIBCPP_TEMPLATE_VIS normal_distribution
4230{
4231public:
4232    // types
4233    typedef _RealType result_type;
4234
4235    class _LIBCPP_TEMPLATE_VIS param_type
4236    {
4237        result_type __mean_;
4238        result_type __stddev_;
4239    public:
4240        typedef normal_distribution distribution_type;
4241
4242        _LIBCPP_INLINE_VISIBILITY
4243        explicit param_type(result_type __mean = 0, result_type __stddev = 1)
4244            : __mean_(__mean), __stddev_(__stddev) {}
4245
4246        _LIBCPP_INLINE_VISIBILITY
4247        result_type mean() const {return __mean_;}
4248        _LIBCPP_INLINE_VISIBILITY
4249        result_type stddev() const {return __stddev_;}
4250
4251        friend _LIBCPP_INLINE_VISIBILITY
4252            bool operator==(const param_type& __x, const param_type& __y)
4253            {return __x.__mean_ == __y.__mean_ && __x.__stddev_ == __y.__stddev_;}
4254        friend _LIBCPP_INLINE_VISIBILITY
4255            bool operator!=(const param_type& __x, const param_type& __y)
4256            {return !(__x == __y);}
4257    };
4258
4259private:
4260    param_type __p_;
4261    result_type _V_;
4262    bool _V_hot_;
4263
4264public:
4265    // constructors and reset functions
4266    _LIBCPP_INLINE_VISIBILITY
4267    explicit normal_distribution(result_type __mean = 0, result_type __stddev = 1)
4268        : __p_(param_type(__mean, __stddev)), _V_hot_(false) {}
4269    _LIBCPP_INLINE_VISIBILITY
4270    explicit normal_distribution(const param_type& __p)
4271        : __p_(__p), _V_hot_(false) {}
4272    _LIBCPP_INLINE_VISIBILITY
4273    void reset() {_V_hot_ = false;}
4274
4275    // generating functions
4276    template<class _URNG>
4277        _LIBCPP_INLINE_VISIBILITY
4278        result_type operator()(_URNG& __g)
4279        {return (*this)(__g, __p_);}
4280    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4281
4282    // property functions
4283    _LIBCPP_INLINE_VISIBILITY
4284    result_type mean() const {return __p_.mean();}
4285    _LIBCPP_INLINE_VISIBILITY
4286    result_type stddev() const {return __p_.stddev();}
4287
4288    _LIBCPP_INLINE_VISIBILITY
4289    param_type param() const {return __p_;}
4290    _LIBCPP_INLINE_VISIBILITY
4291    void param(const param_type& __p) {__p_ = __p;}
4292
4293    _LIBCPP_INLINE_VISIBILITY
4294    result_type min() const {return -numeric_limits<result_type>::infinity();}
4295    _LIBCPP_INLINE_VISIBILITY
4296    result_type max() const {return numeric_limits<result_type>::infinity();}
4297
4298    friend _LIBCPP_INLINE_VISIBILITY
4299        bool operator==(const normal_distribution& __x,
4300                        const normal_distribution& __y)
4301        {return __x.__p_ == __y.__p_ && __x._V_hot_ == __y._V_hot_ &&
4302                (!__x._V_hot_ || __x._V_ == __y._V_);}
4303    friend _LIBCPP_INLINE_VISIBILITY
4304        bool operator!=(const normal_distribution& __x,
4305                        const normal_distribution& __y)
4306        {return !(__x == __y);}
4307
4308    template <class _CharT, class _Traits, class _RT>
4309    friend
4310    basic_ostream<_CharT, _Traits>&
4311    operator<<(basic_ostream<_CharT, _Traits>& __os,
4312               const normal_distribution<_RT>& __x);
4313
4314    template <class _CharT, class _Traits, class _RT>
4315    friend
4316    basic_istream<_CharT, _Traits>&
4317    operator>>(basic_istream<_CharT, _Traits>& __is,
4318               normal_distribution<_RT>& __x);
4319};
4320
4321template <class _RealType>
4322template<class _URNG>
4323_RealType
4324normal_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4325{
4326    result_type _Up;
4327    if (_V_hot_)
4328    {
4329        _V_hot_ = false;
4330        _Up = _V_;
4331    }
4332    else
4333    {
4334        uniform_real_distribution<result_type> _Uni(-1, 1);
4335        result_type __u;
4336        result_type __v;
4337        result_type __s;
4338        do
4339        {
4340            __u = _Uni(__g);
4341            __v = _Uni(__g);
4342            __s = __u * __u + __v * __v;
4343        } while (__s > 1 || __s == 0);
4344        result_type _Fp = _VSTD::sqrt(-2 * _VSTD::log(__s) / __s);
4345        _V_ = __v * _Fp;
4346        _V_hot_ = true;
4347        _Up = __u * _Fp;
4348    }
4349    return _Up * __p.stddev() + __p.mean();
4350}
4351
4352template <class _CharT, class _Traits, class _RT>
4353basic_ostream<_CharT, _Traits>&
4354operator<<(basic_ostream<_CharT, _Traits>& __os,
4355           const normal_distribution<_RT>& __x)
4356{
4357    __save_flags<_CharT, _Traits> __lx(__os);
4358    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4359               ios_base::scientific);
4360    _CharT __sp = __os.widen(' ');
4361    __os.fill(__sp);
4362    __os << __x.mean() << __sp << __x.stddev() << __sp << __x._V_hot_;
4363    if (__x._V_hot_)
4364        __os << __sp << __x._V_;
4365    return __os;
4366}
4367
4368template <class _CharT, class _Traits, class _RT>
4369basic_istream<_CharT, _Traits>&
4370operator>>(basic_istream<_CharT, _Traits>& __is,
4371           normal_distribution<_RT>& __x)
4372{
4373    typedef normal_distribution<_RT> _Eng;
4374    typedef typename _Eng::result_type result_type;
4375    typedef typename _Eng::param_type param_type;
4376    __save_flags<_CharT, _Traits> __lx(__is);
4377    __is.flags(ios_base::dec | ios_base::skipws);
4378    result_type __mean;
4379    result_type __stddev;
4380    result_type _Vp = 0;
4381    bool _V_hot = false;
4382    __is >> __mean >> __stddev >> _V_hot;
4383    if (_V_hot)
4384        __is >> _Vp;
4385    if (!__is.fail())
4386    {
4387        __x.param(param_type(__mean, __stddev));
4388        __x._V_hot_ = _V_hot;
4389        __x._V_ = _Vp;
4390    }
4391    return __is;
4392}
4393
4394// lognormal_distribution
4395
4396template<class _RealType = double>
4397class _LIBCPP_TEMPLATE_VIS lognormal_distribution
4398{
4399public:
4400    // types
4401    typedef _RealType result_type;
4402
4403    class _LIBCPP_TEMPLATE_VIS param_type
4404    {
4405        normal_distribution<result_type> __nd_;
4406    public:
4407        typedef lognormal_distribution distribution_type;
4408
4409        _LIBCPP_INLINE_VISIBILITY
4410        explicit param_type(result_type __m = 0, result_type __s = 1)
4411            : __nd_(__m, __s) {}
4412
4413        _LIBCPP_INLINE_VISIBILITY
4414        result_type m() const {return __nd_.mean();}
4415        _LIBCPP_INLINE_VISIBILITY
4416        result_type s() const {return __nd_.stddev();}
4417
4418        friend _LIBCPP_INLINE_VISIBILITY
4419            bool operator==(const param_type& __x, const param_type& __y)
4420            {return __x.__nd_ == __y.__nd_;}
4421        friend _LIBCPP_INLINE_VISIBILITY
4422            bool operator!=(const param_type& __x, const param_type& __y)
4423            {return !(__x == __y);}
4424        friend class lognormal_distribution;
4425
4426        template <class _CharT, class _Traits, class _RT>
4427        friend
4428        basic_ostream<_CharT, _Traits>&
4429        operator<<(basic_ostream<_CharT, _Traits>& __os,
4430                   const lognormal_distribution<_RT>& __x);
4431
4432        template <class _CharT, class _Traits, class _RT>
4433        friend
4434        basic_istream<_CharT, _Traits>&
4435        operator>>(basic_istream<_CharT, _Traits>& __is,
4436                   lognormal_distribution<_RT>& __x);
4437    };
4438
4439private:
4440    param_type __p_;
4441
4442public:
4443    // constructor and reset functions
4444    _LIBCPP_INLINE_VISIBILITY
4445    explicit lognormal_distribution(result_type __m = 0, result_type __s = 1)
4446        : __p_(param_type(__m, __s)) {}
4447    _LIBCPP_INLINE_VISIBILITY
4448    explicit lognormal_distribution(const param_type& __p)
4449        : __p_(__p) {}
4450    _LIBCPP_INLINE_VISIBILITY
4451    void reset() {__p_.__nd_.reset();}
4452
4453    // generating functions
4454    template<class _URNG>
4455        _LIBCPP_INLINE_VISIBILITY
4456        result_type operator()(_URNG& __g)
4457        {return (*this)(__g, __p_);}
4458    template<class _URNG>
4459        _LIBCPP_INLINE_VISIBILITY
4460        result_type operator()(_URNG& __g, const param_type& __p)
4461        {return _VSTD::exp(const_cast<normal_distribution<result_type>&>(__p.__nd_)(__g));}
4462
4463    // property functions
4464    _LIBCPP_INLINE_VISIBILITY
4465    result_type m() const {return __p_.m();}
4466    _LIBCPP_INLINE_VISIBILITY
4467    result_type s() const {return __p_.s();}
4468
4469    _LIBCPP_INLINE_VISIBILITY
4470    param_type param() const {return __p_;}
4471    _LIBCPP_INLINE_VISIBILITY
4472    void param(const param_type& __p) {__p_ = __p;}
4473
4474    _LIBCPP_INLINE_VISIBILITY
4475    result_type min() const {return 0;}
4476    _LIBCPP_INLINE_VISIBILITY
4477    result_type max() const {return numeric_limits<result_type>::infinity();}
4478
4479    friend _LIBCPP_INLINE_VISIBILITY
4480        bool operator==(const lognormal_distribution& __x,
4481                        const lognormal_distribution& __y)
4482        {return __x.__p_ == __y.__p_;}
4483    friend _LIBCPP_INLINE_VISIBILITY
4484        bool operator!=(const lognormal_distribution& __x,
4485                        const lognormal_distribution& __y)
4486        {return !(__x == __y);}
4487
4488    template <class _CharT, class _Traits, class _RT>
4489    friend
4490    basic_ostream<_CharT, _Traits>&
4491    operator<<(basic_ostream<_CharT, _Traits>& __os,
4492               const lognormal_distribution<_RT>& __x);
4493
4494    template <class _CharT, class _Traits, class _RT>
4495    friend
4496    basic_istream<_CharT, _Traits>&
4497    operator>>(basic_istream<_CharT, _Traits>& __is,
4498               lognormal_distribution<_RT>& __x);
4499};
4500
4501template <class _CharT, class _Traits, class _RT>
4502inline _LIBCPP_INLINE_VISIBILITY
4503basic_ostream<_CharT, _Traits>&
4504operator<<(basic_ostream<_CharT, _Traits>& __os,
4505           const lognormal_distribution<_RT>& __x)
4506{
4507    return __os << __x.__p_.__nd_;
4508}
4509
4510template <class _CharT, class _Traits, class _RT>
4511inline _LIBCPP_INLINE_VISIBILITY
4512basic_istream<_CharT, _Traits>&
4513operator>>(basic_istream<_CharT, _Traits>& __is,
4514           lognormal_distribution<_RT>& __x)
4515{
4516    return __is >> __x.__p_.__nd_;
4517}
4518
4519// poisson_distribution
4520
4521template<class _IntType = int>
4522class _LIBCPP_TEMPLATE_VIS poisson_distribution
4523{
4524public:
4525    // types
4526    typedef _IntType result_type;
4527
4528    class _LIBCPP_TEMPLATE_VIS param_type
4529    {
4530        double __mean_;
4531        double __s_;
4532        double __d_;
4533        double __l_;
4534        double __omega_;
4535        double __c0_;
4536        double __c1_;
4537        double __c2_;
4538        double __c3_;
4539        double __c_;
4540
4541    public:
4542        typedef poisson_distribution distribution_type;
4543
4544        explicit param_type(double __mean = 1.0);
4545
4546        _LIBCPP_INLINE_VISIBILITY
4547        double mean() const {return __mean_;}
4548
4549        friend _LIBCPP_INLINE_VISIBILITY
4550            bool operator==(const param_type& __x, const param_type& __y)
4551            {return __x.__mean_ == __y.__mean_;}
4552        friend _LIBCPP_INLINE_VISIBILITY
4553            bool operator!=(const param_type& __x, const param_type& __y)
4554            {return !(__x == __y);}
4555
4556        friend class poisson_distribution;
4557    };
4558
4559private:
4560    param_type __p_;
4561
4562public:
4563    // constructors and reset functions
4564    _LIBCPP_INLINE_VISIBILITY
4565    explicit poisson_distribution(double __mean = 1.0) : __p_(__mean) {}
4566    _LIBCPP_INLINE_VISIBILITY
4567    explicit poisson_distribution(const param_type& __p) : __p_(__p) {}
4568    _LIBCPP_INLINE_VISIBILITY
4569    void reset() {}
4570
4571    // generating functions
4572    template<class _URNG>
4573        _LIBCPP_INLINE_VISIBILITY
4574        result_type operator()(_URNG& __g)
4575        {return (*this)(__g, __p_);}
4576    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4577
4578    // property functions
4579    _LIBCPP_INLINE_VISIBILITY
4580    double mean() const {return __p_.mean();}
4581
4582    _LIBCPP_INLINE_VISIBILITY
4583    param_type param() const {return __p_;}
4584    _LIBCPP_INLINE_VISIBILITY
4585    void param(const param_type& __p) {__p_ = __p;}
4586
4587    _LIBCPP_INLINE_VISIBILITY
4588    result_type min() const {return 0;}
4589    _LIBCPP_INLINE_VISIBILITY
4590    result_type max() const {return numeric_limits<result_type>::max();}
4591
4592    friend _LIBCPP_INLINE_VISIBILITY
4593        bool operator==(const poisson_distribution& __x,
4594                        const poisson_distribution& __y)
4595        {return __x.__p_ == __y.__p_;}
4596    friend _LIBCPP_INLINE_VISIBILITY
4597        bool operator!=(const poisson_distribution& __x,
4598                        const poisson_distribution& __y)
4599        {return !(__x == __y);}
4600};
4601
4602template<class _IntType>
4603poisson_distribution<_IntType>::param_type::param_type(double __mean)
4604    // According to the standard `inf` is a valid input, but it causes the
4605    // distribution to hang, so we replace it with the maximum representable
4606    // mean.
4607    : __mean_(isinf(__mean) ? numeric_limits<double>::max() : __mean)
4608{
4609    if (__mean_ < 10)
4610    {
4611        __s_ = 0;
4612        __d_ = 0;
4613        __l_ = _VSTD::exp(-__mean_);
4614        __omega_ = 0;
4615        __c3_ = 0;
4616        __c2_ = 0;
4617        __c1_ = 0;
4618        __c0_ = 0;
4619        __c_ = 0;
4620    }
4621    else
4622    {
4623        __s_ = _VSTD::sqrt(__mean_);
4624        __d_ = 6 * __mean_ * __mean_;
4625        __l_ = std::trunc(__mean_ - 1.1484);
4626        __omega_ = .3989423 / __s_;
4627        double __b1_ = .4166667E-1 / __mean_;
4628        double __b2_ = .3 * __b1_ * __b1_;
4629        __c3_ = .1428571 * __b1_ * __b2_;
4630        __c2_ = __b2_ - 15. * __c3_;
4631        __c1_ = __b1_ - 6. * __b2_ + 45. * __c3_;
4632        __c0_ = 1. - __b1_ + 3. * __b2_ - 15. * __c3_;
4633        __c_ = .1069 / __mean_;
4634    }
4635}
4636
4637template <class _IntType>
4638template<class _URNG>
4639_IntType
4640poisson_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
4641{
4642    double __tx;
4643    uniform_real_distribution<double> __urd;
4644    if (__pr.__mean_ < 10)
4645    {
4646         __tx = 0;
4647        for (double __p = __urd(__urng); __p > __pr.__l_; ++__tx)
4648            __p *= __urd(__urng);
4649    }
4650    else
4651    {
4652        double __difmuk;
4653        double __g = __pr.__mean_ + __pr.__s_ * normal_distribution<double>()(__urng);
4654        double __u;
4655        if (__g > 0)
4656        {
4657            __tx = std::trunc(__g);
4658            if (__tx >= __pr.__l_)
4659                return std::__clamp_to_integral<result_type>(__tx);
4660            __difmuk = __pr.__mean_ - __tx;
4661            __u = __urd(__urng);
4662            if (__pr.__d_ * __u >= __difmuk * __difmuk * __difmuk)
4663                return std::__clamp_to_integral<result_type>(__tx);
4664        }
4665        exponential_distribution<double> __edist;
4666        for (bool __using_exp_dist = false; true; __using_exp_dist = true)
4667        {
4668            double __e;
4669            if (__using_exp_dist || __g <= 0)
4670            {
4671                double __t;
4672                do
4673                {
4674                    __e = __edist(__urng);
4675                    __u = __urd(__urng);
4676                    __u += __u - 1;
4677                    __t = 1.8 + (__u < 0 ? -__e : __e);
4678                } while (__t <= -.6744);
4679                __tx = std::trunc(__pr.__mean_ + __pr.__s_ * __t);
4680                __difmuk = __pr.__mean_ - __tx;
4681                __using_exp_dist = true;
4682            }
4683            double __px;
4684            double __py;
4685            if (__tx < 10 && __tx >= 0)
4686            {
4687                const double __fac[] = {1, 1, 2, 6, 24, 120, 720, 5040,
4688                                             40320, 362880};
4689                __px = -__pr.__mean_;
4690                __py = _VSTD::pow(__pr.__mean_, (double)__tx) / __fac[static_cast<int>(__tx)];
4691            }
4692            else
4693            {
4694                double __del = .8333333E-1 / __tx;
4695                __del -= 4.8 * __del * __del * __del;
4696                double __v = __difmuk / __tx;
4697                if (_VSTD::abs(__v) > 0.25)
4698                    __px = __tx * _VSTD::log(1 + __v) - __difmuk - __del;
4699                else
4700                    __px = __tx * __v * __v * (((((((.1250060 * __v + -.1384794) *
4701                           __v + .1421878) * __v + -.1661269) * __v + .2000118) *
4702                           __v + -.2500068) * __v + .3333333) * __v + -.5) - __del;
4703                __py = .3989423 / _VSTD::sqrt(__tx);
4704            }
4705            double __r = (0.5 - __difmuk) / __pr.__s_;
4706            double __r2 = __r * __r;
4707            double __fx = -0.5 * __r2;
4708            double __fy = __pr.__omega_ * (((__pr.__c3_ * __r2 + __pr.__c2_) *
4709                                        __r2 + __pr.__c1_) * __r2 + __pr.__c0_);
4710            if (__using_exp_dist)
4711            {
4712                if (__pr.__c_ * _VSTD::abs(__u) <= __py * _VSTD::exp(__px + __e) -
4713                                                   __fy * _VSTD::exp(__fx + __e))
4714                    break;
4715            }
4716            else
4717            {
4718                if (__fy - __u * __fy <= __py * _VSTD::exp(__px - __fx))
4719                    break;
4720            }
4721        }
4722    }
4723    return std::__clamp_to_integral<result_type>(__tx);
4724}
4725
4726template <class _CharT, class _Traits, class _IntType>
4727basic_ostream<_CharT, _Traits>&
4728operator<<(basic_ostream<_CharT, _Traits>& __os,
4729           const poisson_distribution<_IntType>& __x)
4730{
4731    __save_flags<_CharT, _Traits> __lx(__os);
4732    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4733               ios_base::scientific);
4734    return __os << __x.mean();
4735}
4736
4737template <class _CharT, class _Traits, class _IntType>
4738basic_istream<_CharT, _Traits>&
4739operator>>(basic_istream<_CharT, _Traits>& __is,
4740           poisson_distribution<_IntType>& __x)
4741{
4742    typedef poisson_distribution<_IntType> _Eng;
4743    typedef typename _Eng::param_type param_type;
4744    __save_flags<_CharT, _Traits> __lx(__is);
4745    __is.flags(ios_base::dec | ios_base::skipws);
4746    double __mean;
4747    __is >> __mean;
4748    if (!__is.fail())
4749        __x.param(param_type(__mean));
4750    return __is;
4751}
4752
4753// weibull_distribution
4754
4755template<class _RealType = double>
4756class _LIBCPP_TEMPLATE_VIS weibull_distribution
4757{
4758public:
4759    // types
4760    typedef _RealType result_type;
4761
4762    class _LIBCPP_TEMPLATE_VIS param_type
4763    {
4764        result_type __a_;
4765        result_type __b_;
4766    public:
4767        typedef weibull_distribution distribution_type;
4768
4769        _LIBCPP_INLINE_VISIBILITY
4770        explicit param_type(result_type __a = 1, result_type __b = 1)
4771            : __a_(__a), __b_(__b) {}
4772
4773        _LIBCPP_INLINE_VISIBILITY
4774        result_type a() const {return __a_;}
4775        _LIBCPP_INLINE_VISIBILITY
4776        result_type b() const {return __b_;}
4777
4778        friend _LIBCPP_INLINE_VISIBILITY
4779            bool operator==(const param_type& __x, const param_type& __y)
4780            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
4781        friend _LIBCPP_INLINE_VISIBILITY
4782            bool operator!=(const param_type& __x, const param_type& __y)
4783            {return !(__x == __y);}
4784    };
4785
4786private:
4787    param_type __p_;
4788
4789public:
4790    // constructor and reset functions
4791    _LIBCPP_INLINE_VISIBILITY
4792    explicit weibull_distribution(result_type __a = 1, result_type __b = 1)
4793        : __p_(param_type(__a, __b)) {}
4794    _LIBCPP_INLINE_VISIBILITY
4795    explicit weibull_distribution(const param_type& __p)
4796        : __p_(__p) {}
4797    _LIBCPP_INLINE_VISIBILITY
4798    void reset() {}
4799
4800    // generating functions
4801    template<class _URNG>
4802        _LIBCPP_INLINE_VISIBILITY
4803        result_type operator()(_URNG& __g)
4804        {return (*this)(__g, __p_);}
4805    template<class _URNG>
4806        _LIBCPP_INLINE_VISIBILITY
4807        result_type operator()(_URNG& __g, const param_type& __p)
4808        {return __p.b() *
4809            _VSTD::pow(exponential_distribution<result_type>()(__g), 1/__p.a());}
4810
4811    // property functions
4812    _LIBCPP_INLINE_VISIBILITY
4813    result_type a() const {return __p_.a();}
4814    _LIBCPP_INLINE_VISIBILITY
4815    result_type b() const {return __p_.b();}
4816
4817    _LIBCPP_INLINE_VISIBILITY
4818    param_type param() const {return __p_;}
4819    _LIBCPP_INLINE_VISIBILITY
4820    void param(const param_type& __p) {__p_ = __p;}
4821
4822    _LIBCPP_INLINE_VISIBILITY
4823    result_type min() const {return 0;}
4824    _LIBCPP_INLINE_VISIBILITY
4825    result_type max() const {return numeric_limits<result_type>::infinity();}
4826
4827    friend _LIBCPP_INLINE_VISIBILITY
4828        bool operator==(const weibull_distribution& __x,
4829                        const weibull_distribution& __y)
4830        {return __x.__p_ == __y.__p_;}
4831    friend _LIBCPP_INLINE_VISIBILITY
4832        bool operator!=(const weibull_distribution& __x,
4833                        const weibull_distribution& __y)
4834        {return !(__x == __y);}
4835};
4836
4837template <class _CharT, class _Traits, class _RT>
4838basic_ostream<_CharT, _Traits>&
4839operator<<(basic_ostream<_CharT, _Traits>& __os,
4840           const weibull_distribution<_RT>& __x)
4841{
4842    __save_flags<_CharT, _Traits> __lx(__os);
4843    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4844               ios_base::scientific);
4845    _CharT __sp = __os.widen(' ');
4846    __os.fill(__sp);
4847    __os << __x.a() << __sp << __x.b();
4848    return __os;
4849}
4850
4851template <class _CharT, class _Traits, class _RT>
4852basic_istream<_CharT, _Traits>&
4853operator>>(basic_istream<_CharT, _Traits>& __is,
4854           weibull_distribution<_RT>& __x)
4855{
4856    typedef weibull_distribution<_RT> _Eng;
4857    typedef typename _Eng::result_type result_type;
4858    typedef typename _Eng::param_type param_type;
4859    __save_flags<_CharT, _Traits> __lx(__is);
4860    __is.flags(ios_base::dec | ios_base::skipws);
4861    result_type __a;
4862    result_type __b;
4863    __is >> __a >> __b;
4864    if (!__is.fail())
4865        __x.param(param_type(__a, __b));
4866    return __is;
4867}
4868
4869template<class _RealType = double>
4870class _LIBCPP_TEMPLATE_VIS extreme_value_distribution
4871{
4872public:
4873    // types
4874    typedef _RealType result_type;
4875
4876    class _LIBCPP_TEMPLATE_VIS param_type
4877    {
4878        result_type __a_;
4879        result_type __b_;
4880    public:
4881        typedef extreme_value_distribution distribution_type;
4882
4883        _LIBCPP_INLINE_VISIBILITY
4884        explicit param_type(result_type __a = 0, result_type __b = 1)
4885            : __a_(__a), __b_(__b) {}
4886
4887        _LIBCPP_INLINE_VISIBILITY
4888        result_type a() const {return __a_;}
4889        _LIBCPP_INLINE_VISIBILITY
4890        result_type b() const {return __b_;}
4891
4892        friend _LIBCPP_INLINE_VISIBILITY
4893            bool operator==(const param_type& __x, const param_type& __y)
4894            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
4895        friend _LIBCPP_INLINE_VISIBILITY
4896            bool operator!=(const param_type& __x, const param_type& __y)
4897            {return !(__x == __y);}
4898    };
4899
4900private:
4901    param_type __p_;
4902
4903public:
4904    // constructor and reset functions
4905    _LIBCPP_INLINE_VISIBILITY
4906    explicit extreme_value_distribution(result_type __a = 0, result_type __b = 1)
4907        : __p_(param_type(__a, __b)) {}
4908    _LIBCPP_INLINE_VISIBILITY
4909    explicit extreme_value_distribution(const param_type& __p)
4910        : __p_(__p) {}
4911    _LIBCPP_INLINE_VISIBILITY
4912    void reset() {}
4913
4914    // generating functions
4915    template<class _URNG>
4916        _LIBCPP_INLINE_VISIBILITY
4917        result_type operator()(_URNG& __g)
4918        {return (*this)(__g, __p_);}
4919    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4920
4921    // property functions
4922    _LIBCPP_INLINE_VISIBILITY
4923    result_type a() const {return __p_.a();}
4924    _LIBCPP_INLINE_VISIBILITY
4925    result_type b() const {return __p_.b();}
4926
4927    _LIBCPP_INLINE_VISIBILITY
4928    param_type param() const {return __p_;}
4929    _LIBCPP_INLINE_VISIBILITY
4930    void param(const param_type& __p) {__p_ = __p;}
4931
4932    _LIBCPP_INLINE_VISIBILITY
4933    result_type min() const {return -numeric_limits<result_type>::infinity();}
4934    _LIBCPP_INLINE_VISIBILITY
4935    result_type max() const {return numeric_limits<result_type>::infinity();}
4936
4937    friend _LIBCPP_INLINE_VISIBILITY
4938        bool operator==(const extreme_value_distribution& __x,
4939                        const extreme_value_distribution& __y)
4940        {return __x.__p_ == __y.__p_;}
4941    friend _LIBCPP_INLINE_VISIBILITY
4942        bool operator!=(const extreme_value_distribution& __x,
4943                        const extreme_value_distribution& __y)
4944        {return !(__x == __y);}
4945};
4946
4947template<class _RealType>
4948template<class _URNG>
4949_RealType
4950extreme_value_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4951{
4952    return __p.a() - __p.b() *
4953         _VSTD::log(-_VSTD::log(1-uniform_real_distribution<result_type>()(__g)));
4954}
4955
4956template <class _CharT, class _Traits, class _RT>
4957basic_ostream<_CharT, _Traits>&
4958operator<<(basic_ostream<_CharT, _Traits>& __os,
4959           const extreme_value_distribution<_RT>& __x)
4960{
4961    __save_flags<_CharT, _Traits> __lx(__os);
4962    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4963               ios_base::scientific);
4964    _CharT __sp = __os.widen(' ');
4965    __os.fill(__sp);
4966    __os << __x.a() << __sp << __x.b();
4967    return __os;
4968}
4969
4970template <class _CharT, class _Traits, class _RT>
4971basic_istream<_CharT, _Traits>&
4972operator>>(basic_istream<_CharT, _Traits>& __is,
4973           extreme_value_distribution<_RT>& __x)
4974{
4975    typedef extreme_value_distribution<_RT> _Eng;
4976    typedef typename _Eng::result_type result_type;
4977    typedef typename _Eng::param_type param_type;
4978    __save_flags<_CharT, _Traits> __lx(__is);
4979    __is.flags(ios_base::dec | ios_base::skipws);
4980    result_type __a;
4981    result_type __b;
4982    __is >> __a >> __b;
4983    if (!__is.fail())
4984        __x.param(param_type(__a, __b));
4985    return __is;
4986}
4987
4988// gamma_distribution
4989
4990template<class _RealType = double>
4991class _LIBCPP_TEMPLATE_VIS gamma_distribution
4992{
4993public:
4994    // types
4995    typedef _RealType result_type;
4996
4997    class _LIBCPP_TEMPLATE_VIS param_type
4998    {
4999        result_type __alpha_;
5000        result_type __beta_;
5001    public:
5002        typedef gamma_distribution distribution_type;
5003
5004        _LIBCPP_INLINE_VISIBILITY
5005        explicit param_type(result_type __alpha = 1, result_type __beta = 1)
5006            : __alpha_(__alpha), __beta_(__beta) {}
5007
5008        _LIBCPP_INLINE_VISIBILITY
5009        result_type alpha() const {return __alpha_;}
5010        _LIBCPP_INLINE_VISIBILITY
5011        result_type beta() const {return __beta_;}
5012
5013        friend _LIBCPP_INLINE_VISIBILITY
5014            bool operator==(const param_type& __x, const param_type& __y)
5015            {return __x.__alpha_ == __y.__alpha_ && __x.__beta_ == __y.__beta_;}
5016        friend _LIBCPP_INLINE_VISIBILITY
5017            bool operator!=(const param_type& __x, const param_type& __y)
5018            {return !(__x == __y);}
5019    };
5020
5021private:
5022    param_type __p_;
5023
5024public:
5025    // constructors and reset functions
5026    _LIBCPP_INLINE_VISIBILITY
5027    explicit gamma_distribution(result_type __alpha = 1, result_type __beta = 1)
5028        : __p_(param_type(__alpha, __beta)) {}
5029    _LIBCPP_INLINE_VISIBILITY
5030    explicit gamma_distribution(const param_type& __p)
5031        : __p_(__p) {}
5032    _LIBCPP_INLINE_VISIBILITY
5033    void reset() {}
5034
5035    // generating functions
5036    template<class _URNG>
5037        _LIBCPP_INLINE_VISIBILITY
5038        result_type operator()(_URNG& __g)
5039        {return (*this)(__g, __p_);}
5040    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5041
5042    // property functions
5043    _LIBCPP_INLINE_VISIBILITY
5044    result_type alpha() const {return __p_.alpha();}
5045    _LIBCPP_INLINE_VISIBILITY
5046    result_type beta() const {return __p_.beta();}
5047
5048    _LIBCPP_INLINE_VISIBILITY
5049    param_type param() const {return __p_;}
5050    _LIBCPP_INLINE_VISIBILITY
5051    void param(const param_type& __p) {__p_ = __p;}
5052
5053    _LIBCPP_INLINE_VISIBILITY
5054    result_type min() const {return 0;}
5055    _LIBCPP_INLINE_VISIBILITY
5056    result_type max() const {return numeric_limits<result_type>::infinity();}
5057
5058    friend _LIBCPP_INLINE_VISIBILITY
5059        bool operator==(const gamma_distribution& __x,
5060                        const gamma_distribution& __y)
5061        {return __x.__p_ == __y.__p_;}
5062    friend _LIBCPP_INLINE_VISIBILITY
5063        bool operator!=(const gamma_distribution& __x,
5064                        const gamma_distribution& __y)
5065        {return !(__x == __y);}
5066};
5067
5068template <class _RealType>
5069template<class _URNG>
5070_RealType
5071gamma_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5072{
5073    result_type __a = __p.alpha();
5074    uniform_real_distribution<result_type> __gen(0, 1);
5075    exponential_distribution<result_type> __egen;
5076    result_type __x;
5077    if (__a == 1)
5078        __x = __egen(__g);
5079    else if (__a > 1)
5080    {
5081        const result_type __b = __a - 1;
5082        const result_type __c = 3 * __a - result_type(0.75);
5083        while (true)
5084        {
5085            const result_type __u = __gen(__g);
5086            const result_type __v = __gen(__g);
5087            const result_type __w = __u * (1 - __u);
5088            if (__w != 0)
5089            {
5090                const result_type __y = _VSTD::sqrt(__c / __w) *
5091                                        (__u - result_type(0.5));
5092                __x = __b + __y;
5093                if (__x >= 0)
5094                {
5095                    const result_type __z = 64 * __w * __w * __w * __v * __v;
5096                    if (__z <= 1 - 2 * __y * __y / __x)
5097                        break;
5098                    if (_VSTD::log(__z) <= 2 * (__b * _VSTD::log(__x / __b) - __y))
5099                        break;
5100                }
5101            }
5102        }
5103    }
5104    else  // __a < 1
5105    {
5106        while (true)
5107        {
5108            const result_type __u = __gen(__g);
5109            const result_type __es = __egen(__g);
5110            if (__u <= 1 - __a)
5111            {
5112                __x = _VSTD::pow(__u, 1 / __a);
5113                if (__x <= __es)
5114                    break;
5115            }
5116            else
5117            {
5118                const result_type __e = -_VSTD::log((1-__u)/__a);
5119                __x = _VSTD::pow(1 - __a + __a * __e, 1 / __a);
5120                if (__x <= __e + __es)
5121                    break;
5122            }
5123        }
5124    }
5125    return __x * __p.beta();
5126}
5127
5128template <class _CharT, class _Traits, class _RT>
5129basic_ostream<_CharT, _Traits>&
5130operator<<(basic_ostream<_CharT, _Traits>& __os,
5131           const gamma_distribution<_RT>& __x)
5132{
5133    __save_flags<_CharT, _Traits> __lx(__os);
5134    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5135               ios_base::scientific);
5136    _CharT __sp = __os.widen(' ');
5137    __os.fill(__sp);
5138    __os << __x.alpha() << __sp << __x.beta();
5139    return __os;
5140}
5141
5142template <class _CharT, class _Traits, class _RT>
5143basic_istream<_CharT, _Traits>&
5144operator>>(basic_istream<_CharT, _Traits>& __is,
5145           gamma_distribution<_RT>& __x)
5146{
5147    typedef gamma_distribution<_RT> _Eng;
5148    typedef typename _Eng::result_type result_type;
5149    typedef typename _Eng::param_type param_type;
5150    __save_flags<_CharT, _Traits> __lx(__is);
5151    __is.flags(ios_base::dec | ios_base::skipws);
5152    result_type __alpha;
5153    result_type __beta;
5154    __is >> __alpha >> __beta;
5155    if (!__is.fail())
5156        __x.param(param_type(__alpha, __beta));
5157    return __is;
5158}
5159
5160// negative_binomial_distribution
5161
5162template<class _IntType = int>
5163class _LIBCPP_TEMPLATE_VIS negative_binomial_distribution
5164{
5165public:
5166    // types
5167    typedef _IntType result_type;
5168
5169    class _LIBCPP_TEMPLATE_VIS param_type
5170    {
5171        result_type __k_;
5172        double __p_;
5173    public:
5174        typedef negative_binomial_distribution distribution_type;
5175
5176        _LIBCPP_INLINE_VISIBILITY
5177        explicit param_type(result_type __k = 1, double __p = 0.5)
5178            : __k_(__k), __p_(__p) {}
5179
5180        _LIBCPP_INLINE_VISIBILITY
5181        result_type k() const {return __k_;}
5182        _LIBCPP_INLINE_VISIBILITY
5183        double p() const {return __p_;}
5184
5185        friend _LIBCPP_INLINE_VISIBILITY
5186            bool operator==(const param_type& __x, const param_type& __y)
5187            {return __x.__k_ == __y.__k_ && __x.__p_ == __y.__p_;}
5188        friend _LIBCPP_INLINE_VISIBILITY
5189            bool operator!=(const param_type& __x, const param_type& __y)
5190            {return !(__x == __y);}
5191    };
5192
5193private:
5194    param_type __p_;
5195
5196public:
5197    // constructor and reset functions
5198    _LIBCPP_INLINE_VISIBILITY
5199    explicit negative_binomial_distribution(result_type __k = 1, double __p = 0.5)
5200        : __p_(__k, __p) {}
5201    _LIBCPP_INLINE_VISIBILITY
5202    explicit negative_binomial_distribution(const param_type& __p) : __p_(__p) {}
5203    _LIBCPP_INLINE_VISIBILITY
5204    void reset() {}
5205
5206    // generating functions
5207    template<class _URNG>
5208        _LIBCPP_INLINE_VISIBILITY
5209        result_type operator()(_URNG& __g)
5210        {return (*this)(__g, __p_);}
5211    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5212
5213    // property functions
5214    _LIBCPP_INLINE_VISIBILITY
5215    result_type k() const {return __p_.k();}
5216    _LIBCPP_INLINE_VISIBILITY
5217    double p() const {return __p_.p();}
5218
5219    _LIBCPP_INLINE_VISIBILITY
5220    param_type param() const {return __p_;}
5221    _LIBCPP_INLINE_VISIBILITY
5222    void param(const param_type& __p) {__p_ = __p;}
5223
5224    _LIBCPP_INLINE_VISIBILITY
5225    result_type min() const {return 0;}
5226    _LIBCPP_INLINE_VISIBILITY
5227    result_type max() const {return numeric_limits<result_type>::max();}
5228
5229    friend _LIBCPP_INLINE_VISIBILITY
5230        bool operator==(const negative_binomial_distribution& __x,
5231                        const negative_binomial_distribution& __y)
5232        {return __x.__p_ == __y.__p_;}
5233    friend _LIBCPP_INLINE_VISIBILITY
5234        bool operator!=(const negative_binomial_distribution& __x,
5235                        const negative_binomial_distribution& __y)
5236        {return !(__x == __y);}
5237};
5238
5239template <class _IntType>
5240template<class _URNG>
5241_IntType
5242negative_binomial_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
5243{
5244    result_type __k = __pr.k();
5245    double __p = __pr.p();
5246    if (__k <= 21 * __p)
5247    {
5248        bernoulli_distribution __gen(__p);
5249        result_type __f = 0;
5250        result_type __s = 0;
5251        while (__s < __k)
5252        {
5253            if (__gen(__urng))
5254                ++__s;
5255            else
5256                ++__f;
5257        }
5258        return __f;
5259    }
5260    return poisson_distribution<result_type>(gamma_distribution<double>
5261                                            (__k, (1-__p)/__p)(__urng))(__urng);
5262}
5263
5264template <class _CharT, class _Traits, class _IntType>
5265basic_ostream<_CharT, _Traits>&
5266operator<<(basic_ostream<_CharT, _Traits>& __os,
5267           const negative_binomial_distribution<_IntType>& __x)
5268{
5269    __save_flags<_CharT, _Traits> __lx(__os);
5270    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5271               ios_base::scientific);
5272    _CharT __sp = __os.widen(' ');
5273    __os.fill(__sp);
5274    return __os << __x.k() << __sp << __x.p();
5275}
5276
5277template <class _CharT, class _Traits, class _IntType>
5278basic_istream<_CharT, _Traits>&
5279operator>>(basic_istream<_CharT, _Traits>& __is,
5280           negative_binomial_distribution<_IntType>& __x)
5281{
5282    typedef negative_binomial_distribution<_IntType> _Eng;
5283    typedef typename _Eng::result_type result_type;
5284    typedef typename _Eng::param_type param_type;
5285    __save_flags<_CharT, _Traits> __lx(__is);
5286    __is.flags(ios_base::dec | ios_base::skipws);
5287    result_type __k;
5288    double __p;
5289    __is >> __k >> __p;
5290    if (!__is.fail())
5291        __x.param(param_type(__k, __p));
5292    return __is;
5293}
5294
5295// geometric_distribution
5296
5297template<class _IntType = int>
5298class _LIBCPP_TEMPLATE_VIS geometric_distribution
5299{
5300public:
5301    // types
5302    typedef _IntType result_type;
5303
5304    class _LIBCPP_TEMPLATE_VIS param_type
5305    {
5306        double __p_;
5307    public:
5308        typedef geometric_distribution distribution_type;
5309
5310        _LIBCPP_INLINE_VISIBILITY
5311        explicit param_type(double __p = 0.5) : __p_(__p) {}
5312
5313        _LIBCPP_INLINE_VISIBILITY
5314        double p() const {return __p_;}
5315
5316        friend _LIBCPP_INLINE_VISIBILITY
5317            bool operator==(const param_type& __x, const param_type& __y)
5318            {return __x.__p_ == __y.__p_;}
5319        friend _LIBCPP_INLINE_VISIBILITY
5320            bool operator!=(const param_type& __x, const param_type& __y)
5321            {return !(__x == __y);}
5322    };
5323
5324private:
5325    param_type __p_;
5326
5327public:
5328    // constructors and reset functions
5329    _LIBCPP_INLINE_VISIBILITY
5330    explicit geometric_distribution(double __p = 0.5) : __p_(__p) {}
5331    _LIBCPP_INLINE_VISIBILITY
5332    explicit geometric_distribution(const param_type& __p) : __p_(__p) {}
5333    _LIBCPP_INLINE_VISIBILITY
5334    void reset() {}
5335
5336    // generating functions
5337    template<class _URNG>
5338        _LIBCPP_INLINE_VISIBILITY
5339        result_type operator()(_URNG& __g)
5340        {return (*this)(__g, __p_);}
5341    template<class _URNG>
5342        _LIBCPP_INLINE_VISIBILITY
5343        result_type operator()(_URNG& __g, const param_type& __p)
5344        {return negative_binomial_distribution<result_type>(1, __p.p())(__g);}
5345
5346    // property functions
5347    _LIBCPP_INLINE_VISIBILITY
5348    double p() const {return __p_.p();}
5349
5350    _LIBCPP_INLINE_VISIBILITY
5351    param_type param() const {return __p_;}
5352    _LIBCPP_INLINE_VISIBILITY
5353    void param(const param_type& __p) {__p_ = __p;}
5354
5355    _LIBCPP_INLINE_VISIBILITY
5356    result_type min() const {return 0;}
5357    _LIBCPP_INLINE_VISIBILITY
5358    result_type max() const {return numeric_limits<result_type>::max();}
5359
5360    friend _LIBCPP_INLINE_VISIBILITY
5361        bool operator==(const geometric_distribution& __x,
5362                        const geometric_distribution& __y)
5363        {return __x.__p_ == __y.__p_;}
5364    friend _LIBCPP_INLINE_VISIBILITY
5365        bool operator!=(const geometric_distribution& __x,
5366                        const geometric_distribution& __y)
5367        {return !(__x == __y);}
5368};
5369
5370template <class _CharT, class _Traits, class _IntType>
5371basic_ostream<_CharT, _Traits>&
5372operator<<(basic_ostream<_CharT, _Traits>& __os,
5373           const geometric_distribution<_IntType>& __x)
5374{
5375    __save_flags<_CharT, _Traits> __lx(__os);
5376    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5377               ios_base::scientific);
5378    return __os << __x.p();
5379}
5380
5381template <class _CharT, class _Traits, class _IntType>
5382basic_istream<_CharT, _Traits>&
5383operator>>(basic_istream<_CharT, _Traits>& __is,
5384           geometric_distribution<_IntType>& __x)
5385{
5386    typedef geometric_distribution<_IntType> _Eng;
5387    typedef typename _Eng::param_type param_type;
5388    __save_flags<_CharT, _Traits> __lx(__is);
5389    __is.flags(ios_base::dec | ios_base::skipws);
5390    double __p;
5391    __is >> __p;
5392    if (!__is.fail())
5393        __x.param(param_type(__p));
5394    return __is;
5395}
5396
5397// chi_squared_distribution
5398
5399template<class _RealType = double>
5400class _LIBCPP_TEMPLATE_VIS chi_squared_distribution
5401{
5402public:
5403    // types
5404    typedef _RealType result_type;
5405
5406    class _LIBCPP_TEMPLATE_VIS param_type
5407    {
5408        result_type __n_;
5409    public:
5410        typedef chi_squared_distribution distribution_type;
5411
5412        _LIBCPP_INLINE_VISIBILITY
5413        explicit param_type(result_type __n = 1) : __n_(__n) {}
5414
5415        _LIBCPP_INLINE_VISIBILITY
5416        result_type n() const {return __n_;}
5417
5418        friend _LIBCPP_INLINE_VISIBILITY
5419            bool operator==(const param_type& __x, const param_type& __y)
5420            {return __x.__n_ == __y.__n_;}
5421        friend _LIBCPP_INLINE_VISIBILITY
5422            bool operator!=(const param_type& __x, const param_type& __y)
5423            {return !(__x == __y);}
5424    };
5425
5426private:
5427    param_type __p_;
5428
5429public:
5430    // constructor and reset functions
5431    _LIBCPP_INLINE_VISIBILITY
5432    explicit chi_squared_distribution(result_type __n = 1)
5433        : __p_(param_type(__n)) {}
5434    _LIBCPP_INLINE_VISIBILITY
5435    explicit chi_squared_distribution(const param_type& __p)
5436        : __p_(__p) {}
5437    _LIBCPP_INLINE_VISIBILITY
5438    void reset() {}
5439
5440    // generating functions
5441    template<class _URNG>
5442        _LIBCPP_INLINE_VISIBILITY
5443        result_type operator()(_URNG& __g)
5444        {return (*this)(__g, __p_);}
5445    template<class _URNG>
5446        _LIBCPP_INLINE_VISIBILITY
5447        result_type operator()(_URNG& __g, const param_type& __p)
5448        {return gamma_distribution<result_type>(__p.n() / 2, 2)(__g);}
5449
5450    // property functions
5451    _LIBCPP_INLINE_VISIBILITY
5452    result_type n() const {return __p_.n();}
5453
5454    _LIBCPP_INLINE_VISIBILITY
5455    param_type param() const {return __p_;}
5456    _LIBCPP_INLINE_VISIBILITY
5457    void param(const param_type& __p) {__p_ = __p;}
5458
5459    _LIBCPP_INLINE_VISIBILITY
5460    result_type min() const {return 0;}
5461    _LIBCPP_INLINE_VISIBILITY
5462    result_type max() const {return numeric_limits<result_type>::infinity();}
5463
5464    friend _LIBCPP_INLINE_VISIBILITY
5465        bool operator==(const chi_squared_distribution& __x,
5466                        const chi_squared_distribution& __y)
5467        {return __x.__p_ == __y.__p_;}
5468    friend _LIBCPP_INLINE_VISIBILITY
5469        bool operator!=(const chi_squared_distribution& __x,
5470                        const chi_squared_distribution& __y)
5471        {return !(__x == __y);}
5472};
5473
5474template <class _CharT, class _Traits, class _RT>
5475basic_ostream<_CharT, _Traits>&
5476operator<<(basic_ostream<_CharT, _Traits>& __os,
5477           const chi_squared_distribution<_RT>& __x)
5478{
5479    __save_flags<_CharT, _Traits> __lx(__os);
5480    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5481               ios_base::scientific);
5482    __os << __x.n();
5483    return __os;
5484}
5485
5486template <class _CharT, class _Traits, class _RT>
5487basic_istream<_CharT, _Traits>&
5488operator>>(basic_istream<_CharT, _Traits>& __is,
5489           chi_squared_distribution<_RT>& __x)
5490{
5491    typedef chi_squared_distribution<_RT> _Eng;
5492    typedef typename _Eng::result_type result_type;
5493    typedef typename _Eng::param_type param_type;
5494    __save_flags<_CharT, _Traits> __lx(__is);
5495    __is.flags(ios_base::dec | ios_base::skipws);
5496    result_type __n;
5497    __is >> __n;
5498    if (!__is.fail())
5499        __x.param(param_type(__n));
5500    return __is;
5501}
5502
5503// cauchy_distribution
5504
5505template<class _RealType = double>
5506class _LIBCPP_TEMPLATE_VIS cauchy_distribution
5507{
5508public:
5509    // types
5510    typedef _RealType result_type;
5511
5512    class _LIBCPP_TEMPLATE_VIS param_type
5513    {
5514        result_type __a_;
5515        result_type __b_;
5516    public:
5517        typedef cauchy_distribution distribution_type;
5518
5519        _LIBCPP_INLINE_VISIBILITY
5520        explicit param_type(result_type __a = 0, result_type __b = 1)
5521            : __a_(__a), __b_(__b) {}
5522
5523        _LIBCPP_INLINE_VISIBILITY
5524        result_type a() const {return __a_;}
5525        _LIBCPP_INLINE_VISIBILITY
5526        result_type b() const {return __b_;}
5527
5528        friend _LIBCPP_INLINE_VISIBILITY
5529            bool operator==(const param_type& __x, const param_type& __y)
5530            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
5531        friend _LIBCPP_INLINE_VISIBILITY
5532            bool operator!=(const param_type& __x, const param_type& __y)
5533            {return !(__x == __y);}
5534    };
5535
5536private:
5537    param_type __p_;
5538
5539public:
5540    // constructor and reset functions
5541    _LIBCPP_INLINE_VISIBILITY
5542    explicit cauchy_distribution(result_type __a = 0, result_type __b = 1)
5543        : __p_(param_type(__a, __b)) {}
5544    _LIBCPP_INLINE_VISIBILITY
5545    explicit cauchy_distribution(const param_type& __p)
5546        : __p_(__p) {}
5547    _LIBCPP_INLINE_VISIBILITY
5548    void reset() {}
5549
5550    // generating functions
5551    template<class _URNG>
5552        _LIBCPP_INLINE_VISIBILITY
5553        result_type operator()(_URNG& __g)
5554        {return (*this)(__g, __p_);}
5555    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
5556
5557    // property functions
5558    _LIBCPP_INLINE_VISIBILITY
5559    result_type a() const {return __p_.a();}
5560    _LIBCPP_INLINE_VISIBILITY
5561    result_type b() const {return __p_.b();}
5562
5563    _LIBCPP_INLINE_VISIBILITY
5564    param_type param() const {return __p_;}
5565    _LIBCPP_INLINE_VISIBILITY
5566    void param(const param_type& __p) {__p_ = __p;}
5567
5568    _LIBCPP_INLINE_VISIBILITY
5569    result_type min() const {return -numeric_limits<result_type>::infinity();}
5570    _LIBCPP_INLINE_VISIBILITY
5571    result_type max() const {return numeric_limits<result_type>::infinity();}
5572
5573    friend _LIBCPP_INLINE_VISIBILITY
5574        bool operator==(const cauchy_distribution& __x,
5575                        const cauchy_distribution& __y)
5576        {return __x.__p_ == __y.__p_;}
5577    friend _LIBCPP_INLINE_VISIBILITY
5578        bool operator!=(const cauchy_distribution& __x,
5579                        const cauchy_distribution& __y)
5580        {return !(__x == __y);}
5581};
5582
5583template <class _RealType>
5584template<class _URNG>
5585inline
5586_RealType
5587cauchy_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5588{
5589    uniform_real_distribution<result_type> __gen;
5590    // purposefully let tan arg get as close to pi/2 as it wants, tan will return a finite
5591    return __p.a() + __p.b() * _VSTD::tan(3.1415926535897932384626433832795 * __gen(__g));
5592}
5593
5594template <class _CharT, class _Traits, class _RT>
5595basic_ostream<_CharT, _Traits>&
5596operator<<(basic_ostream<_CharT, _Traits>& __os,
5597           const cauchy_distribution<_RT>& __x)
5598{
5599    __save_flags<_CharT, _Traits> __lx(__os);
5600    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5601               ios_base::scientific);
5602    _CharT __sp = __os.widen(' ');
5603    __os.fill(__sp);
5604    __os << __x.a() << __sp << __x.b();
5605    return __os;
5606}
5607
5608template <class _CharT, class _Traits, class _RT>
5609basic_istream<_CharT, _Traits>&
5610operator>>(basic_istream<_CharT, _Traits>& __is,
5611           cauchy_distribution<_RT>& __x)
5612{
5613    typedef cauchy_distribution<_RT> _Eng;
5614    typedef typename _Eng::result_type result_type;
5615    typedef typename _Eng::param_type param_type;
5616    __save_flags<_CharT, _Traits> __lx(__is);
5617    __is.flags(ios_base::dec | ios_base::skipws);
5618    result_type __a;
5619    result_type __b;
5620    __is >> __a >> __b;
5621    if (!__is.fail())
5622        __x.param(param_type(__a, __b));
5623    return __is;
5624}
5625
5626// fisher_f_distribution
5627
5628template<class _RealType = double>
5629class _LIBCPP_TEMPLATE_VIS fisher_f_distribution
5630{
5631public:
5632    // types
5633    typedef _RealType result_type;
5634
5635    class _LIBCPP_TEMPLATE_VIS param_type
5636    {
5637        result_type __m_;
5638        result_type __n_;
5639    public:
5640        typedef fisher_f_distribution distribution_type;
5641
5642        _LIBCPP_INLINE_VISIBILITY
5643        explicit param_type(result_type __m = 1, result_type __n = 1)
5644            : __m_(__m), __n_(__n) {}
5645
5646        _LIBCPP_INLINE_VISIBILITY
5647        result_type m() const {return __m_;}
5648        _LIBCPP_INLINE_VISIBILITY
5649        result_type n() const {return __n_;}
5650
5651        friend _LIBCPP_INLINE_VISIBILITY
5652            bool operator==(const param_type& __x, const param_type& __y)
5653            {return __x.__m_ == __y.__m_ && __x.__n_ == __y.__n_;}
5654        friend _LIBCPP_INLINE_VISIBILITY
5655            bool operator!=(const param_type& __x, const param_type& __y)
5656            {return !(__x == __y);}
5657    };
5658
5659private:
5660    param_type __p_;
5661
5662public:
5663    // constructor and reset functions
5664    _LIBCPP_INLINE_VISIBILITY
5665    explicit fisher_f_distribution(result_type __m = 1, result_type __n = 1)
5666        : __p_(param_type(__m, __n)) {}
5667    _LIBCPP_INLINE_VISIBILITY
5668    explicit fisher_f_distribution(const param_type& __p)
5669        : __p_(__p) {}
5670    _LIBCPP_INLINE_VISIBILITY
5671    void reset() {}
5672
5673    // generating functions
5674    template<class _URNG>
5675        _LIBCPP_INLINE_VISIBILITY
5676        result_type operator()(_URNG& __g)
5677        {return (*this)(__g, __p_);}
5678    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5679
5680    // property functions
5681    _LIBCPP_INLINE_VISIBILITY
5682    result_type m() const {return __p_.m();}
5683    _LIBCPP_INLINE_VISIBILITY
5684    result_type n() const {return __p_.n();}
5685
5686    _LIBCPP_INLINE_VISIBILITY
5687    param_type param() const {return __p_;}
5688    _LIBCPP_INLINE_VISIBILITY
5689    void param(const param_type& __p) {__p_ = __p;}
5690
5691    _LIBCPP_INLINE_VISIBILITY
5692    result_type min() const {return 0;}
5693    _LIBCPP_INLINE_VISIBILITY
5694    result_type max() const {return numeric_limits<result_type>::infinity();}
5695
5696    friend _LIBCPP_INLINE_VISIBILITY
5697        bool operator==(const fisher_f_distribution& __x,
5698                        const fisher_f_distribution& __y)
5699        {return __x.__p_ == __y.__p_;}
5700    friend _LIBCPP_INLINE_VISIBILITY
5701        bool operator!=(const fisher_f_distribution& __x,
5702                        const fisher_f_distribution& __y)
5703        {return !(__x == __y);}
5704};
5705
5706template <class _RealType>
5707template<class _URNG>
5708_RealType
5709fisher_f_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5710{
5711    gamma_distribution<result_type> __gdm(__p.m() * result_type(.5));
5712    gamma_distribution<result_type> __gdn(__p.n() * result_type(.5));
5713    return __p.n() * __gdm(__g) / (__p.m() * __gdn(__g));
5714}
5715
5716template <class _CharT, class _Traits, class _RT>
5717basic_ostream<_CharT, _Traits>&
5718operator<<(basic_ostream<_CharT, _Traits>& __os,
5719           const fisher_f_distribution<_RT>& __x)
5720{
5721    __save_flags<_CharT, _Traits> __lx(__os);
5722    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5723               ios_base::scientific);
5724    _CharT __sp = __os.widen(' ');
5725    __os.fill(__sp);
5726    __os << __x.m() << __sp << __x.n();
5727    return __os;
5728}
5729
5730template <class _CharT, class _Traits, class _RT>
5731basic_istream<_CharT, _Traits>&
5732operator>>(basic_istream<_CharT, _Traits>& __is,
5733           fisher_f_distribution<_RT>& __x)
5734{
5735    typedef fisher_f_distribution<_RT> _Eng;
5736    typedef typename _Eng::result_type result_type;
5737    typedef typename _Eng::param_type param_type;
5738    __save_flags<_CharT, _Traits> __lx(__is);
5739    __is.flags(ios_base::dec | ios_base::skipws);
5740    result_type __m;
5741    result_type __n;
5742    __is >> __m >> __n;
5743    if (!__is.fail())
5744        __x.param(param_type(__m, __n));
5745    return __is;
5746}
5747
5748// student_t_distribution
5749
5750template<class _RealType = double>
5751class _LIBCPP_TEMPLATE_VIS student_t_distribution
5752{
5753public:
5754    // types
5755    typedef _RealType result_type;
5756
5757    class _LIBCPP_TEMPLATE_VIS param_type
5758    {
5759        result_type __n_;
5760    public:
5761        typedef student_t_distribution distribution_type;
5762
5763        _LIBCPP_INLINE_VISIBILITY
5764        explicit param_type(result_type __n = 1) : __n_(__n) {}
5765
5766        _LIBCPP_INLINE_VISIBILITY
5767        result_type n() const {return __n_;}
5768
5769        friend _LIBCPP_INLINE_VISIBILITY
5770            bool operator==(const param_type& __x, const param_type& __y)
5771            {return __x.__n_ == __y.__n_;}
5772        friend _LIBCPP_INLINE_VISIBILITY
5773            bool operator!=(const param_type& __x, const param_type& __y)
5774            {return !(__x == __y);}
5775    };
5776
5777private:
5778    param_type __p_;
5779    normal_distribution<result_type> __nd_;
5780
5781public:
5782    // constructor and reset functions
5783    _LIBCPP_INLINE_VISIBILITY
5784    explicit student_t_distribution(result_type __n = 1)
5785        : __p_(param_type(__n)) {}
5786    _LIBCPP_INLINE_VISIBILITY
5787    explicit student_t_distribution(const param_type& __p)
5788        : __p_(__p) {}
5789    _LIBCPP_INLINE_VISIBILITY
5790    void reset() {__nd_.reset();}
5791
5792    // generating functions
5793    template<class _URNG>
5794        _LIBCPP_INLINE_VISIBILITY
5795        result_type operator()(_URNG& __g)
5796        {return (*this)(__g, __p_);}
5797    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5798
5799    // property functions
5800    _LIBCPP_INLINE_VISIBILITY
5801    result_type n() const {return __p_.n();}
5802
5803    _LIBCPP_INLINE_VISIBILITY
5804    param_type param() const {return __p_;}
5805    _LIBCPP_INLINE_VISIBILITY
5806    void param(const param_type& __p) {__p_ = __p;}
5807
5808    _LIBCPP_INLINE_VISIBILITY
5809    result_type min() const {return -numeric_limits<result_type>::infinity();}
5810    _LIBCPP_INLINE_VISIBILITY
5811    result_type max() const {return numeric_limits<result_type>::infinity();}
5812
5813    friend _LIBCPP_INLINE_VISIBILITY
5814        bool operator==(const student_t_distribution& __x,
5815                        const student_t_distribution& __y)
5816        {return __x.__p_ == __y.__p_;}
5817    friend _LIBCPP_INLINE_VISIBILITY
5818        bool operator!=(const student_t_distribution& __x,
5819                        const student_t_distribution& __y)
5820        {return !(__x == __y);}
5821};
5822
5823template <class _RealType>
5824template<class _URNG>
5825_RealType
5826student_t_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5827{
5828    gamma_distribution<result_type> __gd(__p.n() * .5, 2);
5829    return __nd_(__g) * _VSTD::sqrt(__p.n()/__gd(__g));
5830}
5831
5832template <class _CharT, class _Traits, class _RT>
5833basic_ostream<_CharT, _Traits>&
5834operator<<(basic_ostream<_CharT, _Traits>& __os,
5835           const student_t_distribution<_RT>& __x)
5836{
5837    __save_flags<_CharT, _Traits> __lx(__os);
5838    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5839               ios_base::scientific);
5840    __os << __x.n();
5841    return __os;
5842}
5843
5844template <class _CharT, class _Traits, class _RT>
5845basic_istream<_CharT, _Traits>&
5846operator>>(basic_istream<_CharT, _Traits>& __is,
5847           student_t_distribution<_RT>& __x)
5848{
5849    typedef student_t_distribution<_RT> _Eng;
5850    typedef typename _Eng::result_type result_type;
5851    typedef typename _Eng::param_type param_type;
5852    __save_flags<_CharT, _Traits> __lx(__is);
5853    __is.flags(ios_base::dec | ios_base::skipws);
5854    result_type __n;
5855    __is >> __n;
5856    if (!__is.fail())
5857        __x.param(param_type(__n));
5858    return __is;
5859}
5860
5861// discrete_distribution
5862
5863template<class _IntType = int>
5864class _LIBCPP_TEMPLATE_VIS discrete_distribution
5865{
5866public:
5867    // types
5868    typedef _IntType result_type;
5869
5870    class _LIBCPP_TEMPLATE_VIS param_type
5871    {
5872        vector<double> __p_;
5873    public:
5874        typedef discrete_distribution distribution_type;
5875
5876        _LIBCPP_INLINE_VISIBILITY
5877        param_type() {}
5878        template<class _InputIterator>
5879            _LIBCPP_INLINE_VISIBILITY
5880            param_type(_InputIterator __f, _InputIterator __l)
5881            : __p_(__f, __l) {__init();}
5882#ifndef _LIBCPP_CXX03_LANG
5883        _LIBCPP_INLINE_VISIBILITY
5884        param_type(initializer_list<double> __wl)
5885            : __p_(__wl.begin(), __wl.end()) {__init();}
5886#endif  // _LIBCPP_CXX03_LANG
5887        template<class _UnaryOperation>
5888            param_type(size_t __nw, double __xmin, double __xmax,
5889                       _UnaryOperation __fw);
5890
5891        vector<double> probabilities() const;
5892
5893        friend _LIBCPP_INLINE_VISIBILITY
5894            bool operator==(const param_type& __x, const param_type& __y)
5895            {return __x.__p_ == __y.__p_;}
5896        friend _LIBCPP_INLINE_VISIBILITY
5897            bool operator!=(const param_type& __x, const param_type& __y)
5898            {return !(__x == __y);}
5899
5900    private:
5901        void __init();
5902
5903        friend class discrete_distribution;
5904
5905        template <class _CharT, class _Traits, class _IT>
5906        friend
5907        basic_ostream<_CharT, _Traits>&
5908        operator<<(basic_ostream<_CharT, _Traits>& __os,
5909                   const discrete_distribution<_IT>& __x);
5910
5911        template <class _CharT, class _Traits, class _IT>
5912        friend
5913        basic_istream<_CharT, _Traits>&
5914        operator>>(basic_istream<_CharT, _Traits>& __is,
5915                   discrete_distribution<_IT>& __x);
5916    };
5917
5918private:
5919    param_type __p_;
5920
5921public:
5922    // constructor and reset functions
5923    _LIBCPP_INLINE_VISIBILITY
5924    discrete_distribution() {}
5925    template<class _InputIterator>
5926        _LIBCPP_INLINE_VISIBILITY
5927        discrete_distribution(_InputIterator __f, _InputIterator __l)
5928            : __p_(__f, __l) {}
5929#ifndef _LIBCPP_CXX03_LANG
5930    _LIBCPP_INLINE_VISIBILITY
5931    discrete_distribution(initializer_list<double> __wl)
5932        : __p_(__wl) {}
5933#endif  // _LIBCPP_CXX03_LANG
5934    template<class _UnaryOperation>
5935        _LIBCPP_INLINE_VISIBILITY
5936        discrete_distribution(size_t __nw, double __xmin, double __xmax,
5937                              _UnaryOperation __fw)
5938        : __p_(__nw, __xmin, __xmax, __fw) {}
5939    _LIBCPP_INLINE_VISIBILITY
5940    explicit discrete_distribution(const param_type& __p)
5941        : __p_(__p) {}
5942    _LIBCPP_INLINE_VISIBILITY
5943    void reset() {}
5944
5945    // generating functions
5946    template<class _URNG>
5947        _LIBCPP_INLINE_VISIBILITY
5948        result_type operator()(_URNG& __g)
5949        {return (*this)(__g, __p_);}
5950    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5951
5952    // property functions
5953    _LIBCPP_INLINE_VISIBILITY
5954    vector<double> probabilities() const {return __p_.probabilities();}
5955
5956    _LIBCPP_INLINE_VISIBILITY
5957    param_type param() const {return __p_;}
5958    _LIBCPP_INLINE_VISIBILITY
5959    void param(const param_type& __p) {__p_ = __p;}
5960
5961    _LIBCPP_INLINE_VISIBILITY
5962    result_type min() const {return 0;}
5963    _LIBCPP_INLINE_VISIBILITY
5964    result_type max() const {return __p_.__p_.size();}
5965
5966    friend _LIBCPP_INLINE_VISIBILITY
5967        bool operator==(const discrete_distribution& __x,
5968                        const discrete_distribution& __y)
5969        {return __x.__p_ == __y.__p_;}
5970    friend _LIBCPP_INLINE_VISIBILITY
5971        bool operator!=(const discrete_distribution& __x,
5972                        const discrete_distribution& __y)
5973        {return !(__x == __y);}
5974
5975    template <class _CharT, class _Traits, class _IT>
5976    friend
5977    basic_ostream<_CharT, _Traits>&
5978    operator<<(basic_ostream<_CharT, _Traits>& __os,
5979               const discrete_distribution<_IT>& __x);
5980
5981    template <class _CharT, class _Traits, class _IT>
5982    friend
5983    basic_istream<_CharT, _Traits>&
5984    operator>>(basic_istream<_CharT, _Traits>& __is,
5985               discrete_distribution<_IT>& __x);
5986};
5987
5988template<class _IntType>
5989template<class _UnaryOperation>
5990discrete_distribution<_IntType>::param_type::param_type(size_t __nw,
5991                                                        double __xmin,
5992                                                        double __xmax,
5993                                                        _UnaryOperation __fw)
5994{
5995    if (__nw > 1)
5996    {
5997        __p_.reserve(__nw - 1);
5998        double __d = (__xmax - __xmin) / __nw;
5999        double __d2 = __d / 2;
6000        for (size_t __k = 0; __k < __nw; ++__k)
6001            __p_.push_back(__fw(__xmin + __k * __d + __d2));
6002        __init();
6003    }
6004}
6005
6006template<class _IntType>
6007void
6008discrete_distribution<_IntType>::param_type::__init()
6009{
6010    if (!__p_.empty())
6011    {
6012        if (__p_.size() > 1)
6013        {
6014            double __s = _VSTD::accumulate(__p_.begin(), __p_.end(), 0.0);
6015            for (_VSTD::vector<double>::iterator __i = __p_.begin(), __e = __p_.end();
6016                                                                       __i < __e; ++__i)
6017                *__i /= __s;
6018            vector<double> __t(__p_.size() - 1);
6019            _VSTD::partial_sum(__p_.begin(), __p_.end() - 1, __t.begin());
6020            swap(__p_, __t);
6021        }
6022        else
6023        {
6024            __p_.clear();
6025            __p_.shrink_to_fit();
6026        }
6027    }
6028}
6029
6030template<class _IntType>
6031vector<double>
6032discrete_distribution<_IntType>::param_type::probabilities() const
6033{
6034    size_t __n = __p_.size();
6035    _VSTD::vector<double> __p(__n+1);
6036    _VSTD::adjacent_difference(__p_.begin(), __p_.end(), __p.begin());
6037    if (__n > 0)
6038        __p[__n] = 1 - __p_[__n-1];
6039    else
6040        __p[0] = 1;
6041    return __p;
6042}
6043
6044template<class _IntType>
6045template<class _URNG>
6046_IntType
6047discrete_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
6048{
6049    uniform_real_distribution<double> __gen;
6050    return static_cast<_IntType>(
6051           _VSTD::upper_bound(__p.__p_.begin(), __p.__p_.end(), __gen(__g)) -
6052                                                              __p.__p_.begin());
6053}
6054
6055template <class _CharT, class _Traits, class _IT>
6056basic_ostream<_CharT, _Traits>&
6057operator<<(basic_ostream<_CharT, _Traits>& __os,
6058           const discrete_distribution<_IT>& __x)
6059{
6060    __save_flags<_CharT, _Traits> __lx(__os);
6061    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
6062               ios_base::scientific);
6063    _CharT __sp = __os.widen(' ');
6064    __os.fill(__sp);
6065    size_t __n = __x.__p_.__p_.size();
6066    __os << __n;
6067    for (size_t __i = 0; __i < __n; ++__i)
6068        __os << __sp << __x.__p_.__p_[__i];
6069    return __os;
6070}
6071
6072template <class _CharT, class _Traits, class _IT>
6073basic_istream<_CharT, _Traits>&
6074operator>>(basic_istream<_CharT, _Traits>& __is,
6075           discrete_distribution<_IT>& __x)
6076{
6077    __save_flags<_CharT, _Traits> __lx(__is);
6078    __is.flags(ios_base::dec | ios_base::skipws);
6079    size_t __n;
6080    __is >> __n;
6081    vector<double> __p(__n);
6082    for (size_t __i = 0; __i < __n; ++__i)
6083        __is >> __p[__i];
6084    if (!__is.fail())
6085        swap(__x.__p_.__p_, __p);
6086    return __is;
6087}
6088
6089// piecewise_constant_distribution
6090
6091template<class _RealType = double>
6092class _LIBCPP_TEMPLATE_VIS piecewise_constant_distribution
6093{
6094public:
6095    // types
6096    typedef _RealType result_type;
6097
6098    class _LIBCPP_TEMPLATE_VIS param_type
6099    {
6100        vector<result_type> __b_;
6101        vector<result_type> __densities_;
6102        vector<result_type> __areas_;
6103    public:
6104        typedef piecewise_constant_distribution distribution_type;
6105
6106        param_type();
6107        template<class _InputIteratorB, class _InputIteratorW>
6108            param_type(_InputIteratorB __fB, _InputIteratorB __lB,
6109                       _InputIteratorW __fW);
6110#ifndef _LIBCPP_CXX03_LANG
6111        template<class _UnaryOperation>
6112            param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
6113#endif  // _LIBCPP_CXX03_LANG
6114        template<class _UnaryOperation>
6115            param_type(size_t __nw, result_type __xmin, result_type __xmax,
6116                       _UnaryOperation __fw);
6117        param_type(param_type const&) = default;
6118        param_type & operator=(const param_type& __rhs);
6119
6120        _LIBCPP_INLINE_VISIBILITY
6121        vector<result_type> intervals() const {return __b_;}
6122        _LIBCPP_INLINE_VISIBILITY
6123        vector<result_type> densities() const {return __densities_;}
6124
6125        friend _LIBCPP_INLINE_VISIBILITY
6126            bool operator==(const param_type& __x, const param_type& __y)
6127            {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
6128        friend _LIBCPP_INLINE_VISIBILITY
6129            bool operator!=(const param_type& __x, const param_type& __y)
6130            {return !(__x == __y);}
6131
6132    private:
6133        void __init();
6134
6135        friend class piecewise_constant_distribution;
6136
6137        template <class _CharT, class _Traits, class _RT>
6138        friend
6139        basic_ostream<_CharT, _Traits>&
6140        operator<<(basic_ostream<_CharT, _Traits>& __os,
6141                   const piecewise_constant_distribution<_RT>& __x);
6142
6143        template <class _CharT, class _Traits, class _RT>
6144        friend
6145        basic_istream<_CharT, _Traits>&
6146        operator>>(basic_istream<_CharT, _Traits>& __is,
6147                   piecewise_constant_distribution<_RT>& __x);
6148    };
6149
6150private:
6151    param_type __p_;
6152
6153public:
6154    // constructor and reset functions
6155    _LIBCPP_INLINE_VISIBILITY
6156    piecewise_constant_distribution() {}
6157    template<class _InputIteratorB, class _InputIteratorW>
6158        _LIBCPP_INLINE_VISIBILITY
6159        piecewise_constant_distribution(_InputIteratorB __fB,
6160                                        _InputIteratorB __lB,
6161                                        _InputIteratorW __fW)
6162        : __p_(__fB, __lB, __fW) {}
6163
6164#ifndef _LIBCPP_CXX03_LANG
6165    template<class _UnaryOperation>
6166        _LIBCPP_INLINE_VISIBILITY
6167        piecewise_constant_distribution(initializer_list<result_type> __bl,
6168                                        _UnaryOperation __fw)
6169        : __p_(__bl, __fw) {}
6170#endif  // _LIBCPP_CXX03_LANG
6171
6172    template<class _UnaryOperation>
6173        _LIBCPP_INLINE_VISIBILITY
6174        piecewise_constant_distribution(size_t __nw, result_type __xmin,
6175                                        result_type __xmax, _UnaryOperation __fw)
6176        : __p_(__nw, __xmin, __xmax, __fw) {}
6177
6178    _LIBCPP_INLINE_VISIBILITY
6179    explicit piecewise_constant_distribution(const param_type& __p)
6180        : __p_(__p) {}
6181
6182    _LIBCPP_INLINE_VISIBILITY
6183    void reset() {}
6184
6185    // generating functions
6186    template<class _URNG>
6187        _LIBCPP_INLINE_VISIBILITY
6188        result_type operator()(_URNG& __g)
6189        {return (*this)(__g, __p_);}
6190    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
6191
6192    // property functions
6193    _LIBCPP_INLINE_VISIBILITY
6194    vector<result_type> intervals() const {return __p_.intervals();}
6195    _LIBCPP_INLINE_VISIBILITY
6196    vector<result_type> densities() const {return __p_.densities();}
6197
6198    _LIBCPP_INLINE_VISIBILITY
6199    param_type param() const {return __p_;}
6200    _LIBCPP_INLINE_VISIBILITY
6201    void param(const param_type& __p) {__p_ = __p;}
6202
6203    _LIBCPP_INLINE_VISIBILITY
6204    result_type min() const {return __p_.__b_.front();}
6205    _LIBCPP_INLINE_VISIBILITY
6206    result_type max() const {return __p_.__b_.back();}
6207
6208    friend _LIBCPP_INLINE_VISIBILITY
6209        bool operator==(const piecewise_constant_distribution& __x,
6210                        const piecewise_constant_distribution& __y)
6211        {return __x.__p_ == __y.__p_;}
6212    friend _LIBCPP_INLINE_VISIBILITY
6213        bool operator!=(const piecewise_constant_distribution& __x,
6214                           const piecewise_constant_distribution& __y)
6215        {return !(__x == __y);}
6216
6217    template <class _CharT, class _Traits, class _RT>
6218    friend
6219    basic_ostream<_CharT, _Traits>&
6220    operator<<(basic_ostream<_CharT, _Traits>& __os,
6221               const piecewise_constant_distribution<_RT>& __x);
6222
6223    template <class _CharT, class _Traits, class _RT>
6224    friend
6225    basic_istream<_CharT, _Traits>&
6226    operator>>(basic_istream<_CharT, _Traits>& __is,
6227               piecewise_constant_distribution<_RT>& __x);
6228};
6229
6230template<class _RealType>
6231typename piecewise_constant_distribution<_RealType>::param_type &
6232piecewise_constant_distribution<_RealType>::param_type::operator=
6233                                                       (const param_type& __rhs)
6234{
6235//  These can throw
6236    __b_.reserve        (__rhs.__b_.size ());
6237    __densities_.reserve(__rhs.__densities_.size());
6238    __areas_.reserve    (__rhs.__areas_.size());
6239
6240//  These can not throw
6241    __b_         = __rhs.__b_;
6242    __densities_ = __rhs.__densities_;
6243    __areas_     =  __rhs.__areas_;
6244    return *this;
6245}
6246
6247template<class _RealType>
6248void
6249piecewise_constant_distribution<_RealType>::param_type::__init()
6250{
6251    // __densities_ contains non-normalized areas
6252    result_type __total_area = _VSTD::accumulate(__densities_.begin(),
6253                                                __densities_.end(),
6254                                                result_type());
6255    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6256        __densities_[__i] /= __total_area;
6257    // __densities_ contains normalized areas
6258    __areas_.assign(__densities_.size(), result_type());
6259    _VSTD::partial_sum(__densities_.begin(), __densities_.end() - 1,
6260                                                          __areas_.begin() + 1);
6261    // __areas_ contains partial sums of normalized areas: [0, __densities_ - 1]
6262    __densities_.back() = 1 - __areas_.back();  // correct round off error
6263    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6264        __densities_[__i] /= (__b_[__i+1] - __b_[__i]);
6265    // __densities_ now contains __densities_
6266}
6267
6268template<class _RealType>
6269piecewise_constant_distribution<_RealType>::param_type::param_type()
6270    : __b_(2),
6271      __densities_(1, 1.0),
6272      __areas_(1, 0.0)
6273{
6274    __b_[1] = 1;
6275}
6276
6277template<class _RealType>
6278template<class _InputIteratorB, class _InputIteratorW>
6279piecewise_constant_distribution<_RealType>::param_type::param_type(
6280        _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
6281    : __b_(__fB, __lB)
6282{
6283    if (__b_.size() < 2)
6284    {
6285        __b_.resize(2);
6286        __b_[0] = 0;
6287        __b_[1] = 1;
6288        __densities_.assign(1, 1.0);
6289        __areas_.assign(1, 0.0);
6290    }
6291    else
6292    {
6293        __densities_.reserve(__b_.size() - 1);
6294        for (size_t __i = 0; __i < __b_.size() - 1; ++__i, ++__fW)
6295            __densities_.push_back(*__fW);
6296        __init();
6297    }
6298}
6299
6300#ifndef _LIBCPP_CXX03_LANG
6301
6302template<class _RealType>
6303template<class _UnaryOperation>
6304piecewise_constant_distribution<_RealType>::param_type::param_type(
6305        initializer_list<result_type> __bl, _UnaryOperation __fw)
6306    : __b_(__bl.begin(), __bl.end())
6307{
6308    if (__b_.size() < 2)
6309    {
6310        __b_.resize(2);
6311        __b_[0] = 0;
6312        __b_[1] = 1;
6313        __densities_.assign(1, 1.0);
6314        __areas_.assign(1, 0.0);
6315    }
6316    else
6317    {
6318        __densities_.reserve(__b_.size() - 1);
6319        for (size_t __i = 0; __i < __b_.size() - 1; ++__i)
6320            __densities_.push_back(__fw((__b_[__i+1] + __b_[__i])*.5));
6321        __init();
6322    }
6323}
6324
6325#endif  // _LIBCPP_CXX03_LANG
6326
6327template<class _RealType>
6328template<class _UnaryOperation>
6329piecewise_constant_distribution<_RealType>::param_type::param_type(
6330        size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
6331    : __b_(__nw == 0 ? 2 : __nw + 1)
6332{
6333    size_t __n = __b_.size() - 1;
6334    result_type __d = (__xmax - __xmin) / __n;
6335    __densities_.reserve(__n);
6336    for (size_t __i = 0; __i < __n; ++__i)
6337    {
6338        __b_[__i] = __xmin + __i * __d;
6339        __densities_.push_back(__fw(__b_[__i] + __d*.5));
6340    }
6341    __b_[__n] = __xmax;
6342    __init();
6343}
6344
6345template<class _RealType>
6346template<class _URNG>
6347_RealType
6348piecewise_constant_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
6349{
6350    typedef uniform_real_distribution<result_type> _Gen;
6351    result_type __u = _Gen()(__g);
6352    ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
6353                                      __u) - __p.__areas_.begin() - 1;
6354    return (__u - __p.__areas_[__k]) / __p.__densities_[__k] + __p.__b_[__k];
6355}
6356
6357template <class _CharT, class _Traits, class _RT>
6358basic_ostream<_CharT, _Traits>&
6359operator<<(basic_ostream<_CharT, _Traits>& __os,
6360           const piecewise_constant_distribution<_RT>& __x)
6361{
6362    __save_flags<_CharT, _Traits> __lx(__os);
6363    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
6364               ios_base::scientific);
6365    _CharT __sp = __os.widen(' ');
6366    __os.fill(__sp);
6367    size_t __n = __x.__p_.__b_.size();
6368    __os << __n;
6369    for (size_t __i = 0; __i < __n; ++__i)
6370        __os << __sp << __x.__p_.__b_[__i];
6371    __n = __x.__p_.__densities_.size();
6372    __os << __sp << __n;
6373    for (size_t __i = 0; __i < __n; ++__i)
6374        __os << __sp << __x.__p_.__densities_[__i];
6375    __n = __x.__p_.__areas_.size();
6376    __os << __sp << __n;
6377    for (size_t __i = 0; __i < __n; ++__i)
6378        __os << __sp << __x.__p_.__areas_[__i];
6379    return __os;
6380}
6381
6382template <class _CharT, class _Traits, class _RT>
6383basic_istream<_CharT, _Traits>&
6384operator>>(basic_istream<_CharT, _Traits>& __is,
6385           piecewise_constant_distribution<_RT>& __x)
6386{
6387    typedef piecewise_constant_distribution<_RT> _Eng;
6388    typedef typename _Eng::result_type result_type;
6389    __save_flags<_CharT, _Traits> __lx(__is);
6390    __is.flags(ios_base::dec | ios_base::skipws);
6391    size_t __n;
6392    __is >> __n;
6393    vector<result_type> __b(__n);
6394    for (size_t __i = 0; __i < __n; ++__i)
6395        __is >> __b[__i];
6396    __is >> __n;
6397    vector<result_type> __densities(__n);
6398    for (size_t __i = 0; __i < __n; ++__i)
6399        __is >> __densities[__i];
6400    __is >> __n;
6401    vector<result_type> __areas(__n);
6402    for (size_t __i = 0; __i < __n; ++__i)
6403        __is >> __areas[__i];
6404    if (!__is.fail())
6405    {
6406        swap(__x.__p_.__b_, __b);
6407        swap(__x.__p_.__densities_, __densities);
6408        swap(__x.__p_.__areas_, __areas);
6409    }
6410    return __is;
6411}
6412
6413// piecewise_linear_distribution
6414
6415template<class _RealType = double>
6416class _LIBCPP_TEMPLATE_VIS piecewise_linear_distribution
6417{
6418public:
6419    // types
6420    typedef _RealType result_type;
6421
6422    class _LIBCPP_TEMPLATE_VIS param_type
6423    {
6424        vector<result_type> __b_;
6425        vector<result_type> __densities_;
6426        vector<result_type> __areas_;
6427    public:
6428        typedef piecewise_linear_distribution distribution_type;
6429
6430        param_type();
6431        template<class _InputIteratorB, class _InputIteratorW>
6432            param_type(_InputIteratorB __fB, _InputIteratorB __lB,
6433                       _InputIteratorW __fW);
6434#ifndef _LIBCPP_CXX03_LANG
6435        template<class _UnaryOperation>
6436            param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
6437#endif  // _LIBCPP_CXX03_LANG
6438        template<class _UnaryOperation>
6439            param_type(size_t __nw, result_type __xmin, result_type __xmax,
6440                       _UnaryOperation __fw);
6441        param_type(param_type const&) = default;
6442        param_type & operator=(const param_type& __rhs);
6443
6444        _LIBCPP_INLINE_VISIBILITY
6445        vector<result_type> intervals() const {return __b_;}
6446        _LIBCPP_INLINE_VISIBILITY
6447        vector<result_type> densities() const {return __densities_;}
6448
6449        friend _LIBCPP_INLINE_VISIBILITY
6450            bool operator==(const param_type& __x, const param_type& __y)
6451            {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
6452        friend _LIBCPP_INLINE_VISIBILITY
6453            bool operator!=(const param_type& __x, const param_type& __y)
6454            {return !(__x == __y);}
6455
6456    private:
6457        void __init();
6458
6459        friend class piecewise_linear_distribution;
6460
6461        template <class _CharT, class _Traits, class _RT>
6462        friend
6463        basic_ostream<_CharT, _Traits>&
6464        operator<<(basic_ostream<_CharT, _Traits>& __os,
6465                   const piecewise_linear_distribution<_RT>& __x);
6466
6467        template <class _CharT, class _Traits, class _RT>
6468        friend
6469        basic_istream<_CharT, _Traits>&
6470        operator>>(basic_istream<_CharT, _Traits>& __is,
6471                   piecewise_linear_distribution<_RT>& __x);
6472    };
6473
6474private:
6475    param_type __p_;
6476
6477public:
6478    // constructor and reset functions
6479    _LIBCPP_INLINE_VISIBILITY
6480    piecewise_linear_distribution() {}
6481    template<class _InputIteratorB, class _InputIteratorW>
6482        _LIBCPP_INLINE_VISIBILITY
6483        piecewise_linear_distribution(_InputIteratorB __fB,
6484                                      _InputIteratorB __lB,
6485                                      _InputIteratorW __fW)
6486        : __p_(__fB, __lB, __fW) {}
6487
6488#ifndef _LIBCPP_CXX03_LANG
6489    template<class _UnaryOperation>
6490        _LIBCPP_INLINE_VISIBILITY
6491        piecewise_linear_distribution(initializer_list<result_type> __bl,
6492                                      _UnaryOperation __fw)
6493        : __p_(__bl, __fw) {}
6494#endif  // _LIBCPP_CXX03_LANG
6495
6496    template<class _UnaryOperation>
6497        _LIBCPP_INLINE_VISIBILITY
6498        piecewise_linear_distribution(size_t __nw, result_type __xmin,
6499                                      result_type __xmax, _UnaryOperation __fw)
6500        : __p_(__nw, __xmin, __xmax, __fw) {}
6501
6502    _LIBCPP_INLINE_VISIBILITY
6503    explicit piecewise_linear_distribution(const param_type& __p)
6504        : __p_(__p) {}
6505
6506    _LIBCPP_INLINE_VISIBILITY
6507    void reset() {}
6508
6509    // generating functions
6510    template<class _URNG>
6511        _LIBCPP_INLINE_VISIBILITY
6512        result_type operator()(_URNG& __g)
6513        {return (*this)(__g, __p_);}
6514    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
6515
6516    // property functions
6517    _LIBCPP_INLINE_VISIBILITY
6518    vector<result_type> intervals() const {return __p_.intervals();}
6519    _LIBCPP_INLINE_VISIBILITY
6520    vector<result_type> densities() const {return __p_.densities();}
6521
6522    _LIBCPP_INLINE_VISIBILITY
6523    param_type param() const {return __p_;}
6524    _LIBCPP_INLINE_VISIBILITY
6525    void param(const param_type& __p) {__p_ = __p;}
6526
6527    _LIBCPP_INLINE_VISIBILITY
6528    result_type min() const {return __p_.__b_.front();}
6529    _LIBCPP_INLINE_VISIBILITY
6530    result_type max() const {return __p_.__b_.back();}
6531
6532    friend _LIBCPP_INLINE_VISIBILITY
6533        bool operator==(const piecewise_linear_distribution& __x,
6534                        const piecewise_linear_distribution& __y)
6535        {return __x.__p_ == __y.__p_;}
6536    friend _LIBCPP_INLINE_VISIBILITY
6537        bool operator!=(const piecewise_linear_distribution& __x,
6538                        const piecewise_linear_distribution& __y)
6539        {return !(__x == __y);}
6540
6541    template <class _CharT, class _Traits, class _RT>
6542    friend
6543    basic_ostream<_CharT, _Traits>&
6544    operator<<(basic_ostream<_CharT, _Traits>& __os,
6545               const piecewise_linear_distribution<_RT>& __x);
6546
6547    template <class _CharT, class _Traits, class _RT>
6548    friend
6549    basic_istream<_CharT, _Traits>&
6550    operator>>(basic_istream<_CharT, _Traits>& __is,
6551               piecewise_linear_distribution<_RT>& __x);
6552};
6553
6554template<class _RealType>
6555typename piecewise_linear_distribution<_RealType>::param_type &
6556piecewise_linear_distribution<_RealType>::param_type::operator=
6557                                                       (const param_type& __rhs)
6558{
6559//  These can throw
6560    __b_.reserve        (__rhs.__b_.size ());
6561    __densities_.reserve(__rhs.__densities_.size());
6562    __areas_.reserve    (__rhs.__areas_.size());
6563
6564//  These can not throw
6565    __b_         = __rhs.__b_;
6566    __densities_ = __rhs.__densities_;
6567    __areas_     =  __rhs.__areas_;
6568    return *this;
6569}
6570
6571
6572template<class _RealType>
6573void
6574piecewise_linear_distribution<_RealType>::param_type::__init()
6575{
6576    __areas_.assign(__densities_.size() - 1, result_type());
6577    result_type _Sp = 0;
6578    for (size_t __i = 0; __i < __areas_.size(); ++__i)
6579    {
6580        __areas_[__i] = (__densities_[__i+1] + __densities_[__i]) *
6581                        (__b_[__i+1] - __b_[__i]) * .5;
6582        _Sp += __areas_[__i];
6583    }
6584    for (size_t __i = __areas_.size(); __i > 1;)
6585    {
6586        --__i;
6587        __areas_[__i] = __areas_[__i-1] / _Sp;
6588    }
6589    __areas_[0] = 0;
6590    for (size_t __i = 1; __i < __areas_.size(); ++__i)
6591        __areas_[__i] += __areas_[__i-1];
6592    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6593        __densities_[__i] /= _Sp;
6594}
6595
6596template<class _RealType>
6597piecewise_linear_distribution<_RealType>::param_type::param_type()
6598    : __b_(2),
6599      __densities_(2, 1.0),
6600      __areas_(1, 0.0)
6601{
6602    __b_[1] = 1;
6603}
6604
6605template<class _RealType>
6606template<class _InputIteratorB, class _InputIteratorW>
6607piecewise_linear_distribution<_RealType>::param_type::param_type(
6608        _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
6609    : __b_(__fB, __lB)
6610{
6611    if (__b_.size() < 2)
6612    {
6613        __b_.resize(2);
6614        __b_[0] = 0;
6615        __b_[1] = 1;
6616        __densities_.assign(2, 1.0);
6617        __areas_.assign(1, 0.0);
6618    }
6619    else
6620    {
6621        __densities_.reserve(__b_.size());
6622        for (size_t __i = 0; __i < __b_.size(); ++__i, ++__fW)
6623            __densities_.push_back(*__fW);
6624        __init();
6625    }
6626}
6627
6628#ifndef _LIBCPP_CXX03_LANG
6629
6630template<class _RealType>
6631template<class _UnaryOperation>
6632piecewise_linear_distribution<_RealType>::param_type::param_type(
6633        initializer_list<result_type> __bl, _UnaryOperation __fw)
6634    : __b_(__bl.begin(), __bl.end())
6635{
6636    if (__b_.size() < 2)
6637    {
6638        __b_.resize(2);
6639        __b_[0] = 0;
6640        __b_[1] = 1;
6641        __densities_.assign(2, 1.0);
6642        __areas_.assign(1, 0.0);
6643    }
6644    else
6645    {
6646        __densities_.reserve(__b_.size());
6647        for (size_t __i = 0; __i < __b_.size(); ++__i)
6648            __densities_.push_back(__fw(__b_[__i]));
6649        __init();
6650    }
6651}
6652
6653#endif  // _LIBCPP_CXX03_LANG
6654
6655template<class _RealType>
6656template<class _UnaryOperation>
6657piecewise_linear_distribution<_RealType>::param_type::param_type(
6658        size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
6659    : __b_(__nw == 0 ? 2 : __nw + 1)
6660{
6661    size_t __n = __b_.size() - 1;
6662    result_type __d = (__xmax - __xmin) / __n;
6663    __densities_.reserve(__b_.size());
6664    for (size_t __i = 0; __i < __n; ++__i)
6665    {
6666        __b_[__i] = __xmin + __i * __d;
6667        __densities_.push_back(__fw(__b_[__i]));
6668    }
6669    __b_[__n] = __xmax;
6670    __densities_.push_back(__fw(__b_[__n]));
6671    __init();
6672}
6673
6674template<class _RealType>
6675template<class _URNG>
6676_RealType
6677piecewise_linear_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
6678{
6679    typedef uniform_real_distribution<result_type> _Gen;
6680    result_type __u = _Gen()(__g);
6681    ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
6682                                      __u) - __p.__areas_.begin() - 1;
6683    __u -= __p.__areas_[__k];
6684    const result_type __dk = __p.__densities_[__k];
6685    const result_type __dk1 = __p.__densities_[__k+1];
6686    const result_type __deltad = __dk1 - __dk;
6687    const result_type __bk = __p.__b_[__k];
6688    if (__deltad == 0)
6689        return __u / __dk + __bk;
6690    const result_type __bk1 = __p.__b_[__k+1];
6691    const result_type __deltab = __bk1 - __bk;
6692    return (__bk * __dk1 - __bk1 * __dk +
6693        _VSTD::sqrt(__deltab * (__deltab * __dk * __dk + 2 * __deltad * __u))) /
6694        __deltad;
6695}
6696
6697template <class _CharT, class _Traits, class _RT>
6698basic_ostream<_CharT, _Traits>&
6699operator<<(basic_ostream<_CharT, _Traits>& __os,
6700           const piecewise_linear_distribution<_RT>& __x)
6701{
6702    __save_flags<_CharT, _Traits> __lx(__os);
6703    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
6704               ios_base::scientific);
6705    _CharT __sp = __os.widen(' ');
6706    __os.fill(__sp);
6707    size_t __n = __x.__p_.__b_.size();
6708    __os << __n;
6709    for (size_t __i = 0; __i < __n; ++__i)
6710        __os << __sp << __x.__p_.__b_[__i];
6711    __n = __x.__p_.__densities_.size();
6712    __os << __sp << __n;
6713    for (size_t __i = 0; __i < __n; ++__i)
6714        __os << __sp << __x.__p_.__densities_[__i];
6715    __n = __x.__p_.__areas_.size();
6716    __os << __sp << __n;
6717    for (size_t __i = 0; __i < __n; ++__i)
6718        __os << __sp << __x.__p_.__areas_[__i];
6719    return __os;
6720}
6721
6722template <class _CharT, class _Traits, class _RT>
6723basic_istream<_CharT, _Traits>&
6724operator>>(basic_istream<_CharT, _Traits>& __is,
6725           piecewise_linear_distribution<_RT>& __x)
6726{
6727    typedef piecewise_linear_distribution<_RT> _Eng;
6728    typedef typename _Eng::result_type result_type;
6729    __save_flags<_CharT, _Traits> __lx(__is);
6730    __is.flags(ios_base::dec | ios_base::skipws);
6731    size_t __n;
6732    __is >> __n;
6733    vector<result_type> __b(__n);
6734    for (size_t __i = 0; __i < __n; ++__i)
6735        __is >> __b[__i];
6736    __is >> __n;
6737    vector<result_type> __densities(__n);
6738    for (size_t __i = 0; __i < __n; ++__i)
6739        __is >> __densities[__i];
6740    __is >> __n;
6741    vector<result_type> __areas(__n);
6742    for (size_t __i = 0; __i < __n; ++__i)
6743        __is >> __areas[__i];
6744    if (!__is.fail())
6745    {
6746        swap(__x.__p_.__b_, __b);
6747        swap(__x.__p_.__densities_, __densities);
6748        swap(__x.__p_.__areas_, __areas);
6749    }
6750    return __is;
6751}
6752
6753_LIBCPP_END_NAMESPACE_STD
6754
6755_LIBCPP_POP_MACROS
6756
6757#endif  // _LIBCPP_RANDOM
6758