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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 <iosfwd>
1646
1647#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1648#pragma GCC system_header
1649#endif
1650
1651_LIBCPP_PUSH_MACROS
1652#include <__undef_macros>
1653
1654
1655_LIBCPP_BEGIN_NAMESPACE_STD
1656
1657// __is_seed_sequence
1658
1659template <class _Sseq, class _Engine>
1660struct __is_seed_sequence
1661{
1662    static _LIBCPP_CONSTEXPR const bool value =
1663              !is_convertible<_Sseq, typename _Engine::result_type>::value &&
1664              !is_same<typename remove_cv<_Sseq>::type, _Engine>::value;
1665};
1666
1667// linear_congruential_engine
1668
1669template <unsigned long long __a, unsigned long long __c,
1670          unsigned long long __m, unsigned long long _Mp,
1671          bool _MightOverflow = (__a != 0 && __m != 0 && __m-1 > (_Mp-__c)/__a),
1672          bool _OverflowOK = ((__m|__m-1) > __m), // m = 2^n
1673          bool _SchrageOK = (__a != 0 && __m != 0 && __m % __a <= __m / __a)> // r <= q
1674struct __lce_alg_picker
1675{
1676    static_assert(__a != 0 || __m != 0 || !_MightOverflow || _OverflowOK || _SchrageOK,
1677                  "The current values of a, c, and m cannot generate a number "
1678                  "within bounds of linear_congruential_engine.");
1679
1680    static _LIBCPP_CONSTEXPR const bool __use_schrage = _MightOverflow &&
1681                                                        !_OverflowOK &&
1682                                                        _SchrageOK;
1683};
1684
1685template <unsigned long long __a, unsigned long long __c,
1686          unsigned long long __m, unsigned long long _Mp,
1687          bool _UseSchrage = __lce_alg_picker<__a, __c, __m, _Mp>::__use_schrage>
1688struct __lce_ta;
1689
1690// 64
1691
1692template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
1693struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), true>
1694{
1695    typedef unsigned long long result_type;
1696    _LIBCPP_INLINE_VISIBILITY
1697    static result_type next(result_type __x)
1698    {
1699        // Schrage's algorithm
1700        const result_type __q = __m / __a;
1701        const result_type __r = __m % __a;
1702        const result_type __t0 = __a * (__x % __q);
1703        const result_type __t1 = __r * (__x / __q);
1704        __x = __t0 + (__t0 < __t1) * __m - __t1;
1705        __x += __c - (__x >= __m - __c) * __m;
1706        return __x;
1707    }
1708};
1709
1710template <unsigned long long __a, unsigned long long __m>
1711struct __lce_ta<__a, 0, __m, (unsigned long long)(~0), true>
1712{
1713    typedef unsigned long long result_type;
1714    _LIBCPP_INLINE_VISIBILITY
1715    static result_type next(result_type __x)
1716    {
1717        // Schrage's algorithm
1718        const result_type __q = __m / __a;
1719        const result_type __r = __m % __a;
1720        const result_type __t0 = __a * (__x % __q);
1721        const result_type __t1 = __r * (__x / __q);
1722        __x = __t0 + (__t0 < __t1) * __m - __t1;
1723        return __x;
1724    }
1725};
1726
1727template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
1728struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), false>
1729{
1730    typedef unsigned long long result_type;
1731    _LIBCPP_INLINE_VISIBILITY
1732    static result_type next(result_type __x)
1733    {
1734        return (__a * __x + __c) % __m;
1735    }
1736};
1737
1738template <unsigned long long __a, unsigned long long __c>
1739struct __lce_ta<__a, __c, 0, (unsigned long long)(~0), false>
1740{
1741    typedef unsigned long long result_type;
1742    _LIBCPP_INLINE_VISIBILITY
1743    static result_type next(result_type __x)
1744    {
1745        return __a * __x + __c;
1746    }
1747};
1748
1749// 32
1750
1751template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
1752struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), true>
1753{
1754    typedef unsigned result_type;
1755    _LIBCPP_INLINE_VISIBILITY
1756    static result_type next(result_type __x)
1757    {
1758        const result_type __a = static_cast<result_type>(_Ap);
1759        const result_type __c = static_cast<result_type>(_Cp);
1760        const result_type __m = static_cast<result_type>(_Mp);
1761        // Schrage's algorithm
1762        const result_type __q = __m / __a;
1763        const result_type __r = __m % __a;
1764        const result_type __t0 = __a * (__x % __q);
1765        const result_type __t1 = __r * (__x / __q);
1766        __x = __t0 + (__t0 < __t1) * __m - __t1;
1767        __x += __c - (__x >= __m - __c) * __m;
1768        return __x;
1769    }
1770};
1771
1772template <unsigned long long _Ap, unsigned long long _Mp>
1773struct __lce_ta<_Ap, 0, _Mp, unsigned(~0), true>
1774{
1775    typedef unsigned result_type;
1776    _LIBCPP_INLINE_VISIBILITY
1777    static result_type next(result_type __x)
1778    {
1779        const result_type __a = static_cast<result_type>(_Ap);
1780        const result_type __m = static_cast<result_type>(_Mp);
1781        // Schrage's algorithm
1782        const result_type __q = __m / __a;
1783        const result_type __r = __m % __a;
1784        const result_type __t0 = __a * (__x % __q);
1785        const result_type __t1 = __r * (__x / __q);
1786        __x = __t0 + (__t0 < __t1) * __m - __t1;
1787        return __x;
1788    }
1789};
1790
1791template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
1792struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), false>
1793{
1794    typedef unsigned result_type;
1795    _LIBCPP_INLINE_VISIBILITY
1796    static result_type next(result_type __x)
1797    {
1798        const result_type __a = static_cast<result_type>(_Ap);
1799        const result_type __c = static_cast<result_type>(_Cp);
1800        const result_type __m = static_cast<result_type>(_Mp);
1801        return (__a * __x + __c) % __m;
1802    }
1803};
1804
1805template <unsigned long long _Ap, unsigned long long _Cp>
1806struct __lce_ta<_Ap, _Cp, 0, unsigned(~0), false>
1807{
1808    typedef unsigned result_type;
1809    _LIBCPP_INLINE_VISIBILITY
1810    static result_type next(result_type __x)
1811    {
1812        const result_type __a = static_cast<result_type>(_Ap);
1813        const result_type __c = static_cast<result_type>(_Cp);
1814        return __a * __x + __c;
1815    }
1816};
1817
1818// 16
1819
1820template <unsigned long long __a, unsigned long long __c, unsigned long long __m, bool __b>
1821struct __lce_ta<__a, __c, __m, (unsigned short)(~0), __b>
1822{
1823    typedef unsigned short result_type;
1824    _LIBCPP_INLINE_VISIBILITY
1825    static result_type next(result_type __x)
1826    {
1827        return static_cast<result_type>(__lce_ta<__a, __c, __m, unsigned(~0)>::next(__x));
1828    }
1829};
1830
1831template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1832class _LIBCPP_TEMPLATE_VIS linear_congruential_engine;
1833
1834template <class _CharT, class _Traits,
1835          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1836_LIBCPP_INLINE_VISIBILITY
1837basic_ostream<_CharT, _Traits>&
1838operator<<(basic_ostream<_CharT, _Traits>& __os,
1839           const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
1840
1841template <class _CharT, class _Traits,
1842          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1843basic_istream<_CharT, _Traits>&
1844operator>>(basic_istream<_CharT, _Traits>& __is,
1845           linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
1846
1847template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1848class _LIBCPP_TEMPLATE_VIS linear_congruential_engine
1849{
1850public:
1851    // types
1852    typedef _UIntType result_type;
1853
1854private:
1855    result_type __x_;
1856
1857    static _LIBCPP_CONSTEXPR const result_type _Mp = result_type(~0);
1858
1859    static_assert(__m == 0 || __a < __m, "linear_congruential_engine invalid parameters");
1860    static_assert(__m == 0 || __c < __m, "linear_congruential_engine invalid parameters");
1861    static_assert(_VSTD::is_unsigned<_UIntType>::value, "_UIntType must be unsigned type");
1862public:
1863    static _LIBCPP_CONSTEXPR const result_type _Min = __c == 0u ? 1u: 0u;
1864    static _LIBCPP_CONSTEXPR const result_type _Max = __m - 1u;
1865    static_assert(_Min < _Max,           "linear_congruential_engine invalid parameters");
1866
1867    // engine characteristics
1868    static _LIBCPP_CONSTEXPR const result_type multiplier = __a;
1869    static _LIBCPP_CONSTEXPR const result_type increment = __c;
1870    static _LIBCPP_CONSTEXPR const result_type modulus = __m;
1871    _LIBCPP_INLINE_VISIBILITY
1872    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
1873    _LIBCPP_INLINE_VISIBILITY
1874    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
1875    static _LIBCPP_CONSTEXPR const result_type default_seed = 1u;
1876
1877    // constructors and seeding functions
1878    _LIBCPP_INLINE_VISIBILITY
1879    explicit linear_congruential_engine(result_type __s = default_seed)
1880        {seed(__s);}
1881    template<class _Sseq>
1882        _LIBCPP_INLINE_VISIBILITY
1883        explicit linear_congruential_engine(_Sseq& __q,
1884        typename enable_if<__is_seed_sequence<_Sseq, linear_congruential_engine>::value>::type* = 0)
1885        {seed(__q);}
1886    _LIBCPP_INLINE_VISIBILITY
1887    void seed(result_type __s = default_seed)
1888        {seed(integral_constant<bool, __m == 0>(),
1889              integral_constant<bool, __c == 0>(), __s);}
1890    template<class _Sseq>
1891        _LIBCPP_INLINE_VISIBILITY
1892        typename enable_if
1893        <
1894            __is_seed_sequence<_Sseq, linear_congruential_engine>::value,
1895            void
1896        >::type
1897        seed(_Sseq& __q)
1898            {__seed(__q, integral_constant<unsigned,
1899                1 + (__m == 0 ? (sizeof(result_type) * __CHAR_BIT__ - 1)/32
1900                             :  (__m > 0x100000000ull))>());}
1901
1902    // generating functions
1903    _LIBCPP_INLINE_VISIBILITY
1904    result_type operator()()
1905        {return __x_ = static_cast<result_type>(__lce_ta<__a, __c, __m, _Mp>::next(__x_));}
1906    _LIBCPP_INLINE_VISIBILITY
1907    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
1908
1909    friend _LIBCPP_INLINE_VISIBILITY
1910    bool operator==(const linear_congruential_engine& __x,
1911                    const linear_congruential_engine& __y)
1912        {return __x.__x_ == __y.__x_;}
1913    friend _LIBCPP_INLINE_VISIBILITY
1914    bool operator!=(const linear_congruential_engine& __x,
1915                    const linear_congruential_engine& __y)
1916        {return !(__x == __y);}
1917
1918private:
1919
1920    _LIBCPP_INLINE_VISIBILITY
1921    void seed(true_type, true_type, result_type __s) {__x_ = __s == 0 ? 1 : __s;}
1922    _LIBCPP_INLINE_VISIBILITY
1923    void seed(true_type, false_type, result_type __s) {__x_ = __s;}
1924    _LIBCPP_INLINE_VISIBILITY
1925    void seed(false_type, true_type, result_type __s) {__x_ = __s % __m == 0 ?
1926                                                                 1 : __s % __m;}
1927    _LIBCPP_INLINE_VISIBILITY
1928    void seed(false_type, false_type, result_type __s) {__x_ = __s % __m;}
1929
1930    template<class _Sseq>
1931        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
1932    template<class _Sseq>
1933        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
1934
1935    template <class _CharT, class _Traits,
1936              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1937    friend
1938    basic_ostream<_CharT, _Traits>&
1939    operator<<(basic_ostream<_CharT, _Traits>& __os,
1940               const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
1941
1942    template <class _CharT, class _Traits,
1943              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1944    friend
1945    basic_istream<_CharT, _Traits>&
1946    operator>>(basic_istream<_CharT, _Traits>& __is,
1947               linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
1948};
1949
1950template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1951    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1952    linear_congruential_engine<_UIntType, __a, __c, __m>::multiplier;
1953
1954template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1955    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1956    linear_congruential_engine<_UIntType, __a, __c, __m>::increment;
1957
1958template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1959    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1960    linear_congruential_engine<_UIntType, __a, __c, __m>::modulus;
1961
1962template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1963    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1964    linear_congruential_engine<_UIntType, __a, __c, __m>::default_seed;
1965
1966template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1967template<class _Sseq>
1968void
1969linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
1970                                                 integral_constant<unsigned, 1>)
1971{
1972    const unsigned __k = 1;
1973    uint32_t __ar[__k+3];
1974    __q.generate(__ar, __ar + __k + 3);
1975    result_type __s = static_cast<result_type>(__ar[3] % __m);
1976    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
1977}
1978
1979template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1980template<class _Sseq>
1981void
1982linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
1983                                                 integral_constant<unsigned, 2>)
1984{
1985    const unsigned __k = 2;
1986    uint32_t __ar[__k+3];
1987    __q.generate(__ar, __ar + __k + 3);
1988    result_type __s = static_cast<result_type>((__ar[3] +
1989                                              ((uint64_t)__ar[4] << 32)) % __m);
1990    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
1991}
1992
1993template <class _CharT, class _Traits,
1994          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1995inline _LIBCPP_INLINE_VISIBILITY
1996basic_ostream<_CharT, _Traits>&
1997operator<<(basic_ostream<_CharT, _Traits>& __os,
1998           const linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
1999{
2000    __save_flags<_CharT, _Traits> __lx(__os);
2001    typedef basic_ostream<_CharT, _Traits> _Ostream;
2002    __os.flags(_Ostream::dec | _Ostream::left);
2003    __os.fill(__os.widen(' '));
2004    return __os << __x.__x_;
2005}
2006
2007template <class _CharT, class _Traits,
2008          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
2009basic_istream<_CharT, _Traits>&
2010operator>>(basic_istream<_CharT, _Traits>& __is,
2011           linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
2012{
2013    __save_flags<_CharT, _Traits> __lx(__is);
2014    typedef basic_istream<_CharT, _Traits> _Istream;
2015    __is.flags(_Istream::dec | _Istream::skipws);
2016    _UIntType __t;
2017    __is >> __t;
2018    if (!__is.fail())
2019        __x.__x_ = __t;
2020    return __is;
2021}
2022
2023typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
2024                                                                   minstd_rand0;
2025typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
2026                                                                    minstd_rand;
2027typedef minstd_rand                                       default_random_engine;
2028// mersenne_twister_engine
2029
2030template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2031          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2032          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2033class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine;
2034
2035template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2036          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2037          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2038bool
2039operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2040                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2041           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2042                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2043
2044template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2045          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2046          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2047_LIBCPP_INLINE_VISIBILITY
2048bool
2049operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2050                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2051           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2052                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2053
2054template <class _CharT, class _Traits,
2055          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2056          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2057          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2058basic_ostream<_CharT, _Traits>&
2059operator<<(basic_ostream<_CharT, _Traits>& __os,
2060           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2061                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2062
2063template <class _CharT, class _Traits,
2064          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2065          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2066          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2067basic_istream<_CharT, _Traits>&
2068operator>>(basic_istream<_CharT, _Traits>& __is,
2069           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2070                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2071
2072template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2073          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2074          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2075class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine
2076{
2077public:
2078    // types
2079    typedef _UIntType result_type;
2080
2081private:
2082    result_type __x_[__n];
2083    size_t      __i_;
2084
2085    static_assert(  0 <  __m, "mersenne_twister_engine invalid parameters");
2086    static_assert(__m <= __n, "mersenne_twister_engine invalid parameters");
2087    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
2088    static_assert(__w <= _Dt, "mersenne_twister_engine invalid parameters");
2089    static_assert(  2 <= __w, "mersenne_twister_engine invalid parameters");
2090    static_assert(__r <= __w, "mersenne_twister_engine invalid parameters");
2091    static_assert(__u <= __w, "mersenne_twister_engine invalid parameters");
2092    static_assert(__s <= __w, "mersenne_twister_engine invalid parameters");
2093    static_assert(__t <= __w, "mersenne_twister_engine invalid parameters");
2094    static_assert(__l <= __w, "mersenne_twister_engine invalid parameters");
2095public:
2096    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
2097    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
2098                                                      (result_type(1) << __w) - result_type(1);
2099    static_assert(_Min < _Max, "mersenne_twister_engine invalid parameters");
2100    static_assert(__a <= _Max, "mersenne_twister_engine invalid parameters");
2101    static_assert(__b <= _Max, "mersenne_twister_engine invalid parameters");
2102    static_assert(__c <= _Max, "mersenne_twister_engine invalid parameters");
2103    static_assert(__d <= _Max, "mersenne_twister_engine invalid parameters");
2104    static_assert(__f <= _Max, "mersenne_twister_engine invalid parameters");
2105
2106    // engine characteristics
2107    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
2108    static _LIBCPP_CONSTEXPR const size_t state_size = __n;
2109    static _LIBCPP_CONSTEXPR const size_t shift_size = __m;
2110    static _LIBCPP_CONSTEXPR const size_t mask_bits = __r;
2111    static _LIBCPP_CONSTEXPR const result_type xor_mask = __a;
2112    static _LIBCPP_CONSTEXPR const size_t tempering_u = __u;
2113    static _LIBCPP_CONSTEXPR const result_type tempering_d = __d;
2114    static _LIBCPP_CONSTEXPR const size_t tempering_s = __s;
2115    static _LIBCPP_CONSTEXPR const result_type tempering_b = __b;
2116    static _LIBCPP_CONSTEXPR const size_t tempering_t = __t;
2117    static _LIBCPP_CONSTEXPR const result_type tempering_c = __c;
2118    static _LIBCPP_CONSTEXPR const size_t tempering_l = __l;
2119    static _LIBCPP_CONSTEXPR const result_type initialization_multiplier = __f;
2120    _LIBCPP_INLINE_VISIBILITY
2121    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
2122    _LIBCPP_INLINE_VISIBILITY
2123    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
2124    static _LIBCPP_CONSTEXPR const result_type default_seed = 5489u;
2125
2126    // constructors and seeding functions
2127    _LIBCPP_INLINE_VISIBILITY
2128    explicit mersenne_twister_engine(result_type __sd = default_seed)
2129        {seed(__sd);}
2130    template<class _Sseq>
2131        _LIBCPP_INLINE_VISIBILITY
2132        explicit mersenne_twister_engine(_Sseq& __q,
2133        typename enable_if<__is_seed_sequence<_Sseq, mersenne_twister_engine>::value>::type* = 0)
2134        {seed(__q);}
2135    void seed(result_type __sd = default_seed);
2136    template<class _Sseq>
2137        _LIBCPP_INLINE_VISIBILITY
2138        typename enable_if
2139        <
2140            __is_seed_sequence<_Sseq, mersenne_twister_engine>::value,
2141            void
2142        >::type
2143        seed(_Sseq& __q)
2144            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2145
2146    // generating functions
2147    result_type operator()();
2148    _LIBCPP_INLINE_VISIBILITY
2149    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2150
2151    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2152              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2153              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2154    friend
2155    bool
2156    operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2157                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2158               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2159                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2160
2161    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2162              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2163              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2164    friend
2165    bool
2166    operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2167                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2168               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2169                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2170
2171    template <class _CharT, class _Traits,
2172              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2173              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2174              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2175    friend
2176    basic_ostream<_CharT, _Traits>&
2177    operator<<(basic_ostream<_CharT, _Traits>& __os,
2178               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2179                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2180
2181    template <class _CharT, class _Traits,
2182              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2183              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2184              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2185    friend
2186    basic_istream<_CharT, _Traits>&
2187    operator>>(basic_istream<_CharT, _Traits>& __is,
2188               mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2189                                       _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2190private:
2191
2192    template<class _Sseq>
2193        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
2194    template<class _Sseq>
2195        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
2196
2197    template <size_t __count>
2198        _LIBCPP_INLINE_VISIBILITY
2199        static
2200        typename enable_if
2201        <
2202            __count < __w,
2203            result_type
2204        >::type
2205        __lshift(result_type __x) {return (__x << __count) & _Max;}
2206
2207    template <size_t __count>
2208        _LIBCPP_INLINE_VISIBILITY
2209        static
2210        typename enable_if
2211        <
2212            (__count >= __w),
2213            result_type
2214        >::type
2215        __lshift(result_type) {return result_type(0);}
2216
2217    template <size_t __count>
2218        _LIBCPP_INLINE_VISIBILITY
2219        static
2220        typename enable_if
2221        <
2222            __count < _Dt,
2223            result_type
2224        >::type
2225        __rshift(result_type __x) {return __x >> __count;}
2226
2227    template <size_t __count>
2228        _LIBCPP_INLINE_VISIBILITY
2229        static
2230        typename enable_if
2231        <
2232            (__count >= _Dt),
2233            result_type
2234        >::type
2235        __rshift(result_type) {return result_type(0);}
2236};
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>::word_size;
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 size_t
2248    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::state_size;
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>::shift_size;
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 size_t
2260    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::mask_bits;
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 typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2266    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::xor_mask;
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 size_t
2272    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_u;
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 typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2278    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_d;
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 size_t
2284    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_s;
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 typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2290    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_b;
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 size_t
2296    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_t;
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>::tempering_c;
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>
2307    _LIBCPP_CONSTEXPR const size_t
2308    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_l;
2309
2310template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2311          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2312          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2313    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2314    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::initialization_multiplier;
2315
2316template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2317          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2318          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2319    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2320    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::default_seed;
2321
2322template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2323          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2324          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2325void
2326mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2327    __t, __c, __l, __f>::seed(result_type __sd)
2328    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
2329{   // __w >= 2
2330    __x_[0] = __sd & _Max;
2331    for (size_t __i = 1; __i < __n; ++__i)
2332        __x_[__i] = (__f * (__x_[__i-1] ^ __rshift<__w - 2>(__x_[__i-1])) + __i) & _Max;
2333    __i_ = 0;
2334}
2335
2336template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2337          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2338          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2339template<class _Sseq>
2340void
2341mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2342    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 1>)
2343{
2344    const unsigned __k = 1;
2345    uint32_t __ar[__n * __k];
2346    __q.generate(__ar, __ar + __n * __k);
2347    for (size_t __i = 0; __i < __n; ++__i)
2348        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
2349    const result_type __mask = __r == _Dt ? result_type(~0) :
2350                                       (result_type(1) << __r) - result_type(1);
2351    __i_ = 0;
2352    if ((__x_[0] & ~__mask) == 0)
2353    {
2354        for (size_t __i = 1; __i < __n; ++__i)
2355            if (__x_[__i] != 0)
2356                return;
2357        __x_[0] = result_type(1) << (__w - 1);
2358    }
2359}
2360
2361template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2362          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2363          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2364template<class _Sseq>
2365void
2366mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2367    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 2>)
2368{
2369    const unsigned __k = 2;
2370    uint32_t __ar[__n * __k];
2371    __q.generate(__ar, __ar + __n * __k);
2372    for (size_t __i = 0; __i < __n; ++__i)
2373        __x_[__i] = static_cast<result_type>(
2374            (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
2375    const result_type __mask = __r == _Dt ? result_type(~0) :
2376                                       (result_type(1) << __r) - result_type(1);
2377    __i_ = 0;
2378    if ((__x_[0] & ~__mask) == 0)
2379    {
2380        for (size_t __i = 1; __i < __n; ++__i)
2381            if (__x_[__i] != 0)
2382                return;
2383        __x_[0] = result_type(1) << (__w - 1);
2384    }
2385}
2386
2387template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2388          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2389          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2390_UIntType
2391mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2392    __t, __c, __l, __f>::operator()()
2393{
2394    const size_t __j = (__i_ + 1) % __n;
2395    const result_type __mask = __r == _Dt ? result_type(~0) :
2396                                       (result_type(1) << __r) - result_type(1);
2397    const result_type _Yp = (__x_[__i_] & ~__mask) | (__x_[__j] & __mask);
2398    const size_t __k = (__i_ + __m) % __n;
2399    __x_[__i_] = __x_[__k] ^ __rshift<1>(_Yp) ^ (__a * (_Yp & 1));
2400    result_type __z = __x_[__i_] ^ (__rshift<__u>(__x_[__i_]) & __d);
2401    __i_ = __j;
2402    __z ^= __lshift<__s>(__z) & __b;
2403    __z ^= __lshift<__t>(__z) & __c;
2404    return __z ^ __rshift<__l>(__z);
2405}
2406
2407template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2408          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2409          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2410bool
2411operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2412                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2413           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2414                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
2415{
2416    if (__x.__i_ == __y.__i_)
2417        return _VSTD::equal(__x.__x_, __x.__x_ + _Np, __y.__x_);
2418    if (__x.__i_ == 0 || __y.__i_ == 0)
2419    {
2420        size_t __j = _VSTD::min(_Np - __x.__i_, _Np - __y.__i_);
2421        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
2422                         __y.__x_ + __y.__i_))
2423            return false;
2424        if (__x.__i_ == 0)
2425            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Np, __y.__x_);
2426        return _VSTD::equal(__x.__x_, __x.__x_ + (_Np - __j), __y.__x_ + __j);
2427    }
2428    if (__x.__i_ < __y.__i_)
2429    {
2430        size_t __j = _Np - __y.__i_;
2431        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
2432                         __y.__x_ + __y.__i_))
2433            return false;
2434        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Np,
2435                         __y.__x_))
2436            return false;
2437        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
2438                           __y.__x_ + (_Np - (__x.__i_ + __j)));
2439    }
2440    size_t __j = _Np - __x.__i_;
2441    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
2442                     __x.__x_ + __x.__i_))
2443        return false;
2444    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Np,
2445                     __x.__x_))
2446        return false;
2447    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
2448                       __x.__x_ + (_Np - (__y.__i_ + __j)));
2449}
2450
2451template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2452          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2453          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2454inline _LIBCPP_INLINE_VISIBILITY
2455bool
2456operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2457                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2458           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2459                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
2460{
2461    return !(__x == __y);
2462}
2463
2464template <class _CharT, class _Traits,
2465          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2466          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2467          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2468basic_ostream<_CharT, _Traits>&
2469operator<<(basic_ostream<_CharT, _Traits>& __os,
2470           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2471                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
2472{
2473    __save_flags<_CharT, _Traits> __lx(__os);
2474    typedef basic_ostream<_CharT, _Traits> _Ostream;
2475    __os.flags(_Ostream::dec | _Ostream::left);
2476    _CharT __sp = __os.widen(' ');
2477    __os.fill(__sp);
2478    __os << __x.__x_[__x.__i_];
2479    for (size_t __j = __x.__i_ + 1; __j < _Np; ++__j)
2480        __os << __sp << __x.__x_[__j];
2481    for (size_t __j = 0; __j < __x.__i_; ++__j)
2482        __os << __sp << __x.__x_[__j];
2483    return __os;
2484}
2485
2486template <class _CharT, class _Traits,
2487          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2488          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2489          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2490basic_istream<_CharT, _Traits>&
2491operator>>(basic_istream<_CharT, _Traits>& __is,
2492           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2493                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
2494{
2495    __save_flags<_CharT, _Traits> __lx(__is);
2496    typedef basic_istream<_CharT, _Traits> _Istream;
2497    __is.flags(_Istream::dec | _Istream::skipws);
2498    _UInt __t[_Np];
2499    for (size_t __i = 0; __i < _Np; ++__i)
2500        __is >> __t[__i];
2501    if (!__is.fail())
2502    {
2503        for (size_t __i = 0; __i < _Np; ++__i)
2504            __x.__x_[__i] = __t[__i];
2505        __x.__i_ = 0;
2506    }
2507    return __is;
2508}
2509
2510typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
2511                                0x9908b0df, 11, 0xffffffff,
2512                                7,  0x9d2c5680,
2513                                15, 0xefc60000,
2514                                18, 1812433253>                         mt19937;
2515typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
2516                                0xb5026f5aa96619e9ULL, 29, 0x5555555555555555ULL,
2517                                17, 0x71d67fffeda60000ULL,
2518                                37, 0xfff7eee000000000ULL,
2519                                43, 6364136223846793005ULL>          mt19937_64;
2520
2521// subtract_with_carry_engine
2522
2523template<class _UIntType, size_t __w, size_t __s, size_t __r>
2524class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine;
2525
2526template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2527bool
2528operator==(
2529    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2530    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2531
2532template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2533_LIBCPP_INLINE_VISIBILITY
2534bool
2535operator!=(
2536    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2537    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2538
2539template <class _CharT, class _Traits,
2540          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2541basic_ostream<_CharT, _Traits>&
2542operator<<(basic_ostream<_CharT, _Traits>& __os,
2543           const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2544
2545template <class _CharT, class _Traits,
2546          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2547basic_istream<_CharT, _Traits>&
2548operator>>(basic_istream<_CharT, _Traits>& __is,
2549           subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2550
2551template<class _UIntType, size_t __w, size_t __s, size_t __r>
2552class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine
2553{
2554public:
2555    // types
2556    typedef _UIntType result_type;
2557
2558private:
2559    result_type __x_[__r];
2560    result_type  __c_;
2561    size_t      __i_;
2562
2563    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
2564    static_assert(  0 <  __w, "subtract_with_carry_engine invalid parameters");
2565    static_assert(__w <= _Dt, "subtract_with_carry_engine invalid parameters");
2566    static_assert(  0 <  __s, "subtract_with_carry_engine invalid parameters");
2567    static_assert(__s <  __r, "subtract_with_carry_engine invalid parameters");
2568public:
2569    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
2570    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
2571                                                      (result_type(1) << __w) - result_type(1);
2572    static_assert(_Min < _Max, "subtract_with_carry_engine invalid parameters");
2573
2574    // engine characteristics
2575    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
2576    static _LIBCPP_CONSTEXPR const size_t short_lag = __s;
2577    static _LIBCPP_CONSTEXPR const size_t long_lag = __r;
2578    _LIBCPP_INLINE_VISIBILITY
2579    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
2580    _LIBCPP_INLINE_VISIBILITY
2581    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
2582    static _LIBCPP_CONSTEXPR const result_type default_seed = 19780503u;
2583
2584    // constructors and seeding functions
2585    _LIBCPP_INLINE_VISIBILITY
2586    explicit subtract_with_carry_engine(result_type __sd = default_seed)
2587        {seed(__sd);}
2588    template<class _Sseq>
2589        _LIBCPP_INLINE_VISIBILITY
2590        explicit subtract_with_carry_engine(_Sseq& __q,
2591        typename enable_if<__is_seed_sequence<_Sseq, subtract_with_carry_engine>::value>::type* = 0)
2592        {seed(__q);}
2593    _LIBCPP_INLINE_VISIBILITY
2594    void seed(result_type __sd = default_seed)
2595        {seed(__sd, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2596    template<class _Sseq>
2597        _LIBCPP_INLINE_VISIBILITY
2598        typename enable_if
2599        <
2600            __is_seed_sequence<_Sseq, subtract_with_carry_engine>::value,
2601            void
2602        >::type
2603        seed(_Sseq& __q)
2604            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2605
2606    // generating functions
2607    result_type operator()();
2608    _LIBCPP_INLINE_VISIBILITY
2609    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2610
2611    template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2612    friend
2613    bool
2614    operator==(
2615        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2616        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2617
2618    template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2619    friend
2620    bool
2621    operator!=(
2622        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2623        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2624
2625    template <class _CharT, class _Traits,
2626              class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2627    friend
2628    basic_ostream<_CharT, _Traits>&
2629    operator<<(basic_ostream<_CharT, _Traits>& __os,
2630               const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2631
2632    template <class _CharT, class _Traits,
2633              class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2634    friend
2635    basic_istream<_CharT, _Traits>&
2636    operator>>(basic_istream<_CharT, _Traits>& __is,
2637               subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2638
2639private:
2640
2641    void seed(result_type __sd, integral_constant<unsigned, 1>);
2642    void seed(result_type __sd, integral_constant<unsigned, 2>);
2643    template<class _Sseq>
2644        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
2645    template<class _Sseq>
2646        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
2647};
2648
2649template<class _UIntType, size_t __w, size_t __s, size_t __r>
2650    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::word_size;
2651
2652template<class _UIntType, size_t __w, size_t __s, size_t __r>
2653    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::short_lag;
2654
2655template<class _UIntType, size_t __w, size_t __s, size_t __r>
2656    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::long_lag;
2657
2658template<class _UIntType, size_t __w, size_t __s, size_t __r>
2659    _LIBCPP_CONSTEXPR const typename subtract_with_carry_engine<_UIntType, __w, __s, __r>::result_type
2660    subtract_with_carry_engine<_UIntType, __w, __s, __r>::default_seed;
2661
2662template<class _UIntType, size_t __w, size_t __s, size_t __r>
2663void
2664subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
2665        integral_constant<unsigned, 1>)
2666{
2667    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
2668        __e(__sd == 0u ? default_seed : __sd);
2669    for (size_t __i = 0; __i < __r; ++__i)
2670        __x_[__i] = static_cast<result_type>(__e() & _Max);
2671    __c_ = __x_[__r-1] == 0;
2672    __i_ = 0;
2673}
2674
2675template<class _UIntType, size_t __w, size_t __s, size_t __r>
2676void
2677subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
2678        integral_constant<unsigned, 2>)
2679{
2680    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
2681        __e(__sd == 0u ? default_seed : __sd);
2682    for (size_t __i = 0; __i < __r; ++__i)
2683    {
2684        result_type __e0 = __e();
2685        __x_[__i] = static_cast<result_type>(
2686                                    (__e0 + ((uint64_t)__e() << 32)) & _Max);
2687    }
2688    __c_ = __x_[__r-1] == 0;
2689    __i_ = 0;
2690}
2691
2692template<class _UIntType, size_t __w, size_t __s, size_t __r>
2693template<class _Sseq>
2694void
2695subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
2696        integral_constant<unsigned, 1>)
2697{
2698    const unsigned __k = 1;
2699    uint32_t __ar[__r * __k];
2700    __q.generate(__ar, __ar + __r * __k);
2701    for (size_t __i = 0; __i < __r; ++__i)
2702        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
2703    __c_ = __x_[__r-1] == 0;
2704    __i_ = 0;
2705}
2706
2707template<class _UIntType, size_t __w, size_t __s, size_t __r>
2708template<class _Sseq>
2709void
2710subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
2711        integral_constant<unsigned, 2>)
2712{
2713    const unsigned __k = 2;
2714    uint32_t __ar[__r * __k];
2715    __q.generate(__ar, __ar + __r * __k);
2716    for (size_t __i = 0; __i < __r; ++__i)
2717        __x_[__i] = static_cast<result_type>(
2718                  (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
2719    __c_ = __x_[__r-1] == 0;
2720    __i_ = 0;
2721}
2722
2723template<class _UIntType, size_t __w, size_t __s, size_t __r>
2724_UIntType
2725subtract_with_carry_engine<_UIntType, __w, __s, __r>::operator()()
2726{
2727    const result_type& __xs = __x_[(__i_ + (__r - __s)) % __r];
2728    result_type& __xr = __x_[__i_];
2729    result_type __new_c = __c_ == 0 ? __xs < __xr : __xs != 0 ? __xs <= __xr : 1;
2730    __xr = (__xs - __xr - __c_) & _Max;
2731    __c_ = __new_c;
2732    __i_ = (__i_ + 1) % __r;
2733    return __xr;
2734}
2735
2736template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2737bool
2738operator==(
2739    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2740    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
2741{
2742    if (__x.__c_ != __y.__c_)
2743        return false;
2744    if (__x.__i_ == __y.__i_)
2745        return _VSTD::equal(__x.__x_, __x.__x_ + _Rp, __y.__x_);
2746    if (__x.__i_ == 0 || __y.__i_ == 0)
2747    {
2748        size_t __j = _VSTD::min(_Rp - __x.__i_, _Rp - __y.__i_);
2749        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
2750                         __y.__x_ + __y.__i_))
2751            return false;
2752        if (__x.__i_ == 0)
2753            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Rp, __y.__x_);
2754        return _VSTD::equal(__x.__x_, __x.__x_ + (_Rp - __j), __y.__x_ + __j);
2755    }
2756    if (__x.__i_ < __y.__i_)
2757    {
2758        size_t __j = _Rp - __y.__i_;
2759        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
2760                         __y.__x_ + __y.__i_))
2761            return false;
2762        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Rp,
2763                         __y.__x_))
2764            return false;
2765        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
2766                           __y.__x_ + (_Rp - (__x.__i_ + __j)));
2767    }
2768    size_t __j = _Rp - __x.__i_;
2769    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
2770                     __x.__x_ + __x.__i_))
2771        return false;
2772    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Rp,
2773                     __x.__x_))
2774        return false;
2775    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
2776                       __x.__x_ + (_Rp - (__y.__i_ + __j)));
2777}
2778
2779template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2780inline _LIBCPP_INLINE_VISIBILITY
2781bool
2782operator!=(
2783    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2784    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
2785{
2786    return !(__x == __y);
2787}
2788
2789template <class _CharT, class _Traits,
2790          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2791basic_ostream<_CharT, _Traits>&
2792operator<<(basic_ostream<_CharT, _Traits>& __os,
2793           const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
2794{
2795    __save_flags<_CharT, _Traits> __lx(__os);
2796    typedef basic_ostream<_CharT, _Traits> _Ostream;
2797    __os.flags(_Ostream::dec | _Ostream::left);
2798    _CharT __sp = __os.widen(' ');
2799    __os.fill(__sp);
2800    __os << __x.__x_[__x.__i_];
2801    for (size_t __j = __x.__i_ + 1; __j < _Rp; ++__j)
2802        __os << __sp << __x.__x_[__j];
2803    for (size_t __j = 0; __j < __x.__i_; ++__j)
2804        __os << __sp << __x.__x_[__j];
2805    __os << __sp << __x.__c_;
2806    return __os;
2807}
2808
2809template <class _CharT, class _Traits,
2810          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2811basic_istream<_CharT, _Traits>&
2812operator>>(basic_istream<_CharT, _Traits>& __is,
2813           subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
2814{
2815    __save_flags<_CharT, _Traits> __lx(__is);
2816    typedef basic_istream<_CharT, _Traits> _Istream;
2817    __is.flags(_Istream::dec | _Istream::skipws);
2818    _UInt __t[_Rp+1];
2819    for (size_t __i = 0; __i < _Rp+1; ++__i)
2820        __is >> __t[__i];
2821    if (!__is.fail())
2822    {
2823        for (size_t __i = 0; __i < _Rp; ++__i)
2824            __x.__x_[__i] = __t[__i];
2825        __x.__c_ = __t[_Rp];
2826        __x.__i_ = 0;
2827    }
2828    return __is;
2829}
2830
2831typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
2832typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
2833
2834// discard_block_engine
2835
2836template<class _Engine, size_t __p, size_t __r>
2837class _LIBCPP_TEMPLATE_VIS discard_block_engine
2838{
2839    _Engine __e_;
2840    int     __n_;
2841
2842    static_assert(  0 <  __r, "discard_block_engine invalid parameters");
2843    static_assert(__r <= __p, "discard_block_engine invalid parameters");
2844    static_assert(__r <= INT_MAX, "discard_block_engine invalid parameters");
2845public:
2846    // types
2847    typedef typename _Engine::result_type result_type;
2848
2849    // engine characteristics
2850    static _LIBCPP_CONSTEXPR const size_t block_size = __p;
2851    static _LIBCPP_CONSTEXPR const size_t used_block = __r;
2852
2853#ifdef _LIBCPP_CXX03_LANG
2854    static const result_type _Min = _Engine::_Min;
2855    static const result_type _Max = _Engine::_Max;
2856#else
2857    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
2858    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
2859#endif
2860
2861    _LIBCPP_INLINE_VISIBILITY
2862    static _LIBCPP_CONSTEXPR result_type min() { return _Engine::min(); }
2863    _LIBCPP_INLINE_VISIBILITY
2864    static _LIBCPP_CONSTEXPR result_type max() { return _Engine::max(); }
2865
2866    // constructors and seeding functions
2867    _LIBCPP_INLINE_VISIBILITY
2868    discard_block_engine() : __n_(0) {}
2869    _LIBCPP_INLINE_VISIBILITY
2870    explicit discard_block_engine(const _Engine& __e)
2871        : __e_(__e), __n_(0) {}
2872#ifndef _LIBCPP_CXX03_LANG
2873    _LIBCPP_INLINE_VISIBILITY
2874    explicit discard_block_engine(_Engine&& __e)
2875        : __e_(_VSTD::move(__e)), __n_(0) {}
2876#endif  // _LIBCPP_CXX03_LANG
2877    _LIBCPP_INLINE_VISIBILITY
2878    explicit discard_block_engine(result_type __sd) : __e_(__sd), __n_(0) {}
2879    template<class _Sseq>
2880        _LIBCPP_INLINE_VISIBILITY
2881        explicit discard_block_engine(_Sseq& __q,
2882        typename enable_if<__is_seed_sequence<_Sseq, discard_block_engine>::value &&
2883                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
2884        : __e_(__q), __n_(0) {}
2885    _LIBCPP_INLINE_VISIBILITY
2886    void seed() {__e_.seed(); __n_ = 0;}
2887    _LIBCPP_INLINE_VISIBILITY
2888    void seed(result_type __sd) {__e_.seed(__sd); __n_ = 0;}
2889    template<class _Sseq>
2890        _LIBCPP_INLINE_VISIBILITY
2891        typename enable_if
2892        <
2893            __is_seed_sequence<_Sseq, discard_block_engine>::value,
2894            void
2895        >::type
2896        seed(_Sseq& __q) {__e_.seed(__q); __n_ = 0;}
2897
2898    // generating functions
2899    result_type operator()();
2900    _LIBCPP_INLINE_VISIBILITY
2901    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2902
2903    // property functions
2904    _LIBCPP_INLINE_VISIBILITY
2905    const _Engine& base() const _NOEXCEPT {return __e_;}
2906
2907    template<class _Eng, size_t _Pp, size_t _Rp>
2908    friend
2909    bool
2910    operator==(
2911        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2912        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
2913
2914    template<class _Eng, size_t _Pp, size_t _Rp>
2915    friend
2916    bool
2917    operator!=(
2918        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2919        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
2920
2921    template <class _CharT, class _Traits,
2922              class _Eng, size_t _Pp, size_t _Rp>
2923    friend
2924    basic_ostream<_CharT, _Traits>&
2925    operator<<(basic_ostream<_CharT, _Traits>& __os,
2926               const discard_block_engine<_Eng, _Pp, _Rp>& __x);
2927
2928    template <class _CharT, class _Traits,
2929              class _Eng, size_t _Pp, size_t _Rp>
2930    friend
2931    basic_istream<_CharT, _Traits>&
2932    operator>>(basic_istream<_CharT, _Traits>& __is,
2933               discard_block_engine<_Eng, _Pp, _Rp>& __x);
2934};
2935
2936template<class _Engine, size_t __p, size_t __r>
2937    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::block_size;
2938
2939template<class _Engine, size_t __p, size_t __r>
2940    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::used_block;
2941
2942template<class _Engine, size_t __p, size_t __r>
2943typename discard_block_engine<_Engine, __p, __r>::result_type
2944discard_block_engine<_Engine, __p, __r>::operator()()
2945{
2946    if (__n_ >= static_cast<int>(__r))
2947    {
2948        __e_.discard(__p - __r);
2949        __n_ = 0;
2950    }
2951    ++__n_;
2952    return __e_();
2953}
2954
2955template<class _Eng, size_t _Pp, size_t _Rp>
2956inline _LIBCPP_INLINE_VISIBILITY
2957bool
2958operator==(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2959           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
2960{
2961    return __x.__n_ == __y.__n_ && __x.__e_ == __y.__e_;
2962}
2963
2964template<class _Eng, size_t _Pp, size_t _Rp>
2965inline _LIBCPP_INLINE_VISIBILITY
2966bool
2967operator!=(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2968           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
2969{
2970    return !(__x == __y);
2971}
2972
2973template <class _CharT, class _Traits,
2974          class _Eng, size_t _Pp, size_t _Rp>
2975basic_ostream<_CharT, _Traits>&
2976operator<<(basic_ostream<_CharT, _Traits>& __os,
2977           const discard_block_engine<_Eng, _Pp, _Rp>& __x)
2978{
2979    __save_flags<_CharT, _Traits> __lx(__os);
2980    typedef basic_ostream<_CharT, _Traits> _Ostream;
2981    __os.flags(_Ostream::dec | _Ostream::left);
2982    _CharT __sp = __os.widen(' ');
2983    __os.fill(__sp);
2984    return __os << __x.__e_ << __sp << __x.__n_;
2985}
2986
2987template <class _CharT, class _Traits,
2988          class _Eng, size_t _Pp, size_t _Rp>
2989basic_istream<_CharT, _Traits>&
2990operator>>(basic_istream<_CharT, _Traits>& __is,
2991           discard_block_engine<_Eng, _Pp, _Rp>& __x)
2992{
2993    __save_flags<_CharT, _Traits> __lx(__is);
2994    typedef basic_istream<_CharT, _Traits> _Istream;
2995    __is.flags(_Istream::dec | _Istream::skipws);
2996    _Eng __e;
2997    int __n;
2998    __is >> __e >> __n;
2999    if (!__is.fail())
3000    {
3001        __x.__e_ = __e;
3002        __x.__n_ = __n;
3003    }
3004    return __is;
3005}
3006
3007typedef discard_block_engine<ranlux24_base, 223, 23> ranlux24;
3008typedef discard_block_engine<ranlux48_base, 389, 11> ranlux48;
3009
3010// independent_bits_engine
3011
3012template<class _Engine, size_t __w, class _UIntType>
3013class _LIBCPP_TEMPLATE_VIS independent_bits_engine
3014{
3015    template <class _UInt, _UInt _R0, size_t _Wp, size_t _Mp>
3016    class __get_n
3017    {
3018        static _LIBCPP_CONSTEXPR const size_t _Dt = numeric_limits<_UInt>::digits;
3019        static _LIBCPP_CONSTEXPR const size_t _Np = _Wp / _Mp + (_Wp % _Mp != 0);
3020        static _LIBCPP_CONSTEXPR const size_t _W0 = _Wp / _Np;
3021        static _LIBCPP_CONSTEXPR const _UInt _Y0 = _W0 >= _Dt ? 0 : (_R0 >> _W0) << _W0;
3022    public:
3023        static _LIBCPP_CONSTEXPR const size_t value = _R0 - _Y0 > _Y0 / _Np ? _Np + 1 : _Np;
3024    };
3025public:
3026    // types
3027    typedef _UIntType result_type;
3028
3029private:
3030    _Engine __e_;
3031
3032    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
3033    static_assert(  0 <  __w, "independent_bits_engine invalid parameters");
3034    static_assert(__w <= _Dt, "independent_bits_engine invalid parameters");
3035
3036    typedef typename _Engine::result_type _Engine_result_type;
3037    typedef typename conditional
3038        <
3039            sizeof(_Engine_result_type) <= sizeof(result_type),
3040                result_type,
3041                _Engine_result_type
3042        >::type _Working_result_type;
3043#ifdef _LIBCPP_CXX03_LANG
3044    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
3045                                          + _Working_result_type(1);
3046#else
3047    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
3048                                                            + _Working_result_type(1);
3049#endif
3050    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
3051    static _LIBCPP_CONSTEXPR const size_t __n = __get_n<_Working_result_type, _Rp, __w, __m>::value;
3052    static _LIBCPP_CONSTEXPR const size_t __w0 = __w / __n;
3053    static _LIBCPP_CONSTEXPR const size_t __n0 = __n - __w % __n;
3054    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
3055    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
3056    static _LIBCPP_CONSTEXPR const _Working_result_type __y0 = __w0 >= _WDt ? 0 :
3057                                                               (_Rp >> __w0) << __w0;
3058    static _LIBCPP_CONSTEXPR const _Working_result_type __y1 = __w0 >= _WDt - 1 ? 0 :
3059                                                               (_Rp >> (__w0+1)) << (__w0+1);
3060    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask0 = __w0 > 0 ?
3061                                _Engine_result_type(~0) >> (_EDt - __w0) :
3062                                _Engine_result_type(0);
3063    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask1 = __w0 < _EDt - 1 ?
3064                                _Engine_result_type(~0) >> (_EDt - (__w0 + 1)) :
3065                                _Engine_result_type(~0);
3066public:
3067    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
3068    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
3069                                                      (result_type(1) << __w) - result_type(1);
3070    static_assert(_Min < _Max, "independent_bits_engine invalid parameters");
3071
3072    // engine characteristics
3073    _LIBCPP_INLINE_VISIBILITY
3074    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
3075    _LIBCPP_INLINE_VISIBILITY
3076    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
3077
3078    // constructors and seeding functions
3079    _LIBCPP_INLINE_VISIBILITY
3080    independent_bits_engine() {}
3081    _LIBCPP_INLINE_VISIBILITY
3082    explicit independent_bits_engine(const _Engine& __e)
3083        : __e_(__e) {}
3084#ifndef _LIBCPP_CXX03_LANG
3085    _LIBCPP_INLINE_VISIBILITY
3086    explicit independent_bits_engine(_Engine&& __e)
3087        : __e_(_VSTD::move(__e)) {}
3088#endif  // _LIBCPP_CXX03_LANG
3089    _LIBCPP_INLINE_VISIBILITY
3090    explicit independent_bits_engine(result_type __sd) : __e_(__sd) {}
3091    template<class _Sseq>
3092        _LIBCPP_INLINE_VISIBILITY
3093        explicit independent_bits_engine(_Sseq& __q,
3094        typename enable_if<__is_seed_sequence<_Sseq, independent_bits_engine>::value &&
3095                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
3096         : __e_(__q) {}
3097    _LIBCPP_INLINE_VISIBILITY
3098    void seed() {__e_.seed();}
3099    _LIBCPP_INLINE_VISIBILITY
3100    void seed(result_type __sd) {__e_.seed(__sd);}
3101    template<class _Sseq>
3102        _LIBCPP_INLINE_VISIBILITY
3103        typename enable_if
3104        <
3105            __is_seed_sequence<_Sseq, independent_bits_engine>::value,
3106            void
3107        >::type
3108        seed(_Sseq& __q) {__e_.seed(__q);}
3109
3110    // generating functions
3111    _LIBCPP_INLINE_VISIBILITY
3112    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
3113    _LIBCPP_INLINE_VISIBILITY
3114    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
3115
3116    // property functions
3117    _LIBCPP_INLINE_VISIBILITY
3118    const _Engine& base() const _NOEXCEPT {return __e_;}
3119
3120    template<class _Eng, size_t _Wp, class _UInt>
3121    friend
3122    bool
3123    operator==(
3124        const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3125        const independent_bits_engine<_Eng, _Wp, _UInt>& __y);
3126
3127    template<class _Eng, size_t _Wp, class _UInt>
3128    friend
3129    bool
3130    operator!=(
3131        const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3132        const independent_bits_engine<_Eng, _Wp, _UInt>& __y);
3133
3134    template <class _CharT, class _Traits,
3135              class _Eng, size_t _Wp, class _UInt>
3136    friend
3137    basic_ostream<_CharT, _Traits>&
3138    operator<<(basic_ostream<_CharT, _Traits>& __os,
3139               const independent_bits_engine<_Eng, _Wp, _UInt>& __x);
3140
3141    template <class _CharT, class _Traits,
3142              class _Eng, size_t _Wp, class _UInt>
3143    friend
3144    basic_istream<_CharT, _Traits>&
3145    operator>>(basic_istream<_CharT, _Traits>& __is,
3146               independent_bits_engine<_Eng, _Wp, _UInt>& __x);
3147
3148private:
3149    _LIBCPP_INLINE_VISIBILITY
3150    result_type __eval(false_type);
3151    result_type __eval(true_type);
3152
3153    template <size_t __count>
3154        _LIBCPP_INLINE_VISIBILITY
3155        static
3156        typename enable_if
3157        <
3158            __count < _Dt,
3159            result_type
3160        >::type
3161        __lshift(result_type __x) {return __x << __count;}
3162
3163    template <size_t __count>
3164        _LIBCPP_INLINE_VISIBILITY
3165        static
3166        typename enable_if
3167        <
3168            (__count >= _Dt),
3169            result_type
3170        >::type
3171        __lshift(result_type) {return result_type(0);}
3172};
3173
3174template<class _Engine, size_t __w, class _UIntType>
3175inline
3176_UIntType
3177independent_bits_engine<_Engine, __w, _UIntType>::__eval(false_type)
3178{
3179    return static_cast<result_type>(__e_() & __mask0);
3180}
3181
3182template<class _Engine, size_t __w, class _UIntType>
3183_UIntType
3184independent_bits_engine<_Engine, __w, _UIntType>::__eval(true_type)
3185{
3186    result_type _Sp = 0;
3187    for (size_t __k = 0; __k < __n0; ++__k)
3188    {
3189        _Engine_result_type __u;
3190        do
3191        {
3192            __u = __e_() - _Engine::min();
3193        } while (__u >= __y0);
3194        _Sp = static_cast<result_type>(__lshift<__w0>(_Sp) + (__u & __mask0));
3195    }
3196    for (size_t __k = __n0; __k < __n; ++__k)
3197    {
3198        _Engine_result_type __u;
3199        do
3200        {
3201            __u = __e_() - _Engine::min();
3202        } while (__u >= __y1);
3203        _Sp = static_cast<result_type>(__lshift<__w0+1>(_Sp) + (__u & __mask1));
3204    }
3205    return _Sp;
3206}
3207
3208template<class _Eng, size_t _Wp, class _UInt>
3209inline _LIBCPP_INLINE_VISIBILITY
3210bool
3211operator==(
3212    const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3213    const independent_bits_engine<_Eng, _Wp, _UInt>& __y)
3214{
3215    return __x.base() == __y.base();
3216}
3217
3218template<class _Eng, size_t _Wp, class _UInt>
3219inline _LIBCPP_INLINE_VISIBILITY
3220bool
3221operator!=(
3222    const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3223    const independent_bits_engine<_Eng, _Wp, _UInt>& __y)
3224{
3225    return !(__x == __y);
3226}
3227
3228template <class _CharT, class _Traits,
3229          class _Eng, size_t _Wp, class _UInt>
3230basic_ostream<_CharT, _Traits>&
3231operator<<(basic_ostream<_CharT, _Traits>& __os,
3232           const independent_bits_engine<_Eng, _Wp, _UInt>& __x)
3233{
3234    return __os << __x.base();
3235}
3236
3237template <class _CharT, class _Traits,
3238          class _Eng, size_t _Wp, class _UInt>
3239basic_istream<_CharT, _Traits>&
3240operator>>(basic_istream<_CharT, _Traits>& __is,
3241           independent_bits_engine<_Eng, _Wp, _UInt>& __x)
3242{
3243    _Eng __e;
3244    __is >> __e;
3245    if (!__is.fail())
3246        __x.__e_ = __e;
3247    return __is;
3248}
3249
3250// shuffle_order_engine
3251
3252template <uint64_t _Xp, uint64_t _Yp>
3253struct __ugcd
3254{
3255    static _LIBCPP_CONSTEXPR const uint64_t value = __ugcd<_Yp, _Xp % _Yp>::value;
3256};
3257
3258template <uint64_t _Xp>
3259struct __ugcd<_Xp, 0>
3260{
3261    static _LIBCPP_CONSTEXPR const uint64_t value = _Xp;
3262};
3263
3264template <uint64_t _Np, uint64_t _Dp>
3265class __uratio
3266{
3267    static_assert(_Dp != 0, "__uratio divide by 0");
3268    static _LIBCPP_CONSTEXPR const uint64_t __gcd = __ugcd<_Np, _Dp>::value;
3269public:
3270    static _LIBCPP_CONSTEXPR const uint64_t num = _Np / __gcd;
3271    static _LIBCPP_CONSTEXPR const uint64_t den = _Dp / __gcd;
3272
3273    typedef __uratio<num, den> type;
3274};
3275
3276template<class _Engine, size_t __k>
3277class _LIBCPP_TEMPLATE_VIS shuffle_order_engine
3278{
3279    static_assert(0 < __k, "shuffle_order_engine invalid parameters");
3280public:
3281    // types
3282    typedef typename _Engine::result_type result_type;
3283
3284private:
3285    _Engine __e_;
3286    result_type _V_[__k];
3287    result_type _Y_;
3288
3289public:
3290    // engine characteristics
3291    static _LIBCPP_CONSTEXPR const size_t table_size = __k;
3292
3293#ifdef _LIBCPP_CXX03_LANG
3294    static const result_type _Min = _Engine::_Min;
3295    static const result_type _Max = _Engine::_Max;
3296#else
3297    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
3298    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
3299#endif
3300    static_assert(_Min < _Max, "shuffle_order_engine invalid parameters");
3301    _LIBCPP_INLINE_VISIBILITY
3302    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
3303    _LIBCPP_INLINE_VISIBILITY
3304    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
3305
3306    static _LIBCPP_CONSTEXPR const unsigned long long _Rp = _Max - _Min + 1ull;
3307
3308    // constructors and seeding functions
3309    _LIBCPP_INLINE_VISIBILITY
3310    shuffle_order_engine() {__init();}
3311    _LIBCPP_INLINE_VISIBILITY
3312    explicit shuffle_order_engine(const _Engine& __e)
3313        : __e_(__e) {__init();}
3314#ifndef _LIBCPP_CXX03_LANG
3315    _LIBCPP_INLINE_VISIBILITY
3316    explicit shuffle_order_engine(_Engine&& __e)
3317        : __e_(_VSTD::move(__e)) {__init();}
3318#endif  // _LIBCPP_CXX03_LANG
3319    _LIBCPP_INLINE_VISIBILITY
3320    explicit shuffle_order_engine(result_type __sd) : __e_(__sd) {__init();}
3321    template<class _Sseq>
3322        _LIBCPP_INLINE_VISIBILITY
3323        explicit shuffle_order_engine(_Sseq& __q,
3324        typename enable_if<__is_seed_sequence<_Sseq, shuffle_order_engine>::value &&
3325                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
3326         : __e_(__q) {__init();}
3327    _LIBCPP_INLINE_VISIBILITY
3328    void seed() {__e_.seed(); __init();}
3329    _LIBCPP_INLINE_VISIBILITY
3330    void seed(result_type __sd) {__e_.seed(__sd); __init();}
3331    template<class _Sseq>
3332        _LIBCPP_INLINE_VISIBILITY
3333        typename enable_if
3334        <
3335            __is_seed_sequence<_Sseq, shuffle_order_engine>::value,
3336            void
3337        >::type
3338        seed(_Sseq& __q) {__e_.seed(__q); __init();}
3339
3340    // generating functions
3341    _LIBCPP_INLINE_VISIBILITY
3342    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
3343    _LIBCPP_INLINE_VISIBILITY
3344    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
3345
3346    // property functions
3347    _LIBCPP_INLINE_VISIBILITY
3348    const _Engine& base() const _NOEXCEPT {return __e_;}
3349
3350private:
3351    template<class _Eng, size_t _Kp>
3352    friend
3353    bool
3354    operator==(
3355        const shuffle_order_engine<_Eng, _Kp>& __x,
3356        const shuffle_order_engine<_Eng, _Kp>& __y);
3357
3358    template<class _Eng, size_t _Kp>
3359    friend
3360    bool
3361    operator!=(
3362        const shuffle_order_engine<_Eng, _Kp>& __x,
3363        const shuffle_order_engine<_Eng, _Kp>& __y);
3364
3365    template <class _CharT, class _Traits,
3366              class _Eng, size_t _Kp>
3367    friend
3368    basic_ostream<_CharT, _Traits>&
3369    operator<<(basic_ostream<_CharT, _Traits>& __os,
3370               const shuffle_order_engine<_Eng, _Kp>& __x);
3371
3372    template <class _CharT, class _Traits,
3373              class _Eng, size_t _Kp>
3374    friend
3375    basic_istream<_CharT, _Traits>&
3376    operator>>(basic_istream<_CharT, _Traits>& __is,
3377               shuffle_order_engine<_Eng, _Kp>& __x);
3378
3379    _LIBCPP_INLINE_VISIBILITY
3380    void __init()
3381    {
3382        for (size_t __i = 0; __i < __k; ++__i)
3383            _V_[__i] = __e_();
3384        _Y_ = __e_();
3385    }
3386
3387    _LIBCPP_INLINE_VISIBILITY
3388    result_type __eval(false_type) {return __eval2(integral_constant<bool, __k & 1>());}
3389    _LIBCPP_INLINE_VISIBILITY
3390    result_type __eval(true_type) {return __eval(__uratio<__k, _Rp>());}
3391
3392    _LIBCPP_INLINE_VISIBILITY
3393    result_type __eval2(false_type) {return __eval(__uratio<__k/2, 0x8000000000000000ull>());}
3394    _LIBCPP_INLINE_VISIBILITY
3395    result_type __eval2(true_type) {return __evalf<__k, 0>();}
3396
3397    template <uint64_t _Np, uint64_t _Dp>
3398        _LIBCPP_INLINE_VISIBILITY
3399        typename enable_if
3400        <
3401            (__uratio<_Np, _Dp>::num > 0xFFFFFFFFFFFFFFFFull / (_Max - _Min)),
3402            result_type
3403        >::type
3404        __eval(__uratio<_Np, _Dp>)
3405            {return __evalf<__uratio<_Np, _Dp>::num, __uratio<_Np, _Dp>::den>();}
3406
3407    template <uint64_t _Np, uint64_t _Dp>
3408        _LIBCPP_INLINE_VISIBILITY
3409        typename enable_if
3410        <
3411            __uratio<_Np, _Dp>::num <= 0xFFFFFFFFFFFFFFFFull / (_Max - _Min),
3412            result_type
3413        >::type
3414        __eval(__uratio<_Np, _Dp>)
3415        {
3416            const size_t __j = static_cast<size_t>(__uratio<_Np, _Dp>::num * (_Y_ - _Min)
3417                                                   / __uratio<_Np, _Dp>::den);
3418            _Y_ = _V_[__j];
3419            _V_[__j] = __e_();
3420            return _Y_;
3421        }
3422
3423    template <uint64_t __n, uint64_t __d>
3424        _LIBCPP_INLINE_VISIBILITY
3425        result_type __evalf()
3426        {
3427            const double _Fp = __d == 0 ?
3428                __n / (2. * 0x8000000000000000ull) :
3429                __n / (double)__d;
3430            const size_t __j = static_cast<size_t>(_Fp * (_Y_ - _Min));
3431            _Y_ = _V_[__j];
3432            _V_[__j] = __e_();
3433            return _Y_;
3434        }
3435};
3436
3437template<class _Engine, size_t __k>
3438    _LIBCPP_CONSTEXPR const size_t shuffle_order_engine<_Engine, __k>::table_size;
3439
3440template<class _Eng, size_t _Kp>
3441bool
3442operator==(
3443    const shuffle_order_engine<_Eng, _Kp>& __x,
3444    const shuffle_order_engine<_Eng, _Kp>& __y)
3445{
3446    return __x._Y_ == __y._Y_ && _VSTD::equal(__x._V_, __x._V_ + _Kp, __y._V_) &&
3447           __x.__e_ == __y.__e_;
3448}
3449
3450template<class _Eng, size_t _Kp>
3451inline _LIBCPP_INLINE_VISIBILITY
3452bool
3453operator!=(
3454    const shuffle_order_engine<_Eng, _Kp>& __x,
3455    const shuffle_order_engine<_Eng, _Kp>& __y)
3456{
3457    return !(__x == __y);
3458}
3459
3460template <class _CharT, class _Traits,
3461          class _Eng, size_t _Kp>
3462basic_ostream<_CharT, _Traits>&
3463operator<<(basic_ostream<_CharT, _Traits>& __os,
3464           const shuffle_order_engine<_Eng, _Kp>& __x)
3465{
3466    __save_flags<_CharT, _Traits> __lx(__os);
3467    typedef basic_ostream<_CharT, _Traits> _Ostream;
3468    __os.flags(_Ostream::dec | _Ostream::left);
3469    _CharT __sp = __os.widen(' ');
3470    __os.fill(__sp);
3471    __os << __x.__e_ << __sp << __x._V_[0];
3472    for (size_t __i = 1; __i < _Kp; ++__i)
3473        __os << __sp << __x._V_[__i];
3474    return __os << __sp << __x._Y_;
3475}
3476
3477template <class _CharT, class _Traits,
3478          class _Eng, size_t _Kp>
3479basic_istream<_CharT, _Traits>&
3480operator>>(basic_istream<_CharT, _Traits>& __is,
3481           shuffle_order_engine<_Eng, _Kp>& __x)
3482{
3483    typedef typename shuffle_order_engine<_Eng, _Kp>::result_type result_type;
3484    __save_flags<_CharT, _Traits> __lx(__is);
3485    typedef basic_istream<_CharT, _Traits> _Istream;
3486    __is.flags(_Istream::dec | _Istream::skipws);
3487    _Eng __e;
3488    result_type _Vp[_Kp+1];
3489    __is >> __e;
3490    for (size_t __i = 0; __i < _Kp+1; ++__i)
3491        __is >> _Vp[__i];
3492    if (!__is.fail())
3493    {
3494        __x.__e_ = __e;
3495        for (size_t __i = 0; __i < _Kp; ++__i)
3496            __x._V_[__i] = _Vp[__i];
3497        __x._Y_ = _Vp[_Kp];
3498    }
3499    return __is;
3500}
3501
3502typedef shuffle_order_engine<minstd_rand0, 256>                         knuth_b;
3503
3504// random_device
3505
3506#if !defined(_LIBCPP_HAS_NO_RANDOM_DEVICE)
3507
3508class _LIBCPP_TYPE_VIS random_device
3509{
3510#ifdef _LIBCPP_USING_DEV_RANDOM
3511    int __f_;
3512#endif // defined(_LIBCPP_USING_DEV_RANDOM)
3513public:
3514    // types
3515    typedef unsigned result_type;
3516
3517    // generator characteristics
3518    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
3519    static _LIBCPP_CONSTEXPR const result_type _Max = 0xFFFFFFFFu;
3520
3521    _LIBCPP_INLINE_VISIBILITY
3522    static _LIBCPP_CONSTEXPR result_type min() { return _Min;}
3523    _LIBCPP_INLINE_VISIBILITY
3524    static _LIBCPP_CONSTEXPR result_type max() { return _Max;}
3525
3526    // constructors
3527    explicit random_device(const string& __token = "/dev/urandom");
3528    ~random_device();
3529
3530    // generating functions
3531    result_type operator()();
3532
3533    // property functions
3534    double entropy() const _NOEXCEPT;
3535
3536private:
3537    // no copy functions
3538    random_device(const random_device&); // = delete;
3539    random_device& operator=(const random_device&); // = delete;
3540};
3541
3542#endif // !_LIBCPP_HAS_NO_RANDOM_DEVICE
3543
3544// seed_seq
3545
3546class _LIBCPP_TEMPLATE_VIS seed_seq
3547{
3548public:
3549    // types
3550    typedef uint32_t result_type;
3551
3552private:
3553    vector<result_type> __v_;
3554
3555    template<class _InputIterator>
3556        void init(_InputIterator __first, _InputIterator __last);
3557public:
3558    // constructors
3559    _LIBCPP_INLINE_VISIBILITY
3560    seed_seq() _NOEXCEPT {}
3561#ifndef _LIBCPP_CXX03_LANG
3562    template<class _Tp>
3563        _LIBCPP_INLINE_VISIBILITY
3564        seed_seq(initializer_list<_Tp> __il) {init(__il.begin(), __il.end());}
3565#endif  // _LIBCPP_CXX03_LANG
3566
3567    template<class _InputIterator>
3568        _LIBCPP_INLINE_VISIBILITY
3569        seed_seq(_InputIterator __first, _InputIterator __last)
3570             {init(__first, __last);}
3571
3572    // generating functions
3573    template<class _RandomAccessIterator>
3574        void generate(_RandomAccessIterator __first, _RandomAccessIterator __last);
3575
3576    // property functions
3577    _LIBCPP_INLINE_VISIBILITY
3578    size_t size() const _NOEXCEPT {return __v_.size();}
3579    template<class _OutputIterator>
3580        _LIBCPP_INLINE_VISIBILITY
3581        void param(_OutputIterator __dest) const
3582            {_VSTD::copy(__v_.begin(), __v_.end(), __dest);}
3583
3584private:
3585    // no copy functions
3586    seed_seq(const seed_seq&); // = delete;
3587    void operator=(const seed_seq&); // = delete;
3588
3589    _LIBCPP_INLINE_VISIBILITY
3590    static result_type _Tp(result_type __x) {return __x ^ (__x >> 27);}
3591};
3592
3593template<class _InputIterator>
3594void
3595seed_seq::init(_InputIterator __first, _InputIterator __last)
3596{
3597    for (_InputIterator __s = __first; __s != __last; ++__s)
3598        __v_.push_back(*__s & 0xFFFFFFFF);
3599}
3600
3601template<class _RandomAccessIterator>
3602void
3603seed_seq::generate(_RandomAccessIterator __first, _RandomAccessIterator __last)
3604{
3605    if (__first != __last)
3606    {
3607        _VSTD::fill(__first, __last, 0x8b8b8b8b);
3608        const size_t __n = static_cast<size_t>(__last - __first);
3609        const size_t __s = __v_.size();
3610        const size_t __t = (__n >= 623) ? 11
3611                         : (__n >= 68) ? 7
3612                         : (__n >= 39) ? 5
3613                         : (__n >= 7)  ? 3
3614                         : (__n - 1) / 2;
3615        const size_t __p = (__n - __t) / 2;
3616        const size_t __q = __p + __t;
3617        const size_t __m = _VSTD::max(__s + 1, __n);
3618        // __k = 0;
3619        {
3620            result_type __r = 1664525 * _Tp(__first[0] ^ __first[__p]
3621                                                      ^  __first[__n - 1]);
3622            __first[__p] += __r;
3623            __r += __s;
3624            __first[__q] += __r;
3625            __first[0] = __r;
3626        }
3627        for (size_t __k = 1; __k <= __s; ++__k)
3628        {
3629            const size_t __kmodn = __k % __n;
3630            const size_t __kpmodn = (__k + __p) % __n;
3631            result_type __r = 1664525 * _Tp(__first[__kmodn] ^ __first[__kpmodn]
3632                                           ^ __first[(__k - 1) % __n]);
3633            __first[__kpmodn] += __r;
3634            __r +=  __kmodn + __v_[__k-1];
3635            __first[(__k + __q) % __n] += __r;
3636            __first[__kmodn] = __r;
3637        }
3638        for (size_t __k = __s + 1; __k < __m; ++__k)
3639        {
3640            const size_t __kmodn = __k % __n;
3641            const size_t __kpmodn = (__k + __p) % __n;
3642            result_type __r = 1664525 * _Tp(__first[__kmodn] ^ __first[__kpmodn]
3643                                           ^ __first[(__k - 1) % __n]);
3644            __first[__kpmodn] += __r;
3645            __r +=  __kmodn;
3646            __first[(__k + __q) % __n] += __r;
3647            __first[__kmodn] = __r;
3648        }
3649        for (size_t __k = __m; __k < __m + __n; ++__k)
3650        {
3651            const size_t __kmodn = __k % __n;
3652            const size_t __kpmodn = (__k + __p) % __n;
3653            result_type __r = 1566083941 * _Tp(__first[__kmodn] +
3654                                              __first[__kpmodn] +
3655                                              __first[(__k - 1) % __n]);
3656            __first[__kpmodn] ^= __r;
3657            __r -= __kmodn;
3658            __first[(__k + __q) % __n] ^= __r;
3659            __first[__kmodn] = __r;
3660        }
3661    }
3662}
3663
3664// generate_canonical
3665
3666template<class _RealType, size_t __bits, class _URNG>
3667_RealType
3668generate_canonical(_URNG& __g)
3669{
3670    const size_t _Dt = numeric_limits<_RealType>::digits;
3671    const size_t __b = _Dt < __bits ? _Dt : __bits;
3672#ifdef _LIBCPP_CXX03_LANG
3673    const size_t __logR = __log2<uint64_t, _URNG::_Max - _URNG::_Min + uint64_t(1)>::value;
3674#else
3675    const size_t __logR = __log2<uint64_t, _URNG::max() - _URNG::min() + uint64_t(1)>::value;
3676#endif
3677    const size_t __k = __b / __logR + (__b % __logR != 0) + (__b == 0);
3678    const _RealType _Rp = static_cast<_RealType>(_URNG::max() - _URNG::min()) + _RealType(1);
3679    _RealType __base = _Rp;
3680    _RealType _Sp = __g() - _URNG::min();
3681    for (size_t __i = 1; __i < __k; ++__i, __base *= _Rp)
3682        _Sp += (__g() - _URNG::min()) * __base;
3683    return _Sp / __base;
3684}
3685
3686// uniform_int_distribution
3687
3688// in <algorithm>
3689
3690template <class _CharT, class _Traits, class _IT>
3691basic_ostream<_CharT, _Traits>&
3692operator<<(basic_ostream<_CharT, _Traits>& __os,
3693           const uniform_int_distribution<_IT>& __x)
3694{
3695    __save_flags<_CharT, _Traits> __lx(__os);
3696    typedef basic_ostream<_CharT, _Traits> _Ostream;
3697    __os.flags(_Ostream::dec | _Ostream::left);
3698    _CharT __sp = __os.widen(' ');
3699    __os.fill(__sp);
3700    return __os << __x.a() << __sp << __x.b();
3701}
3702
3703template <class _CharT, class _Traits, class _IT>
3704basic_istream<_CharT, _Traits>&
3705operator>>(basic_istream<_CharT, _Traits>& __is,
3706           uniform_int_distribution<_IT>& __x)
3707{
3708    typedef uniform_int_distribution<_IT> _Eng;
3709    typedef typename _Eng::result_type result_type;
3710    typedef typename _Eng::param_type param_type;
3711    __save_flags<_CharT, _Traits> __lx(__is);
3712    typedef basic_istream<_CharT, _Traits> _Istream;
3713    __is.flags(_Istream::dec | _Istream::skipws);
3714    result_type __a;
3715    result_type __b;
3716    __is >> __a >> __b;
3717    if (!__is.fail())
3718        __x.param(param_type(__a, __b));
3719    return __is;
3720}
3721
3722// uniform_real_distribution
3723
3724template<class _RealType = double>
3725class _LIBCPP_TEMPLATE_VIS uniform_real_distribution
3726{
3727public:
3728    // types
3729    typedef _RealType result_type;
3730
3731    class _LIBCPP_TEMPLATE_VIS param_type
3732    {
3733        result_type __a_;
3734        result_type __b_;
3735    public:
3736        typedef uniform_real_distribution distribution_type;
3737
3738        _LIBCPP_INLINE_VISIBILITY
3739        explicit param_type(result_type __a = 0,
3740                            result_type __b = 1)
3741            : __a_(__a), __b_(__b) {}
3742
3743        _LIBCPP_INLINE_VISIBILITY
3744        result_type a() const {return __a_;}
3745        _LIBCPP_INLINE_VISIBILITY
3746        result_type b() const {return __b_;}
3747
3748        friend _LIBCPP_INLINE_VISIBILITY
3749        bool operator==(const param_type& __x, const param_type& __y)
3750            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
3751        friend _LIBCPP_INLINE_VISIBILITY
3752        bool operator!=(const param_type& __x, const param_type& __y)
3753            {return !(__x == __y);}
3754    };
3755
3756private:
3757    param_type __p_;
3758
3759public:
3760    // constructors and reset functions
3761    _LIBCPP_INLINE_VISIBILITY
3762    explicit uniform_real_distribution(result_type __a = 0, result_type __b = 1)
3763        : __p_(param_type(__a, __b)) {}
3764    _LIBCPP_INLINE_VISIBILITY
3765    explicit uniform_real_distribution(const param_type& __p) : __p_(__p) {}
3766    _LIBCPP_INLINE_VISIBILITY
3767    void reset() {}
3768
3769    // generating functions
3770    template<class _URNG>
3771        _LIBCPP_INLINE_VISIBILITY
3772        result_type operator()(_URNG& __g)
3773        {return (*this)(__g, __p_);}
3774    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
3775
3776    // property functions
3777    _LIBCPP_INLINE_VISIBILITY
3778    result_type a() const {return __p_.a();}
3779    _LIBCPP_INLINE_VISIBILITY
3780    result_type b() const {return __p_.b();}
3781
3782    _LIBCPP_INLINE_VISIBILITY
3783    param_type param() const {return __p_;}
3784    _LIBCPP_INLINE_VISIBILITY
3785    void param(const param_type& __p) {__p_ = __p;}
3786
3787    _LIBCPP_INLINE_VISIBILITY
3788    result_type min() const {return a();}
3789    _LIBCPP_INLINE_VISIBILITY
3790    result_type max() const {return b();}
3791
3792    friend _LIBCPP_INLINE_VISIBILITY
3793        bool operator==(const uniform_real_distribution& __x,
3794                        const uniform_real_distribution& __y)
3795        {return __x.__p_ == __y.__p_;}
3796    friend _LIBCPP_INLINE_VISIBILITY
3797        bool operator!=(const uniform_real_distribution& __x,
3798                        const uniform_real_distribution& __y)
3799        {return !(__x == __y);}
3800};
3801
3802template<class _RealType>
3803template<class _URNG>
3804inline
3805typename uniform_real_distribution<_RealType>::result_type
3806uniform_real_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
3807{
3808    return (__p.b() - __p.a())
3809        * _VSTD::generate_canonical<_RealType, numeric_limits<_RealType>::digits>(__g)
3810        + __p.a();
3811}
3812
3813template <class _CharT, class _Traits, class _RT>
3814basic_ostream<_CharT, _Traits>&
3815operator<<(basic_ostream<_CharT, _Traits>& __os,
3816           const uniform_real_distribution<_RT>& __x)
3817{
3818    __save_flags<_CharT, _Traits> __lx(__os);
3819    typedef basic_ostream<_CharT, _Traits> _OStream;
3820    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
3821               _OStream::scientific);
3822    _CharT __sp = __os.widen(' ');
3823    __os.fill(__sp);
3824    return __os << __x.a() << __sp << __x.b();
3825}
3826
3827template <class _CharT, class _Traits, class _RT>
3828basic_istream<_CharT, _Traits>&
3829operator>>(basic_istream<_CharT, _Traits>& __is,
3830           uniform_real_distribution<_RT>& __x)
3831{
3832    typedef uniform_real_distribution<_RT> _Eng;
3833    typedef typename _Eng::result_type result_type;
3834    typedef typename _Eng::param_type param_type;
3835    __save_flags<_CharT, _Traits> __lx(__is);
3836    typedef basic_istream<_CharT, _Traits> _Istream;
3837    __is.flags(_Istream::dec | _Istream::skipws);
3838    result_type __a;
3839    result_type __b;
3840    __is >> __a >> __b;
3841    if (!__is.fail())
3842        __x.param(param_type(__a, __b));
3843    return __is;
3844}
3845
3846// bernoulli_distribution
3847
3848class _LIBCPP_TEMPLATE_VIS bernoulli_distribution
3849{
3850public:
3851    // types
3852    typedef bool result_type;
3853
3854    class _LIBCPP_TEMPLATE_VIS param_type
3855    {
3856        double __p_;
3857    public:
3858        typedef bernoulli_distribution distribution_type;
3859
3860        _LIBCPP_INLINE_VISIBILITY
3861        explicit param_type(double __p = 0.5) : __p_(__p) {}
3862
3863        _LIBCPP_INLINE_VISIBILITY
3864        double p() const {return __p_;}
3865
3866        friend _LIBCPP_INLINE_VISIBILITY
3867            bool operator==(const param_type& __x, const param_type& __y)
3868            {return __x.__p_ == __y.__p_;}
3869        friend _LIBCPP_INLINE_VISIBILITY
3870            bool operator!=(const param_type& __x, const param_type& __y)
3871            {return !(__x == __y);}
3872    };
3873
3874private:
3875    param_type __p_;
3876
3877public:
3878    // constructors and reset functions
3879    _LIBCPP_INLINE_VISIBILITY
3880    explicit bernoulli_distribution(double __p = 0.5)
3881        : __p_(param_type(__p)) {}
3882    _LIBCPP_INLINE_VISIBILITY
3883    explicit bernoulli_distribution(const param_type& __p) : __p_(__p) {}
3884    _LIBCPP_INLINE_VISIBILITY
3885    void reset() {}
3886
3887    // generating functions
3888    template<class _URNG>
3889        _LIBCPP_INLINE_VISIBILITY
3890        result_type operator()(_URNG& __g)
3891        {return (*this)(__g, __p_);}
3892    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
3893
3894    // property functions
3895    _LIBCPP_INLINE_VISIBILITY
3896    double p() const {return __p_.p();}
3897
3898    _LIBCPP_INLINE_VISIBILITY
3899    param_type param() const {return __p_;}
3900    _LIBCPP_INLINE_VISIBILITY
3901    void param(const param_type& __p) {__p_ = __p;}
3902
3903    _LIBCPP_INLINE_VISIBILITY
3904    result_type min() const {return false;}
3905    _LIBCPP_INLINE_VISIBILITY
3906    result_type max() const {return true;}
3907
3908    friend _LIBCPP_INLINE_VISIBILITY
3909        bool operator==(const bernoulli_distribution& __x,
3910                        const bernoulli_distribution& __y)
3911        {return __x.__p_ == __y.__p_;}
3912    friend _LIBCPP_INLINE_VISIBILITY
3913        bool operator!=(const bernoulli_distribution& __x,
3914                        const bernoulli_distribution& __y)
3915        {return !(__x == __y);}
3916};
3917
3918template<class _URNG>
3919inline
3920bernoulli_distribution::result_type
3921bernoulli_distribution::operator()(_URNG& __g, const param_type& __p)
3922{
3923    uniform_real_distribution<double> __gen;
3924    return __gen(__g) < __p.p();
3925}
3926
3927template <class _CharT, class _Traits>
3928basic_ostream<_CharT, _Traits>&
3929operator<<(basic_ostream<_CharT, _Traits>& __os, const bernoulli_distribution& __x)
3930{
3931    __save_flags<_CharT, _Traits> __lx(__os);
3932    typedef basic_ostream<_CharT, _Traits> _OStream;
3933    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
3934               _OStream::scientific);
3935    _CharT __sp = __os.widen(' ');
3936    __os.fill(__sp);
3937    return __os << __x.p();
3938}
3939
3940template <class _CharT, class _Traits>
3941basic_istream<_CharT, _Traits>&
3942operator>>(basic_istream<_CharT, _Traits>& __is, bernoulli_distribution& __x)
3943{
3944    typedef bernoulli_distribution _Eng;
3945    typedef typename _Eng::param_type param_type;
3946    __save_flags<_CharT, _Traits> __lx(__is);
3947    typedef basic_istream<_CharT, _Traits> _Istream;
3948    __is.flags(_Istream::dec | _Istream::skipws);
3949    double __p;
3950    __is >> __p;
3951    if (!__is.fail())
3952        __x.param(param_type(__p));
3953    return __is;
3954}
3955
3956// binomial_distribution
3957
3958template<class _IntType = int>
3959class _LIBCPP_TEMPLATE_VIS binomial_distribution
3960{
3961public:
3962    // types
3963    typedef _IntType result_type;
3964
3965    class _LIBCPP_TEMPLATE_VIS param_type
3966    {
3967        result_type __t_;
3968        double __p_;
3969        double __pr_;
3970        double __odds_ratio_;
3971        result_type __r0_;
3972    public:
3973        typedef binomial_distribution distribution_type;
3974
3975        explicit param_type(result_type __t = 1, double __p = 0.5);
3976
3977        _LIBCPP_INLINE_VISIBILITY
3978        result_type t() const {return __t_;}
3979        _LIBCPP_INLINE_VISIBILITY
3980        double p() const {return __p_;}
3981
3982        friend _LIBCPP_INLINE_VISIBILITY
3983            bool operator==(const param_type& __x, const param_type& __y)
3984            {return __x.__t_ == __y.__t_ && __x.__p_ == __y.__p_;}
3985        friend _LIBCPP_INLINE_VISIBILITY
3986            bool operator!=(const param_type& __x, const param_type& __y)
3987            {return !(__x == __y);}
3988
3989        friend class binomial_distribution;
3990    };
3991
3992private:
3993    param_type __p_;
3994
3995public:
3996    // constructors and reset functions
3997    _LIBCPP_INLINE_VISIBILITY
3998    explicit binomial_distribution(result_type __t = 1, double __p = 0.5)
3999        : __p_(param_type(__t, __p)) {}
4000    _LIBCPP_INLINE_VISIBILITY
4001    explicit binomial_distribution(const param_type& __p) : __p_(__p) {}
4002    _LIBCPP_INLINE_VISIBILITY
4003    void reset() {}
4004
4005    // generating functions
4006    template<class _URNG>
4007        _LIBCPP_INLINE_VISIBILITY
4008        result_type operator()(_URNG& __g)
4009        {return (*this)(__g, __p_);}
4010    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4011
4012    // property functions
4013    _LIBCPP_INLINE_VISIBILITY
4014    result_type t() const {return __p_.t();}
4015    _LIBCPP_INLINE_VISIBILITY
4016    double p() const {return __p_.p();}
4017
4018    _LIBCPP_INLINE_VISIBILITY
4019    param_type param() const {return __p_;}
4020    _LIBCPP_INLINE_VISIBILITY
4021    void param(const param_type& __p) {__p_ = __p;}
4022
4023    _LIBCPP_INLINE_VISIBILITY
4024    result_type min() const {return 0;}
4025    _LIBCPP_INLINE_VISIBILITY
4026    result_type max() const {return t();}
4027
4028    friend _LIBCPP_INLINE_VISIBILITY
4029        bool operator==(const binomial_distribution& __x,
4030                        const binomial_distribution& __y)
4031        {return __x.__p_ == __y.__p_;}
4032    friend _LIBCPP_INLINE_VISIBILITY
4033        bool operator!=(const binomial_distribution& __x,
4034                        const binomial_distribution& __y)
4035        {return !(__x == __y);}
4036};
4037
4038#ifndef _LIBCPP_MSVCRT_LIKE
4039extern "C" double lgamma_r(double, int *);
4040#endif
4041
4042inline _LIBCPP_INLINE_VISIBILITY double __libcpp_lgamma(double __d) {
4043#if defined(_LIBCPP_MSVCRT_LIKE)
4044  return lgamma(__d);
4045#else
4046  int __sign;
4047  return lgamma_r(__d, &__sign);
4048#endif
4049}
4050
4051template<class _IntType>
4052binomial_distribution<_IntType>::param_type::param_type(const result_type __t, const double __p)
4053    : __t_(__t), __p_(__p)
4054{
4055    if (0 < __p_ && __p_ < 1)
4056    {
4057        __r0_ = static_cast<result_type>((__t_ + 1) * __p_);
4058        __pr_ = _VSTD::exp(__libcpp_lgamma(__t_ + 1.) -
4059                           __libcpp_lgamma(__r0_ + 1.) -
4060                           __libcpp_lgamma(__t_ - __r0_ + 1.) + __r0_ * _VSTD::log(__p_) +
4061                           (__t_ - __r0_) * _VSTD::log(1 - __p_));
4062        __odds_ratio_ = __p_ / (1 - __p_);
4063    }
4064}
4065
4066// Reference: Kemp, C.D. (1986). `A modal method for generating binomial
4067//           variables', Commun. Statist. - Theor. Meth. 15(3), 805-813.
4068template<class _IntType>
4069template<class _URNG>
4070_IntType
4071binomial_distribution<_IntType>::operator()(_URNG& __g, const param_type& __pr)
4072{
4073    if (__pr.__t_ == 0 || __pr.__p_ == 0)
4074        return 0;
4075    if (__pr.__p_ == 1)
4076        return __pr.__t_;
4077    uniform_real_distribution<double> __gen;
4078    double __u = __gen(__g) - __pr.__pr_;
4079    if (__u < 0)
4080        return __pr.__r0_;
4081    double __pu = __pr.__pr_;
4082    double __pd = __pu;
4083    result_type __ru = __pr.__r0_;
4084    result_type __rd = __ru;
4085    while (true)
4086    {
4087        bool __break = true;
4088        if (__rd >= 1)
4089        {
4090            __pd *= __rd / (__pr.__odds_ratio_ * (__pr.__t_ - __rd + 1));
4091            __u -= __pd;
4092            __break = false;
4093            if (__u < 0)
4094                return __rd - 1;
4095        }
4096        if ( __rd != 0 )
4097            --__rd;
4098        ++__ru;
4099        if (__ru <= __pr.__t_)
4100        {
4101            __pu *= (__pr.__t_ - __ru + 1) * __pr.__odds_ratio_ / __ru;
4102            __u -= __pu;
4103            __break = false;
4104            if (__u < 0)
4105                return __ru;
4106        }
4107        if (__break)
4108            return 0;
4109    }
4110}
4111
4112template <class _CharT, class _Traits, class _IntType>
4113basic_ostream<_CharT, _Traits>&
4114operator<<(basic_ostream<_CharT, _Traits>& __os,
4115           const binomial_distribution<_IntType>& __x)
4116{
4117    __save_flags<_CharT, _Traits> __lx(__os);
4118    typedef basic_ostream<_CharT, _Traits> _OStream;
4119    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
4120               _OStream::scientific);
4121    _CharT __sp = __os.widen(' ');
4122    __os.fill(__sp);
4123    return __os << __x.t() << __sp << __x.p();
4124}
4125
4126template <class _CharT, class _Traits, class _IntType>
4127basic_istream<_CharT, _Traits>&
4128operator>>(basic_istream<_CharT, _Traits>& __is,
4129           binomial_distribution<_IntType>& __x)
4130{
4131    typedef binomial_distribution<_IntType> _Eng;
4132    typedef typename _Eng::result_type result_type;
4133    typedef typename _Eng::param_type param_type;
4134    __save_flags<_CharT, _Traits> __lx(__is);
4135    typedef basic_istream<_CharT, _Traits> _Istream;
4136    __is.flags(_Istream::dec | _Istream::skipws);
4137    result_type __t;
4138    double __p;
4139    __is >> __t >> __p;
4140    if (!__is.fail())
4141        __x.param(param_type(__t, __p));
4142    return __is;
4143}
4144
4145// exponential_distribution
4146
4147template<class _RealType = double>
4148class _LIBCPP_TEMPLATE_VIS exponential_distribution
4149{
4150public:
4151    // types
4152    typedef _RealType result_type;
4153
4154    class _LIBCPP_TEMPLATE_VIS param_type
4155    {
4156        result_type __lambda_;
4157    public:
4158        typedef exponential_distribution distribution_type;
4159
4160        _LIBCPP_INLINE_VISIBILITY
4161        explicit param_type(result_type __lambda = 1) : __lambda_(__lambda) {}
4162
4163        _LIBCPP_INLINE_VISIBILITY
4164        result_type lambda() const {return __lambda_;}
4165
4166        friend _LIBCPP_INLINE_VISIBILITY
4167            bool operator==(const param_type& __x, const param_type& __y)
4168            {return __x.__lambda_ == __y.__lambda_;}
4169        friend _LIBCPP_INLINE_VISIBILITY
4170            bool operator!=(const param_type& __x, const param_type& __y)
4171            {return !(__x == __y);}
4172    };
4173
4174private:
4175    param_type __p_;
4176
4177public:
4178    // constructors and reset functions
4179    _LIBCPP_INLINE_VISIBILITY
4180    explicit exponential_distribution(result_type __lambda = 1)
4181        : __p_(param_type(__lambda)) {}
4182    _LIBCPP_INLINE_VISIBILITY
4183    explicit exponential_distribution(const param_type& __p) : __p_(__p) {}
4184    _LIBCPP_INLINE_VISIBILITY
4185    void reset() {}
4186
4187    // generating functions
4188    template<class _URNG>
4189        _LIBCPP_INLINE_VISIBILITY
4190        result_type operator()(_URNG& __g)
4191        {return (*this)(__g, __p_);}
4192    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4193
4194    // property functions
4195    _LIBCPP_INLINE_VISIBILITY
4196    result_type lambda() const {return __p_.lambda();}
4197
4198    _LIBCPP_INLINE_VISIBILITY
4199    param_type param() const {return __p_;}
4200    _LIBCPP_INLINE_VISIBILITY
4201    void param(const param_type& __p) {__p_ = __p;}
4202
4203    _LIBCPP_INLINE_VISIBILITY
4204    result_type min() const {return 0;}
4205    _LIBCPP_INLINE_VISIBILITY
4206    result_type max() const {return numeric_limits<result_type>::infinity();}
4207
4208    friend _LIBCPP_INLINE_VISIBILITY
4209        bool operator==(const exponential_distribution& __x,
4210                        const exponential_distribution& __y)
4211        {return __x.__p_ == __y.__p_;}
4212    friend _LIBCPP_INLINE_VISIBILITY
4213        bool operator!=(const exponential_distribution& __x,
4214                        const exponential_distribution& __y)
4215        {return !(__x == __y);}
4216};
4217
4218template <class _RealType>
4219template<class _URNG>
4220_RealType
4221exponential_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4222{
4223    return -_VSTD::log
4224                  (
4225                      result_type(1) -
4226                      _VSTD::generate_canonical<result_type,
4227                                       numeric_limits<result_type>::digits>(__g)
4228                  )
4229                  / __p.lambda();
4230}
4231
4232template <class _CharT, class _Traits, class _RealType>
4233basic_ostream<_CharT, _Traits>&
4234operator<<(basic_ostream<_CharT, _Traits>& __os,
4235           const exponential_distribution<_RealType>& __x)
4236{
4237    __save_flags<_CharT, _Traits> __lx(__os);
4238    typedef basic_ostream<_CharT, _Traits> _OStream;
4239    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
4240               _OStream::scientific);
4241    return __os << __x.lambda();
4242}
4243
4244template <class _CharT, class _Traits, class _RealType>
4245basic_istream<_CharT, _Traits>&
4246operator>>(basic_istream<_CharT, _Traits>& __is,
4247           exponential_distribution<_RealType>& __x)
4248{
4249    typedef exponential_distribution<_RealType> _Eng;
4250    typedef typename _Eng::result_type result_type;
4251    typedef typename _Eng::param_type param_type;
4252    __save_flags<_CharT, _Traits> __lx(__is);
4253    typedef basic_istream<_CharT, _Traits> _Istream;
4254    __is.flags(_Istream::dec | _Istream::skipws);
4255    result_type __lambda;
4256    __is >> __lambda;
4257    if (!__is.fail())
4258        __x.param(param_type(__lambda));
4259    return __is;
4260}
4261
4262// normal_distribution
4263
4264template<class _RealType = double>
4265class _LIBCPP_TEMPLATE_VIS normal_distribution
4266{
4267public:
4268    // types
4269    typedef _RealType result_type;
4270
4271    class _LIBCPP_TEMPLATE_VIS param_type
4272    {
4273        result_type __mean_;
4274        result_type __stddev_;
4275    public:
4276        typedef normal_distribution distribution_type;
4277
4278        _LIBCPP_INLINE_VISIBILITY
4279        explicit param_type(result_type __mean = 0, result_type __stddev = 1)
4280            : __mean_(__mean), __stddev_(__stddev) {}
4281
4282        _LIBCPP_INLINE_VISIBILITY
4283        result_type mean() const {return __mean_;}
4284        _LIBCPP_INLINE_VISIBILITY
4285        result_type stddev() const {return __stddev_;}
4286
4287        friend _LIBCPP_INLINE_VISIBILITY
4288            bool operator==(const param_type& __x, const param_type& __y)
4289            {return __x.__mean_ == __y.__mean_ && __x.__stddev_ == __y.__stddev_;}
4290        friend _LIBCPP_INLINE_VISIBILITY
4291            bool operator!=(const param_type& __x, const param_type& __y)
4292            {return !(__x == __y);}
4293    };
4294
4295private:
4296    param_type __p_;
4297    result_type _V_;
4298    bool _V_hot_;
4299
4300public:
4301    // constructors and reset functions
4302    _LIBCPP_INLINE_VISIBILITY
4303    explicit normal_distribution(result_type __mean = 0, result_type __stddev = 1)
4304        : __p_(param_type(__mean, __stddev)), _V_hot_(false) {}
4305    _LIBCPP_INLINE_VISIBILITY
4306    explicit normal_distribution(const param_type& __p)
4307        : __p_(__p), _V_hot_(false) {}
4308    _LIBCPP_INLINE_VISIBILITY
4309    void reset() {_V_hot_ = false;}
4310
4311    // generating functions
4312    template<class _URNG>
4313        _LIBCPP_INLINE_VISIBILITY
4314        result_type operator()(_URNG& __g)
4315        {return (*this)(__g, __p_);}
4316    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4317
4318    // property functions
4319    _LIBCPP_INLINE_VISIBILITY
4320    result_type mean() const {return __p_.mean();}
4321    _LIBCPP_INLINE_VISIBILITY
4322    result_type stddev() const {return __p_.stddev();}
4323
4324    _LIBCPP_INLINE_VISIBILITY
4325    param_type param() const {return __p_;}
4326    _LIBCPP_INLINE_VISIBILITY
4327    void param(const param_type& __p) {__p_ = __p;}
4328
4329    _LIBCPP_INLINE_VISIBILITY
4330    result_type min() const {return -numeric_limits<result_type>::infinity();}
4331    _LIBCPP_INLINE_VISIBILITY
4332    result_type max() const {return numeric_limits<result_type>::infinity();}
4333
4334    friend _LIBCPP_INLINE_VISIBILITY
4335        bool operator==(const normal_distribution& __x,
4336                        const normal_distribution& __y)
4337        {return __x.__p_ == __y.__p_ && __x._V_hot_ == __y._V_hot_ &&
4338                (!__x._V_hot_ || __x._V_ == __y._V_);}
4339    friend _LIBCPP_INLINE_VISIBILITY
4340        bool operator!=(const normal_distribution& __x,
4341                        const normal_distribution& __y)
4342        {return !(__x == __y);}
4343
4344    template <class _CharT, class _Traits, class _RT>
4345    friend
4346    basic_ostream<_CharT, _Traits>&
4347    operator<<(basic_ostream<_CharT, _Traits>& __os,
4348               const normal_distribution<_RT>& __x);
4349
4350    template <class _CharT, class _Traits, class _RT>
4351    friend
4352    basic_istream<_CharT, _Traits>&
4353    operator>>(basic_istream<_CharT, _Traits>& __is,
4354               normal_distribution<_RT>& __x);
4355};
4356
4357template <class _RealType>
4358template<class _URNG>
4359_RealType
4360normal_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4361{
4362    result_type _Up;
4363    if (_V_hot_)
4364    {
4365        _V_hot_ = false;
4366        _Up = _V_;
4367    }
4368    else
4369    {
4370        uniform_real_distribution<result_type> _Uni(-1, 1);
4371        result_type __u;
4372        result_type __v;
4373        result_type __s;
4374        do
4375        {
4376            __u = _Uni(__g);
4377            __v = _Uni(__g);
4378            __s = __u * __u + __v * __v;
4379        } while (__s > 1 || __s == 0);
4380        result_type _Fp = _VSTD::sqrt(-2 * _VSTD::log(__s) / __s);
4381        _V_ = __v * _Fp;
4382        _V_hot_ = true;
4383        _Up = __u * _Fp;
4384    }
4385    return _Up * __p.stddev() + __p.mean();
4386}
4387
4388template <class _CharT, class _Traits, class _RT>
4389basic_ostream<_CharT, _Traits>&
4390operator<<(basic_ostream<_CharT, _Traits>& __os,
4391           const normal_distribution<_RT>& __x)
4392{
4393    __save_flags<_CharT, _Traits> __lx(__os);
4394    typedef basic_ostream<_CharT, _Traits> _OStream;
4395    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
4396               _OStream::scientific);
4397    _CharT __sp = __os.widen(' ');
4398    __os.fill(__sp);
4399    __os << __x.mean() << __sp << __x.stddev() << __sp << __x._V_hot_;
4400    if (__x._V_hot_)
4401        __os << __sp << __x._V_;
4402    return __os;
4403}
4404
4405template <class _CharT, class _Traits, class _RT>
4406basic_istream<_CharT, _Traits>&
4407operator>>(basic_istream<_CharT, _Traits>& __is,
4408           normal_distribution<_RT>& __x)
4409{
4410    typedef normal_distribution<_RT> _Eng;
4411    typedef typename _Eng::result_type result_type;
4412    typedef typename _Eng::param_type param_type;
4413    __save_flags<_CharT, _Traits> __lx(__is);
4414    typedef basic_istream<_CharT, _Traits> _Istream;
4415    __is.flags(_Istream::dec | _Istream::skipws);
4416    result_type __mean;
4417    result_type __stddev;
4418    result_type _Vp = 0;
4419    bool _V_hot = false;
4420    __is >> __mean >> __stddev >> _V_hot;
4421    if (_V_hot)
4422        __is >> _Vp;
4423    if (!__is.fail())
4424    {
4425        __x.param(param_type(__mean, __stddev));
4426        __x._V_hot_ = _V_hot;
4427        __x._V_ = _Vp;
4428    }
4429    return __is;
4430}
4431
4432// lognormal_distribution
4433
4434template<class _RealType = double>
4435class _LIBCPP_TEMPLATE_VIS lognormal_distribution
4436{
4437public:
4438    // types
4439    typedef _RealType result_type;
4440
4441    class _LIBCPP_TEMPLATE_VIS param_type
4442    {
4443        normal_distribution<result_type> __nd_;
4444    public:
4445        typedef lognormal_distribution distribution_type;
4446
4447        _LIBCPP_INLINE_VISIBILITY
4448        explicit param_type(result_type __m = 0, result_type __s = 1)
4449            : __nd_(__m, __s) {}
4450
4451        _LIBCPP_INLINE_VISIBILITY
4452        result_type m() const {return __nd_.mean();}
4453        _LIBCPP_INLINE_VISIBILITY
4454        result_type s() const {return __nd_.stddev();}
4455
4456        friend _LIBCPP_INLINE_VISIBILITY
4457            bool operator==(const param_type& __x, const param_type& __y)
4458            {return __x.__nd_ == __y.__nd_;}
4459        friend _LIBCPP_INLINE_VISIBILITY
4460            bool operator!=(const param_type& __x, const param_type& __y)
4461            {return !(__x == __y);}
4462        friend class lognormal_distribution;
4463
4464        template <class _CharT, class _Traits, class _RT>
4465        friend
4466        basic_ostream<_CharT, _Traits>&
4467        operator<<(basic_ostream<_CharT, _Traits>& __os,
4468                   const lognormal_distribution<_RT>& __x);
4469
4470        template <class _CharT, class _Traits, class _RT>
4471        friend
4472        basic_istream<_CharT, _Traits>&
4473        operator>>(basic_istream<_CharT, _Traits>& __is,
4474                   lognormal_distribution<_RT>& __x);
4475    };
4476
4477private:
4478    param_type __p_;
4479
4480public:
4481    // constructor and reset functions
4482    _LIBCPP_INLINE_VISIBILITY
4483    explicit lognormal_distribution(result_type __m = 0, result_type __s = 1)
4484        : __p_(param_type(__m, __s)) {}
4485    _LIBCPP_INLINE_VISIBILITY
4486    explicit lognormal_distribution(const param_type& __p)
4487        : __p_(__p) {}
4488    _LIBCPP_INLINE_VISIBILITY
4489    void reset() {__p_.__nd_.reset();}
4490
4491    // generating functions
4492    template<class _URNG>
4493        _LIBCPP_INLINE_VISIBILITY
4494        result_type operator()(_URNG& __g)
4495        {return (*this)(__g, __p_);}
4496    template<class _URNG>
4497        _LIBCPP_INLINE_VISIBILITY
4498        result_type operator()(_URNG& __g, const param_type& __p)
4499        {return _VSTD::exp(const_cast<normal_distribution<result_type>&>(__p.__nd_)(__g));}
4500
4501    // property functions
4502    _LIBCPP_INLINE_VISIBILITY
4503    result_type m() const {return __p_.m();}
4504    _LIBCPP_INLINE_VISIBILITY
4505    result_type s() const {return __p_.s();}
4506
4507    _LIBCPP_INLINE_VISIBILITY
4508    param_type param() const {return __p_;}
4509    _LIBCPP_INLINE_VISIBILITY
4510    void param(const param_type& __p) {__p_ = __p;}
4511
4512    _LIBCPP_INLINE_VISIBILITY
4513    result_type min() const {return 0;}
4514    _LIBCPP_INLINE_VISIBILITY
4515    result_type max() const {return numeric_limits<result_type>::infinity();}
4516
4517    friend _LIBCPP_INLINE_VISIBILITY
4518        bool operator==(const lognormal_distribution& __x,
4519                        const lognormal_distribution& __y)
4520        {return __x.__p_ == __y.__p_;}
4521    friend _LIBCPP_INLINE_VISIBILITY
4522        bool operator!=(const lognormal_distribution& __x,
4523                        const lognormal_distribution& __y)
4524        {return !(__x == __y);}
4525
4526    template <class _CharT, class _Traits, class _RT>
4527    friend
4528    basic_ostream<_CharT, _Traits>&
4529    operator<<(basic_ostream<_CharT, _Traits>& __os,
4530               const lognormal_distribution<_RT>& __x);
4531
4532    template <class _CharT, class _Traits, class _RT>
4533    friend
4534    basic_istream<_CharT, _Traits>&
4535    operator>>(basic_istream<_CharT, _Traits>& __is,
4536               lognormal_distribution<_RT>& __x);
4537};
4538
4539template <class _CharT, class _Traits, class _RT>
4540inline _LIBCPP_INLINE_VISIBILITY
4541basic_ostream<_CharT, _Traits>&
4542operator<<(basic_ostream<_CharT, _Traits>& __os,
4543           const lognormal_distribution<_RT>& __x)
4544{
4545    return __os << __x.__p_.__nd_;
4546}
4547
4548template <class _CharT, class _Traits, class _RT>
4549inline _LIBCPP_INLINE_VISIBILITY
4550basic_istream<_CharT, _Traits>&
4551operator>>(basic_istream<_CharT, _Traits>& __is,
4552           lognormal_distribution<_RT>& __x)
4553{
4554    return __is >> __x.__p_.__nd_;
4555}
4556
4557// poisson_distribution
4558
4559template<class _IntType = int>
4560class _LIBCPP_TEMPLATE_VIS poisson_distribution
4561{
4562public:
4563    // types
4564    typedef _IntType result_type;
4565
4566    class _LIBCPP_TEMPLATE_VIS param_type
4567    {
4568        double __mean_;
4569        double __s_;
4570        double __d_;
4571        double __l_;
4572        double __omega_;
4573        double __c0_;
4574        double __c1_;
4575        double __c2_;
4576        double __c3_;
4577        double __c_;
4578
4579    public:
4580        typedef poisson_distribution distribution_type;
4581
4582        explicit param_type(double __mean = 1.0);
4583
4584        _LIBCPP_INLINE_VISIBILITY
4585        double mean() const {return __mean_;}
4586
4587        friend _LIBCPP_INLINE_VISIBILITY
4588            bool operator==(const param_type& __x, const param_type& __y)
4589            {return __x.__mean_ == __y.__mean_;}
4590        friend _LIBCPP_INLINE_VISIBILITY
4591            bool operator!=(const param_type& __x, const param_type& __y)
4592            {return !(__x == __y);}
4593
4594        friend class poisson_distribution;
4595    };
4596
4597private:
4598    param_type __p_;
4599
4600public:
4601    // constructors and reset functions
4602    _LIBCPP_INLINE_VISIBILITY
4603    explicit poisson_distribution(double __mean = 1.0) : __p_(__mean) {}
4604    _LIBCPP_INLINE_VISIBILITY
4605    explicit poisson_distribution(const param_type& __p) : __p_(__p) {}
4606    _LIBCPP_INLINE_VISIBILITY
4607    void reset() {}
4608
4609    // generating functions
4610    template<class _URNG>
4611        _LIBCPP_INLINE_VISIBILITY
4612        result_type operator()(_URNG& __g)
4613        {return (*this)(__g, __p_);}
4614    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4615
4616    // property functions
4617    _LIBCPP_INLINE_VISIBILITY
4618    double mean() const {return __p_.mean();}
4619
4620    _LIBCPP_INLINE_VISIBILITY
4621    param_type param() const {return __p_;}
4622    _LIBCPP_INLINE_VISIBILITY
4623    void param(const param_type& __p) {__p_ = __p;}
4624
4625    _LIBCPP_INLINE_VISIBILITY
4626    result_type min() const {return 0;}
4627    _LIBCPP_INLINE_VISIBILITY
4628    result_type max() const {return numeric_limits<result_type>::max();}
4629
4630    friend _LIBCPP_INLINE_VISIBILITY
4631        bool operator==(const poisson_distribution& __x,
4632                        const poisson_distribution& __y)
4633        {return __x.__p_ == __y.__p_;}
4634    friend _LIBCPP_INLINE_VISIBILITY
4635        bool operator!=(const poisson_distribution& __x,
4636                        const poisson_distribution& __y)
4637        {return !(__x == __y);}
4638};
4639
4640template<class _IntType>
4641poisson_distribution<_IntType>::param_type::param_type(double __mean)
4642    // According to the standard `inf` is a valid input, but it causes the
4643    // distribution to hang, so we replace it with the maximum representable
4644    // mean.
4645    : __mean_(isinf(__mean) ? numeric_limits<double>::max() : __mean)
4646{
4647    if (__mean_ < 10)
4648    {
4649        __s_ = 0;
4650        __d_ = 0;
4651        __l_ = _VSTD::exp(-__mean_);
4652        __omega_ = 0;
4653        __c3_ = 0;
4654        __c2_ = 0;
4655        __c1_ = 0;
4656        __c0_ = 0;
4657        __c_ = 0;
4658    }
4659    else
4660    {
4661        __s_ = _VSTD::sqrt(__mean_);
4662        __d_ = 6 * __mean_ * __mean_;
4663        __l_ = _VSTD::trunc(__mean_ - 1.1484);
4664        __omega_ = .3989423 / __s_;
4665        double __b1_ = .4166667E-1 / __mean_;
4666        double __b2_ = .3 * __b1_ * __b1_;
4667        __c3_ = .1428571 * __b1_ * __b2_;
4668        __c2_ = __b2_ - 15. * __c3_;
4669        __c1_ = __b1_ - 6. * __b2_ + 45. * __c3_;
4670        __c0_ = 1. - __b1_ + 3. * __b2_ - 15. * __c3_;
4671        __c_ = .1069 / __mean_;
4672    }
4673}
4674
4675template <class _IntType>
4676template<class _URNG>
4677_IntType
4678poisson_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
4679{
4680    double __tx;
4681    uniform_real_distribution<double> __urd;
4682    if (__pr.__mean_ < 10)
4683    {
4684         __tx = 0;
4685        for (double __p = __urd(__urng); __p > __pr.__l_; ++__tx)
4686            __p *= __urd(__urng);
4687    }
4688    else
4689    {
4690        double __difmuk;
4691        double __g = __pr.__mean_ + __pr.__s_ * normal_distribution<double>()(__urng);
4692        double __u;
4693        if (__g > 0)
4694        {
4695            __tx = _VSTD::trunc(__g);
4696            if (__tx >= __pr.__l_)
4697                return _VSTD::__clamp_to_integral<result_type>(__tx);
4698            __difmuk = __pr.__mean_ - __tx;
4699            __u = __urd(__urng);
4700            if (__pr.__d_ * __u >= __difmuk * __difmuk * __difmuk)
4701                return _VSTD::__clamp_to_integral<result_type>(__tx);
4702        }
4703        exponential_distribution<double> __edist;
4704        for (bool __using_exp_dist = false; true; __using_exp_dist = true)
4705        {
4706            double __e;
4707            if (__using_exp_dist || __g <= 0)
4708            {
4709                double __t;
4710                do
4711                {
4712                    __e = __edist(__urng);
4713                    __u = __urd(__urng);
4714                    __u += __u - 1;
4715                    __t = 1.8 + (__u < 0 ? -__e : __e);
4716                } while (__t <= -.6744);
4717                __tx = _VSTD::trunc(__pr.__mean_ + __pr.__s_ * __t);
4718                __difmuk = __pr.__mean_ - __tx;
4719                __using_exp_dist = true;
4720            }
4721            double __px;
4722            double __py;
4723            if (__tx < 10 && __tx >= 0)
4724            {
4725                const double __fac[] = {1, 1, 2, 6, 24, 120, 720, 5040,
4726                                             40320, 362880};
4727                __px = -__pr.__mean_;
4728                __py = _VSTD::pow(__pr.__mean_, (double)__tx) / __fac[static_cast<int>(__tx)];
4729            }
4730            else
4731            {
4732                double __del = .8333333E-1 / __tx;
4733                __del -= 4.8 * __del * __del * __del;
4734                double __v = __difmuk / __tx;
4735                if (_VSTD::abs(__v) > 0.25)
4736                    __px = __tx * _VSTD::log(1 + __v) - __difmuk - __del;
4737                else
4738                    __px = __tx * __v * __v * (((((((.1250060 * __v + -.1384794) *
4739                           __v + .1421878) * __v + -.1661269) * __v + .2000118) *
4740                           __v + -.2500068) * __v + .3333333) * __v + -.5) - __del;
4741                __py = .3989423 / _VSTD::sqrt(__tx);
4742            }
4743            double __r = (0.5 - __difmuk) / __pr.__s_;
4744            double __r2 = __r * __r;
4745            double __fx = -0.5 * __r2;
4746            double __fy = __pr.__omega_ * (((__pr.__c3_ * __r2 + __pr.__c2_) *
4747                                        __r2 + __pr.__c1_) * __r2 + __pr.__c0_);
4748            if (__using_exp_dist)
4749            {
4750                if (__pr.__c_ * _VSTD::abs(__u) <= __py * _VSTD::exp(__px + __e) -
4751                                                   __fy * _VSTD::exp(__fx + __e))
4752                    break;
4753            }
4754            else
4755            {
4756                if (__fy - __u * __fy <= __py * _VSTD::exp(__px - __fx))
4757                    break;
4758            }
4759        }
4760    }
4761    return _VSTD::__clamp_to_integral<result_type>(__tx);
4762}
4763
4764template <class _CharT, class _Traits, class _IntType>
4765basic_ostream<_CharT, _Traits>&
4766operator<<(basic_ostream<_CharT, _Traits>& __os,
4767           const poisson_distribution<_IntType>& __x)
4768{
4769    __save_flags<_CharT, _Traits> __lx(__os);
4770    typedef basic_ostream<_CharT, _Traits> _OStream;
4771    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
4772               _OStream::scientific);
4773    return __os << __x.mean();
4774}
4775
4776template <class _CharT, class _Traits, class _IntType>
4777basic_istream<_CharT, _Traits>&
4778operator>>(basic_istream<_CharT, _Traits>& __is,
4779           poisson_distribution<_IntType>& __x)
4780{
4781    typedef poisson_distribution<_IntType> _Eng;
4782    typedef typename _Eng::param_type param_type;
4783    __save_flags<_CharT, _Traits> __lx(__is);
4784    typedef basic_istream<_CharT, _Traits> _Istream;
4785    __is.flags(_Istream::dec | _Istream::skipws);
4786    double __mean;
4787    __is >> __mean;
4788    if (!__is.fail())
4789        __x.param(param_type(__mean));
4790    return __is;
4791}
4792
4793// weibull_distribution
4794
4795template<class _RealType = double>
4796class _LIBCPP_TEMPLATE_VIS weibull_distribution
4797{
4798public:
4799    // types
4800    typedef _RealType result_type;
4801
4802    class _LIBCPP_TEMPLATE_VIS param_type
4803    {
4804        result_type __a_;
4805        result_type __b_;
4806    public:
4807        typedef weibull_distribution distribution_type;
4808
4809        _LIBCPP_INLINE_VISIBILITY
4810        explicit param_type(result_type __a = 1, result_type __b = 1)
4811            : __a_(__a), __b_(__b) {}
4812
4813        _LIBCPP_INLINE_VISIBILITY
4814        result_type a() const {return __a_;}
4815        _LIBCPP_INLINE_VISIBILITY
4816        result_type b() const {return __b_;}
4817
4818        friend _LIBCPP_INLINE_VISIBILITY
4819            bool operator==(const param_type& __x, const param_type& __y)
4820            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
4821        friend _LIBCPP_INLINE_VISIBILITY
4822            bool operator!=(const param_type& __x, const param_type& __y)
4823            {return !(__x == __y);}
4824    };
4825
4826private:
4827    param_type __p_;
4828
4829public:
4830    // constructor and reset functions
4831    _LIBCPP_INLINE_VISIBILITY
4832    explicit weibull_distribution(result_type __a = 1, result_type __b = 1)
4833        : __p_(param_type(__a, __b)) {}
4834    _LIBCPP_INLINE_VISIBILITY
4835    explicit weibull_distribution(const param_type& __p)
4836        : __p_(__p) {}
4837    _LIBCPP_INLINE_VISIBILITY
4838    void reset() {}
4839
4840    // generating functions
4841    template<class _URNG>
4842        _LIBCPP_INLINE_VISIBILITY
4843        result_type operator()(_URNG& __g)
4844        {return (*this)(__g, __p_);}
4845    template<class _URNG>
4846        _LIBCPP_INLINE_VISIBILITY
4847        result_type operator()(_URNG& __g, const param_type& __p)
4848        {return __p.b() *
4849            _VSTD::pow(exponential_distribution<result_type>()(__g), 1/__p.a());}
4850
4851    // property functions
4852    _LIBCPP_INLINE_VISIBILITY
4853    result_type a() const {return __p_.a();}
4854    _LIBCPP_INLINE_VISIBILITY
4855    result_type b() const {return __p_.b();}
4856
4857    _LIBCPP_INLINE_VISIBILITY
4858    param_type param() const {return __p_;}
4859    _LIBCPP_INLINE_VISIBILITY
4860    void param(const param_type& __p) {__p_ = __p;}
4861
4862    _LIBCPP_INLINE_VISIBILITY
4863    result_type min() const {return 0;}
4864    _LIBCPP_INLINE_VISIBILITY
4865    result_type max() const {return numeric_limits<result_type>::infinity();}
4866
4867    friend _LIBCPP_INLINE_VISIBILITY
4868        bool operator==(const weibull_distribution& __x,
4869                        const weibull_distribution& __y)
4870        {return __x.__p_ == __y.__p_;}
4871    friend _LIBCPP_INLINE_VISIBILITY
4872        bool operator!=(const weibull_distribution& __x,
4873                        const weibull_distribution& __y)
4874        {return !(__x == __y);}
4875};
4876
4877template <class _CharT, class _Traits, class _RT>
4878basic_ostream<_CharT, _Traits>&
4879operator<<(basic_ostream<_CharT, _Traits>& __os,
4880           const weibull_distribution<_RT>& __x)
4881{
4882    __save_flags<_CharT, _Traits> __lx(__os);
4883    typedef basic_ostream<_CharT, _Traits> _OStream;
4884    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
4885               _OStream::scientific);
4886    _CharT __sp = __os.widen(' ');
4887    __os.fill(__sp);
4888    __os << __x.a() << __sp << __x.b();
4889    return __os;
4890}
4891
4892template <class _CharT, class _Traits, class _RT>
4893basic_istream<_CharT, _Traits>&
4894operator>>(basic_istream<_CharT, _Traits>& __is,
4895           weibull_distribution<_RT>& __x)
4896{
4897    typedef weibull_distribution<_RT> _Eng;
4898    typedef typename _Eng::result_type result_type;
4899    typedef typename _Eng::param_type param_type;
4900    __save_flags<_CharT, _Traits> __lx(__is);
4901    typedef basic_istream<_CharT, _Traits> _Istream;
4902    __is.flags(_Istream::dec | _Istream::skipws);
4903    result_type __a;
4904    result_type __b;
4905    __is >> __a >> __b;
4906    if (!__is.fail())
4907        __x.param(param_type(__a, __b));
4908    return __is;
4909}
4910
4911template<class _RealType = double>
4912class _LIBCPP_TEMPLATE_VIS extreme_value_distribution
4913{
4914public:
4915    // types
4916    typedef _RealType result_type;
4917
4918    class _LIBCPP_TEMPLATE_VIS param_type
4919    {
4920        result_type __a_;
4921        result_type __b_;
4922    public:
4923        typedef extreme_value_distribution distribution_type;
4924
4925        _LIBCPP_INLINE_VISIBILITY
4926        explicit param_type(result_type __a = 0, result_type __b = 1)
4927            : __a_(__a), __b_(__b) {}
4928
4929        _LIBCPP_INLINE_VISIBILITY
4930        result_type a() const {return __a_;}
4931        _LIBCPP_INLINE_VISIBILITY
4932        result_type b() const {return __b_;}
4933
4934        friend _LIBCPP_INLINE_VISIBILITY
4935            bool operator==(const param_type& __x, const param_type& __y)
4936            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
4937        friend _LIBCPP_INLINE_VISIBILITY
4938            bool operator!=(const param_type& __x, const param_type& __y)
4939            {return !(__x == __y);}
4940    };
4941
4942private:
4943    param_type __p_;
4944
4945public:
4946    // constructor and reset functions
4947    _LIBCPP_INLINE_VISIBILITY
4948    explicit extreme_value_distribution(result_type __a = 0, result_type __b = 1)
4949        : __p_(param_type(__a, __b)) {}
4950    _LIBCPP_INLINE_VISIBILITY
4951    explicit extreme_value_distribution(const param_type& __p)
4952        : __p_(__p) {}
4953    _LIBCPP_INLINE_VISIBILITY
4954    void reset() {}
4955
4956    // generating functions
4957    template<class _URNG>
4958        _LIBCPP_INLINE_VISIBILITY
4959        result_type operator()(_URNG& __g)
4960        {return (*this)(__g, __p_);}
4961    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4962
4963    // property functions
4964    _LIBCPP_INLINE_VISIBILITY
4965    result_type a() const {return __p_.a();}
4966    _LIBCPP_INLINE_VISIBILITY
4967    result_type b() const {return __p_.b();}
4968
4969    _LIBCPP_INLINE_VISIBILITY
4970    param_type param() const {return __p_;}
4971    _LIBCPP_INLINE_VISIBILITY
4972    void param(const param_type& __p) {__p_ = __p;}
4973
4974    _LIBCPP_INLINE_VISIBILITY
4975    result_type min() const {return -numeric_limits<result_type>::infinity();}
4976    _LIBCPP_INLINE_VISIBILITY
4977    result_type max() const {return numeric_limits<result_type>::infinity();}
4978
4979    friend _LIBCPP_INLINE_VISIBILITY
4980        bool operator==(const extreme_value_distribution& __x,
4981                        const extreme_value_distribution& __y)
4982        {return __x.__p_ == __y.__p_;}
4983    friend _LIBCPP_INLINE_VISIBILITY
4984        bool operator!=(const extreme_value_distribution& __x,
4985                        const extreme_value_distribution& __y)
4986        {return !(__x == __y);}
4987};
4988
4989template<class _RealType>
4990template<class _URNG>
4991_RealType
4992extreme_value_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4993{
4994    return __p.a() - __p.b() *
4995         _VSTD::log(-_VSTD::log(1-uniform_real_distribution<result_type>()(__g)));
4996}
4997
4998template <class _CharT, class _Traits, class _RT>
4999basic_ostream<_CharT, _Traits>&
5000operator<<(basic_ostream<_CharT, _Traits>& __os,
5001           const extreme_value_distribution<_RT>& __x)
5002{
5003    __save_flags<_CharT, _Traits> __lx(__os);
5004    typedef basic_ostream<_CharT, _Traits> _OStream;
5005    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
5006               _OStream::scientific);
5007    _CharT __sp = __os.widen(' ');
5008    __os.fill(__sp);
5009    __os << __x.a() << __sp << __x.b();
5010    return __os;
5011}
5012
5013template <class _CharT, class _Traits, class _RT>
5014basic_istream<_CharT, _Traits>&
5015operator>>(basic_istream<_CharT, _Traits>& __is,
5016           extreme_value_distribution<_RT>& __x)
5017{
5018    typedef extreme_value_distribution<_RT> _Eng;
5019    typedef typename _Eng::result_type result_type;
5020    typedef typename _Eng::param_type param_type;
5021    __save_flags<_CharT, _Traits> __lx(__is);
5022    typedef basic_istream<_CharT, _Traits> _Istream;
5023    __is.flags(_Istream::dec | _Istream::skipws);
5024    result_type __a;
5025    result_type __b;
5026    __is >> __a >> __b;
5027    if (!__is.fail())
5028        __x.param(param_type(__a, __b));
5029    return __is;
5030}
5031
5032// gamma_distribution
5033
5034template<class _RealType = double>
5035class _LIBCPP_TEMPLATE_VIS gamma_distribution
5036{
5037public:
5038    // types
5039    typedef _RealType result_type;
5040
5041    class _LIBCPP_TEMPLATE_VIS param_type
5042    {
5043        result_type __alpha_;
5044        result_type __beta_;
5045    public:
5046        typedef gamma_distribution distribution_type;
5047
5048        _LIBCPP_INLINE_VISIBILITY
5049        explicit param_type(result_type __alpha = 1, result_type __beta = 1)
5050            : __alpha_(__alpha), __beta_(__beta) {}
5051
5052        _LIBCPP_INLINE_VISIBILITY
5053        result_type alpha() const {return __alpha_;}
5054        _LIBCPP_INLINE_VISIBILITY
5055        result_type beta() const {return __beta_;}
5056
5057        friend _LIBCPP_INLINE_VISIBILITY
5058            bool operator==(const param_type& __x, const param_type& __y)
5059            {return __x.__alpha_ == __y.__alpha_ && __x.__beta_ == __y.__beta_;}
5060        friend _LIBCPP_INLINE_VISIBILITY
5061            bool operator!=(const param_type& __x, const param_type& __y)
5062            {return !(__x == __y);}
5063    };
5064
5065private:
5066    param_type __p_;
5067
5068public:
5069    // constructors and reset functions
5070    _LIBCPP_INLINE_VISIBILITY
5071    explicit gamma_distribution(result_type __alpha = 1, result_type __beta = 1)
5072        : __p_(param_type(__alpha, __beta)) {}
5073    _LIBCPP_INLINE_VISIBILITY
5074    explicit gamma_distribution(const param_type& __p)
5075        : __p_(__p) {}
5076    _LIBCPP_INLINE_VISIBILITY
5077    void reset() {}
5078
5079    // generating functions
5080    template<class _URNG>
5081        _LIBCPP_INLINE_VISIBILITY
5082        result_type operator()(_URNG& __g)
5083        {return (*this)(__g, __p_);}
5084    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5085
5086    // property functions
5087    _LIBCPP_INLINE_VISIBILITY
5088    result_type alpha() const {return __p_.alpha();}
5089    _LIBCPP_INLINE_VISIBILITY
5090    result_type beta() const {return __p_.beta();}
5091
5092    _LIBCPP_INLINE_VISIBILITY
5093    param_type param() const {return __p_;}
5094    _LIBCPP_INLINE_VISIBILITY
5095    void param(const param_type& __p) {__p_ = __p;}
5096
5097    _LIBCPP_INLINE_VISIBILITY
5098    result_type min() const {return 0;}
5099    _LIBCPP_INLINE_VISIBILITY
5100    result_type max() const {return numeric_limits<result_type>::infinity();}
5101
5102    friend _LIBCPP_INLINE_VISIBILITY
5103        bool operator==(const gamma_distribution& __x,
5104                        const gamma_distribution& __y)
5105        {return __x.__p_ == __y.__p_;}
5106    friend _LIBCPP_INLINE_VISIBILITY
5107        bool operator!=(const gamma_distribution& __x,
5108                        const gamma_distribution& __y)
5109        {return !(__x == __y);}
5110};
5111
5112template <class _RealType>
5113template<class _URNG>
5114_RealType
5115gamma_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5116{
5117    result_type __a = __p.alpha();
5118    uniform_real_distribution<result_type> __gen(0, 1);
5119    exponential_distribution<result_type> __egen;
5120    result_type __x;
5121    if (__a == 1)
5122        __x = __egen(__g);
5123    else if (__a > 1)
5124    {
5125        const result_type __b = __a - 1;
5126        const result_type __c = 3 * __a - result_type(0.75);
5127        while (true)
5128        {
5129            const result_type __u = __gen(__g);
5130            const result_type __v = __gen(__g);
5131            const result_type __w = __u * (1 - __u);
5132            if (__w != 0)
5133            {
5134                const result_type __y = _VSTD::sqrt(__c / __w) *
5135                                        (__u - result_type(0.5));
5136                __x = __b + __y;
5137                if (__x >= 0)
5138                {
5139                    const result_type __z = 64 * __w * __w * __w * __v * __v;
5140                    if (__z <= 1 - 2 * __y * __y / __x)
5141                        break;
5142                    if (_VSTD::log(__z) <= 2 * (__b * _VSTD::log(__x / __b) - __y))
5143                        break;
5144                }
5145            }
5146        }
5147    }
5148    else  // __a < 1
5149    {
5150        while (true)
5151        {
5152            const result_type __u = __gen(__g);
5153            const result_type __es = __egen(__g);
5154            if (__u <= 1 - __a)
5155            {
5156                __x = _VSTD::pow(__u, 1 / __a);
5157                if (__x <= __es)
5158                    break;
5159            }
5160            else
5161            {
5162                const result_type __e = -_VSTD::log((1-__u)/__a);
5163                __x = _VSTD::pow(1 - __a + __a * __e, 1 / __a);
5164                if (__x <= __e + __es)
5165                    break;
5166            }
5167        }
5168    }
5169    return __x * __p.beta();
5170}
5171
5172template <class _CharT, class _Traits, class _RT>
5173basic_ostream<_CharT, _Traits>&
5174operator<<(basic_ostream<_CharT, _Traits>& __os,
5175           const gamma_distribution<_RT>& __x)
5176{
5177    __save_flags<_CharT, _Traits> __lx(__os);
5178    typedef basic_ostream<_CharT, _Traits> _OStream;
5179    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
5180               _OStream::scientific);
5181    _CharT __sp = __os.widen(' ');
5182    __os.fill(__sp);
5183    __os << __x.alpha() << __sp << __x.beta();
5184    return __os;
5185}
5186
5187template <class _CharT, class _Traits, class _RT>
5188basic_istream<_CharT, _Traits>&
5189operator>>(basic_istream<_CharT, _Traits>& __is,
5190           gamma_distribution<_RT>& __x)
5191{
5192    typedef gamma_distribution<_RT> _Eng;
5193    typedef typename _Eng::result_type result_type;
5194    typedef typename _Eng::param_type param_type;
5195    __save_flags<_CharT, _Traits> __lx(__is);
5196    typedef basic_istream<_CharT, _Traits> _Istream;
5197    __is.flags(_Istream::dec | _Istream::skipws);
5198    result_type __alpha;
5199    result_type __beta;
5200    __is >> __alpha >> __beta;
5201    if (!__is.fail())
5202        __x.param(param_type(__alpha, __beta));
5203    return __is;
5204}
5205
5206// negative_binomial_distribution
5207
5208template<class _IntType = int>
5209class _LIBCPP_TEMPLATE_VIS negative_binomial_distribution
5210{
5211public:
5212    // types
5213    typedef _IntType result_type;
5214
5215    class _LIBCPP_TEMPLATE_VIS param_type
5216    {
5217        result_type __k_;
5218        double __p_;
5219    public:
5220        typedef negative_binomial_distribution distribution_type;
5221
5222        _LIBCPP_INLINE_VISIBILITY
5223        explicit param_type(result_type __k = 1, double __p = 0.5)
5224            : __k_(__k), __p_(__p) {}
5225
5226        _LIBCPP_INLINE_VISIBILITY
5227        result_type k() const {return __k_;}
5228        _LIBCPP_INLINE_VISIBILITY
5229        double p() const {return __p_;}
5230
5231        friend _LIBCPP_INLINE_VISIBILITY
5232            bool operator==(const param_type& __x, const param_type& __y)
5233            {return __x.__k_ == __y.__k_ && __x.__p_ == __y.__p_;}
5234        friend _LIBCPP_INLINE_VISIBILITY
5235            bool operator!=(const param_type& __x, const param_type& __y)
5236            {return !(__x == __y);}
5237    };
5238
5239private:
5240    param_type __p_;
5241
5242public:
5243    // constructor and reset functions
5244    _LIBCPP_INLINE_VISIBILITY
5245    explicit negative_binomial_distribution(result_type __k = 1, double __p = 0.5)
5246        : __p_(__k, __p) {}
5247    _LIBCPP_INLINE_VISIBILITY
5248    explicit negative_binomial_distribution(const param_type& __p) : __p_(__p) {}
5249    _LIBCPP_INLINE_VISIBILITY
5250    void reset() {}
5251
5252    // generating functions
5253    template<class _URNG>
5254        _LIBCPP_INLINE_VISIBILITY
5255        result_type operator()(_URNG& __g)
5256        {return (*this)(__g, __p_);}
5257    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5258
5259    // property functions
5260    _LIBCPP_INLINE_VISIBILITY
5261    result_type k() const {return __p_.k();}
5262    _LIBCPP_INLINE_VISIBILITY
5263    double p() const {return __p_.p();}
5264
5265    _LIBCPP_INLINE_VISIBILITY
5266    param_type param() const {return __p_;}
5267    _LIBCPP_INLINE_VISIBILITY
5268    void param(const param_type& __p) {__p_ = __p;}
5269
5270    _LIBCPP_INLINE_VISIBILITY
5271    result_type min() const {return 0;}
5272    _LIBCPP_INLINE_VISIBILITY
5273    result_type max() const {return numeric_limits<result_type>::max();}
5274
5275    friend _LIBCPP_INLINE_VISIBILITY
5276        bool operator==(const negative_binomial_distribution& __x,
5277                        const negative_binomial_distribution& __y)
5278        {return __x.__p_ == __y.__p_;}
5279    friend _LIBCPP_INLINE_VISIBILITY
5280        bool operator!=(const negative_binomial_distribution& __x,
5281                        const negative_binomial_distribution& __y)
5282        {return !(__x == __y);}
5283};
5284
5285template <class _IntType>
5286template<class _URNG>
5287_IntType
5288negative_binomial_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
5289{
5290    result_type __k = __pr.k();
5291    double __p = __pr.p();
5292    if (__k <= 21 * __p)
5293    {
5294        bernoulli_distribution __gen(__p);
5295        result_type __f = 0;
5296        result_type __s = 0;
5297        while (__s < __k)
5298        {
5299            if (__gen(__urng))
5300                ++__s;
5301            else
5302                ++__f;
5303        }
5304        return __f;
5305    }
5306    return poisson_distribution<result_type>(gamma_distribution<double>
5307                                            (__k, (1-__p)/__p)(__urng))(__urng);
5308}
5309
5310template <class _CharT, class _Traits, class _IntType>
5311basic_ostream<_CharT, _Traits>&
5312operator<<(basic_ostream<_CharT, _Traits>& __os,
5313           const negative_binomial_distribution<_IntType>& __x)
5314{
5315    __save_flags<_CharT, _Traits> __lx(__os);
5316    typedef basic_ostream<_CharT, _Traits> _OStream;
5317    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
5318               _OStream::scientific);
5319    _CharT __sp = __os.widen(' ');
5320    __os.fill(__sp);
5321    return __os << __x.k() << __sp << __x.p();
5322}
5323
5324template <class _CharT, class _Traits, class _IntType>
5325basic_istream<_CharT, _Traits>&
5326operator>>(basic_istream<_CharT, _Traits>& __is,
5327           negative_binomial_distribution<_IntType>& __x)
5328{
5329    typedef negative_binomial_distribution<_IntType> _Eng;
5330    typedef typename _Eng::result_type result_type;
5331    typedef typename _Eng::param_type param_type;
5332    __save_flags<_CharT, _Traits> __lx(__is);
5333    typedef basic_istream<_CharT, _Traits> _Istream;
5334    __is.flags(_Istream::dec | _Istream::skipws);
5335    result_type __k;
5336    double __p;
5337    __is >> __k >> __p;
5338    if (!__is.fail())
5339        __x.param(param_type(__k, __p));
5340    return __is;
5341}
5342
5343// geometric_distribution
5344
5345template<class _IntType = int>
5346class _LIBCPP_TEMPLATE_VIS geometric_distribution
5347{
5348public:
5349    // types
5350    typedef _IntType result_type;
5351
5352    class _LIBCPP_TEMPLATE_VIS param_type
5353    {
5354        double __p_;
5355    public:
5356        typedef geometric_distribution distribution_type;
5357
5358        _LIBCPP_INLINE_VISIBILITY
5359        explicit param_type(double __p = 0.5) : __p_(__p) {}
5360
5361        _LIBCPP_INLINE_VISIBILITY
5362        double p() const {return __p_;}
5363
5364        friend _LIBCPP_INLINE_VISIBILITY
5365            bool operator==(const param_type& __x, const param_type& __y)
5366            {return __x.__p_ == __y.__p_;}
5367        friend _LIBCPP_INLINE_VISIBILITY
5368            bool operator!=(const param_type& __x, const param_type& __y)
5369            {return !(__x == __y);}
5370    };
5371
5372private:
5373    param_type __p_;
5374
5375public:
5376    // constructors and reset functions
5377    _LIBCPP_INLINE_VISIBILITY
5378    explicit geometric_distribution(double __p = 0.5) : __p_(__p) {}
5379    _LIBCPP_INLINE_VISIBILITY
5380    explicit geometric_distribution(const param_type& __p) : __p_(__p) {}
5381    _LIBCPP_INLINE_VISIBILITY
5382    void reset() {}
5383
5384    // generating functions
5385    template<class _URNG>
5386        _LIBCPP_INLINE_VISIBILITY
5387        result_type operator()(_URNG& __g)
5388        {return (*this)(__g, __p_);}
5389    template<class _URNG>
5390        _LIBCPP_INLINE_VISIBILITY
5391        result_type operator()(_URNG& __g, const param_type& __p)
5392        {return negative_binomial_distribution<result_type>(1, __p.p())(__g);}
5393
5394    // property functions
5395    _LIBCPP_INLINE_VISIBILITY
5396    double p() const {return __p_.p();}
5397
5398    _LIBCPP_INLINE_VISIBILITY
5399    param_type param() const {return __p_;}
5400    _LIBCPP_INLINE_VISIBILITY
5401    void param(const param_type& __p) {__p_ = __p;}
5402
5403    _LIBCPP_INLINE_VISIBILITY
5404    result_type min() const {return 0;}
5405    _LIBCPP_INLINE_VISIBILITY
5406    result_type max() const {return numeric_limits<result_type>::max();}
5407
5408    friend _LIBCPP_INLINE_VISIBILITY
5409        bool operator==(const geometric_distribution& __x,
5410                        const geometric_distribution& __y)
5411        {return __x.__p_ == __y.__p_;}
5412    friend _LIBCPP_INLINE_VISIBILITY
5413        bool operator!=(const geometric_distribution& __x,
5414                        const geometric_distribution& __y)
5415        {return !(__x == __y);}
5416};
5417
5418template <class _CharT, class _Traits, class _IntType>
5419basic_ostream<_CharT, _Traits>&
5420operator<<(basic_ostream<_CharT, _Traits>& __os,
5421           const geometric_distribution<_IntType>& __x)
5422{
5423    __save_flags<_CharT, _Traits> __lx(__os);
5424    typedef basic_ostream<_CharT, _Traits> _OStream;
5425    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
5426               _OStream::scientific);
5427    return __os << __x.p();
5428}
5429
5430template <class _CharT, class _Traits, class _IntType>
5431basic_istream<_CharT, _Traits>&
5432operator>>(basic_istream<_CharT, _Traits>& __is,
5433           geometric_distribution<_IntType>& __x)
5434{
5435    typedef geometric_distribution<_IntType> _Eng;
5436    typedef typename _Eng::param_type param_type;
5437    __save_flags<_CharT, _Traits> __lx(__is);
5438    typedef basic_istream<_CharT, _Traits> _Istream;
5439    __is.flags(_Istream::dec | _Istream::skipws);
5440    double __p;
5441    __is >> __p;
5442    if (!__is.fail())
5443        __x.param(param_type(__p));
5444    return __is;
5445}
5446
5447// chi_squared_distribution
5448
5449template<class _RealType = double>
5450class _LIBCPP_TEMPLATE_VIS chi_squared_distribution
5451{
5452public:
5453    // types
5454    typedef _RealType result_type;
5455
5456    class _LIBCPP_TEMPLATE_VIS param_type
5457    {
5458        result_type __n_;
5459    public:
5460        typedef chi_squared_distribution distribution_type;
5461
5462        _LIBCPP_INLINE_VISIBILITY
5463        explicit param_type(result_type __n = 1) : __n_(__n) {}
5464
5465        _LIBCPP_INLINE_VISIBILITY
5466        result_type n() const {return __n_;}
5467
5468        friend _LIBCPP_INLINE_VISIBILITY
5469            bool operator==(const param_type& __x, const param_type& __y)
5470            {return __x.__n_ == __y.__n_;}
5471        friend _LIBCPP_INLINE_VISIBILITY
5472            bool operator!=(const param_type& __x, const param_type& __y)
5473            {return !(__x == __y);}
5474    };
5475
5476private:
5477    param_type __p_;
5478
5479public:
5480    // constructor and reset functions
5481    _LIBCPP_INLINE_VISIBILITY
5482    explicit chi_squared_distribution(result_type __n = 1)
5483        : __p_(param_type(__n)) {}
5484    _LIBCPP_INLINE_VISIBILITY
5485    explicit chi_squared_distribution(const param_type& __p)
5486        : __p_(__p) {}
5487    _LIBCPP_INLINE_VISIBILITY
5488    void reset() {}
5489
5490    // generating functions
5491    template<class _URNG>
5492        _LIBCPP_INLINE_VISIBILITY
5493        result_type operator()(_URNG& __g)
5494        {return (*this)(__g, __p_);}
5495    template<class _URNG>
5496        _LIBCPP_INLINE_VISIBILITY
5497        result_type operator()(_URNG& __g, const param_type& __p)
5498        {return gamma_distribution<result_type>(__p.n() / 2, 2)(__g);}
5499
5500    // property functions
5501    _LIBCPP_INLINE_VISIBILITY
5502    result_type n() const {return __p_.n();}
5503
5504    _LIBCPP_INLINE_VISIBILITY
5505    param_type param() const {return __p_;}
5506    _LIBCPP_INLINE_VISIBILITY
5507    void param(const param_type& __p) {__p_ = __p;}
5508
5509    _LIBCPP_INLINE_VISIBILITY
5510    result_type min() const {return 0;}
5511    _LIBCPP_INLINE_VISIBILITY
5512    result_type max() const {return numeric_limits<result_type>::infinity();}
5513
5514    friend _LIBCPP_INLINE_VISIBILITY
5515        bool operator==(const chi_squared_distribution& __x,
5516                        const chi_squared_distribution& __y)
5517        {return __x.__p_ == __y.__p_;}
5518    friend _LIBCPP_INLINE_VISIBILITY
5519        bool operator!=(const chi_squared_distribution& __x,
5520                        const chi_squared_distribution& __y)
5521        {return !(__x == __y);}
5522};
5523
5524template <class _CharT, class _Traits, class _RT>
5525basic_ostream<_CharT, _Traits>&
5526operator<<(basic_ostream<_CharT, _Traits>& __os,
5527           const chi_squared_distribution<_RT>& __x)
5528{
5529    __save_flags<_CharT, _Traits> __lx(__os);
5530    typedef basic_ostream<_CharT, _Traits> _OStream;
5531    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
5532               _OStream::scientific);
5533    __os << __x.n();
5534    return __os;
5535}
5536
5537template <class _CharT, class _Traits, class _RT>
5538basic_istream<_CharT, _Traits>&
5539operator>>(basic_istream<_CharT, _Traits>& __is,
5540           chi_squared_distribution<_RT>& __x)
5541{
5542    typedef chi_squared_distribution<_RT> _Eng;
5543    typedef typename _Eng::result_type result_type;
5544    typedef typename _Eng::param_type param_type;
5545    __save_flags<_CharT, _Traits> __lx(__is);
5546    typedef basic_istream<_CharT, _Traits> _Istream;
5547    __is.flags(_Istream::dec | _Istream::skipws);
5548    result_type __n;
5549    __is >> __n;
5550    if (!__is.fail())
5551        __x.param(param_type(__n));
5552    return __is;
5553}
5554
5555// cauchy_distribution
5556
5557template<class _RealType = double>
5558class _LIBCPP_TEMPLATE_VIS cauchy_distribution
5559{
5560public:
5561    // types
5562    typedef _RealType result_type;
5563
5564    class _LIBCPP_TEMPLATE_VIS param_type
5565    {
5566        result_type __a_;
5567        result_type __b_;
5568    public:
5569        typedef cauchy_distribution distribution_type;
5570
5571        _LIBCPP_INLINE_VISIBILITY
5572        explicit param_type(result_type __a = 0, result_type __b = 1)
5573            : __a_(__a), __b_(__b) {}
5574
5575        _LIBCPP_INLINE_VISIBILITY
5576        result_type a() const {return __a_;}
5577        _LIBCPP_INLINE_VISIBILITY
5578        result_type b() const {return __b_;}
5579
5580        friend _LIBCPP_INLINE_VISIBILITY
5581            bool operator==(const param_type& __x, const param_type& __y)
5582            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
5583        friend _LIBCPP_INLINE_VISIBILITY
5584            bool operator!=(const param_type& __x, const param_type& __y)
5585            {return !(__x == __y);}
5586    };
5587
5588private:
5589    param_type __p_;
5590
5591public:
5592    // constructor and reset functions
5593    _LIBCPP_INLINE_VISIBILITY
5594    explicit cauchy_distribution(result_type __a = 0, result_type __b = 1)
5595        : __p_(param_type(__a, __b)) {}
5596    _LIBCPP_INLINE_VISIBILITY
5597    explicit cauchy_distribution(const param_type& __p)
5598        : __p_(__p) {}
5599    _LIBCPP_INLINE_VISIBILITY
5600    void reset() {}
5601
5602    // generating functions
5603    template<class _URNG>
5604        _LIBCPP_INLINE_VISIBILITY
5605        result_type operator()(_URNG& __g)
5606        {return (*this)(__g, __p_);}
5607    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
5608
5609    // property functions
5610    _LIBCPP_INLINE_VISIBILITY
5611    result_type a() const {return __p_.a();}
5612    _LIBCPP_INLINE_VISIBILITY
5613    result_type b() const {return __p_.b();}
5614
5615    _LIBCPP_INLINE_VISIBILITY
5616    param_type param() const {return __p_;}
5617    _LIBCPP_INLINE_VISIBILITY
5618    void param(const param_type& __p) {__p_ = __p;}
5619
5620    _LIBCPP_INLINE_VISIBILITY
5621    result_type min() const {return -numeric_limits<result_type>::infinity();}
5622    _LIBCPP_INLINE_VISIBILITY
5623    result_type max() const {return numeric_limits<result_type>::infinity();}
5624
5625    friend _LIBCPP_INLINE_VISIBILITY
5626        bool operator==(const cauchy_distribution& __x,
5627                        const cauchy_distribution& __y)
5628        {return __x.__p_ == __y.__p_;}
5629    friend _LIBCPP_INLINE_VISIBILITY
5630        bool operator!=(const cauchy_distribution& __x,
5631                        const cauchy_distribution& __y)
5632        {return !(__x == __y);}
5633};
5634
5635template <class _RealType>
5636template<class _URNG>
5637inline
5638_RealType
5639cauchy_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5640{
5641    uniform_real_distribution<result_type> __gen;
5642    // purposefully let tan arg get as close to pi/2 as it wants, tan will return a finite
5643    return __p.a() + __p.b() * _VSTD::tan(3.1415926535897932384626433832795 * __gen(__g));
5644}
5645
5646template <class _CharT, class _Traits, class _RT>
5647basic_ostream<_CharT, _Traits>&
5648operator<<(basic_ostream<_CharT, _Traits>& __os,
5649           const cauchy_distribution<_RT>& __x)
5650{
5651    __save_flags<_CharT, _Traits> __lx(__os);
5652    typedef basic_ostream<_CharT, _Traits> _OStream;
5653    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
5654               _OStream::scientific);
5655    _CharT __sp = __os.widen(' ');
5656    __os.fill(__sp);
5657    __os << __x.a() << __sp << __x.b();
5658    return __os;
5659}
5660
5661template <class _CharT, class _Traits, class _RT>
5662basic_istream<_CharT, _Traits>&
5663operator>>(basic_istream<_CharT, _Traits>& __is,
5664           cauchy_distribution<_RT>& __x)
5665{
5666    typedef cauchy_distribution<_RT> _Eng;
5667    typedef typename _Eng::result_type result_type;
5668    typedef typename _Eng::param_type param_type;
5669    __save_flags<_CharT, _Traits> __lx(__is);
5670    typedef basic_istream<_CharT, _Traits> _Istream;
5671    __is.flags(_Istream::dec | _Istream::skipws);
5672    result_type __a;
5673    result_type __b;
5674    __is >> __a >> __b;
5675    if (!__is.fail())
5676        __x.param(param_type(__a, __b));
5677    return __is;
5678}
5679
5680// fisher_f_distribution
5681
5682template<class _RealType = double>
5683class _LIBCPP_TEMPLATE_VIS fisher_f_distribution
5684{
5685public:
5686    // types
5687    typedef _RealType result_type;
5688
5689    class _LIBCPP_TEMPLATE_VIS param_type
5690    {
5691        result_type __m_;
5692        result_type __n_;
5693    public:
5694        typedef fisher_f_distribution distribution_type;
5695
5696        _LIBCPP_INLINE_VISIBILITY
5697        explicit param_type(result_type __m = 1, result_type __n = 1)
5698            : __m_(__m), __n_(__n) {}
5699
5700        _LIBCPP_INLINE_VISIBILITY
5701        result_type m() const {return __m_;}
5702        _LIBCPP_INLINE_VISIBILITY
5703        result_type n() const {return __n_;}
5704
5705        friend _LIBCPP_INLINE_VISIBILITY
5706            bool operator==(const param_type& __x, const param_type& __y)
5707            {return __x.__m_ == __y.__m_ && __x.__n_ == __y.__n_;}
5708        friend _LIBCPP_INLINE_VISIBILITY
5709            bool operator!=(const param_type& __x, const param_type& __y)
5710            {return !(__x == __y);}
5711    };
5712
5713private:
5714    param_type __p_;
5715
5716public:
5717    // constructor and reset functions
5718    _LIBCPP_INLINE_VISIBILITY
5719    explicit fisher_f_distribution(result_type __m = 1, result_type __n = 1)
5720        : __p_(param_type(__m, __n)) {}
5721    _LIBCPP_INLINE_VISIBILITY
5722    explicit fisher_f_distribution(const param_type& __p)
5723        : __p_(__p) {}
5724    _LIBCPP_INLINE_VISIBILITY
5725    void reset() {}
5726
5727    // generating functions
5728    template<class _URNG>
5729        _LIBCPP_INLINE_VISIBILITY
5730        result_type operator()(_URNG& __g)
5731        {return (*this)(__g, __p_);}
5732    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5733
5734    // property functions
5735    _LIBCPP_INLINE_VISIBILITY
5736    result_type m() const {return __p_.m();}
5737    _LIBCPP_INLINE_VISIBILITY
5738    result_type n() const {return __p_.n();}
5739
5740    _LIBCPP_INLINE_VISIBILITY
5741    param_type param() const {return __p_;}
5742    _LIBCPP_INLINE_VISIBILITY
5743    void param(const param_type& __p) {__p_ = __p;}
5744
5745    _LIBCPP_INLINE_VISIBILITY
5746    result_type min() const {return 0;}
5747    _LIBCPP_INLINE_VISIBILITY
5748    result_type max() const {return numeric_limits<result_type>::infinity();}
5749
5750    friend _LIBCPP_INLINE_VISIBILITY
5751        bool operator==(const fisher_f_distribution& __x,
5752                        const fisher_f_distribution& __y)
5753        {return __x.__p_ == __y.__p_;}
5754    friend _LIBCPP_INLINE_VISIBILITY
5755        bool operator!=(const fisher_f_distribution& __x,
5756                        const fisher_f_distribution& __y)
5757        {return !(__x == __y);}
5758};
5759
5760template <class _RealType>
5761template<class _URNG>
5762_RealType
5763fisher_f_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5764{
5765    gamma_distribution<result_type> __gdm(__p.m() * result_type(.5));
5766    gamma_distribution<result_type> __gdn(__p.n() * result_type(.5));
5767    return __p.n() * __gdm(__g) / (__p.m() * __gdn(__g));
5768}
5769
5770template <class _CharT, class _Traits, class _RT>
5771basic_ostream<_CharT, _Traits>&
5772operator<<(basic_ostream<_CharT, _Traits>& __os,
5773           const fisher_f_distribution<_RT>& __x)
5774{
5775    __save_flags<_CharT, _Traits> __lx(__os);
5776    typedef basic_ostream<_CharT, _Traits> _OStream;
5777    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
5778               _OStream::scientific);
5779    _CharT __sp = __os.widen(' ');
5780    __os.fill(__sp);
5781    __os << __x.m() << __sp << __x.n();
5782    return __os;
5783}
5784
5785template <class _CharT, class _Traits, class _RT>
5786basic_istream<_CharT, _Traits>&
5787operator>>(basic_istream<_CharT, _Traits>& __is,
5788           fisher_f_distribution<_RT>& __x)
5789{
5790    typedef fisher_f_distribution<_RT> _Eng;
5791    typedef typename _Eng::result_type result_type;
5792    typedef typename _Eng::param_type param_type;
5793    __save_flags<_CharT, _Traits> __lx(__is);
5794    typedef basic_istream<_CharT, _Traits> _Istream;
5795    __is.flags(_Istream::dec | _Istream::skipws);
5796    result_type __m;
5797    result_type __n;
5798    __is >> __m >> __n;
5799    if (!__is.fail())
5800        __x.param(param_type(__m, __n));
5801    return __is;
5802}
5803
5804// student_t_distribution
5805
5806template<class _RealType = double>
5807class _LIBCPP_TEMPLATE_VIS student_t_distribution
5808{
5809public:
5810    // types
5811    typedef _RealType result_type;
5812
5813    class _LIBCPP_TEMPLATE_VIS param_type
5814    {
5815        result_type __n_;
5816    public:
5817        typedef student_t_distribution distribution_type;
5818
5819        _LIBCPP_INLINE_VISIBILITY
5820        explicit param_type(result_type __n = 1) : __n_(__n) {}
5821
5822        _LIBCPP_INLINE_VISIBILITY
5823        result_type n() const {return __n_;}
5824
5825        friend _LIBCPP_INLINE_VISIBILITY
5826            bool operator==(const param_type& __x, const param_type& __y)
5827            {return __x.__n_ == __y.__n_;}
5828        friend _LIBCPP_INLINE_VISIBILITY
5829            bool operator!=(const param_type& __x, const param_type& __y)
5830            {return !(__x == __y);}
5831    };
5832
5833private:
5834    param_type __p_;
5835    normal_distribution<result_type> __nd_;
5836
5837public:
5838    // constructor and reset functions
5839    _LIBCPP_INLINE_VISIBILITY
5840    explicit student_t_distribution(result_type __n = 1)
5841        : __p_(param_type(__n)) {}
5842    _LIBCPP_INLINE_VISIBILITY
5843    explicit student_t_distribution(const param_type& __p)
5844        : __p_(__p) {}
5845    _LIBCPP_INLINE_VISIBILITY
5846    void reset() {__nd_.reset();}
5847
5848    // generating functions
5849    template<class _URNG>
5850        _LIBCPP_INLINE_VISIBILITY
5851        result_type operator()(_URNG& __g)
5852        {return (*this)(__g, __p_);}
5853    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5854
5855    // property functions
5856    _LIBCPP_INLINE_VISIBILITY
5857    result_type n() const {return __p_.n();}
5858
5859    _LIBCPP_INLINE_VISIBILITY
5860    param_type param() const {return __p_;}
5861    _LIBCPP_INLINE_VISIBILITY
5862    void param(const param_type& __p) {__p_ = __p;}
5863
5864    _LIBCPP_INLINE_VISIBILITY
5865    result_type min() const {return -numeric_limits<result_type>::infinity();}
5866    _LIBCPP_INLINE_VISIBILITY
5867    result_type max() const {return numeric_limits<result_type>::infinity();}
5868
5869    friend _LIBCPP_INLINE_VISIBILITY
5870        bool operator==(const student_t_distribution& __x,
5871                        const student_t_distribution& __y)
5872        {return __x.__p_ == __y.__p_;}
5873    friend _LIBCPP_INLINE_VISIBILITY
5874        bool operator!=(const student_t_distribution& __x,
5875                        const student_t_distribution& __y)
5876        {return !(__x == __y);}
5877};
5878
5879template <class _RealType>
5880template<class _URNG>
5881_RealType
5882student_t_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5883{
5884    gamma_distribution<result_type> __gd(__p.n() * .5, 2);
5885    return __nd_(__g) * _VSTD::sqrt(__p.n()/__gd(__g));
5886}
5887
5888template <class _CharT, class _Traits, class _RT>
5889basic_ostream<_CharT, _Traits>&
5890operator<<(basic_ostream<_CharT, _Traits>& __os,
5891           const student_t_distribution<_RT>& __x)
5892{
5893    __save_flags<_CharT, _Traits> __lx(__os);
5894    typedef basic_ostream<_CharT, _Traits> _OStream;
5895    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
5896               _OStream::scientific);
5897    __os << __x.n();
5898    return __os;
5899}
5900
5901template <class _CharT, class _Traits, class _RT>
5902basic_istream<_CharT, _Traits>&
5903operator>>(basic_istream<_CharT, _Traits>& __is,
5904           student_t_distribution<_RT>& __x)
5905{
5906    typedef student_t_distribution<_RT> _Eng;
5907    typedef typename _Eng::result_type result_type;
5908    typedef typename _Eng::param_type param_type;
5909    __save_flags<_CharT, _Traits> __lx(__is);
5910    typedef basic_istream<_CharT, _Traits> _Istream;
5911    __is.flags(_Istream::dec | _Istream::skipws);
5912    result_type __n;
5913    __is >> __n;
5914    if (!__is.fail())
5915        __x.param(param_type(__n));
5916    return __is;
5917}
5918
5919// discrete_distribution
5920
5921template<class _IntType = int>
5922class _LIBCPP_TEMPLATE_VIS discrete_distribution
5923{
5924public:
5925    // types
5926    typedef _IntType result_type;
5927
5928    class _LIBCPP_TEMPLATE_VIS param_type
5929    {
5930        vector<double> __p_;
5931    public:
5932        typedef discrete_distribution distribution_type;
5933
5934        _LIBCPP_INLINE_VISIBILITY
5935        param_type() {}
5936        template<class _InputIterator>
5937            _LIBCPP_INLINE_VISIBILITY
5938            param_type(_InputIterator __f, _InputIterator __l)
5939            : __p_(__f, __l) {__init();}
5940#ifndef _LIBCPP_CXX03_LANG
5941        _LIBCPP_INLINE_VISIBILITY
5942        param_type(initializer_list<double> __wl)
5943            : __p_(__wl.begin(), __wl.end()) {__init();}
5944#endif  // _LIBCPP_CXX03_LANG
5945        template<class _UnaryOperation>
5946            param_type(size_t __nw, double __xmin, double __xmax,
5947                       _UnaryOperation __fw);
5948
5949        vector<double> probabilities() const;
5950
5951        friend _LIBCPP_INLINE_VISIBILITY
5952            bool operator==(const param_type& __x, const param_type& __y)
5953            {return __x.__p_ == __y.__p_;}
5954        friend _LIBCPP_INLINE_VISIBILITY
5955            bool operator!=(const param_type& __x, const param_type& __y)
5956            {return !(__x == __y);}
5957
5958    private:
5959        void __init();
5960
5961        friend class discrete_distribution;
5962
5963        template <class _CharT, class _Traits, class _IT>
5964        friend
5965        basic_ostream<_CharT, _Traits>&
5966        operator<<(basic_ostream<_CharT, _Traits>& __os,
5967                   const discrete_distribution<_IT>& __x);
5968
5969        template <class _CharT, class _Traits, class _IT>
5970        friend
5971        basic_istream<_CharT, _Traits>&
5972        operator>>(basic_istream<_CharT, _Traits>& __is,
5973                   discrete_distribution<_IT>& __x);
5974    };
5975
5976private:
5977    param_type __p_;
5978
5979public:
5980    // constructor and reset functions
5981    _LIBCPP_INLINE_VISIBILITY
5982    discrete_distribution() {}
5983    template<class _InputIterator>
5984        _LIBCPP_INLINE_VISIBILITY
5985        discrete_distribution(_InputIterator __f, _InputIterator __l)
5986            : __p_(__f, __l) {}
5987#ifndef _LIBCPP_CXX03_LANG
5988    _LIBCPP_INLINE_VISIBILITY
5989    discrete_distribution(initializer_list<double> __wl)
5990        : __p_(__wl) {}
5991#endif  // _LIBCPP_CXX03_LANG
5992    template<class _UnaryOperation>
5993        _LIBCPP_INLINE_VISIBILITY
5994        discrete_distribution(size_t __nw, double __xmin, double __xmax,
5995                              _UnaryOperation __fw)
5996        : __p_(__nw, __xmin, __xmax, __fw) {}
5997    _LIBCPP_INLINE_VISIBILITY
5998    explicit discrete_distribution(const param_type& __p)
5999        : __p_(__p) {}
6000    _LIBCPP_INLINE_VISIBILITY
6001    void reset() {}
6002
6003    // generating functions
6004    template<class _URNG>
6005        _LIBCPP_INLINE_VISIBILITY
6006        result_type operator()(_URNG& __g)
6007        {return (*this)(__g, __p_);}
6008    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
6009
6010    // property functions
6011    _LIBCPP_INLINE_VISIBILITY
6012    vector<double> probabilities() const {return __p_.probabilities();}
6013
6014    _LIBCPP_INLINE_VISIBILITY
6015    param_type param() const {return __p_;}
6016    _LIBCPP_INLINE_VISIBILITY
6017    void param(const param_type& __p) {__p_ = __p;}
6018
6019    _LIBCPP_INLINE_VISIBILITY
6020    result_type min() const {return 0;}
6021    _LIBCPP_INLINE_VISIBILITY
6022    result_type max() const {return __p_.__p_.size();}
6023
6024    friend _LIBCPP_INLINE_VISIBILITY
6025        bool operator==(const discrete_distribution& __x,
6026                        const discrete_distribution& __y)
6027        {return __x.__p_ == __y.__p_;}
6028    friend _LIBCPP_INLINE_VISIBILITY
6029        bool operator!=(const discrete_distribution& __x,
6030                        const discrete_distribution& __y)
6031        {return !(__x == __y);}
6032
6033    template <class _CharT, class _Traits, class _IT>
6034    friend
6035    basic_ostream<_CharT, _Traits>&
6036    operator<<(basic_ostream<_CharT, _Traits>& __os,
6037               const discrete_distribution<_IT>& __x);
6038
6039    template <class _CharT, class _Traits, class _IT>
6040    friend
6041    basic_istream<_CharT, _Traits>&
6042    operator>>(basic_istream<_CharT, _Traits>& __is,
6043               discrete_distribution<_IT>& __x);
6044};
6045
6046template<class _IntType>
6047template<class _UnaryOperation>
6048discrete_distribution<_IntType>::param_type::param_type(size_t __nw,
6049                                                        double __xmin,
6050                                                        double __xmax,
6051                                                        _UnaryOperation __fw)
6052{
6053    if (__nw > 1)
6054    {
6055        __p_.reserve(__nw - 1);
6056        double __d = (__xmax - __xmin) / __nw;
6057        double __d2 = __d / 2;
6058        for (size_t __k = 0; __k < __nw; ++__k)
6059            __p_.push_back(__fw(__xmin + __k * __d + __d2));
6060        __init();
6061    }
6062}
6063
6064template<class _IntType>
6065void
6066discrete_distribution<_IntType>::param_type::__init()
6067{
6068    if (!__p_.empty())
6069    {
6070        if (__p_.size() > 1)
6071        {
6072            double __s = _VSTD::accumulate(__p_.begin(), __p_.end(), 0.0);
6073            for (_VSTD::vector<double>::iterator __i = __p_.begin(), __e = __p_.end();
6074                                                                       __i < __e; ++__i)
6075                *__i /= __s;
6076            vector<double> __t(__p_.size() - 1);
6077            _VSTD::partial_sum(__p_.begin(), __p_.end() - 1, __t.begin());
6078            swap(__p_, __t);
6079        }
6080        else
6081        {
6082            __p_.clear();
6083            __p_.shrink_to_fit();
6084        }
6085    }
6086}
6087
6088template<class _IntType>
6089vector<double>
6090discrete_distribution<_IntType>::param_type::probabilities() const
6091{
6092    size_t __n = __p_.size();
6093    _VSTD::vector<double> __p(__n+1);
6094    _VSTD::adjacent_difference(__p_.begin(), __p_.end(), __p.begin());
6095    if (__n > 0)
6096        __p[__n] = 1 - __p_[__n-1];
6097    else
6098        __p[0] = 1;
6099    return __p;
6100}
6101
6102template<class _IntType>
6103template<class _URNG>
6104_IntType
6105discrete_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
6106{
6107    uniform_real_distribution<double> __gen;
6108    return static_cast<_IntType>(
6109           _VSTD::upper_bound(__p.__p_.begin(), __p.__p_.end(), __gen(__g)) -
6110                                                              __p.__p_.begin());
6111}
6112
6113template <class _CharT, class _Traits, class _IT>
6114basic_ostream<_CharT, _Traits>&
6115operator<<(basic_ostream<_CharT, _Traits>& __os,
6116           const discrete_distribution<_IT>& __x)
6117{
6118    __save_flags<_CharT, _Traits> __lx(__os);
6119    typedef basic_ostream<_CharT, _Traits> _OStream;
6120    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
6121               _OStream::scientific);
6122    _CharT __sp = __os.widen(' ');
6123    __os.fill(__sp);
6124    size_t __n = __x.__p_.__p_.size();
6125    __os << __n;
6126    for (size_t __i = 0; __i < __n; ++__i)
6127        __os << __sp << __x.__p_.__p_[__i];
6128    return __os;
6129}
6130
6131template <class _CharT, class _Traits, class _IT>
6132basic_istream<_CharT, _Traits>&
6133operator>>(basic_istream<_CharT, _Traits>& __is,
6134           discrete_distribution<_IT>& __x)
6135{
6136    __save_flags<_CharT, _Traits> __lx(__is);
6137    typedef basic_istream<_CharT, _Traits> _Istream;
6138    __is.flags(_Istream::dec | _Istream::skipws);
6139    size_t __n;
6140    __is >> __n;
6141    vector<double> __p(__n);
6142    for (size_t __i = 0; __i < __n; ++__i)
6143        __is >> __p[__i];
6144    if (!__is.fail())
6145        swap(__x.__p_.__p_, __p);
6146    return __is;
6147}
6148
6149// piecewise_constant_distribution
6150
6151template<class _RealType = double>
6152class _LIBCPP_TEMPLATE_VIS piecewise_constant_distribution
6153{
6154public:
6155    // types
6156    typedef _RealType result_type;
6157
6158    class _LIBCPP_TEMPLATE_VIS param_type
6159    {
6160        vector<result_type> __b_;
6161        vector<result_type> __densities_;
6162        vector<result_type> __areas_;
6163    public:
6164        typedef piecewise_constant_distribution distribution_type;
6165
6166        param_type();
6167        template<class _InputIteratorB, class _InputIteratorW>
6168            param_type(_InputIteratorB __fB, _InputIteratorB __lB,
6169                       _InputIteratorW __fW);
6170#ifndef _LIBCPP_CXX03_LANG
6171        template<class _UnaryOperation>
6172            param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
6173#endif  // _LIBCPP_CXX03_LANG
6174        template<class _UnaryOperation>
6175            param_type(size_t __nw, result_type __xmin, result_type __xmax,
6176                       _UnaryOperation __fw);
6177        param_type(param_type const&) = default;
6178        param_type & operator=(const param_type& __rhs);
6179
6180        _LIBCPP_INLINE_VISIBILITY
6181        vector<result_type> intervals() const {return __b_;}
6182        _LIBCPP_INLINE_VISIBILITY
6183        vector<result_type> densities() const {return __densities_;}
6184
6185        friend _LIBCPP_INLINE_VISIBILITY
6186            bool operator==(const param_type& __x, const param_type& __y)
6187            {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
6188        friend _LIBCPP_INLINE_VISIBILITY
6189            bool operator!=(const param_type& __x, const param_type& __y)
6190            {return !(__x == __y);}
6191
6192    private:
6193        void __init();
6194
6195        friend class piecewise_constant_distribution;
6196
6197        template <class _CharT, class _Traits, class _RT>
6198        friend
6199        basic_ostream<_CharT, _Traits>&
6200        operator<<(basic_ostream<_CharT, _Traits>& __os,
6201                   const piecewise_constant_distribution<_RT>& __x);
6202
6203        template <class _CharT, class _Traits, class _RT>
6204        friend
6205        basic_istream<_CharT, _Traits>&
6206        operator>>(basic_istream<_CharT, _Traits>& __is,
6207                   piecewise_constant_distribution<_RT>& __x);
6208    };
6209
6210private:
6211    param_type __p_;
6212
6213public:
6214    // constructor and reset functions
6215    _LIBCPP_INLINE_VISIBILITY
6216    piecewise_constant_distribution() {}
6217    template<class _InputIteratorB, class _InputIteratorW>
6218        _LIBCPP_INLINE_VISIBILITY
6219        piecewise_constant_distribution(_InputIteratorB __fB,
6220                                        _InputIteratorB __lB,
6221                                        _InputIteratorW __fW)
6222        : __p_(__fB, __lB, __fW) {}
6223
6224#ifndef _LIBCPP_CXX03_LANG
6225    template<class _UnaryOperation>
6226        _LIBCPP_INLINE_VISIBILITY
6227        piecewise_constant_distribution(initializer_list<result_type> __bl,
6228                                        _UnaryOperation __fw)
6229        : __p_(__bl, __fw) {}
6230#endif  // _LIBCPP_CXX03_LANG
6231
6232    template<class _UnaryOperation>
6233        _LIBCPP_INLINE_VISIBILITY
6234        piecewise_constant_distribution(size_t __nw, result_type __xmin,
6235                                        result_type __xmax, _UnaryOperation __fw)
6236        : __p_(__nw, __xmin, __xmax, __fw) {}
6237
6238    _LIBCPP_INLINE_VISIBILITY
6239    explicit piecewise_constant_distribution(const param_type& __p)
6240        : __p_(__p) {}
6241
6242    _LIBCPP_INLINE_VISIBILITY
6243    void reset() {}
6244
6245    // generating functions
6246    template<class _URNG>
6247        _LIBCPP_INLINE_VISIBILITY
6248        result_type operator()(_URNG& __g)
6249        {return (*this)(__g, __p_);}
6250    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
6251
6252    // property functions
6253    _LIBCPP_INLINE_VISIBILITY
6254    vector<result_type> intervals() const {return __p_.intervals();}
6255    _LIBCPP_INLINE_VISIBILITY
6256    vector<result_type> densities() const {return __p_.densities();}
6257
6258    _LIBCPP_INLINE_VISIBILITY
6259    param_type param() const {return __p_;}
6260    _LIBCPP_INLINE_VISIBILITY
6261    void param(const param_type& __p) {__p_ = __p;}
6262
6263    _LIBCPP_INLINE_VISIBILITY
6264    result_type min() const {return __p_.__b_.front();}
6265    _LIBCPP_INLINE_VISIBILITY
6266    result_type max() const {return __p_.__b_.back();}
6267
6268    friend _LIBCPP_INLINE_VISIBILITY
6269        bool operator==(const piecewise_constant_distribution& __x,
6270                        const piecewise_constant_distribution& __y)
6271        {return __x.__p_ == __y.__p_;}
6272    friend _LIBCPP_INLINE_VISIBILITY
6273        bool operator!=(const piecewise_constant_distribution& __x,
6274                           const piecewise_constant_distribution& __y)
6275        {return !(__x == __y);}
6276
6277    template <class _CharT, class _Traits, class _RT>
6278    friend
6279    basic_ostream<_CharT, _Traits>&
6280    operator<<(basic_ostream<_CharT, _Traits>& __os,
6281               const piecewise_constant_distribution<_RT>& __x);
6282
6283    template <class _CharT, class _Traits, class _RT>
6284    friend
6285    basic_istream<_CharT, _Traits>&
6286    operator>>(basic_istream<_CharT, _Traits>& __is,
6287               piecewise_constant_distribution<_RT>& __x);
6288};
6289
6290template<class _RealType>
6291typename piecewise_constant_distribution<_RealType>::param_type &
6292piecewise_constant_distribution<_RealType>::param_type::operator=
6293                                                       (const param_type& __rhs)
6294{
6295//  These can throw
6296    __b_.reserve        (__rhs.__b_.size ());
6297    __densities_.reserve(__rhs.__densities_.size());
6298    __areas_.reserve    (__rhs.__areas_.size());
6299
6300//  These can not throw
6301    __b_         = __rhs.__b_;
6302    __densities_ = __rhs.__densities_;
6303    __areas_     =  __rhs.__areas_;
6304    return *this;
6305}
6306
6307template<class _RealType>
6308void
6309piecewise_constant_distribution<_RealType>::param_type::__init()
6310{
6311    // __densities_ contains non-normalized areas
6312    result_type __total_area = _VSTD::accumulate(__densities_.begin(),
6313                                                __densities_.end(),
6314                                                result_type());
6315    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6316        __densities_[__i] /= __total_area;
6317    // __densities_ contains normalized areas
6318    __areas_.assign(__densities_.size(), result_type());
6319    _VSTD::partial_sum(__densities_.begin(), __densities_.end() - 1,
6320                                                          __areas_.begin() + 1);
6321    // __areas_ contains partial sums of normalized areas: [0, __densities_ - 1]
6322    __densities_.back() = 1 - __areas_.back();  // correct round off error
6323    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6324        __densities_[__i] /= (__b_[__i+1] - __b_[__i]);
6325    // __densities_ now contains __densities_
6326}
6327
6328template<class _RealType>
6329piecewise_constant_distribution<_RealType>::param_type::param_type()
6330    : __b_(2),
6331      __densities_(1, 1.0),
6332      __areas_(1, 0.0)
6333{
6334    __b_[1] = 1;
6335}
6336
6337template<class _RealType>
6338template<class _InputIteratorB, class _InputIteratorW>
6339piecewise_constant_distribution<_RealType>::param_type::param_type(
6340        _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
6341    : __b_(__fB, __lB)
6342{
6343    if (__b_.size() < 2)
6344    {
6345        __b_.resize(2);
6346        __b_[0] = 0;
6347        __b_[1] = 1;
6348        __densities_.assign(1, 1.0);
6349        __areas_.assign(1, 0.0);
6350    }
6351    else
6352    {
6353        __densities_.reserve(__b_.size() - 1);
6354        for (size_t __i = 0; __i < __b_.size() - 1; ++__i, ++__fW)
6355            __densities_.push_back(*__fW);
6356        __init();
6357    }
6358}
6359
6360#ifndef _LIBCPP_CXX03_LANG
6361
6362template<class _RealType>
6363template<class _UnaryOperation>
6364piecewise_constant_distribution<_RealType>::param_type::param_type(
6365        initializer_list<result_type> __bl, _UnaryOperation __fw)
6366    : __b_(__bl.begin(), __bl.end())
6367{
6368    if (__b_.size() < 2)
6369    {
6370        __b_.resize(2);
6371        __b_[0] = 0;
6372        __b_[1] = 1;
6373        __densities_.assign(1, 1.0);
6374        __areas_.assign(1, 0.0);
6375    }
6376    else
6377    {
6378        __densities_.reserve(__b_.size() - 1);
6379        for (size_t __i = 0; __i < __b_.size() - 1; ++__i)
6380            __densities_.push_back(__fw((__b_[__i+1] + __b_[__i])*.5));
6381        __init();
6382    }
6383}
6384
6385#endif  // _LIBCPP_CXX03_LANG
6386
6387template<class _RealType>
6388template<class _UnaryOperation>
6389piecewise_constant_distribution<_RealType>::param_type::param_type(
6390        size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
6391    : __b_(__nw == 0 ? 2 : __nw + 1)
6392{
6393    size_t __n = __b_.size() - 1;
6394    result_type __d = (__xmax - __xmin) / __n;
6395    __densities_.reserve(__n);
6396    for (size_t __i = 0; __i < __n; ++__i)
6397    {
6398        __b_[__i] = __xmin + __i * __d;
6399        __densities_.push_back(__fw(__b_[__i] + __d*.5));
6400    }
6401    __b_[__n] = __xmax;
6402    __init();
6403}
6404
6405template<class _RealType>
6406template<class _URNG>
6407_RealType
6408piecewise_constant_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
6409{
6410    typedef uniform_real_distribution<result_type> _Gen;
6411    result_type __u = _Gen()(__g);
6412    ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
6413                                      __u) - __p.__areas_.begin() - 1;
6414    return (__u - __p.__areas_[__k]) / __p.__densities_[__k] + __p.__b_[__k];
6415}
6416
6417template <class _CharT, class _Traits, class _RT>
6418basic_ostream<_CharT, _Traits>&
6419operator<<(basic_ostream<_CharT, _Traits>& __os,
6420           const piecewise_constant_distribution<_RT>& __x)
6421{
6422    __save_flags<_CharT, _Traits> __lx(__os);
6423    typedef basic_ostream<_CharT, _Traits> _OStream;
6424    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
6425               _OStream::scientific);
6426    _CharT __sp = __os.widen(' ');
6427    __os.fill(__sp);
6428    size_t __n = __x.__p_.__b_.size();
6429    __os << __n;
6430    for (size_t __i = 0; __i < __n; ++__i)
6431        __os << __sp << __x.__p_.__b_[__i];
6432    __n = __x.__p_.__densities_.size();
6433    __os << __sp << __n;
6434    for (size_t __i = 0; __i < __n; ++__i)
6435        __os << __sp << __x.__p_.__densities_[__i];
6436    __n = __x.__p_.__areas_.size();
6437    __os << __sp << __n;
6438    for (size_t __i = 0; __i < __n; ++__i)
6439        __os << __sp << __x.__p_.__areas_[__i];
6440    return __os;
6441}
6442
6443template <class _CharT, class _Traits, class _RT>
6444basic_istream<_CharT, _Traits>&
6445operator>>(basic_istream<_CharT, _Traits>& __is,
6446           piecewise_constant_distribution<_RT>& __x)
6447{
6448    typedef piecewise_constant_distribution<_RT> _Eng;
6449    typedef typename _Eng::result_type result_type;
6450    __save_flags<_CharT, _Traits> __lx(__is);
6451    typedef basic_istream<_CharT, _Traits> _Istream;
6452    __is.flags(_Istream::dec | _Istream::skipws);
6453    size_t __n;
6454    __is >> __n;
6455    vector<result_type> __b(__n);
6456    for (size_t __i = 0; __i < __n; ++__i)
6457        __is >> __b[__i];
6458    __is >> __n;
6459    vector<result_type> __densities(__n);
6460    for (size_t __i = 0; __i < __n; ++__i)
6461        __is >> __densities[__i];
6462    __is >> __n;
6463    vector<result_type> __areas(__n);
6464    for (size_t __i = 0; __i < __n; ++__i)
6465        __is >> __areas[__i];
6466    if (!__is.fail())
6467    {
6468        swap(__x.__p_.__b_, __b);
6469        swap(__x.__p_.__densities_, __densities);
6470        swap(__x.__p_.__areas_, __areas);
6471    }
6472    return __is;
6473}
6474
6475// piecewise_linear_distribution
6476
6477template<class _RealType = double>
6478class _LIBCPP_TEMPLATE_VIS piecewise_linear_distribution
6479{
6480public:
6481    // types
6482    typedef _RealType result_type;
6483
6484    class _LIBCPP_TEMPLATE_VIS param_type
6485    {
6486        vector<result_type> __b_;
6487        vector<result_type> __densities_;
6488        vector<result_type> __areas_;
6489    public:
6490        typedef piecewise_linear_distribution distribution_type;
6491
6492        param_type();
6493        template<class _InputIteratorB, class _InputIteratorW>
6494            param_type(_InputIteratorB __fB, _InputIteratorB __lB,
6495                       _InputIteratorW __fW);
6496#ifndef _LIBCPP_CXX03_LANG
6497        template<class _UnaryOperation>
6498            param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
6499#endif  // _LIBCPP_CXX03_LANG
6500        template<class _UnaryOperation>
6501            param_type(size_t __nw, result_type __xmin, result_type __xmax,
6502                       _UnaryOperation __fw);
6503        param_type(param_type const&) = default;
6504        param_type & operator=(const param_type& __rhs);
6505
6506        _LIBCPP_INLINE_VISIBILITY
6507        vector<result_type> intervals() const {return __b_;}
6508        _LIBCPP_INLINE_VISIBILITY
6509        vector<result_type> densities() const {return __densities_;}
6510
6511        friend _LIBCPP_INLINE_VISIBILITY
6512            bool operator==(const param_type& __x, const param_type& __y)
6513            {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
6514        friend _LIBCPP_INLINE_VISIBILITY
6515            bool operator!=(const param_type& __x, const param_type& __y)
6516            {return !(__x == __y);}
6517
6518    private:
6519        void __init();
6520
6521        friend class piecewise_linear_distribution;
6522
6523        template <class _CharT, class _Traits, class _RT>
6524        friend
6525        basic_ostream<_CharT, _Traits>&
6526        operator<<(basic_ostream<_CharT, _Traits>& __os,
6527                   const piecewise_linear_distribution<_RT>& __x);
6528
6529        template <class _CharT, class _Traits, class _RT>
6530        friend
6531        basic_istream<_CharT, _Traits>&
6532        operator>>(basic_istream<_CharT, _Traits>& __is,
6533                   piecewise_linear_distribution<_RT>& __x);
6534    };
6535
6536private:
6537    param_type __p_;
6538
6539public:
6540    // constructor and reset functions
6541    _LIBCPP_INLINE_VISIBILITY
6542    piecewise_linear_distribution() {}
6543    template<class _InputIteratorB, class _InputIteratorW>
6544        _LIBCPP_INLINE_VISIBILITY
6545        piecewise_linear_distribution(_InputIteratorB __fB,
6546                                      _InputIteratorB __lB,
6547                                      _InputIteratorW __fW)
6548        : __p_(__fB, __lB, __fW) {}
6549
6550#ifndef _LIBCPP_CXX03_LANG
6551    template<class _UnaryOperation>
6552        _LIBCPP_INLINE_VISIBILITY
6553        piecewise_linear_distribution(initializer_list<result_type> __bl,
6554                                      _UnaryOperation __fw)
6555        : __p_(__bl, __fw) {}
6556#endif  // _LIBCPP_CXX03_LANG
6557
6558    template<class _UnaryOperation>
6559        _LIBCPP_INLINE_VISIBILITY
6560        piecewise_linear_distribution(size_t __nw, result_type __xmin,
6561                                      result_type __xmax, _UnaryOperation __fw)
6562        : __p_(__nw, __xmin, __xmax, __fw) {}
6563
6564    _LIBCPP_INLINE_VISIBILITY
6565    explicit piecewise_linear_distribution(const param_type& __p)
6566        : __p_(__p) {}
6567
6568    _LIBCPP_INLINE_VISIBILITY
6569    void reset() {}
6570
6571    // generating functions
6572    template<class _URNG>
6573        _LIBCPP_INLINE_VISIBILITY
6574        result_type operator()(_URNG& __g)
6575        {return (*this)(__g, __p_);}
6576    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
6577
6578    // property functions
6579    _LIBCPP_INLINE_VISIBILITY
6580    vector<result_type> intervals() const {return __p_.intervals();}
6581    _LIBCPP_INLINE_VISIBILITY
6582    vector<result_type> densities() const {return __p_.densities();}
6583
6584    _LIBCPP_INLINE_VISIBILITY
6585    param_type param() const {return __p_;}
6586    _LIBCPP_INLINE_VISIBILITY
6587    void param(const param_type& __p) {__p_ = __p;}
6588
6589    _LIBCPP_INLINE_VISIBILITY
6590    result_type min() const {return __p_.__b_.front();}
6591    _LIBCPP_INLINE_VISIBILITY
6592    result_type max() const {return __p_.__b_.back();}
6593
6594    friend _LIBCPP_INLINE_VISIBILITY
6595        bool operator==(const piecewise_linear_distribution& __x,
6596                        const piecewise_linear_distribution& __y)
6597        {return __x.__p_ == __y.__p_;}
6598    friend _LIBCPP_INLINE_VISIBILITY
6599        bool operator!=(const piecewise_linear_distribution& __x,
6600                        const piecewise_linear_distribution& __y)
6601        {return !(__x == __y);}
6602
6603    template <class _CharT, class _Traits, class _RT>
6604    friend
6605    basic_ostream<_CharT, _Traits>&
6606    operator<<(basic_ostream<_CharT, _Traits>& __os,
6607               const piecewise_linear_distribution<_RT>& __x);
6608
6609    template <class _CharT, class _Traits, class _RT>
6610    friend
6611    basic_istream<_CharT, _Traits>&
6612    operator>>(basic_istream<_CharT, _Traits>& __is,
6613               piecewise_linear_distribution<_RT>& __x);
6614};
6615
6616template<class _RealType>
6617typename piecewise_linear_distribution<_RealType>::param_type &
6618piecewise_linear_distribution<_RealType>::param_type::operator=
6619                                                       (const param_type& __rhs)
6620{
6621//  These can throw
6622    __b_.reserve        (__rhs.__b_.size ());
6623    __densities_.reserve(__rhs.__densities_.size());
6624    __areas_.reserve    (__rhs.__areas_.size());
6625
6626//  These can not throw
6627    __b_         = __rhs.__b_;
6628    __densities_ = __rhs.__densities_;
6629    __areas_     =  __rhs.__areas_;
6630    return *this;
6631}
6632
6633
6634template<class _RealType>
6635void
6636piecewise_linear_distribution<_RealType>::param_type::__init()
6637{
6638    __areas_.assign(__densities_.size() - 1, result_type());
6639    result_type _Sp = 0;
6640    for (size_t __i = 0; __i < __areas_.size(); ++__i)
6641    {
6642        __areas_[__i] = (__densities_[__i+1] + __densities_[__i]) *
6643                        (__b_[__i+1] - __b_[__i]) * .5;
6644        _Sp += __areas_[__i];
6645    }
6646    for (size_t __i = __areas_.size(); __i > 1;)
6647    {
6648        --__i;
6649        __areas_[__i] = __areas_[__i-1] / _Sp;
6650    }
6651    __areas_[0] = 0;
6652    for (size_t __i = 1; __i < __areas_.size(); ++__i)
6653        __areas_[__i] += __areas_[__i-1];
6654    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6655        __densities_[__i] /= _Sp;
6656}
6657
6658template<class _RealType>
6659piecewise_linear_distribution<_RealType>::param_type::param_type()
6660    : __b_(2),
6661      __densities_(2, 1.0),
6662      __areas_(1, 0.0)
6663{
6664    __b_[1] = 1;
6665}
6666
6667template<class _RealType>
6668template<class _InputIteratorB, class _InputIteratorW>
6669piecewise_linear_distribution<_RealType>::param_type::param_type(
6670        _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
6671    : __b_(__fB, __lB)
6672{
6673    if (__b_.size() < 2)
6674    {
6675        __b_.resize(2);
6676        __b_[0] = 0;
6677        __b_[1] = 1;
6678        __densities_.assign(2, 1.0);
6679        __areas_.assign(1, 0.0);
6680    }
6681    else
6682    {
6683        __densities_.reserve(__b_.size());
6684        for (size_t __i = 0; __i < __b_.size(); ++__i, ++__fW)
6685            __densities_.push_back(*__fW);
6686        __init();
6687    }
6688}
6689
6690#ifndef _LIBCPP_CXX03_LANG
6691
6692template<class _RealType>
6693template<class _UnaryOperation>
6694piecewise_linear_distribution<_RealType>::param_type::param_type(
6695        initializer_list<result_type> __bl, _UnaryOperation __fw)
6696    : __b_(__bl.begin(), __bl.end())
6697{
6698    if (__b_.size() < 2)
6699    {
6700        __b_.resize(2);
6701        __b_[0] = 0;
6702        __b_[1] = 1;
6703        __densities_.assign(2, 1.0);
6704        __areas_.assign(1, 0.0);
6705    }
6706    else
6707    {
6708        __densities_.reserve(__b_.size());
6709        for (size_t __i = 0; __i < __b_.size(); ++__i)
6710            __densities_.push_back(__fw(__b_[__i]));
6711        __init();
6712    }
6713}
6714
6715#endif  // _LIBCPP_CXX03_LANG
6716
6717template<class _RealType>
6718template<class _UnaryOperation>
6719piecewise_linear_distribution<_RealType>::param_type::param_type(
6720        size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
6721    : __b_(__nw == 0 ? 2 : __nw + 1)
6722{
6723    size_t __n = __b_.size() - 1;
6724    result_type __d = (__xmax - __xmin) / __n;
6725    __densities_.reserve(__b_.size());
6726    for (size_t __i = 0; __i < __n; ++__i)
6727    {
6728        __b_[__i] = __xmin + __i * __d;
6729        __densities_.push_back(__fw(__b_[__i]));
6730    }
6731    __b_[__n] = __xmax;
6732    __densities_.push_back(__fw(__b_[__n]));
6733    __init();
6734}
6735
6736template<class _RealType>
6737template<class _URNG>
6738_RealType
6739piecewise_linear_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
6740{
6741    typedef uniform_real_distribution<result_type> _Gen;
6742    result_type __u = _Gen()(__g);
6743    ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
6744                                      __u) - __p.__areas_.begin() - 1;
6745    __u -= __p.__areas_[__k];
6746    const result_type __dk = __p.__densities_[__k];
6747    const result_type __dk1 = __p.__densities_[__k+1];
6748    const result_type __deltad = __dk1 - __dk;
6749    const result_type __bk = __p.__b_[__k];
6750    if (__deltad == 0)
6751        return __u / __dk + __bk;
6752    const result_type __bk1 = __p.__b_[__k+1];
6753    const result_type __deltab = __bk1 - __bk;
6754    return (__bk * __dk1 - __bk1 * __dk +
6755        _VSTD::sqrt(__deltab * (__deltab * __dk * __dk + 2 * __deltad * __u))) /
6756        __deltad;
6757}
6758
6759template <class _CharT, class _Traits, class _RT>
6760basic_ostream<_CharT, _Traits>&
6761operator<<(basic_ostream<_CharT, _Traits>& __os,
6762           const piecewise_linear_distribution<_RT>& __x)
6763{
6764    __save_flags<_CharT, _Traits> __lx(__os);
6765    typedef basic_ostream<_CharT, _Traits> _OStream;
6766    __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
6767               _OStream::scientific);
6768    _CharT __sp = __os.widen(' ');
6769    __os.fill(__sp);
6770    size_t __n = __x.__p_.__b_.size();
6771    __os << __n;
6772    for (size_t __i = 0; __i < __n; ++__i)
6773        __os << __sp << __x.__p_.__b_[__i];
6774    __n = __x.__p_.__densities_.size();
6775    __os << __sp << __n;
6776    for (size_t __i = 0; __i < __n; ++__i)
6777        __os << __sp << __x.__p_.__densities_[__i];
6778    __n = __x.__p_.__areas_.size();
6779    __os << __sp << __n;
6780    for (size_t __i = 0; __i < __n; ++__i)
6781        __os << __sp << __x.__p_.__areas_[__i];
6782    return __os;
6783}
6784
6785template <class _CharT, class _Traits, class _RT>
6786basic_istream<_CharT, _Traits>&
6787operator>>(basic_istream<_CharT, _Traits>& __is,
6788           piecewise_linear_distribution<_RT>& __x)
6789{
6790    typedef piecewise_linear_distribution<_RT> _Eng;
6791    typedef typename _Eng::result_type result_type;
6792    __save_flags<_CharT, _Traits> __lx(__is);
6793    typedef basic_istream<_CharT, _Traits> _Istream;
6794    __is.flags(_Istream::dec | _Istream::skipws);
6795    size_t __n;
6796    __is >> __n;
6797    vector<result_type> __b(__n);
6798    for (size_t __i = 0; __i < __n; ++__i)
6799        __is >> __b[__i];
6800    __is >> __n;
6801    vector<result_type> __densities(__n);
6802    for (size_t __i = 0; __i < __n; ++__i)
6803        __is >> __densities[__i];
6804    __is >> __n;
6805    vector<result_type> __areas(__n);
6806    for (size_t __i = 0; __i < __n; ++__i)
6807        __is >> __areas[__i];
6808    if (!__is.fail())
6809    {
6810        swap(__x.__p_.__b_, __b);
6811        swap(__x.__p_.__densities_, __densities);
6812        swap(__x.__p_.__areas_, __areas);
6813    }
6814    return __is;
6815}
6816
6817_LIBCPP_END_NAMESPACE_STD
6818
6819_LIBCPP_POP_MACROS
6820
6821#endif  // _LIBCPP_RANDOM
6822