xref: /freebsd-12.1/contrib/libc++/include/random (revision 2cab237b)
1// -*- C++ -*-
2//===--------------------------- random -----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_RANDOM
12#define _LIBCPP_RANDOM
13
14/*
15    random synopsis
16
17#include <initializer_list>
18
19namespace std
20{
21
22// Engines
23
24template <class UIntType, UIntType a, UIntType c, UIntType m>
25class linear_congruential_engine
26{
27public:
28    // types
29    typedef UIntType result_type;
30
31    // engine characteristics
32    static constexpr result_type multiplier = a;
33    static constexpr result_type increment = c;
34    static constexpr result_type modulus = m;
35    static constexpr result_type min() { return c == 0u ? 1u: 0u;}
36    static constexpr result_type max() { return m - 1u;}
37    static constexpr result_type default_seed = 1u;
38
39    // constructors and seeding functions
40    explicit linear_congruential_engine(result_type s = default_seed);
41    template<class Sseq> explicit linear_congruential_engine(Sseq& q);
42    void seed(result_type s = default_seed);
43    template<class Sseq> void seed(Sseq& q);
44
45    // generating functions
46    result_type operator()();
47    void discard(unsigned long long z);
48};
49
50template <class UIntType, UIntType a, UIntType c, UIntType m>
51bool
52operator==(const linear_congruential_engine<UIntType, a, c, m>& x,
53           const linear_congruential_engine<UIntType, a, c, m>& y);
54
55template <class UIntType, UIntType a, UIntType c, UIntType m>
56bool
57operator!=(const linear_congruential_engine<UIntType, a, c, m>& x,
58           const linear_congruential_engine<UIntType, a, c, m>& y);
59
60template <class charT, class traits,
61          class UIntType, UIntType a, UIntType c, UIntType m>
62basic_ostream<charT, traits>&
63operator<<(basic_ostream<charT, traits>& os,
64           const linear_congruential_engine<UIntType, a, c, m>& x);
65
66template <class charT, class traits,
67          class UIntType, UIntType a, UIntType c, UIntType m>
68basic_istream<charT, traits>&
69operator>>(basic_istream<charT, traits>& is,
70           linear_congruential_engine<UIntType, a, c, m>& x);
71
72template <class UIntType, size_t w, size_t n, size_t m, size_t r,
73          UIntType a, size_t u, UIntType d, size_t s,
74          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
75class mersenne_twister_engine
76{
77public:
78    // types
79    typedef UIntType result_type;
80
81    // engine characteristics
82    static constexpr size_t word_size = w;
83    static constexpr size_t state_size = n;
84    static constexpr size_t shift_size = m;
85    static constexpr size_t mask_bits = r;
86    static constexpr result_type xor_mask = a;
87    static constexpr size_t tempering_u = u;
88    static constexpr result_type tempering_d = d;
89    static constexpr size_t tempering_s = s;
90    static constexpr result_type tempering_b = b;
91    static constexpr size_t tempering_t = t;
92    static constexpr result_type tempering_c = c;
93    static constexpr size_t tempering_l = l;
94    static constexpr result_type initialization_multiplier = f;
95    static constexpr result_type min () { return 0; }
96    static constexpr result_type max() { return 2^w - 1; }
97    static constexpr result_type default_seed = 5489u;
98
99    // constructors and seeding functions
100    explicit mersenne_twister_engine(result_type value = default_seed);
101    template<class Sseq> explicit mersenne_twister_engine(Sseq& q);
102    void seed(result_type value = default_seed);
103    template<class Sseq> void seed(Sseq& q);
104
105    // generating functions
106    result_type operator()();
107    void discard(unsigned long long z);
108};
109
110template <class UIntType, size_t w, size_t n, size_t m, size_t r,
111          UIntType a, size_t u, UIntType d, size_t s,
112          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
113bool
114operator==(
115    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x,
116    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& y);
117
118template <class UIntType, size_t w, size_t n, size_t m, size_t r,
119          UIntType a, size_t u, UIntType d, size_t s,
120          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
121bool
122operator!=(
123    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x,
124    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& y);
125
126template <class charT, class traits,
127          class UIntType, size_t w, size_t n, size_t m, size_t r,
128          UIntType a, size_t u, UIntType d, size_t s,
129          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
130basic_ostream<charT, traits>&
131operator<<(basic_ostream<charT, traits>& os,
132           const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x);
133
134template <class charT, class traits,
135          class UIntType, size_t w, size_t n, size_t m, size_t r,
136          UIntType a, size_t u, UIntType d, size_t s,
137          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
138basic_istream<charT, traits>&
139operator>>(basic_istream<charT, traits>& is,
140           mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x);
141
142template<class UIntType, size_t w, size_t s, size_t r>
143class subtract_with_carry_engine
144{
145public:
146    // types
147    typedef UIntType result_type;
148
149    // engine characteristics
150    static constexpr size_t word_size = w;
151    static constexpr size_t short_lag = s;
152    static constexpr size_t long_lag = r;
153    static constexpr result_type min() { return 0; }
154    static constexpr result_type max() { return m-1; }
155    static constexpr result_type default_seed = 19780503u;
156
157    // constructors and seeding functions
158    explicit subtract_with_carry_engine(result_type value = default_seed);
159    template<class Sseq> explicit subtract_with_carry_engine(Sseq& q);
160    void seed(result_type value = default_seed);
161    template<class Sseq> void seed(Sseq& q);
162
163    // generating functions
164    result_type operator()();
165    void discard(unsigned long long z);
166};
167
168template<class UIntType, size_t w, size_t s, size_t r>
169bool
170operator==(
171    const subtract_with_carry_engine<UIntType, w, s, r>& x,
172    const subtract_with_carry_engine<UIntType, w, s, r>& y);
173
174template<class UIntType, size_t w, size_t s, size_t r>
175bool
176operator!=(
177    const subtract_with_carry_engine<UIntType, w, s, r>& x,
178    const subtract_with_carry_engine<UIntType, w, s, r>& y);
179
180template <class charT, class traits,
181          class UIntType, size_t w, size_t s, size_t r>
182basic_ostream<charT, traits>&
183operator<<(basic_ostream<charT, traits>& os,
184           const subtract_with_carry_engine<UIntType, w, s, r>& x);
185
186template <class charT, class traits,
187          class UIntType, size_t w, size_t s, size_t r>
188basic_istream<charT, traits>&
189operator>>(basic_istream<charT, traits>& is,
190           subtract_with_carry_engine<UIntType, w, s, r>& x);
191
192template<class Engine, size_t p, size_t r>
193class discard_block_engine
194{
195public:
196    // types
197    typedef typename Engine::result_type result_type;
198
199    // engine characteristics
200    static constexpr size_t block_size = p;
201    static constexpr size_t used_block = r;
202    static constexpr result_type min() { return Engine::min(); }
203    static constexpr result_type max() { return Engine::max(); }
204
205    // constructors and seeding functions
206    discard_block_engine();
207    explicit discard_block_engine(const Engine& e);
208    explicit discard_block_engine(Engine&& e);
209    explicit discard_block_engine(result_type s);
210    template<class Sseq> explicit discard_block_engine(Sseq& q);
211    void seed();
212    void seed(result_type s);
213    template<class Sseq> void seed(Sseq& q);
214
215    // generating functions
216    result_type operator()();
217    void discard(unsigned long long z);
218
219    // property functions
220    const Engine& base() const noexcept;
221};
222
223template<class Engine, size_t p, size_t r>
224bool
225operator==(
226    const discard_block_engine<Engine, p, r>& x,
227    const discard_block_engine<Engine, p, r>& y);
228
229template<class Engine, size_t p, size_t r>
230bool
231operator!=(
232    const discard_block_engine<Engine, p, r>& x,
233    const discard_block_engine<Engine, p, r>& y);
234
235template <class charT, class traits,
236          class Engine, size_t p, size_t r>
237basic_ostream<charT, traits>&
238operator<<(basic_ostream<charT, traits>& os,
239           const discard_block_engine<Engine, p, r>& x);
240
241template <class charT, class traits,
242          class Engine, size_t p, size_t r>
243basic_istream<charT, traits>&
244operator>>(basic_istream<charT, traits>& is,
245           discard_block_engine<Engine, p, r>& x);
246
247template<class Engine, size_t w, class UIntType>
248class independent_bits_engine
249{
250public:
251    // types
252    typedef UIntType result_type;
253
254    // engine characteristics
255    static constexpr result_type min() { return 0; }
256    static constexpr result_type max() { return 2^w - 1; }
257
258    // constructors and seeding functions
259    independent_bits_engine();
260    explicit independent_bits_engine(const Engine& e);
261    explicit independent_bits_engine(Engine&& e);
262    explicit independent_bits_engine(result_type s);
263    template<class Sseq> explicit independent_bits_engine(Sseq& q);
264    void seed();
265    void seed(result_type s);
266    template<class Sseq> void seed(Sseq& q);
267
268    // generating functions
269    result_type operator()(); void discard(unsigned long long z);
270
271    // property functions
272    const Engine& base() const noexcept;
273};
274
275template<class Engine, size_t w, class UIntType>
276bool
277operator==(
278    const independent_bits_engine<Engine, w, UIntType>& x,
279    const independent_bits_engine<Engine, w, UIntType>& y);
280
281template<class Engine, size_t w, class UIntType>
282bool
283operator!=(
284    const independent_bits_engine<Engine, w, UIntType>& x,
285    const independent_bits_engine<Engine, w, UIntType>& y);
286
287template <class charT, class traits,
288          class Engine, size_t w, class UIntType>
289basic_ostream<charT, traits>&
290operator<<(basic_ostream<charT, traits>& os,
291           const independent_bits_engine<Engine, w, UIntType>& x);
292
293template <class charT, class traits,
294          class Engine, size_t w, class UIntType>
295basic_istream<charT, traits>&
296operator>>(basic_istream<charT, traits>& is,
297           independent_bits_engine<Engine, w, UIntType>& x);
298
299template<class Engine, size_t k>
300class shuffle_order_engine
301{
302public:
303    // types
304    typedef typename Engine::result_type result_type;
305
306    // engine characteristics
307    static constexpr size_t table_size = k;
308    static constexpr result_type min() { return Engine::min; }
309    static constexpr result_type max() { return Engine::max; }
310
311    // constructors and seeding functions
312    shuffle_order_engine();
313    explicit shuffle_order_engine(const Engine& e);
314    explicit shuffle_order_engine(Engine&& e);
315    explicit shuffle_order_engine(result_type s);
316    template<class Sseq> explicit shuffle_order_engine(Sseq& q);
317    void seed();
318    void seed(result_type s);
319    template<class Sseq> void seed(Sseq& q);
320
321    // generating functions
322    result_type operator()();
323    void discard(unsigned long long z);
324
325    // property functions
326    const Engine& base() const noexcept;
327};
328
329template<class Engine, size_t k>
330bool
331operator==(
332    const shuffle_order_engine<Engine, k>& x,
333    const shuffle_order_engine<Engine, k>& y);
334
335template<class Engine, size_t k>
336bool
337operator!=(
338    const shuffle_order_engine<Engine, k>& x,
339    const shuffle_order_engine<Engine, k>& y);
340
341template <class charT, class traits,
342          class Engine, size_t k>
343basic_ostream<charT, traits>&
344operator<<(basic_ostream<charT, traits>& os,
345           const shuffle_order_engine<Engine, k>& x);
346
347template <class charT, class traits,
348          class Engine, size_t k>
349basic_istream<charT, traits>&
350operator>>(basic_istream<charT, traits>& is,
351           shuffle_order_engine<Engine, k>& x);
352
353typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
354                                                                   minstd_rand0;
355typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
356                                                                    minstd_rand;
357typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
358                                0x9908b0df,
359                                11, 0xffffffff,
360                                7,  0x9d2c5680,
361                                15, 0xefc60000,
362                                18, 1812433253>                         mt19937;
363typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
364                                0xb5026f5aa96619e9,
365                                29, 0x5555555555555555,
366                                17, 0x71d67fffeda60000,
367                                37, 0xfff7eee000000000,
368                                43, 6364136223846793005>             mt19937_64;
369typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
370typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
371typedef discard_block_engine<ranlux24_base, 223, 23>                   ranlux24;
372typedef discard_block_engine<ranlux48_base, 389, 11>                   ranlux48;
373typedef shuffle_order_engine<minstd_rand0, 256>                         knuth_b;
374typedef minstd_rand                                       default_random_engine;
375
376// Generators
377
378class random_device
379{
380public:
381    // types
382    typedef unsigned int result_type;
383
384    // generator characteristics
385    static constexpr result_type min() { return numeric_limits<result_type>::min(); }
386    static constexpr result_type max() { return numeric_limits<result_type>::max(); }
387
388    // constructors
389    explicit random_device(const string& token = "/dev/urandom");
390
391    // generating functions
392    result_type operator()();
393
394    // property functions
395    double entropy() const noexcept;
396
397    // no copy functions
398    random_device(const random_device& ) = delete;
399    void operator=(const random_device& ) = delete;
400};
401
402// Utilities
403
404class seed_seq
405{
406public:
407    // types
408    typedef uint_least32_t result_type;
409
410    // constructors
411    seed_seq();
412    template<class T>
413        seed_seq(initializer_list<T> il);
414    template<class InputIterator>
415        seed_seq(InputIterator begin, InputIterator end);
416
417    // generating functions
418    template<class RandomAccessIterator>
419        void generate(RandomAccessIterator begin, RandomAccessIterator end);
420
421    // property functions
422    size_t size() const;
423    template<class OutputIterator>
424        void param(OutputIterator dest) const;
425
426    // no copy functions
427    seed_seq(const seed_seq&) = delete;
428    void operator=(const seed_seq& ) = delete;
429};
430
431template<class RealType, size_t bits, class URNG>
432    RealType generate_canonical(URNG& g);
433
434// Distributions
435
436template<class IntType = int>
437class uniform_int_distribution
438{
439public:
440    // types
441    typedef IntType result_type;
442
443    class param_type
444    {
445    public:
446        typedef uniform_int_distribution distribution_type;
447
448        explicit param_type(IntType a = 0,
449                                    IntType b = numeric_limits<IntType>::max());
450
451        result_type a() const;
452        result_type b() const;
453
454        friend bool operator==(const param_type& x, const param_type& y);
455        friend bool operator!=(const param_type& x, const param_type& y);
456    };
457
458    // constructors and reset functions
459    explicit uniform_int_distribution(IntType a = 0,
460                                    IntType b = numeric_limits<IntType>::max());
461    explicit uniform_int_distribution(const param_type& parm);
462    void reset();
463
464    // generating functions
465    template<class URNG> result_type operator()(URNG& g);
466    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
467
468    // property functions
469    result_type a() const;
470    result_type b() const;
471
472    param_type param() const;
473    void param(const param_type& parm);
474
475    result_type min() const;
476    result_type max() const;
477
478    friend bool operator==(const uniform_int_distribution& x,
479                           const uniform_int_distribution& y);
480    friend bool operator!=(const uniform_int_distribution& x,
481                           const uniform_int_distribution& y);
482
483    template <class charT, class traits>
484    friend
485    basic_ostream<charT, traits>&
486    operator<<(basic_ostream<charT, traits>& os,
487               const uniform_int_distribution& x);
488
489    template <class charT, class traits>
490    friend
491    basic_istream<charT, traits>&
492    operator>>(basic_istream<charT, traits>& is,
493               uniform_int_distribution& x);
494};
495
496template<class RealType = double>
497class uniform_real_distribution
498{
499public:
500    // types
501    typedef RealType result_type;
502
503    class param_type
504    {
505    public:
506        typedef uniform_real_distribution distribution_type;
507
508        explicit param_type(RealType a = 0,
509                            RealType b = 1);
510
511        result_type a() const;
512        result_type b() const;
513
514        friend bool operator==(const param_type& x, const param_type& y);
515        friend bool operator!=(const param_type& x, const param_type& y);
516    };
517
518    // constructors and reset functions
519    explicit uniform_real_distribution(RealType a = 0.0, RealType b = 1.0);
520    explicit uniform_real_distribution(const param_type& parm);
521    void reset();
522
523    // generating functions
524    template<class URNG> result_type operator()(URNG& g);
525    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
526
527    // property functions
528    result_type a() const;
529    result_type b() const;
530
531    param_type param() const;
532    void param(const param_type& parm);
533
534    result_type min() const;
535    result_type max() const;
536
537    friend bool operator==(const uniform_real_distribution& x,
538                           const uniform_real_distribution& y);
539    friend bool operator!=(const uniform_real_distribution& x,
540                           const uniform_real_distribution& y);
541
542    template <class charT, class traits>
543    friend
544    basic_ostream<charT, traits>&
545    operator<<(basic_ostream<charT, traits>& os,
546               const uniform_real_distribution& x);
547
548    template <class charT, class traits>
549    friend
550    basic_istream<charT, traits>&
551    operator>>(basic_istream<charT, traits>& is,
552               uniform_real_distribution& x);
553};
554
555class bernoulli_distribution
556{
557public:
558    // types
559    typedef bool result_type;
560
561    class param_type
562    {
563    public:
564        typedef bernoulli_distribution distribution_type;
565
566        explicit param_type(double p = 0.5);
567
568        double p() const;
569
570        friend bool operator==(const param_type& x, const param_type& y);
571        friend bool operator!=(const param_type& x, const param_type& y);
572    };
573
574    // constructors and reset functions
575    explicit bernoulli_distribution(double p = 0.5);
576    explicit bernoulli_distribution(const param_type& parm);
577    void reset();
578
579    // generating functions
580    template<class URNG> result_type operator()(URNG& g);
581    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
582
583    // property functions
584    double p() const;
585
586    param_type param() const;
587    void param(const param_type& parm);
588
589    result_type min() const;
590    result_type max() const;
591
592    friend bool operator==(const bernoulli_distribution& x,
593                           const bernoulli_distribution& y);
594    friend bool operator!=(const bernoulli_distribution& x,
595                           const bernoulli_distribution& y);
596
597    template <class charT, class traits>
598    friend
599    basic_ostream<charT, traits>&
600    operator<<(basic_ostream<charT, traits>& os,
601               const bernoulli_distribution& x);
602
603    template <class charT, class traits>
604    friend
605    basic_istream<charT, traits>&
606    operator>>(basic_istream<charT, traits>& is,
607               bernoulli_distribution& x);
608};
609
610template<class IntType = int>
611class binomial_distribution
612{
613public:
614    // types
615    typedef IntType result_type;
616
617    class param_type
618    {
619    public:
620        typedef binomial_distribution distribution_type;
621
622        explicit param_type(IntType t = 1, double p = 0.5);
623
624        IntType t() const;
625        double p() const;
626
627        friend bool operator==(const param_type& x, const param_type& y);
628        friend bool operator!=(const param_type& x, const param_type& y);
629    };
630
631    // constructors and reset functions
632    explicit binomial_distribution(IntType t = 1, double p = 0.5);
633    explicit binomial_distribution(const param_type& parm);
634    void reset();
635
636    // generating functions
637    template<class URNG> result_type operator()(URNG& g);
638    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
639
640    // property functions
641    IntType t() const;
642    double p() const;
643
644    param_type param() const;
645    void param(const param_type& parm);
646
647    result_type min() const;
648    result_type max() const;
649
650    friend bool operator==(const binomial_distribution& x,
651                           const binomial_distribution& y);
652    friend bool operator!=(const binomial_distribution& x,
653                           const binomial_distribution& y);
654
655    template <class charT, class traits>
656    friend
657    basic_ostream<charT, traits>&
658    operator<<(basic_ostream<charT, traits>& os,
659               const binomial_distribution& x);
660
661    template <class charT, class traits>
662    friend
663    basic_istream<charT, traits>&
664    operator>>(basic_istream<charT, traits>& is,
665               binomial_distribution& x);
666};
667
668template<class IntType = int>
669class geometric_distribution
670{
671public:
672    // types
673    typedef IntType result_type;
674
675    class param_type
676    {
677    public:
678        typedef geometric_distribution distribution_type;
679
680        explicit param_type(double p = 0.5);
681
682        double p() const;
683
684        friend bool operator==(const param_type& x, const param_type& y);
685        friend bool operator!=(const param_type& x, const param_type& y);
686    };
687
688    // constructors and reset functions
689    explicit geometric_distribution(double p = 0.5);
690    explicit geometric_distribution(const param_type& parm);
691    void reset();
692
693    // generating functions
694    template<class URNG> result_type operator()(URNG& g);
695    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
696
697    // property functions
698    double p() const;
699
700    param_type param() const;
701    void param(const param_type& parm);
702
703    result_type min() const;
704    result_type max() const;
705
706    friend bool operator==(const geometric_distribution& x,
707                           const geometric_distribution& y);
708    friend bool operator!=(const geometric_distribution& x,
709                           const geometric_distribution& y);
710
711    template <class charT, class traits>
712    friend
713    basic_ostream<charT, traits>&
714    operator<<(basic_ostream<charT, traits>& os,
715               const geometric_distribution& x);
716
717    template <class charT, class traits>
718    friend
719    basic_istream<charT, traits>&
720    operator>>(basic_istream<charT, traits>& is,
721               geometric_distribution& x);
722};
723
724template<class IntType = int>
725class negative_binomial_distribution
726{
727public:
728    // types
729    typedef IntType result_type;
730
731    class param_type
732    {
733    public:
734        typedef negative_binomial_distribution distribution_type;
735
736        explicit param_type(result_type k = 1, double p = 0.5);
737
738        result_type k() const;
739        double p() const;
740
741        friend bool operator==(const param_type& x, const param_type& y);
742        friend bool operator!=(const param_type& x, const param_type& y);
743    };
744
745    // constructor and reset functions
746    explicit negative_binomial_distribution(result_type k = 1, double p = 0.5);
747    explicit negative_binomial_distribution(const param_type& parm);
748    void reset();
749
750    // generating functions
751    template<class URNG> result_type operator()(URNG& g);
752    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
753
754    // property functions
755    result_type k() const;
756    double p() const;
757
758    param_type param() const;
759    void param(const param_type& parm);
760
761    result_type min() const;
762    result_type max() const;
763
764    friend bool operator==(const negative_binomial_distribution& x,
765                           const negative_binomial_distribution& y);
766    friend bool operator!=(const negative_binomial_distribution& x,
767                           const negative_binomial_distribution& y);
768
769    template <class charT, class traits>
770    friend
771    basic_ostream<charT, traits>&
772    operator<<(basic_ostream<charT, traits>& os,
773               const negative_binomial_distribution& x);
774
775    template <class charT, class traits>
776    friend
777    basic_istream<charT, traits>&
778    operator>>(basic_istream<charT, traits>& is,
779               negative_binomial_distribution& x);
780};
781
782template<class IntType = int>
783class poisson_distribution
784{
785public:
786    // types
787    typedef IntType result_type;
788
789    class param_type
790    {
791    public:
792        typedef poisson_distribution distribution_type;
793
794        explicit param_type(double mean = 1.0);
795
796        double mean() const;
797
798        friend bool operator==(const param_type& x, const param_type& y);
799        friend bool operator!=(const param_type& x, const param_type& y);
800    };
801
802    // constructors and reset functions
803    explicit poisson_distribution(double mean = 1.0);
804    explicit poisson_distribution(const param_type& parm);
805    void reset();
806
807    // generating functions
808    template<class URNG> result_type operator()(URNG& g);
809    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
810
811    // property functions
812    double mean() const;
813
814    param_type param() const;
815    void param(const param_type& parm);
816
817    result_type min() const;
818    result_type max() const;
819
820    friend bool operator==(const poisson_distribution& x,
821                           const poisson_distribution& y);
822    friend bool operator!=(const poisson_distribution& x,
823                           const poisson_distribution& y);
824
825    template <class charT, class traits>
826    friend
827    basic_ostream<charT, traits>&
828    operator<<(basic_ostream<charT, traits>& os,
829               const poisson_distribution& x);
830
831    template <class charT, class traits>
832    friend
833    basic_istream<charT, traits>&
834    operator>>(basic_istream<charT, traits>& is,
835               poisson_distribution& x);
836};
837
838template<class RealType = double>
839class exponential_distribution
840{
841public:
842    // types
843    typedef RealType result_type;
844
845    class param_type
846    {
847    public:
848        typedef exponential_distribution distribution_type;
849
850        explicit param_type(result_type lambda = 1.0);
851
852        result_type lambda() const;
853
854        friend bool operator==(const param_type& x, const param_type& y);
855        friend bool operator!=(const param_type& x, const param_type& y);
856    };
857
858    // constructors and reset functions
859    explicit exponential_distribution(result_type lambda = 1.0);
860    explicit exponential_distribution(const param_type& parm);
861    void reset();
862
863    // generating functions
864    template<class URNG> result_type operator()(URNG& g);
865    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
866
867    // property functions
868    result_type lambda() const;
869
870    param_type param() const;
871    void param(const param_type& parm);
872
873    result_type min() const;
874    result_type max() const;
875
876    friend bool operator==(const exponential_distribution& x,
877                           const exponential_distribution& y);
878    friend bool operator!=(const exponential_distribution& x,
879                           const exponential_distribution& y);
880
881    template <class charT, class traits>
882    friend
883    basic_ostream<charT, traits>&
884    operator<<(basic_ostream<charT, traits>& os,
885               const exponential_distribution& x);
886
887    template <class charT, class traits>
888    friend
889    basic_istream<charT, traits>&
890    operator>>(basic_istream<charT, traits>& is,
891               exponential_distribution& x);
892};
893
894template<class RealType = double>
895class gamma_distribution
896{
897public:
898    // types
899    typedef RealType result_type;
900
901    class param_type
902    {
903    public:
904        typedef gamma_distribution distribution_type;
905
906        explicit param_type(result_type alpha = 1, result_type beta = 1);
907
908        result_type alpha() const;
909        result_type beta() const;
910
911        friend bool operator==(const param_type& x, const param_type& y);
912        friend bool operator!=(const param_type& x, const param_type& y);
913    };
914
915    // constructors and reset functions
916    explicit gamma_distribution(result_type alpha = 1, result_type beta = 1);
917    explicit gamma_distribution(const param_type& parm);
918    void reset();
919
920    // generating functions
921    template<class URNG> result_type operator()(URNG& g);
922    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
923
924    // property functions
925    result_type alpha() const;
926    result_type beta() const;
927
928    param_type param() const;
929    void param(const param_type& parm);
930
931    result_type min() const;
932    result_type max() const;
933
934    friend bool operator==(const gamma_distribution& x,
935                           const gamma_distribution& y);
936    friend bool operator!=(const gamma_distribution& x,
937                           const gamma_distribution& y);
938
939    template <class charT, class traits>
940    friend
941    basic_ostream<charT, traits>&
942    operator<<(basic_ostream<charT, traits>& os,
943               const gamma_distribution& x);
944
945    template <class charT, class traits>
946    friend
947    basic_istream<charT, traits>&
948    operator>>(basic_istream<charT, traits>& is,
949               gamma_distribution& x);
950};
951
952template<class RealType = double>
953class weibull_distribution
954{
955public:
956    // types
957    typedef RealType result_type;
958
959    class param_type
960    {
961    public:
962        typedef weibull_distribution distribution_type;
963
964        explicit param_type(result_type alpha = 1, result_type beta = 1);
965
966        result_type a() const;
967        result_type b() const;
968
969        friend bool operator==(const param_type& x, const param_type& y);
970        friend bool operator!=(const param_type& x, const param_type& y);
971    };
972
973    // constructor and reset functions
974    explicit weibull_distribution(result_type a = 1, result_type b = 1);
975    explicit weibull_distribution(const param_type& parm);
976    void reset();
977
978    // generating functions
979    template<class URNG> result_type operator()(URNG& g);
980    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
981
982    // property functions
983    result_type a() const;
984    result_type b() const;
985
986    param_type param() const;
987    void param(const param_type& parm);
988
989    result_type min() const;
990    result_type max() const;
991
992    friend bool operator==(const weibull_distribution& x,
993                           const weibull_distribution& y);
994    friend bool operator!=(const weibull_distribution& x,
995                           const weibull_distribution& y);
996
997    template <class charT, class traits>
998    friend
999    basic_ostream<charT, traits>&
1000    operator<<(basic_ostream<charT, traits>& os,
1001               const weibull_distribution& x);
1002
1003    template <class charT, class traits>
1004    friend
1005    basic_istream<charT, traits>&
1006    operator>>(basic_istream<charT, traits>& is,
1007               weibull_distribution& x);
1008};
1009
1010template<class RealType = double>
1011class extreme_value_distribution
1012{
1013public:
1014    // types
1015    typedef RealType result_type;
1016
1017    class param_type
1018    {
1019    public:
1020        typedef extreme_value_distribution distribution_type;
1021
1022        explicit param_type(result_type a = 0, result_type b = 1);
1023
1024        result_type a() const;
1025        result_type b() const;
1026
1027        friend bool operator==(const param_type& x, const param_type& y);
1028        friend bool operator!=(const param_type& x, const param_type& y);
1029    };
1030
1031    // constructor and reset functions
1032    explicit extreme_value_distribution(result_type a = 0, result_type b = 1);
1033    explicit extreme_value_distribution(const param_type& parm);
1034    void reset();
1035
1036    // generating functions
1037    template<class URNG> result_type operator()(URNG& g);
1038    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1039
1040    // property functions
1041    result_type a() const;
1042    result_type b() const;
1043
1044    param_type param() const;
1045    void param(const param_type& parm);
1046
1047    result_type min() const;
1048    result_type max() const;
1049
1050    friend bool operator==(const extreme_value_distribution& x,
1051                           const extreme_value_distribution& y);
1052    friend bool operator!=(const extreme_value_distribution& x,
1053                           const extreme_value_distribution& y);
1054
1055    template <class charT, class traits>
1056    friend
1057    basic_ostream<charT, traits>&
1058    operator<<(basic_ostream<charT, traits>& os,
1059               const extreme_value_distribution& x);
1060
1061    template <class charT, class traits>
1062    friend
1063    basic_istream<charT, traits>&
1064    operator>>(basic_istream<charT, traits>& is,
1065               extreme_value_distribution& x);
1066};
1067
1068template<class RealType = double>
1069class normal_distribution
1070{
1071public:
1072    // types
1073    typedef RealType result_type;
1074
1075    class param_type
1076    {
1077    public:
1078        typedef normal_distribution distribution_type;
1079
1080        explicit param_type(result_type mean = 0, result_type stddev = 1);
1081
1082        result_type mean() const;
1083        result_type stddev() const;
1084
1085        friend bool operator==(const param_type& x, const param_type& y);
1086        friend bool operator!=(const param_type& x, const param_type& y);
1087    };
1088
1089    // constructors and reset functions
1090    explicit normal_distribution(result_type mean = 0, result_type stddev = 1);
1091    explicit normal_distribution(const param_type& parm);
1092    void reset();
1093
1094    // generating functions
1095    template<class URNG> result_type operator()(URNG& g);
1096    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1097
1098    // property functions
1099    result_type mean() const;
1100    result_type stddev() const;
1101
1102    param_type param() const;
1103    void param(const param_type& parm);
1104
1105    result_type min() const;
1106    result_type max() const;
1107
1108    friend bool operator==(const normal_distribution& x,
1109                           const normal_distribution& y);
1110    friend bool operator!=(const normal_distribution& x,
1111                           const normal_distribution& y);
1112
1113    template <class charT, class traits>
1114    friend
1115    basic_ostream<charT, traits>&
1116    operator<<(basic_ostream<charT, traits>& os,
1117               const normal_distribution& x);
1118
1119    template <class charT, class traits>
1120    friend
1121    basic_istream<charT, traits>&
1122    operator>>(basic_istream<charT, traits>& is,
1123               normal_distribution& x);
1124};
1125
1126template<class RealType = double>
1127class lognormal_distribution
1128{
1129public:
1130    // types
1131    typedef RealType result_type;
1132
1133    class param_type
1134    {
1135    public:
1136        typedef lognormal_distribution distribution_type;
1137
1138        explicit param_type(result_type m = 0, result_type s = 1);
1139
1140        result_type m() const;
1141        result_type s() const;
1142
1143        friend bool operator==(const param_type& x, const param_type& y);
1144        friend bool operator!=(const param_type& x, const param_type& y);
1145    };
1146
1147    // constructor and reset functions
1148    explicit lognormal_distribution(result_type m = 0, result_type s = 1);
1149    explicit lognormal_distribution(const param_type& parm);
1150    void reset();
1151
1152    // generating functions
1153    template<class URNG> result_type operator()(URNG& g);
1154    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1155
1156    // property functions
1157    result_type m() const;
1158    result_type s() const;
1159
1160    param_type param() const;
1161    void param(const param_type& parm);
1162
1163    result_type min() const;
1164    result_type max() const;
1165
1166    friend bool operator==(const lognormal_distribution& x,
1167                           const lognormal_distribution& y);
1168    friend bool operator!=(const lognormal_distribution& x,
1169                           const lognormal_distribution& y);
1170
1171    template <class charT, class traits>
1172    friend
1173    basic_ostream<charT, traits>&
1174    operator<<(basic_ostream<charT, traits>& os,
1175               const lognormal_distribution& x);
1176
1177    template <class charT, class traits>
1178    friend
1179    basic_istream<charT, traits>&
1180    operator>>(basic_istream<charT, traits>& is,
1181               lognormal_distribution& x);
1182};
1183
1184template<class RealType = double>
1185class chi_squared_distribution
1186{
1187public:
1188    // types
1189    typedef RealType result_type;
1190
1191    class param_type
1192    {
1193    public:
1194        typedef chi_squared_distribution distribution_type;
1195
1196        explicit param_type(result_type n = 1);
1197
1198        result_type n() const;
1199
1200        friend bool operator==(const param_type& x, const param_type& y);
1201        friend bool operator!=(const param_type& x, const param_type& y);
1202    };
1203
1204    // constructor and reset functions
1205    explicit chi_squared_distribution(result_type n = 1);
1206    explicit chi_squared_distribution(const param_type& parm);
1207    void reset();
1208
1209    // generating functions
1210    template<class URNG> result_type operator()(URNG& g);
1211    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1212
1213    // property functions
1214    result_type n() const;
1215
1216    param_type param() const;
1217    void param(const param_type& parm);
1218
1219    result_type min() const;
1220    result_type max() const;
1221
1222    friend bool operator==(const chi_squared_distribution& x,
1223                           const chi_squared_distribution& y);
1224    friend bool operator!=(const chi_squared_distribution& x,
1225                           const chi_squared_distribution& y);
1226
1227    template <class charT, class traits>
1228    friend
1229    basic_ostream<charT, traits>&
1230    operator<<(basic_ostream<charT, traits>& os,
1231               const chi_squared_distribution& x);
1232
1233    template <class charT, class traits>
1234    friend
1235    basic_istream<charT, traits>&
1236    operator>>(basic_istream<charT, traits>& is,
1237               chi_squared_distribution& x);
1238};
1239
1240template<class RealType = double>
1241class cauchy_distribution
1242{
1243public:
1244    // types
1245    typedef RealType result_type;
1246
1247    class param_type
1248    {
1249    public:
1250        typedef cauchy_distribution distribution_type;
1251
1252        explicit param_type(result_type a = 0, result_type b = 1);
1253
1254        result_type a() const;
1255        result_type b() const;
1256
1257        friend bool operator==(const param_type& x, const param_type& y);
1258        friend bool operator!=(const param_type& x, const param_type& y);
1259    };
1260
1261    // constructor and reset functions
1262    explicit cauchy_distribution(result_type a = 0, result_type b = 1);
1263    explicit cauchy_distribution(const param_type& parm);
1264    void reset();
1265
1266    // generating functions
1267    template<class URNG> result_type operator()(URNG& g);
1268    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1269
1270    // property functions
1271    result_type a() const;
1272    result_type b() const;
1273
1274    param_type param() const;
1275    void param(const param_type& parm);
1276
1277    result_type min() const;
1278    result_type max() const;
1279
1280    friend bool operator==(const cauchy_distribution& x,
1281                           const cauchy_distribution& y);
1282    friend bool operator!=(const cauchy_distribution& x,
1283                           const cauchy_distribution& y);
1284
1285    template <class charT, class traits>
1286    friend
1287    basic_ostream<charT, traits>&
1288    operator<<(basic_ostream<charT, traits>& os,
1289               const cauchy_distribution& x);
1290
1291    template <class charT, class traits>
1292    friend
1293    basic_istream<charT, traits>&
1294    operator>>(basic_istream<charT, traits>& is,
1295               cauchy_distribution& x);
1296};
1297
1298template<class RealType = double>
1299class fisher_f_distribution
1300{
1301public:
1302    // types
1303    typedef RealType result_type;
1304
1305    class param_type
1306    {
1307    public:
1308        typedef fisher_f_distribution distribution_type;
1309
1310        explicit param_type(result_type m = 1, result_type n = 1);
1311
1312        result_type m() const;
1313        result_type n() const;
1314
1315        friend bool operator==(const param_type& x, const param_type& y);
1316        friend bool operator!=(const param_type& x, const param_type& y);
1317    };
1318
1319    // constructor and reset functions
1320    explicit fisher_f_distribution(result_type m = 1, result_type n = 1);
1321    explicit fisher_f_distribution(const param_type& parm);
1322    void reset();
1323
1324    // generating functions
1325    template<class URNG> result_type operator()(URNG& g);
1326    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1327
1328    // property functions
1329    result_type m() const;
1330    result_type n() const;
1331
1332    param_type param() const;
1333    void param(const param_type& parm);
1334
1335    result_type min() const;
1336    result_type max() const;
1337
1338    friend bool operator==(const fisher_f_distribution& x,
1339                           const fisher_f_distribution& y);
1340    friend bool operator!=(const fisher_f_distribution& x,
1341                           const fisher_f_distribution& y);
1342
1343    template <class charT, class traits>
1344    friend
1345    basic_ostream<charT, traits>&
1346    operator<<(basic_ostream<charT, traits>& os,
1347               const fisher_f_distribution& x);
1348
1349    template <class charT, class traits>
1350    friend
1351    basic_istream<charT, traits>&
1352    operator>>(basic_istream<charT, traits>& is,
1353               fisher_f_distribution& x);
1354};
1355
1356template<class RealType = double>
1357class student_t_distribution
1358{
1359public:
1360    // types
1361    typedef RealType result_type;
1362
1363    class param_type
1364    {
1365    public:
1366        typedef student_t_distribution distribution_type;
1367
1368        explicit param_type(result_type n = 1);
1369
1370        result_type n() const;
1371
1372        friend bool operator==(const param_type& x, const param_type& y);
1373        friend bool operator!=(const param_type& x, const param_type& y);
1374    };
1375
1376    // constructor and reset functions
1377    explicit student_t_distribution(result_type n = 1);
1378    explicit student_t_distribution(const param_type& parm);
1379    void reset();
1380
1381    // generating functions
1382    template<class URNG> result_type operator()(URNG& g);
1383    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1384
1385    // property functions
1386    result_type n() const;
1387
1388    param_type param() const;
1389    void param(const param_type& parm);
1390
1391    result_type min() const;
1392    result_type max() const;
1393
1394    friend bool operator==(const student_t_distribution& x,
1395                           const student_t_distribution& y);
1396    friend bool operator!=(const student_t_distribution& x,
1397                           const student_t_distribution& y);
1398
1399    template <class charT, class traits>
1400    friend
1401    basic_ostream<charT, traits>&
1402    operator<<(basic_ostream<charT, traits>& os,
1403               const student_t_distribution& x);
1404
1405    template <class charT, class traits>
1406    friend
1407    basic_istream<charT, traits>&
1408    operator>>(basic_istream<charT, traits>& is,
1409               student_t_distribution& x);
1410};
1411
1412template<class IntType = int>
1413class discrete_distribution
1414{
1415public:
1416    // types
1417    typedef IntType result_type;
1418
1419    class param_type
1420    {
1421    public:
1422        typedef discrete_distribution distribution_type;
1423
1424        param_type();
1425        template<class InputIterator>
1426            param_type(InputIterator firstW, InputIterator lastW);
1427        param_type(initializer_list<double> wl);
1428        template<class UnaryOperation>
1429            param_type(size_t nw, double xmin, double xmax, UnaryOperation fw);
1430
1431        vector<double> probabilities() const;
1432
1433        friend bool operator==(const param_type& x, const param_type& y);
1434        friend bool operator!=(const param_type& x, const param_type& y);
1435    };
1436
1437    // constructor and reset functions
1438    discrete_distribution();
1439    template<class InputIterator>
1440        discrete_distribution(InputIterator firstW, InputIterator lastW);
1441    discrete_distribution(initializer_list<double> wl);
1442    template<class UnaryOperation>
1443        discrete_distribution(size_t nw, double xmin, double xmax,
1444                              UnaryOperation fw);
1445    explicit discrete_distribution(const param_type& parm);
1446    void reset();
1447
1448    // generating functions
1449    template<class URNG> result_type operator()(URNG& g);
1450    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1451
1452    // property functions
1453    vector<double> probabilities() const;
1454
1455    param_type param() const;
1456    void param(const param_type& parm);
1457
1458    result_type min() const;
1459    result_type max() const;
1460
1461    friend bool operator==(const discrete_distribution& x,
1462                           const discrete_distribution& y);
1463    friend bool operator!=(const discrete_distribution& x,
1464                           const discrete_distribution& y);
1465
1466    template <class charT, class traits>
1467    friend
1468    basic_ostream<charT, traits>&
1469    operator<<(basic_ostream<charT, traits>& os,
1470               const discrete_distribution& x);
1471
1472    template <class charT, class traits>
1473    friend
1474    basic_istream<charT, traits>&
1475    operator>>(basic_istream<charT, traits>& is,
1476               discrete_distribution& x);
1477};
1478
1479template<class RealType = double>
1480class piecewise_constant_distribution
1481{
1482    // types
1483    typedef RealType result_type;
1484
1485    class param_type
1486    {
1487    public:
1488        typedef piecewise_constant_distribution distribution_type;
1489
1490        param_type();
1491        template<class InputIteratorB, class InputIteratorW>
1492            param_type(InputIteratorB firstB, InputIteratorB lastB,
1493                       InputIteratorW firstW);
1494        template<class UnaryOperation>
1495            param_type(initializer_list<result_type> bl, UnaryOperation fw);
1496        template<class UnaryOperation>
1497            param_type(size_t nw, result_type xmin, result_type xmax,
1498                       UnaryOperation fw);
1499
1500        vector<result_type> intervals() const;
1501        vector<result_type> densities() const;
1502
1503        friend bool operator==(const param_type& x, const param_type& y);
1504        friend bool operator!=(const param_type& x, const param_type& y);
1505    };
1506
1507    // constructor and reset functions
1508    piecewise_constant_distribution();
1509    template<class InputIteratorB, class InputIteratorW>
1510        piecewise_constant_distribution(InputIteratorB firstB,
1511                                        InputIteratorB lastB,
1512                                        InputIteratorW firstW);
1513    template<class UnaryOperation>
1514        piecewise_constant_distribution(initializer_list<result_type> bl,
1515                                        UnaryOperation fw);
1516    template<class UnaryOperation>
1517        piecewise_constant_distribution(size_t nw, result_type xmin,
1518                                        result_type xmax, UnaryOperation fw);
1519    explicit piecewise_constant_distribution(const param_type& parm);
1520    void reset();
1521
1522    // generating functions
1523    template<class URNG> result_type operator()(URNG& g);
1524    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1525
1526    // property functions
1527    vector<result_type> intervals() const;
1528    vector<result_type> densities() const;
1529
1530    param_type param() const;
1531    void param(const param_type& parm);
1532
1533    result_type min() const;
1534    result_type max() const;
1535
1536    friend bool operator==(const piecewise_constant_distribution& x,
1537                           const piecewise_constant_distribution& y);
1538    friend bool operator!=(const piecewise_constant_distribution& x,
1539                           const piecewise_constant_distribution& y);
1540
1541    template <class charT, class traits>
1542    friend
1543    basic_ostream<charT, traits>&
1544    operator<<(basic_ostream<charT, traits>& os,
1545               const piecewise_constant_distribution& x);
1546
1547    template <class charT, class traits>
1548    friend
1549    basic_istream<charT, traits>&
1550    operator>>(basic_istream<charT, traits>& is,
1551               piecewise_constant_distribution& x);
1552};
1553
1554template<class RealType = double>
1555class piecewise_linear_distribution
1556{
1557    // types
1558    typedef RealType result_type;
1559
1560    class param_type
1561    {
1562    public:
1563        typedef piecewise_linear_distribution distribution_type;
1564
1565        param_type();
1566        template<class InputIteratorB, class InputIteratorW>
1567            param_type(InputIteratorB firstB, InputIteratorB lastB,
1568                       InputIteratorW firstW);
1569        template<class UnaryOperation>
1570            param_type(initializer_list<result_type> bl, UnaryOperation fw);
1571        template<class UnaryOperation>
1572            param_type(size_t nw, result_type xmin, result_type xmax,
1573                       UnaryOperation fw);
1574
1575        vector<result_type> intervals() const;
1576        vector<result_type> densities() const;
1577
1578        friend bool operator==(const param_type& x, const param_type& y);
1579        friend bool operator!=(const param_type& x, const param_type& y);
1580    };
1581
1582    // constructor and reset functions
1583    piecewise_linear_distribution();
1584    template<class InputIteratorB, class InputIteratorW>
1585        piecewise_linear_distribution(InputIteratorB firstB,
1586                                      InputIteratorB lastB,
1587                                      InputIteratorW firstW);
1588
1589    template<class UnaryOperation>
1590        piecewise_linear_distribution(initializer_list<result_type> bl,
1591                                      UnaryOperation fw);
1592
1593    template<class UnaryOperation>
1594        piecewise_linear_distribution(size_t nw, result_type xmin,
1595                                      result_type xmax, UnaryOperation fw);
1596
1597    explicit piecewise_linear_distribution(const param_type& parm);
1598    void reset();
1599
1600    // generating functions
1601    template<class URNG> result_type operator()(URNG& g);
1602    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
1603
1604    // property functions
1605    vector<result_type> intervals() const;
1606    vector<result_type> densities() const;
1607
1608    param_type param() const;
1609    void param(const param_type& parm);
1610
1611    result_type min() const;
1612    result_type max() const;
1613
1614    friend bool operator==(const piecewise_linear_distribution& x,
1615                           const piecewise_linear_distribution& y);
1616    friend bool operator!=(const piecewise_linear_distribution& x,
1617                           const piecewise_linear_distribution& y);
1618
1619    template <class charT, class traits>
1620    friend
1621    basic_ostream<charT, traits>&
1622    operator<<(basic_ostream<charT, traits>& os,
1623               const piecewise_linear_distribution& x);
1624
1625    template <class charT, class traits>
1626    friend
1627    basic_istream<charT, traits>&
1628    operator>>(basic_istream<charT, traits>& is,
1629               piecewise_linear_distribution& x);
1630};
1631
1632} // std
1633*/
1634
1635#include <__config>
1636#include <cstddef>
1637#include <cstdint>
1638#include <cmath>
1639#include <type_traits>
1640#include <initializer_list>
1641#include <limits>
1642#include <algorithm>
1643#include <numeric>
1644#include <vector>
1645#include <string>
1646#include <istream>
1647#include <ostream>
1648
1649#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
1650#pragma GCC system_header
1651#endif
1652
1653_LIBCPP_PUSH_MACROS
1654#include <__undef_macros>
1655
1656
1657_LIBCPP_BEGIN_NAMESPACE_STD
1658
1659// __is_seed_sequence
1660
1661template <class _Sseq, class _Engine>
1662struct __is_seed_sequence
1663{
1664    static _LIBCPP_CONSTEXPR const bool value =
1665              !is_convertible<_Sseq, typename _Engine::result_type>::value &&
1666              !is_same<typename remove_cv<_Sseq>::type, _Engine>::value;
1667};
1668
1669// linear_congruential_engine
1670
1671template <unsigned long long __a, unsigned long long __c,
1672          unsigned long long __m, unsigned long long _Mp,
1673          bool _MightOverflow = (__a != 0 && __m != 0 && __m-1 > (_Mp-__c)/__a)>
1674struct __lce_ta;
1675
1676// 64
1677
1678template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
1679struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), true>
1680{
1681    typedef unsigned long long result_type;
1682    _LIBCPP_INLINE_VISIBILITY
1683    static result_type next(result_type __x)
1684    {
1685        // Schrage's algorithm
1686        const result_type __q = __m / __a;
1687        const result_type __r = __m % __a;
1688        const result_type __t0 = __a * (__x % __q);
1689        const result_type __t1 = __r * (__x / __q);
1690        __x = __t0 + (__t0 < __t1) * __m - __t1;
1691        __x += __c - (__x >= __m - __c) * __m;
1692        return __x;
1693    }
1694};
1695
1696template <unsigned long long __a, unsigned long long __m>
1697struct __lce_ta<__a, 0, __m, (unsigned long long)(~0), true>
1698{
1699    typedef unsigned long long result_type;
1700    _LIBCPP_INLINE_VISIBILITY
1701    static result_type next(result_type __x)
1702    {
1703        // Schrage's algorithm
1704        const result_type __q = __m / __a;
1705        const result_type __r = __m % __a;
1706        const result_type __t0 = __a * (__x % __q);
1707        const result_type __t1 = __r * (__x / __q);
1708        __x = __t0 + (__t0 < __t1) * __m - __t1;
1709        return __x;
1710    }
1711};
1712
1713template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
1714struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), false>
1715{
1716    typedef unsigned long long result_type;
1717    _LIBCPP_INLINE_VISIBILITY
1718    static result_type next(result_type __x)
1719    {
1720        return (__a * __x + __c) % __m;
1721    }
1722};
1723
1724template <unsigned long long __a, unsigned long long __c>
1725struct __lce_ta<__a, __c, 0, (unsigned long long)(~0), false>
1726{
1727    typedef unsigned long long result_type;
1728    _LIBCPP_INLINE_VISIBILITY
1729    static result_type next(result_type __x)
1730    {
1731        return __a * __x + __c;
1732    }
1733};
1734
1735// 32
1736
1737template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
1738struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), true>
1739{
1740    typedef unsigned result_type;
1741    _LIBCPP_INLINE_VISIBILITY
1742    static result_type next(result_type __x)
1743    {
1744        const result_type __a = static_cast<result_type>(_Ap);
1745        const result_type __c = static_cast<result_type>(_Cp);
1746        const result_type __m = static_cast<result_type>(_Mp);
1747        // Schrage's algorithm
1748        const result_type __q = __m / __a;
1749        const result_type __r = __m % __a;
1750        const result_type __t0 = __a * (__x % __q);
1751        const result_type __t1 = __r * (__x / __q);
1752        __x = __t0 + (__t0 < __t1) * __m - __t1;
1753        __x += __c - (__x >= __m - __c) * __m;
1754        return __x;
1755    }
1756};
1757
1758template <unsigned long long _Ap, unsigned long long _Mp>
1759struct __lce_ta<_Ap, 0, _Mp, unsigned(~0), true>
1760{
1761    typedef unsigned result_type;
1762    _LIBCPP_INLINE_VISIBILITY
1763    static result_type next(result_type __x)
1764    {
1765        const result_type __a = static_cast<result_type>(_Ap);
1766        const result_type __m = static_cast<result_type>(_Mp);
1767        // Schrage's algorithm
1768        const result_type __q = __m / __a;
1769        const result_type __r = __m % __a;
1770        const result_type __t0 = __a * (__x % __q);
1771        const result_type __t1 = __r * (__x / __q);
1772        __x = __t0 + (__t0 < __t1) * __m - __t1;
1773        return __x;
1774    }
1775};
1776
1777template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
1778struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), false>
1779{
1780    typedef unsigned result_type;
1781    _LIBCPP_INLINE_VISIBILITY
1782    static result_type next(result_type __x)
1783    {
1784        const result_type __a = static_cast<result_type>(_Ap);
1785        const result_type __c = static_cast<result_type>(_Cp);
1786        const result_type __m = static_cast<result_type>(_Mp);
1787        return (__a * __x + __c) % __m;
1788    }
1789};
1790
1791template <unsigned long long _Ap, unsigned long long _Cp>
1792struct __lce_ta<_Ap, _Cp, 0, 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        return __a * __x + __c;
1801    }
1802};
1803
1804// 16
1805
1806template <unsigned long long __a, unsigned long long __c, unsigned long long __m, bool __b>
1807struct __lce_ta<__a, __c, __m, (unsigned short)(~0), __b>
1808{
1809    typedef unsigned short result_type;
1810    _LIBCPP_INLINE_VISIBILITY
1811    static result_type next(result_type __x)
1812    {
1813        return static_cast<result_type>(__lce_ta<__a, __c, __m, unsigned(~0)>::next(__x));
1814    }
1815};
1816
1817template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1818class _LIBCPP_TEMPLATE_VIS linear_congruential_engine;
1819
1820template <class _CharT, class _Traits,
1821          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1822_LIBCPP_INLINE_VISIBILITY
1823basic_ostream<_CharT, _Traits>&
1824operator<<(basic_ostream<_CharT, _Traits>& __os,
1825           const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
1826
1827template <class _CharT, class _Traits,
1828          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1829basic_istream<_CharT, _Traits>&
1830operator>>(basic_istream<_CharT, _Traits>& __is,
1831           linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
1832
1833template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1834class _LIBCPP_TEMPLATE_VIS linear_congruential_engine
1835{
1836public:
1837    // types
1838    typedef _UIntType result_type;
1839
1840private:
1841    result_type __x_;
1842
1843    static _LIBCPP_CONSTEXPR const result_type _Mp = result_type(~0);
1844
1845    static_assert(__m == 0 || __a < __m, "linear_congruential_engine invalid parameters");
1846    static_assert(__m == 0 || __c < __m, "linear_congruential_engine invalid parameters");
1847public:
1848    static _LIBCPP_CONSTEXPR const result_type _Min = __c == 0u ? 1u: 0u;
1849    static _LIBCPP_CONSTEXPR const result_type _Max = __m - 1u;
1850    static_assert(_Min < _Max,           "linear_congruential_engine invalid parameters");
1851
1852    // engine characteristics
1853    static _LIBCPP_CONSTEXPR const result_type multiplier = __a;
1854    static _LIBCPP_CONSTEXPR const result_type increment = __c;
1855    static _LIBCPP_CONSTEXPR const result_type modulus = __m;
1856    _LIBCPP_INLINE_VISIBILITY
1857    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
1858    _LIBCPP_INLINE_VISIBILITY
1859    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
1860    static _LIBCPP_CONSTEXPR const result_type default_seed = 1u;
1861
1862    // constructors and seeding functions
1863    _LIBCPP_INLINE_VISIBILITY
1864    explicit linear_congruential_engine(result_type __s = default_seed)
1865        {seed(__s);}
1866    template<class _Sseq>
1867        _LIBCPP_INLINE_VISIBILITY
1868        explicit linear_congruential_engine(_Sseq& __q,
1869        typename enable_if<__is_seed_sequence<_Sseq, linear_congruential_engine>::value>::type* = 0)
1870        {seed(__q);}
1871    _LIBCPP_INLINE_VISIBILITY
1872    void seed(result_type __s = default_seed)
1873        {seed(integral_constant<bool, __m == 0>(),
1874              integral_constant<bool, __c == 0>(), __s);}
1875    template<class _Sseq>
1876        _LIBCPP_INLINE_VISIBILITY
1877        typename enable_if
1878        <
1879            __is_seed_sequence<_Sseq, linear_congruential_engine>::value,
1880            void
1881        >::type
1882        seed(_Sseq& __q)
1883            {__seed(__q, integral_constant<unsigned,
1884                1 + (__m == 0 ? (sizeof(result_type) * __CHAR_BIT__ - 1)/32
1885                             :  (__m > 0x100000000ull))>());}
1886
1887    // generating functions
1888    _LIBCPP_INLINE_VISIBILITY
1889    result_type operator()()
1890        {return __x_ = static_cast<result_type>(__lce_ta<__a, __c, __m, _Mp>::next(__x_));}
1891    _LIBCPP_INLINE_VISIBILITY
1892    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
1893
1894    friend _LIBCPP_INLINE_VISIBILITY
1895    bool operator==(const linear_congruential_engine& __x,
1896                    const linear_congruential_engine& __y)
1897        {return __x.__x_ == __y.__x_;}
1898    friend _LIBCPP_INLINE_VISIBILITY
1899    bool operator!=(const linear_congruential_engine& __x,
1900                    const linear_congruential_engine& __y)
1901        {return !(__x == __y);}
1902
1903private:
1904
1905    _LIBCPP_INLINE_VISIBILITY
1906    void seed(true_type, true_type, result_type __s) {__x_ = __s == 0 ? 1 : __s;}
1907    _LIBCPP_INLINE_VISIBILITY
1908    void seed(true_type, false_type, result_type __s) {__x_ = __s;}
1909    _LIBCPP_INLINE_VISIBILITY
1910    void seed(false_type, true_type, result_type __s) {__x_ = __s % __m == 0 ?
1911                                                                 1 : __s % __m;}
1912    _LIBCPP_INLINE_VISIBILITY
1913    void seed(false_type, false_type, result_type __s) {__x_ = __s % __m;}
1914
1915    template<class _Sseq>
1916        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
1917    template<class _Sseq>
1918        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
1919
1920    template <class _CharT, class _Traits,
1921              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1922    friend
1923    basic_ostream<_CharT, _Traits>&
1924    operator<<(basic_ostream<_CharT, _Traits>& __os,
1925               const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
1926
1927    template <class _CharT, class _Traits,
1928              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
1929    friend
1930    basic_istream<_CharT, _Traits>&
1931    operator>>(basic_istream<_CharT, _Traits>& __is,
1932               linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
1933};
1934
1935template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1936    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1937    linear_congruential_engine<_UIntType, __a, __c, __m>::multiplier;
1938
1939template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1940    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1941    linear_congruential_engine<_UIntType, __a, __c, __m>::increment;
1942
1943template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1944    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1945    linear_congruential_engine<_UIntType, __a, __c, __m>::modulus;
1946
1947template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1948    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
1949    linear_congruential_engine<_UIntType, __a, __c, __m>::default_seed;
1950
1951template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1952template<class _Sseq>
1953void
1954linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
1955                                                 integral_constant<unsigned, 1>)
1956{
1957    const unsigned __k = 1;
1958    uint32_t __ar[__k+3];
1959    __q.generate(__ar, __ar + __k + 3);
1960    result_type __s = static_cast<result_type>(__ar[3] % __m);
1961    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
1962}
1963
1964template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1965template<class _Sseq>
1966void
1967linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
1968                                                 integral_constant<unsigned, 2>)
1969{
1970    const unsigned __k = 2;
1971    uint32_t __ar[__k+3];
1972    __q.generate(__ar, __ar + __k + 3);
1973    result_type __s = static_cast<result_type>((__ar[3] +
1974                                              ((uint64_t)__ar[4] << 32)) % __m);
1975    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
1976}
1977
1978template <class _CharT, class _Traits,
1979          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1980inline _LIBCPP_INLINE_VISIBILITY
1981basic_ostream<_CharT, _Traits>&
1982operator<<(basic_ostream<_CharT, _Traits>& __os,
1983           const linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
1984{
1985    __save_flags<_CharT, _Traits> __lx(__os);
1986    __os.flags(ios_base::dec | ios_base::left);
1987    __os.fill(__os.widen(' '));
1988    return __os << __x.__x_;
1989}
1990
1991template <class _CharT, class _Traits,
1992          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
1993basic_istream<_CharT, _Traits>&
1994operator>>(basic_istream<_CharT, _Traits>& __is,
1995           linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
1996{
1997    __save_flags<_CharT, _Traits> __lx(__is);
1998    __is.flags(ios_base::dec | ios_base::skipws);
1999    _UIntType __t;
2000    __is >> __t;
2001    if (!__is.fail())
2002        __x.__x_ = __t;
2003    return __is;
2004}
2005
2006typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
2007                                                                   minstd_rand0;
2008typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
2009                                                                    minstd_rand;
2010typedef minstd_rand                                       default_random_engine;
2011// mersenne_twister_engine
2012
2013template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2014          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2015          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2016class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine;
2017
2018template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2019          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2020          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2021bool
2022operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2023                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2024           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2025                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2026
2027template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2028          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2029          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2030_LIBCPP_INLINE_VISIBILITY
2031bool
2032operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2033                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2034           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2035                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2036
2037template <class _CharT, class _Traits,
2038          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2039          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2040          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2041basic_ostream<_CharT, _Traits>&
2042operator<<(basic_ostream<_CharT, _Traits>& __os,
2043           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2044                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2045
2046template <class _CharT, class _Traits,
2047          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2048          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2049          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2050basic_istream<_CharT, _Traits>&
2051operator>>(basic_istream<_CharT, _Traits>& __is,
2052           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2053                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2054
2055template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2056          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2057          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2058class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine
2059{
2060public:
2061    // types
2062    typedef _UIntType result_type;
2063
2064private:
2065    result_type __x_[__n];
2066    size_t      __i_;
2067
2068    static_assert(  0 <  __m, "mersenne_twister_engine invalid parameters");
2069    static_assert(__m <= __n, "mersenne_twister_engine invalid parameters");
2070    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
2071    static_assert(__w <= _Dt, "mersenne_twister_engine invalid parameters");
2072    static_assert(  2 <= __w, "mersenne_twister_engine invalid parameters");
2073    static_assert(__r <= __w, "mersenne_twister_engine invalid parameters");
2074    static_assert(__u <= __w, "mersenne_twister_engine invalid parameters");
2075    static_assert(__s <= __w, "mersenne_twister_engine invalid parameters");
2076    static_assert(__t <= __w, "mersenne_twister_engine invalid parameters");
2077    static_assert(__l <= __w, "mersenne_twister_engine invalid parameters");
2078public:
2079    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
2080    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
2081                                                      (result_type(1) << __w) - result_type(1);
2082    static_assert(_Min < _Max, "mersenne_twister_engine invalid parameters");
2083    static_assert(__a <= _Max, "mersenne_twister_engine invalid parameters");
2084    static_assert(__b <= _Max, "mersenne_twister_engine invalid parameters");
2085    static_assert(__c <= _Max, "mersenne_twister_engine invalid parameters");
2086    static_assert(__d <= _Max, "mersenne_twister_engine invalid parameters");
2087    static_assert(__f <= _Max, "mersenne_twister_engine invalid parameters");
2088
2089    // engine characteristics
2090    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
2091    static _LIBCPP_CONSTEXPR const size_t state_size = __n;
2092    static _LIBCPP_CONSTEXPR const size_t shift_size = __m;
2093    static _LIBCPP_CONSTEXPR const size_t mask_bits = __r;
2094    static _LIBCPP_CONSTEXPR const result_type xor_mask = __a;
2095    static _LIBCPP_CONSTEXPR const size_t tempering_u = __u;
2096    static _LIBCPP_CONSTEXPR const result_type tempering_d = __d;
2097    static _LIBCPP_CONSTEXPR const size_t tempering_s = __s;
2098    static _LIBCPP_CONSTEXPR const result_type tempering_b = __b;
2099    static _LIBCPP_CONSTEXPR const size_t tempering_t = __t;
2100    static _LIBCPP_CONSTEXPR const result_type tempering_c = __c;
2101    static _LIBCPP_CONSTEXPR const size_t tempering_l = __l;
2102    static _LIBCPP_CONSTEXPR const result_type initialization_multiplier = __f;
2103    _LIBCPP_INLINE_VISIBILITY
2104    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
2105    _LIBCPP_INLINE_VISIBILITY
2106    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
2107    static _LIBCPP_CONSTEXPR const result_type default_seed = 5489u;
2108
2109    // constructors and seeding functions
2110    _LIBCPP_INLINE_VISIBILITY
2111    explicit mersenne_twister_engine(result_type __sd = default_seed)
2112        {seed(__sd);}
2113    template<class _Sseq>
2114        _LIBCPP_INLINE_VISIBILITY
2115        explicit mersenne_twister_engine(_Sseq& __q,
2116        typename enable_if<__is_seed_sequence<_Sseq, mersenne_twister_engine>::value>::type* = 0)
2117        {seed(__q);}
2118    void seed(result_type __sd = default_seed);
2119    template<class _Sseq>
2120        _LIBCPP_INLINE_VISIBILITY
2121        typename enable_if
2122        <
2123            __is_seed_sequence<_Sseq, mersenne_twister_engine>::value,
2124            void
2125        >::type
2126        seed(_Sseq& __q)
2127            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2128
2129    // generating functions
2130    result_type operator()();
2131    _LIBCPP_INLINE_VISIBILITY
2132    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2133
2134    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2135              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2136              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2137    friend
2138    bool
2139    operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2140                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2141               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2142                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2143
2144    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2145              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2146              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2147    friend
2148    bool
2149    operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2150                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2151               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2152                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
2153
2154    template <class _CharT, class _Traits,
2155              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2156              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2157              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2158    friend
2159    basic_ostream<_CharT, _Traits>&
2160    operator<<(basic_ostream<_CharT, _Traits>& __os,
2161               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2162                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2163
2164    template <class _CharT, class _Traits,
2165              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2166              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2167              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2168    friend
2169    basic_istream<_CharT, _Traits>&
2170    operator>>(basic_istream<_CharT, _Traits>& __is,
2171               mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2172                                       _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
2173private:
2174
2175    template<class _Sseq>
2176        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
2177    template<class _Sseq>
2178        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
2179
2180    template <size_t __count>
2181        _LIBCPP_INLINE_VISIBILITY
2182        static
2183        typename enable_if
2184        <
2185            __count < __w,
2186            result_type
2187        >::type
2188        __lshift(result_type __x) {return (__x << __count) & _Max;}
2189
2190    template <size_t __count>
2191        _LIBCPP_INLINE_VISIBILITY
2192        static
2193        typename enable_if
2194        <
2195            (__count >= __w),
2196            result_type
2197        >::type
2198        __lshift(result_type) {return result_type(0);}
2199
2200    template <size_t __count>
2201        _LIBCPP_INLINE_VISIBILITY
2202        static
2203        typename enable_if
2204        <
2205            __count < _Dt,
2206            result_type
2207        >::type
2208        __rshift(result_type __x) {return __x >> __count;}
2209
2210    template <size_t __count>
2211        _LIBCPP_INLINE_VISIBILITY
2212        static
2213        typename enable_if
2214        <
2215            (__count >= _Dt),
2216            result_type
2217        >::type
2218        __rshift(result_type) {return result_type(0);}
2219};
2220
2221template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2222          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2223          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2224    _LIBCPP_CONSTEXPR const size_t
2225    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::word_size;
2226
2227template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2228          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2229          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2230    _LIBCPP_CONSTEXPR const size_t
2231    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::state_size;
2232
2233template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2234          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2235          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2236    _LIBCPP_CONSTEXPR const size_t
2237    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::shift_size;
2238
2239template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2240          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2241          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2242    _LIBCPP_CONSTEXPR const size_t
2243    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::mask_bits;
2244
2245template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2246          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2247          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2248    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2249    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::xor_mask;
2250
2251template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2252          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2253          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2254    _LIBCPP_CONSTEXPR const size_t
2255    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_u;
2256
2257template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2258          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2259          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2260    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2261    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_d;
2262
2263template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2264          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2265          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2266    _LIBCPP_CONSTEXPR const size_t
2267    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_s;
2268
2269template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2270          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2271          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2272    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2273    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_b;
2274
2275template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2276          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2277          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2278    _LIBCPP_CONSTEXPR const size_t
2279    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_t;
2280
2281template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2282          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2283          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2284    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2285    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_c;
2286
2287template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2288          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2289          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2290    _LIBCPP_CONSTEXPR const size_t
2291    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_l;
2292
2293template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2294          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2295          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2296    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2297    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::initialization_multiplier;
2298
2299template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2300          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2301          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2302    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
2303    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::default_seed;
2304
2305template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2306          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2307          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2308void
2309mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2310    __t, __c, __l, __f>::seed(result_type __sd)
2311{   // __w >= 2
2312    __x_[0] = __sd & _Max;
2313    for (size_t __i = 1; __i < __n; ++__i)
2314        __x_[__i] = (__f * (__x_[__i-1] ^ __rshift<__w - 2>(__x_[__i-1])) + __i) & _Max;
2315    __i_ = 0;
2316}
2317
2318template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2319          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2320          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2321template<class _Sseq>
2322void
2323mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2324    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 1>)
2325{
2326    const unsigned __k = 1;
2327    uint32_t __ar[__n * __k];
2328    __q.generate(__ar, __ar + __n * __k);
2329    for (size_t __i = 0; __i < __n; ++__i)
2330        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
2331    const result_type __mask = __r == _Dt ? result_type(~0) :
2332                                       (result_type(1) << __r) - result_type(1);
2333    __i_ = 0;
2334    if ((__x_[0] & ~__mask) == 0)
2335    {
2336        for (size_t __i = 1; __i < __n; ++__i)
2337            if (__x_[__i] != 0)
2338                return;
2339        __x_[0] = _Max;
2340    }
2341}
2342
2343template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2344          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2345          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2346template<class _Sseq>
2347void
2348mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2349    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 2>)
2350{
2351    const unsigned __k = 2;
2352    uint32_t __ar[__n * __k];
2353    __q.generate(__ar, __ar + __n * __k);
2354    for (size_t __i = 0; __i < __n; ++__i)
2355        __x_[__i] = static_cast<result_type>(
2356            (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
2357    const result_type __mask = __r == _Dt ? result_type(~0) :
2358                                       (result_type(1) << __r) - result_type(1);
2359    __i_ = 0;
2360    if ((__x_[0] & ~__mask) == 0)
2361    {
2362        for (size_t __i = 1; __i < __n; ++__i)
2363            if (__x_[__i] != 0)
2364                return;
2365        __x_[0] = _Max;
2366    }
2367}
2368
2369template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
2370          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
2371          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
2372_UIntType
2373mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
2374    __t, __c, __l, __f>::operator()()
2375{
2376    const size_t __j = (__i_ + 1) % __n;
2377    const result_type __mask = __r == _Dt ? result_type(~0) :
2378                                       (result_type(1) << __r) - result_type(1);
2379    const result_type _Yp = (__x_[__i_] & ~__mask) | (__x_[__j] & __mask);
2380    const size_t __k = (__i_ + __m) % __n;
2381    __x_[__i_] = __x_[__k] ^ __rshift<1>(_Yp) ^ (__a * (_Yp & 1));
2382    result_type __z = __x_[__i_] ^ (__rshift<__u>(__x_[__i_]) & __d);
2383    __i_ = __j;
2384    __z ^= __lshift<__s>(__z) & __b;
2385    __z ^= __lshift<__t>(__z) & __c;
2386    return __z ^ __rshift<__l>(__z);
2387}
2388
2389template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2390          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2391          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2392bool
2393operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2394                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2395           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2396                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
2397{
2398    if (__x.__i_ == __y.__i_)
2399        return _VSTD::equal(__x.__x_, __x.__x_ + _Np, __y.__x_);
2400    if (__x.__i_ == 0 || __y.__i_ == 0)
2401    {
2402        size_t __j = _VSTD::min(_Np - __x.__i_, _Np - __y.__i_);
2403        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
2404                         __y.__x_ + __y.__i_))
2405            return false;
2406        if (__x.__i_ == 0)
2407            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Np, __y.__x_);
2408        return _VSTD::equal(__x.__x_, __x.__x_ + (_Np - __j), __y.__x_ + __j);
2409    }
2410    if (__x.__i_ < __y.__i_)
2411    {
2412        size_t __j = _Np - __y.__i_;
2413        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
2414                         __y.__x_ + __y.__i_))
2415            return false;
2416        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Np,
2417                         __y.__x_))
2418            return false;
2419        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
2420                           __y.__x_ + (_Np - (__x.__i_ + __j)));
2421    }
2422    size_t __j = _Np - __x.__i_;
2423    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
2424                     __x.__x_ + __x.__i_))
2425        return false;
2426    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Np,
2427                     __x.__x_))
2428        return false;
2429    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
2430                       __x.__x_ + (_Np - (__y.__i_ + __j)));
2431}
2432
2433template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2434          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2435          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2436inline _LIBCPP_INLINE_VISIBILITY
2437bool
2438operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2439                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
2440           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2441                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
2442{
2443    return !(__x == __y);
2444}
2445
2446template <class _CharT, class _Traits,
2447          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2448          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2449          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2450basic_ostream<_CharT, _Traits>&
2451operator<<(basic_ostream<_CharT, _Traits>& __os,
2452           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2453                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
2454{
2455    __save_flags<_CharT, _Traits> __lx(__os);
2456    __os.flags(ios_base::dec | ios_base::left);
2457    _CharT __sp = __os.widen(' ');
2458    __os.fill(__sp);
2459    __os << __x.__x_[__x.__i_];
2460    for (size_t __j = __x.__i_ + 1; __j < _Np; ++__j)
2461        __os << __sp << __x.__x_[__j];
2462    for (size_t __j = 0; __j < __x.__i_; ++__j)
2463        __os << __sp << __x.__x_[__j];
2464    return __os;
2465}
2466
2467template <class _CharT, class _Traits,
2468          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
2469          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
2470          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
2471basic_istream<_CharT, _Traits>&
2472operator>>(basic_istream<_CharT, _Traits>& __is,
2473           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
2474                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
2475{
2476    __save_flags<_CharT, _Traits> __lx(__is);
2477    __is.flags(ios_base::dec | ios_base::skipws);
2478    _UInt __t[_Np];
2479    for (size_t __i = 0; __i < _Np; ++__i)
2480        __is >> __t[__i];
2481    if (!__is.fail())
2482    {
2483        for (size_t __i = 0; __i < _Np; ++__i)
2484            __x.__x_[__i] = __t[__i];
2485        __x.__i_ = 0;
2486    }
2487    return __is;
2488}
2489
2490typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
2491                                0x9908b0df, 11, 0xffffffff,
2492                                7,  0x9d2c5680,
2493                                15, 0xefc60000,
2494                                18, 1812433253>                         mt19937;
2495typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
2496                                0xb5026f5aa96619e9ULL, 29, 0x5555555555555555ULL,
2497                                17, 0x71d67fffeda60000ULL,
2498                                37, 0xfff7eee000000000ULL,
2499                                43, 6364136223846793005ULL>          mt19937_64;
2500
2501// subtract_with_carry_engine
2502
2503template<class _UIntType, size_t __w, size_t __s, size_t __r>
2504class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine;
2505
2506template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2507bool
2508operator==(
2509    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2510    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2511
2512template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2513_LIBCPP_INLINE_VISIBILITY
2514bool
2515operator!=(
2516    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2517    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2518
2519template <class _CharT, class _Traits,
2520          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2521basic_ostream<_CharT, _Traits>&
2522operator<<(basic_ostream<_CharT, _Traits>& __os,
2523           const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2524
2525template <class _CharT, class _Traits,
2526          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2527basic_istream<_CharT, _Traits>&
2528operator>>(basic_istream<_CharT, _Traits>& __is,
2529           subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2530
2531template<class _UIntType, size_t __w, size_t __s, size_t __r>
2532class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine
2533{
2534public:
2535    // types
2536    typedef _UIntType result_type;
2537
2538private:
2539    result_type __x_[__r];
2540    result_type  __c_;
2541    size_t      __i_;
2542
2543    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
2544    static_assert(  0 <  __w, "subtract_with_carry_engine invalid parameters");
2545    static_assert(__w <= _Dt, "subtract_with_carry_engine invalid parameters");
2546    static_assert(  0 <  __s, "subtract_with_carry_engine invalid parameters");
2547    static_assert(__s <  __r, "subtract_with_carry_engine invalid parameters");
2548public:
2549    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
2550    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
2551                                                      (result_type(1) << __w) - result_type(1);
2552    static_assert(_Min < _Max, "subtract_with_carry_engine invalid parameters");
2553
2554    // engine characteristics
2555    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
2556    static _LIBCPP_CONSTEXPR const size_t short_lag = __s;
2557    static _LIBCPP_CONSTEXPR const size_t long_lag = __r;
2558    _LIBCPP_INLINE_VISIBILITY
2559    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
2560    _LIBCPP_INLINE_VISIBILITY
2561    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
2562    static _LIBCPP_CONSTEXPR const result_type default_seed = 19780503u;
2563
2564    // constructors and seeding functions
2565    _LIBCPP_INLINE_VISIBILITY
2566    explicit subtract_with_carry_engine(result_type __sd = default_seed)
2567        {seed(__sd);}
2568    template<class _Sseq>
2569        _LIBCPP_INLINE_VISIBILITY
2570        explicit subtract_with_carry_engine(_Sseq& __q,
2571        typename enable_if<__is_seed_sequence<_Sseq, subtract_with_carry_engine>::value>::type* = 0)
2572        {seed(__q);}
2573    _LIBCPP_INLINE_VISIBILITY
2574    void seed(result_type __sd = default_seed)
2575        {seed(__sd, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2576    template<class _Sseq>
2577        _LIBCPP_INLINE_VISIBILITY
2578        typename enable_if
2579        <
2580            __is_seed_sequence<_Sseq, subtract_with_carry_engine>::value,
2581            void
2582        >::type
2583        seed(_Sseq& __q)
2584            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
2585
2586    // generating functions
2587    result_type operator()();
2588    _LIBCPP_INLINE_VISIBILITY
2589    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2590
2591    template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2592    friend
2593    bool
2594    operator==(
2595        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2596        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2597
2598    template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2599    friend
2600    bool
2601    operator!=(
2602        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2603        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
2604
2605    template <class _CharT, class _Traits,
2606              class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2607    friend
2608    basic_ostream<_CharT, _Traits>&
2609    operator<<(basic_ostream<_CharT, _Traits>& __os,
2610               const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2611
2612    template <class _CharT, class _Traits,
2613              class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2614    friend
2615    basic_istream<_CharT, _Traits>&
2616    operator>>(basic_istream<_CharT, _Traits>& __is,
2617               subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
2618
2619private:
2620
2621    void seed(result_type __sd, integral_constant<unsigned, 1>);
2622    void seed(result_type __sd, integral_constant<unsigned, 2>);
2623    template<class _Sseq>
2624        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
2625    template<class _Sseq>
2626        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
2627};
2628
2629template<class _UIntType, size_t __w, size_t __s, size_t __r>
2630    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::word_size;
2631
2632template<class _UIntType, size_t __w, size_t __s, size_t __r>
2633    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::short_lag;
2634
2635template<class _UIntType, size_t __w, size_t __s, size_t __r>
2636    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::long_lag;
2637
2638template<class _UIntType, size_t __w, size_t __s, size_t __r>
2639    _LIBCPP_CONSTEXPR const typename subtract_with_carry_engine<_UIntType, __w, __s, __r>::result_type
2640    subtract_with_carry_engine<_UIntType, __w, __s, __r>::default_seed;
2641
2642template<class _UIntType, size_t __w, size_t __s, size_t __r>
2643void
2644subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
2645        integral_constant<unsigned, 1>)
2646{
2647    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
2648        __e(__sd == 0u ? default_seed : __sd);
2649    for (size_t __i = 0; __i < __r; ++__i)
2650        __x_[__i] = static_cast<result_type>(__e() & _Max);
2651    __c_ = __x_[__r-1] == 0;
2652    __i_ = 0;
2653}
2654
2655template<class _UIntType, size_t __w, size_t __s, size_t __r>
2656void
2657subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
2658        integral_constant<unsigned, 2>)
2659{
2660    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
2661        __e(__sd == 0u ? default_seed : __sd);
2662    for (size_t __i = 0; __i < __r; ++__i)
2663    {
2664        result_type __e0 = __e();
2665        __x_[__i] = static_cast<result_type>(
2666                                    (__e0 + ((uint64_t)__e() << 32)) & _Max);
2667    }
2668    __c_ = __x_[__r-1] == 0;
2669    __i_ = 0;
2670}
2671
2672template<class _UIntType, size_t __w, size_t __s, size_t __r>
2673template<class _Sseq>
2674void
2675subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
2676        integral_constant<unsigned, 1>)
2677{
2678    const unsigned __k = 1;
2679    uint32_t __ar[__r * __k];
2680    __q.generate(__ar, __ar + __r * __k);
2681    for (size_t __i = 0; __i < __r; ++__i)
2682        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
2683    __c_ = __x_[__r-1] == 0;
2684    __i_ = 0;
2685}
2686
2687template<class _UIntType, size_t __w, size_t __s, size_t __r>
2688template<class _Sseq>
2689void
2690subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
2691        integral_constant<unsigned, 2>)
2692{
2693    const unsigned __k = 2;
2694    uint32_t __ar[__r * __k];
2695    __q.generate(__ar, __ar + __r * __k);
2696    for (size_t __i = 0; __i < __r; ++__i)
2697        __x_[__i] = static_cast<result_type>(
2698                  (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
2699    __c_ = __x_[__r-1] == 0;
2700    __i_ = 0;
2701}
2702
2703template<class _UIntType, size_t __w, size_t __s, size_t __r>
2704_UIntType
2705subtract_with_carry_engine<_UIntType, __w, __s, __r>::operator()()
2706{
2707    const result_type& __xs = __x_[(__i_ + (__r - __s)) % __r];
2708    result_type& __xr = __x_[__i_];
2709    result_type __new_c = __c_ == 0 ? __xs < __xr : __xs != 0 ? __xs <= __xr : 1;
2710    __xr = (__xs - __xr - __c_) & _Max;
2711    __c_ = __new_c;
2712    __i_ = (__i_ + 1) % __r;
2713    return __xr;
2714}
2715
2716template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2717bool
2718operator==(
2719    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2720    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
2721{
2722    if (__x.__c_ != __y.__c_)
2723        return false;
2724    if (__x.__i_ == __y.__i_)
2725        return _VSTD::equal(__x.__x_, __x.__x_ + _Rp, __y.__x_);
2726    if (__x.__i_ == 0 || __y.__i_ == 0)
2727    {
2728        size_t __j = _VSTD::min(_Rp - __x.__i_, _Rp - __y.__i_);
2729        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
2730                         __y.__x_ + __y.__i_))
2731            return false;
2732        if (__x.__i_ == 0)
2733            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Rp, __y.__x_);
2734        return _VSTD::equal(__x.__x_, __x.__x_ + (_Rp - __j), __y.__x_ + __j);
2735    }
2736    if (__x.__i_ < __y.__i_)
2737    {
2738        size_t __j = _Rp - __y.__i_;
2739        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
2740                         __y.__x_ + __y.__i_))
2741            return false;
2742        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Rp,
2743                         __y.__x_))
2744            return false;
2745        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
2746                           __y.__x_ + (_Rp - (__x.__i_ + __j)));
2747    }
2748    size_t __j = _Rp - __x.__i_;
2749    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
2750                     __x.__x_ + __x.__i_))
2751        return false;
2752    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Rp,
2753                     __x.__x_))
2754        return false;
2755    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
2756                       __x.__x_ + (_Rp - (__y.__i_ + __j)));
2757}
2758
2759template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2760inline _LIBCPP_INLINE_VISIBILITY
2761bool
2762operator!=(
2763    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
2764    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
2765{
2766    return !(__x == __y);
2767}
2768
2769template <class _CharT, class _Traits,
2770          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2771basic_ostream<_CharT, _Traits>&
2772operator<<(basic_ostream<_CharT, _Traits>& __os,
2773           const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
2774{
2775    __save_flags<_CharT, _Traits> __lx(__os);
2776    __os.flags(ios_base::dec | ios_base::left);
2777    _CharT __sp = __os.widen(' ');
2778    __os.fill(__sp);
2779    __os << __x.__x_[__x.__i_];
2780    for (size_t __j = __x.__i_ + 1; __j < _Rp; ++__j)
2781        __os << __sp << __x.__x_[__j];
2782    for (size_t __j = 0; __j < __x.__i_; ++__j)
2783        __os << __sp << __x.__x_[__j];
2784    __os << __sp << __x.__c_;
2785    return __os;
2786}
2787
2788template <class _CharT, class _Traits,
2789          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
2790basic_istream<_CharT, _Traits>&
2791operator>>(basic_istream<_CharT, _Traits>& __is,
2792           subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
2793{
2794    __save_flags<_CharT, _Traits> __lx(__is);
2795    __is.flags(ios_base::dec | ios_base::skipws);
2796    _UInt __t[_Rp+1];
2797    for (size_t __i = 0; __i < _Rp+1; ++__i)
2798        __is >> __t[__i];
2799    if (!__is.fail())
2800    {
2801        for (size_t __i = 0; __i < _Rp; ++__i)
2802            __x.__x_[__i] = __t[__i];
2803        __x.__c_ = __t[_Rp];
2804        __x.__i_ = 0;
2805    }
2806    return __is;
2807}
2808
2809typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
2810typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
2811
2812// discard_block_engine
2813
2814template<class _Engine, size_t __p, size_t __r>
2815class _LIBCPP_TEMPLATE_VIS discard_block_engine
2816{
2817    _Engine __e_;
2818    int     __n_;
2819
2820    static_assert(  0 <  __r, "discard_block_engine invalid parameters");
2821    static_assert(__r <= __p, "discard_block_engine invalid parameters");
2822    static_assert(__r <= INT_MAX, "discard_block_engine invalid parameters");
2823public:
2824    // types
2825    typedef typename _Engine::result_type result_type;
2826
2827    // engine characteristics
2828    static _LIBCPP_CONSTEXPR const size_t block_size = __p;
2829    static _LIBCPP_CONSTEXPR const size_t used_block = __r;
2830
2831#ifdef _LIBCPP_CXX03_LANG
2832    static const result_type _Min = _Engine::_Min;
2833    static const result_type _Max = _Engine::_Max;
2834#else
2835    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
2836    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
2837#endif
2838
2839    _LIBCPP_INLINE_VISIBILITY
2840    static _LIBCPP_CONSTEXPR result_type min() { return _Engine::min(); }
2841    _LIBCPP_INLINE_VISIBILITY
2842    static _LIBCPP_CONSTEXPR result_type max() { return _Engine::max(); }
2843
2844    // constructors and seeding functions
2845    _LIBCPP_INLINE_VISIBILITY
2846    discard_block_engine() : __n_(0) {}
2847    _LIBCPP_INLINE_VISIBILITY
2848    explicit discard_block_engine(const _Engine& __e)
2849        : __e_(__e), __n_(0) {}
2850#ifndef _LIBCPP_CXX03_LANG
2851    _LIBCPP_INLINE_VISIBILITY
2852    explicit discard_block_engine(_Engine&& __e)
2853        : __e_(_VSTD::move(__e)), __n_(0) {}
2854#endif  // _LIBCPP_CXX03_LANG
2855    _LIBCPP_INLINE_VISIBILITY
2856    explicit discard_block_engine(result_type __sd) : __e_(__sd), __n_(0) {}
2857    template<class _Sseq>
2858        _LIBCPP_INLINE_VISIBILITY
2859        explicit discard_block_engine(_Sseq& __q,
2860        typename enable_if<__is_seed_sequence<_Sseq, discard_block_engine>::value &&
2861                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
2862        : __e_(__q), __n_(0) {}
2863    _LIBCPP_INLINE_VISIBILITY
2864    void seed() {__e_.seed(); __n_ = 0;}
2865    _LIBCPP_INLINE_VISIBILITY
2866    void seed(result_type __sd) {__e_.seed(__sd); __n_ = 0;}
2867    template<class _Sseq>
2868        _LIBCPP_INLINE_VISIBILITY
2869        typename enable_if
2870        <
2871            __is_seed_sequence<_Sseq, discard_block_engine>::value,
2872            void
2873        >::type
2874        seed(_Sseq& __q) {__e_.seed(__q); __n_ = 0;}
2875
2876    // generating functions
2877    result_type operator()();
2878    _LIBCPP_INLINE_VISIBILITY
2879    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
2880
2881    // property functions
2882    _LIBCPP_INLINE_VISIBILITY
2883    const _Engine& base() const _NOEXCEPT {return __e_;}
2884
2885    template<class _Eng, size_t _Pp, size_t _Rp>
2886    friend
2887    bool
2888    operator==(
2889        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2890        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
2891
2892    template<class _Eng, size_t _Pp, size_t _Rp>
2893    friend
2894    bool
2895    operator!=(
2896        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2897        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
2898
2899    template <class _CharT, class _Traits,
2900              class _Eng, size_t _Pp, size_t _Rp>
2901    friend
2902    basic_ostream<_CharT, _Traits>&
2903    operator<<(basic_ostream<_CharT, _Traits>& __os,
2904               const discard_block_engine<_Eng, _Pp, _Rp>& __x);
2905
2906    template <class _CharT, class _Traits,
2907              class _Eng, size_t _Pp, size_t _Rp>
2908    friend
2909    basic_istream<_CharT, _Traits>&
2910    operator>>(basic_istream<_CharT, _Traits>& __is,
2911               discard_block_engine<_Eng, _Pp, _Rp>& __x);
2912};
2913
2914template<class _Engine, size_t __p, size_t __r>
2915    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::block_size;
2916
2917template<class _Engine, size_t __p, size_t __r>
2918    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::used_block;
2919
2920template<class _Engine, size_t __p, size_t __r>
2921typename discard_block_engine<_Engine, __p, __r>::result_type
2922discard_block_engine<_Engine, __p, __r>::operator()()
2923{
2924    if (__n_ >= static_cast<int>(__r))
2925    {
2926        __e_.discard(__p - __r);
2927        __n_ = 0;
2928    }
2929    ++__n_;
2930    return __e_();
2931}
2932
2933template<class _Eng, size_t _Pp, size_t _Rp>
2934inline _LIBCPP_INLINE_VISIBILITY
2935bool
2936operator==(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2937           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
2938{
2939    return __x.__n_ == __y.__n_ && __x.__e_ == __y.__e_;
2940}
2941
2942template<class _Eng, size_t _Pp, size_t _Rp>
2943inline _LIBCPP_INLINE_VISIBILITY
2944bool
2945operator!=(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
2946           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
2947{
2948    return !(__x == __y);
2949}
2950
2951template <class _CharT, class _Traits,
2952          class _Eng, size_t _Pp, size_t _Rp>
2953basic_ostream<_CharT, _Traits>&
2954operator<<(basic_ostream<_CharT, _Traits>& __os,
2955           const discard_block_engine<_Eng, _Pp, _Rp>& __x)
2956{
2957    __save_flags<_CharT, _Traits> __lx(__os);
2958    __os.flags(ios_base::dec | ios_base::left);
2959    _CharT __sp = __os.widen(' ');
2960    __os.fill(__sp);
2961    return __os << __x.__e_ << __sp << __x.__n_;
2962}
2963
2964template <class _CharT, class _Traits,
2965          class _Eng, size_t _Pp, size_t _Rp>
2966basic_istream<_CharT, _Traits>&
2967operator>>(basic_istream<_CharT, _Traits>& __is,
2968           discard_block_engine<_Eng, _Pp, _Rp>& __x)
2969{
2970    __save_flags<_CharT, _Traits> __lx(__is);
2971    __is.flags(ios_base::dec | ios_base::skipws);
2972    _Eng __e;
2973    int __n;
2974    __is >> __e >> __n;
2975    if (!__is.fail())
2976    {
2977        __x.__e_ = __e;
2978        __x.__n_ = __n;
2979    }
2980    return __is;
2981}
2982
2983typedef discard_block_engine<ranlux24_base, 223, 23> ranlux24;
2984typedef discard_block_engine<ranlux48_base, 389, 11> ranlux48;
2985
2986// independent_bits_engine
2987
2988template<class _Engine, size_t __w, class _UIntType>
2989class _LIBCPP_TEMPLATE_VIS independent_bits_engine
2990{
2991    template <class _UInt, _UInt _R0, size_t _Wp, size_t _Mp>
2992    class __get_n
2993    {
2994        static _LIBCPP_CONSTEXPR const size_t _Dt = numeric_limits<_UInt>::digits;
2995        static _LIBCPP_CONSTEXPR const size_t _Np = _Wp / _Mp + (_Wp % _Mp != 0);
2996        static _LIBCPP_CONSTEXPR const size_t _W0 = _Wp / _Np;
2997        static _LIBCPP_CONSTEXPR const _UInt _Y0 = _W0 >= _Dt ? 0 : (_R0 >> _W0) << _W0;
2998    public:
2999        static _LIBCPP_CONSTEXPR const size_t value = _R0 - _Y0 > _Y0 / _Np ? _Np + 1 : _Np;
3000    };
3001public:
3002    // types
3003    typedef _UIntType result_type;
3004
3005private:
3006    _Engine __e_;
3007
3008    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
3009    static_assert(  0 <  __w, "independent_bits_engine invalid parameters");
3010    static_assert(__w <= _Dt, "independent_bits_engine invalid parameters");
3011
3012    typedef typename _Engine::result_type _Engine_result_type;
3013    typedef typename conditional
3014        <
3015            sizeof(_Engine_result_type) <= sizeof(result_type),
3016                result_type,
3017                _Engine_result_type
3018        >::type _Working_result_type;
3019#ifdef _LIBCPP_CXX03_LANG
3020    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
3021                                          + _Working_result_type(1);
3022#else
3023    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
3024                                                            + _Working_result_type(1);
3025#endif
3026    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
3027    static _LIBCPP_CONSTEXPR const size_t __n = __get_n<_Working_result_type, _Rp, __w, __m>::value;
3028    static _LIBCPP_CONSTEXPR const size_t __w0 = __w / __n;
3029    static _LIBCPP_CONSTEXPR const size_t __n0 = __n - __w % __n;
3030    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
3031    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
3032    static _LIBCPP_CONSTEXPR const _Working_result_type __y0 = __w0 >= _WDt ? 0 :
3033                                                               (_Rp >> __w0) << __w0;
3034    static _LIBCPP_CONSTEXPR const _Working_result_type __y1 = __w0 >= _WDt - 1 ? 0 :
3035                                                               (_Rp >> (__w0+1)) << (__w0+1);
3036    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask0 = __w0 > 0 ?
3037                                _Engine_result_type(~0) >> (_EDt - __w0) :
3038                                _Engine_result_type(0);
3039    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask1 = __w0 < _EDt - 1 ?
3040                                _Engine_result_type(~0) >> (_EDt - (__w0 + 1)) :
3041                                _Engine_result_type(~0);
3042public:
3043    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
3044    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
3045                                                      (result_type(1) << __w) - result_type(1);
3046    static_assert(_Min < _Max, "independent_bits_engine invalid parameters");
3047
3048    // engine characteristics
3049    _LIBCPP_INLINE_VISIBILITY
3050    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
3051    _LIBCPP_INLINE_VISIBILITY
3052    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
3053
3054    // constructors and seeding functions
3055    _LIBCPP_INLINE_VISIBILITY
3056    independent_bits_engine() {}
3057    _LIBCPP_INLINE_VISIBILITY
3058    explicit independent_bits_engine(const _Engine& __e)
3059        : __e_(__e) {}
3060#ifndef _LIBCPP_CXX03_LANG
3061    _LIBCPP_INLINE_VISIBILITY
3062    explicit independent_bits_engine(_Engine&& __e)
3063        : __e_(_VSTD::move(__e)) {}
3064#endif  // _LIBCPP_CXX03_LANG
3065    _LIBCPP_INLINE_VISIBILITY
3066    explicit independent_bits_engine(result_type __sd) : __e_(__sd) {}
3067    template<class _Sseq>
3068        _LIBCPP_INLINE_VISIBILITY
3069        explicit independent_bits_engine(_Sseq& __q,
3070        typename enable_if<__is_seed_sequence<_Sseq, independent_bits_engine>::value &&
3071                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
3072         : __e_(__q) {}
3073    _LIBCPP_INLINE_VISIBILITY
3074    void seed() {__e_.seed();}
3075    _LIBCPP_INLINE_VISIBILITY
3076    void seed(result_type __sd) {__e_.seed(__sd);}
3077    template<class _Sseq>
3078        _LIBCPP_INLINE_VISIBILITY
3079        typename enable_if
3080        <
3081            __is_seed_sequence<_Sseq, independent_bits_engine>::value,
3082            void
3083        >::type
3084        seed(_Sseq& __q) {__e_.seed(__q);}
3085
3086    // generating functions
3087    _LIBCPP_INLINE_VISIBILITY
3088    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
3089    _LIBCPP_INLINE_VISIBILITY
3090    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
3091
3092    // property functions
3093    _LIBCPP_INLINE_VISIBILITY
3094    const _Engine& base() const _NOEXCEPT {return __e_;}
3095
3096    template<class _Eng, size_t _Wp, class _UInt>
3097    friend
3098    bool
3099    operator==(
3100        const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3101        const independent_bits_engine<_Eng, _Wp, _UInt>& __y);
3102
3103    template<class _Eng, size_t _Wp, class _UInt>
3104    friend
3105    bool
3106    operator!=(
3107        const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3108        const independent_bits_engine<_Eng, _Wp, _UInt>& __y);
3109
3110    template <class _CharT, class _Traits,
3111              class _Eng, size_t _Wp, class _UInt>
3112    friend
3113    basic_ostream<_CharT, _Traits>&
3114    operator<<(basic_ostream<_CharT, _Traits>& __os,
3115               const independent_bits_engine<_Eng, _Wp, _UInt>& __x);
3116
3117    template <class _CharT, class _Traits,
3118              class _Eng, size_t _Wp, class _UInt>
3119    friend
3120    basic_istream<_CharT, _Traits>&
3121    operator>>(basic_istream<_CharT, _Traits>& __is,
3122               independent_bits_engine<_Eng, _Wp, _UInt>& __x);
3123
3124private:
3125    _LIBCPP_INLINE_VISIBILITY
3126    result_type __eval(false_type);
3127    result_type __eval(true_type);
3128
3129    template <size_t __count>
3130        _LIBCPP_INLINE_VISIBILITY
3131        static
3132        typename enable_if
3133        <
3134            __count < _Dt,
3135            result_type
3136        >::type
3137        __lshift(result_type __x) {return __x << __count;}
3138
3139    template <size_t __count>
3140        _LIBCPP_INLINE_VISIBILITY
3141        static
3142        typename enable_if
3143        <
3144            (__count >= _Dt),
3145            result_type
3146        >::type
3147        __lshift(result_type) {return result_type(0);}
3148};
3149
3150template<class _Engine, size_t __w, class _UIntType>
3151inline
3152_UIntType
3153independent_bits_engine<_Engine, __w, _UIntType>::__eval(false_type)
3154{
3155    return static_cast<result_type>(__e_() & __mask0);
3156}
3157
3158template<class _Engine, size_t __w, class _UIntType>
3159_UIntType
3160independent_bits_engine<_Engine, __w, _UIntType>::__eval(true_type)
3161{
3162    result_type _Sp = 0;
3163    for (size_t __k = 0; __k < __n0; ++__k)
3164    {
3165        _Engine_result_type __u;
3166        do
3167        {
3168            __u = __e_() - _Engine::min();
3169        } while (__u >= __y0);
3170        _Sp = static_cast<result_type>(__lshift<__w0>(_Sp) + (__u & __mask0));
3171    }
3172    for (size_t __k = __n0; __k < __n; ++__k)
3173    {
3174        _Engine_result_type __u;
3175        do
3176        {
3177            __u = __e_() - _Engine::min();
3178        } while (__u >= __y1);
3179        _Sp = static_cast<result_type>(__lshift<__w0+1>(_Sp) + (__u & __mask1));
3180    }
3181    return _Sp;
3182}
3183
3184template<class _Eng, size_t _Wp, class _UInt>
3185inline _LIBCPP_INLINE_VISIBILITY
3186bool
3187operator==(
3188    const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3189    const independent_bits_engine<_Eng, _Wp, _UInt>& __y)
3190{
3191    return __x.base() == __y.base();
3192}
3193
3194template<class _Eng, size_t _Wp, class _UInt>
3195inline _LIBCPP_INLINE_VISIBILITY
3196bool
3197operator!=(
3198    const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
3199    const independent_bits_engine<_Eng, _Wp, _UInt>& __y)
3200{
3201    return !(__x == __y);
3202}
3203
3204template <class _CharT, class _Traits,
3205          class _Eng, size_t _Wp, class _UInt>
3206basic_ostream<_CharT, _Traits>&
3207operator<<(basic_ostream<_CharT, _Traits>& __os,
3208           const independent_bits_engine<_Eng, _Wp, _UInt>& __x)
3209{
3210    return __os << __x.base();
3211}
3212
3213template <class _CharT, class _Traits,
3214          class _Eng, size_t _Wp, class _UInt>
3215basic_istream<_CharT, _Traits>&
3216operator>>(basic_istream<_CharT, _Traits>& __is,
3217           independent_bits_engine<_Eng, _Wp, _UInt>& __x)
3218{
3219    _Eng __e;
3220    __is >> __e;
3221    if (!__is.fail())
3222        __x.__e_ = __e;
3223    return __is;
3224}
3225
3226// shuffle_order_engine
3227
3228template <uint64_t _Xp, uint64_t _Yp>
3229struct __ugcd
3230{
3231    static _LIBCPP_CONSTEXPR const uint64_t value = __ugcd<_Yp, _Xp % _Yp>::value;
3232};
3233
3234template <uint64_t _Xp>
3235struct __ugcd<_Xp, 0>
3236{
3237    static _LIBCPP_CONSTEXPR const uint64_t value = _Xp;
3238};
3239
3240template <uint64_t _Np, uint64_t _Dp>
3241class __uratio
3242{
3243    static_assert(_Dp != 0, "__uratio divide by 0");
3244    static _LIBCPP_CONSTEXPR const uint64_t __gcd = __ugcd<_Np, _Dp>::value;
3245public:
3246    static _LIBCPP_CONSTEXPR const uint64_t num = _Np / __gcd;
3247    static _LIBCPP_CONSTEXPR const uint64_t den = _Dp / __gcd;
3248
3249    typedef __uratio<num, den> type;
3250};
3251
3252template<class _Engine, size_t __k>
3253class _LIBCPP_TEMPLATE_VIS shuffle_order_engine
3254{
3255    static_assert(0 < __k, "shuffle_order_engine invalid parameters");
3256public:
3257    // types
3258    typedef typename _Engine::result_type result_type;
3259
3260private:
3261    _Engine __e_;
3262    result_type _V_[__k];
3263    result_type _Y_;
3264
3265public:
3266    // engine characteristics
3267    static _LIBCPP_CONSTEXPR const size_t table_size = __k;
3268
3269#ifdef _LIBCPP_CXX03_LANG
3270    static const result_type _Min = _Engine::_Min;
3271    static const result_type _Max = _Engine::_Max;
3272#else
3273    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
3274    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
3275#endif
3276    static_assert(_Min < _Max, "shuffle_order_engine invalid parameters");
3277    _LIBCPP_INLINE_VISIBILITY
3278    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
3279    _LIBCPP_INLINE_VISIBILITY
3280    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
3281
3282    static _LIBCPP_CONSTEXPR const unsigned long long _Rp = _Max - _Min + 1ull;
3283
3284    // constructors and seeding functions
3285    _LIBCPP_INLINE_VISIBILITY
3286    shuffle_order_engine() {__init();}
3287    _LIBCPP_INLINE_VISIBILITY
3288    explicit shuffle_order_engine(const _Engine& __e)
3289        : __e_(__e) {__init();}
3290#ifndef _LIBCPP_CXX03_LANG
3291    _LIBCPP_INLINE_VISIBILITY
3292    explicit shuffle_order_engine(_Engine&& __e)
3293        : __e_(_VSTD::move(__e)) {__init();}
3294#endif  // _LIBCPP_CXX03_LANG
3295    _LIBCPP_INLINE_VISIBILITY
3296    explicit shuffle_order_engine(result_type __sd) : __e_(__sd) {__init();}
3297    template<class _Sseq>
3298        _LIBCPP_INLINE_VISIBILITY
3299        explicit shuffle_order_engine(_Sseq& __q,
3300        typename enable_if<__is_seed_sequence<_Sseq, shuffle_order_engine>::value &&
3301                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
3302         : __e_(__q) {__init();}
3303    _LIBCPP_INLINE_VISIBILITY
3304    void seed() {__e_.seed(); __init();}
3305    _LIBCPP_INLINE_VISIBILITY
3306    void seed(result_type __sd) {__e_.seed(__sd); __init();}
3307    template<class _Sseq>
3308        _LIBCPP_INLINE_VISIBILITY
3309        typename enable_if
3310        <
3311            __is_seed_sequence<_Sseq, shuffle_order_engine>::value,
3312            void
3313        >::type
3314        seed(_Sseq& __q) {__e_.seed(__q); __init();}
3315
3316    // generating functions
3317    _LIBCPP_INLINE_VISIBILITY
3318    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
3319    _LIBCPP_INLINE_VISIBILITY
3320    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
3321
3322    // property functions
3323    _LIBCPP_INLINE_VISIBILITY
3324    const _Engine& base() const _NOEXCEPT {return __e_;}
3325
3326private:
3327    template<class _Eng, size_t _Kp>
3328    friend
3329    bool
3330    operator==(
3331        const shuffle_order_engine<_Eng, _Kp>& __x,
3332        const shuffle_order_engine<_Eng, _Kp>& __y);
3333
3334    template<class _Eng, size_t _Kp>
3335    friend
3336    bool
3337    operator!=(
3338        const shuffle_order_engine<_Eng, _Kp>& __x,
3339        const shuffle_order_engine<_Eng, _Kp>& __y);
3340
3341    template <class _CharT, class _Traits,
3342              class _Eng, size_t _Kp>
3343    friend
3344    basic_ostream<_CharT, _Traits>&
3345    operator<<(basic_ostream<_CharT, _Traits>& __os,
3346               const shuffle_order_engine<_Eng, _Kp>& __x);
3347
3348    template <class _CharT, class _Traits,
3349              class _Eng, size_t _Kp>
3350    friend
3351    basic_istream<_CharT, _Traits>&
3352    operator>>(basic_istream<_CharT, _Traits>& __is,
3353               shuffle_order_engine<_Eng, _Kp>& __x);
3354
3355    _LIBCPP_INLINE_VISIBILITY
3356    void __init()
3357    {
3358        for (size_t __i = 0; __i < __k; ++__i)
3359            _V_[__i] = __e_();
3360        _Y_ = __e_();
3361    }
3362
3363    _LIBCPP_INLINE_VISIBILITY
3364    result_type __eval(false_type) {return __eval2(integral_constant<bool, __k & 1>());}
3365    _LIBCPP_INLINE_VISIBILITY
3366    result_type __eval(true_type) {return __eval(__uratio<__k, _Rp>());}
3367
3368    _LIBCPP_INLINE_VISIBILITY
3369    result_type __eval2(false_type) {return __eval(__uratio<__k/2, 0x8000000000000000ull>());}
3370    _LIBCPP_INLINE_VISIBILITY
3371    result_type __eval2(true_type) {return __evalf<__k, 0>();}
3372
3373    template <uint64_t _Np, uint64_t _Dp>
3374        _LIBCPP_INLINE_VISIBILITY
3375        typename enable_if
3376        <
3377            (__uratio<_Np, _Dp>::num > 0xFFFFFFFFFFFFFFFFull / (_Max - _Min)),
3378            result_type
3379        >::type
3380        __eval(__uratio<_Np, _Dp>)
3381            {return __evalf<__uratio<_Np, _Dp>::num, __uratio<_Np, _Dp>::den>();}
3382
3383    template <uint64_t _Np, uint64_t _Dp>
3384        _LIBCPP_INLINE_VISIBILITY
3385        typename enable_if
3386        <
3387            __uratio<_Np, _Dp>::num <= 0xFFFFFFFFFFFFFFFFull / (_Max - _Min),
3388            result_type
3389        >::type
3390        __eval(__uratio<_Np, _Dp>)
3391        {
3392            const size_t __j = static_cast<size_t>(__uratio<_Np, _Dp>::num * (_Y_ - _Min)
3393                                                   / __uratio<_Np, _Dp>::den);
3394            _Y_ = _V_[__j];
3395            _V_[__j] = __e_();
3396            return _Y_;
3397        }
3398
3399    template <uint64_t __n, uint64_t __d>
3400        _LIBCPP_INLINE_VISIBILITY
3401        result_type __evalf()
3402        {
3403            const double _Fp = __d == 0 ?
3404                __n / (2. * 0x8000000000000000ull) :
3405                __n / (double)__d;
3406            const size_t __j = static_cast<size_t>(_Fp * (_Y_ - _Min));
3407            _Y_ = _V_[__j];
3408            _V_[__j] = __e_();
3409            return _Y_;
3410        }
3411};
3412
3413template<class _Engine, size_t __k>
3414    _LIBCPP_CONSTEXPR const size_t shuffle_order_engine<_Engine, __k>::table_size;
3415
3416template<class _Eng, size_t _Kp>
3417bool
3418operator==(
3419    const shuffle_order_engine<_Eng, _Kp>& __x,
3420    const shuffle_order_engine<_Eng, _Kp>& __y)
3421{
3422    return __x._Y_ == __y._Y_ && _VSTD::equal(__x._V_, __x._V_ + _Kp, __y._V_) &&
3423           __x.__e_ == __y.__e_;
3424}
3425
3426template<class _Eng, size_t _Kp>
3427inline _LIBCPP_INLINE_VISIBILITY
3428bool
3429operator!=(
3430    const shuffle_order_engine<_Eng, _Kp>& __x,
3431    const shuffle_order_engine<_Eng, _Kp>& __y)
3432{
3433    return !(__x == __y);
3434}
3435
3436template <class _CharT, class _Traits,
3437          class _Eng, size_t _Kp>
3438basic_ostream<_CharT, _Traits>&
3439operator<<(basic_ostream<_CharT, _Traits>& __os,
3440           const shuffle_order_engine<_Eng, _Kp>& __x)
3441{
3442    __save_flags<_CharT, _Traits> __lx(__os);
3443    __os.flags(ios_base::dec | ios_base::left);
3444    _CharT __sp = __os.widen(' ');
3445    __os.fill(__sp);
3446    __os << __x.__e_ << __sp << __x._V_[0];
3447    for (size_t __i = 1; __i < _Kp; ++__i)
3448        __os << __sp << __x._V_[__i];
3449    return __os << __sp << __x._Y_;
3450}
3451
3452template <class _CharT, class _Traits,
3453          class _Eng, size_t _Kp>
3454basic_istream<_CharT, _Traits>&
3455operator>>(basic_istream<_CharT, _Traits>& __is,
3456           shuffle_order_engine<_Eng, _Kp>& __x)
3457{
3458    typedef typename shuffle_order_engine<_Eng, _Kp>::result_type result_type;
3459    __save_flags<_CharT, _Traits> __lx(__is);
3460    __is.flags(ios_base::dec | ios_base::skipws);
3461    _Eng __e;
3462    result_type _Vp[_Kp+1];
3463    __is >> __e;
3464    for (size_t __i = 0; __i < _Kp+1; ++__i)
3465        __is >> _Vp[__i];
3466    if (!__is.fail())
3467    {
3468        __x.__e_ = __e;
3469        for (size_t __i = 0; __i < _Kp; ++__i)
3470            __x._V_[__i] = _Vp[__i];
3471        __x._Y_ = _Vp[_Kp];
3472    }
3473    return __is;
3474}
3475
3476typedef shuffle_order_engine<minstd_rand0, 256>                         knuth_b;
3477
3478// random_device
3479
3480class _LIBCPP_TYPE_VIS random_device
3481{
3482#ifdef _LIBCPP_USING_DEV_RANDOM
3483    int __f_;
3484#endif // defined(_LIBCPP_USING_DEV_RANDOM)
3485public:
3486    // types
3487    typedef unsigned result_type;
3488
3489    // generator characteristics
3490    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
3491    static _LIBCPP_CONSTEXPR const result_type _Max = 0xFFFFFFFFu;
3492
3493    _LIBCPP_INLINE_VISIBILITY
3494    static _LIBCPP_CONSTEXPR result_type min() { return _Min;}
3495    _LIBCPP_INLINE_VISIBILITY
3496    static _LIBCPP_CONSTEXPR result_type max() { return _Max;}
3497
3498    // constructors
3499    explicit random_device(const string& __token = "/dev/urandom");
3500    ~random_device();
3501
3502    // generating functions
3503    result_type operator()();
3504
3505    // property functions
3506    double entropy() const _NOEXCEPT;
3507
3508private:
3509    // no copy functions
3510    random_device(const random_device&); // = delete;
3511    random_device& operator=(const random_device&); // = delete;
3512};
3513
3514// seed_seq
3515
3516class _LIBCPP_TEMPLATE_VIS seed_seq
3517{
3518public:
3519    // types
3520    typedef uint32_t result_type;
3521
3522private:
3523    vector<result_type> __v_;
3524
3525    template<class _InputIterator>
3526        void init(_InputIterator __first, _InputIterator __last);
3527public:
3528    // constructors
3529    _LIBCPP_INLINE_VISIBILITY
3530    seed_seq() _NOEXCEPT {}
3531#ifndef _LIBCPP_CXX03_LANG
3532    template<class _Tp>
3533        _LIBCPP_INLINE_VISIBILITY
3534        seed_seq(initializer_list<_Tp> __il) {init(__il.begin(), __il.end());}
3535#endif  // _LIBCPP_CXX03_LANG
3536
3537    template<class _InputIterator>
3538        _LIBCPP_INLINE_VISIBILITY
3539        seed_seq(_InputIterator __first, _InputIterator __last)
3540             {init(__first, __last);}
3541
3542    // generating functions
3543    template<class _RandomAccessIterator>
3544        void generate(_RandomAccessIterator __first, _RandomAccessIterator __last);
3545
3546    // property functions
3547    _LIBCPP_INLINE_VISIBILITY
3548    size_t size() const _NOEXCEPT {return __v_.size();}
3549    template<class _OutputIterator>
3550        _LIBCPP_INLINE_VISIBILITY
3551        void param(_OutputIterator __dest) const
3552            {_VSTD::copy(__v_.begin(), __v_.end(), __dest);}
3553
3554private:
3555    // no copy functions
3556    seed_seq(const seed_seq&); // = delete;
3557    void operator=(const seed_seq&); // = delete;
3558
3559    _LIBCPP_INLINE_VISIBILITY
3560    static result_type _Tp(result_type __x) {return __x ^ (__x >> 27);}
3561};
3562
3563template<class _InputIterator>
3564void
3565seed_seq::init(_InputIterator __first, _InputIterator __last)
3566{
3567    for (_InputIterator __s = __first; __s != __last; ++__s)
3568        __v_.push_back(*__s & 0xFFFFFFFF);
3569}
3570
3571template<class _RandomAccessIterator>
3572void
3573seed_seq::generate(_RandomAccessIterator __first, _RandomAccessIterator __last)
3574{
3575    if (__first != __last)
3576    {
3577        _VSTD::fill(__first, __last, 0x8b8b8b8b);
3578        const size_t __n = static_cast<size_t>(__last - __first);
3579        const size_t __s = __v_.size();
3580        const size_t __t = (__n >= 623) ? 11
3581                         : (__n >= 68) ? 7
3582                         : (__n >= 39) ? 5
3583                         : (__n >= 7)  ? 3
3584                         : (__n - 1) / 2;
3585        const size_t __p = (__n - __t) / 2;
3586        const size_t __q = __p + __t;
3587        const size_t __m = _VSTD::max(__s + 1, __n);
3588        // __k = 0;
3589        {
3590            result_type __r = 1664525 * _Tp(__first[0] ^ __first[__p]
3591                                                      ^  __first[__n - 1]);
3592            __first[__p] += __r;
3593            __r += __s;
3594            __first[__q] += __r;
3595            __first[0] = __r;
3596        }
3597        for (size_t __k = 1; __k <= __s; ++__k)
3598        {
3599            const size_t __kmodn = __k % __n;
3600            const size_t __kpmodn = (__k + __p) % __n;
3601            result_type __r = 1664525 * _Tp(__first[__kmodn] ^ __first[__kpmodn]
3602                                           ^ __first[(__k - 1) % __n]);
3603            __first[__kpmodn] += __r;
3604            __r +=  __kmodn + __v_[__k-1];
3605            __first[(__k + __q) % __n] += __r;
3606            __first[__kmodn] = __r;
3607        }
3608        for (size_t __k = __s + 1; __k < __m; ++__k)
3609        {
3610            const size_t __kmodn = __k % __n;
3611            const size_t __kpmodn = (__k + __p) % __n;
3612            result_type __r = 1664525 * _Tp(__first[__kmodn] ^ __first[__kpmodn]
3613                                           ^ __first[(__k - 1) % __n]);
3614            __first[__kpmodn] += __r;
3615            __r +=  __kmodn;
3616            __first[(__k + __q) % __n] += __r;
3617            __first[__kmodn] = __r;
3618        }
3619        for (size_t __k = __m; __k < __m + __n; ++__k)
3620        {
3621            const size_t __kmodn = __k % __n;
3622            const size_t __kpmodn = (__k + __p) % __n;
3623            result_type __r = 1566083941 * _Tp(__first[__kmodn] +
3624                                              __first[__kpmodn] +
3625                                              __first[(__k - 1) % __n]);
3626            __first[__kpmodn] ^= __r;
3627            __r -= __kmodn;
3628            __first[(__k + __q) % __n] ^= __r;
3629            __first[__kmodn] = __r;
3630        }
3631    }
3632}
3633
3634// generate_canonical
3635
3636template<class _RealType, size_t __bits, class _URNG>
3637_RealType
3638generate_canonical(_URNG& __g)
3639{
3640    const size_t _Dt = numeric_limits<_RealType>::digits;
3641    const size_t __b = _Dt < __bits ? _Dt : __bits;
3642#ifdef _LIBCPP_CXX03_LANG
3643    const size_t __logR = __log2<uint64_t, _URNG::_Max - _URNG::_Min + uint64_t(1)>::value;
3644#else
3645    const size_t __logR = __log2<uint64_t, _URNG::max() - _URNG::min() + uint64_t(1)>::value;
3646#endif
3647    const size_t __k = __b / __logR + (__b % __logR != 0) + (__b == 0);
3648    const _RealType _Rp = _URNG::max() - _URNG::min() + _RealType(1);
3649    _RealType __base = _Rp;
3650    _RealType _Sp = __g() - _URNG::min();
3651    for (size_t __i = 1; __i < __k; ++__i, __base *= _Rp)
3652        _Sp += (__g() - _URNG::min()) * __base;
3653    return _Sp / __base;
3654}
3655
3656// uniform_int_distribution
3657
3658// in <algorithm>
3659
3660template <class _CharT, class _Traits, class _IT>
3661basic_ostream<_CharT, _Traits>&
3662operator<<(basic_ostream<_CharT, _Traits>& __os,
3663           const uniform_int_distribution<_IT>& __x)
3664{
3665    __save_flags<_CharT, _Traits> __lx(__os);
3666    __os.flags(ios_base::dec | ios_base::left);
3667    _CharT __sp = __os.widen(' ');
3668    __os.fill(__sp);
3669    return __os << __x.a() << __sp << __x.b();
3670}
3671
3672template <class _CharT, class _Traits, class _IT>
3673basic_istream<_CharT, _Traits>&
3674operator>>(basic_istream<_CharT, _Traits>& __is,
3675           uniform_int_distribution<_IT>& __x)
3676{
3677    typedef uniform_int_distribution<_IT> _Eng;
3678    typedef typename _Eng::result_type result_type;
3679    typedef typename _Eng::param_type param_type;
3680    __save_flags<_CharT, _Traits> __lx(__is);
3681    __is.flags(ios_base::dec | ios_base::skipws);
3682    result_type __a;
3683    result_type __b;
3684    __is >> __a >> __b;
3685    if (!__is.fail())
3686        __x.param(param_type(__a, __b));
3687    return __is;
3688}
3689
3690// uniform_real_distribution
3691
3692template<class _RealType = double>
3693class _LIBCPP_TEMPLATE_VIS uniform_real_distribution
3694{
3695public:
3696    // types
3697    typedef _RealType result_type;
3698
3699    class _LIBCPP_TEMPLATE_VIS param_type
3700    {
3701        result_type __a_;
3702        result_type __b_;
3703    public:
3704        typedef uniform_real_distribution distribution_type;
3705
3706        _LIBCPP_INLINE_VISIBILITY
3707        explicit param_type(result_type __a = 0,
3708                            result_type __b = 1)
3709            : __a_(__a), __b_(__b) {}
3710
3711        _LIBCPP_INLINE_VISIBILITY
3712        result_type a() const {return __a_;}
3713        _LIBCPP_INLINE_VISIBILITY
3714        result_type b() const {return __b_;}
3715
3716        friend _LIBCPP_INLINE_VISIBILITY
3717        bool operator==(const param_type& __x, const param_type& __y)
3718            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
3719        friend _LIBCPP_INLINE_VISIBILITY
3720        bool operator!=(const param_type& __x, const param_type& __y)
3721            {return !(__x == __y);}
3722    };
3723
3724private:
3725    param_type __p_;
3726
3727public:
3728    // constructors and reset functions
3729    _LIBCPP_INLINE_VISIBILITY
3730    explicit uniform_real_distribution(result_type __a = 0, result_type __b = 1)
3731        : __p_(param_type(__a, __b)) {}
3732    _LIBCPP_INLINE_VISIBILITY
3733    explicit uniform_real_distribution(const param_type& __p) : __p_(__p) {}
3734    _LIBCPP_INLINE_VISIBILITY
3735    void reset() {}
3736
3737    // generating functions
3738    template<class _URNG>
3739        _LIBCPP_INLINE_VISIBILITY
3740        result_type operator()(_URNG& __g)
3741        {return (*this)(__g, __p_);}
3742    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
3743
3744    // property functions
3745    _LIBCPP_INLINE_VISIBILITY
3746    result_type a() const {return __p_.a();}
3747    _LIBCPP_INLINE_VISIBILITY
3748    result_type b() const {return __p_.b();}
3749
3750    _LIBCPP_INLINE_VISIBILITY
3751    param_type param() const {return __p_;}
3752    _LIBCPP_INLINE_VISIBILITY
3753    void param(const param_type& __p) {__p_ = __p;}
3754
3755    _LIBCPP_INLINE_VISIBILITY
3756    result_type min() const {return a();}
3757    _LIBCPP_INLINE_VISIBILITY
3758    result_type max() const {return b();}
3759
3760    friend _LIBCPP_INLINE_VISIBILITY
3761        bool operator==(const uniform_real_distribution& __x,
3762                        const uniform_real_distribution& __y)
3763        {return __x.__p_ == __y.__p_;}
3764    friend _LIBCPP_INLINE_VISIBILITY
3765        bool operator!=(const uniform_real_distribution& __x,
3766                        const uniform_real_distribution& __y)
3767        {return !(__x == __y);}
3768};
3769
3770template<class _RealType>
3771template<class _URNG>
3772inline
3773typename uniform_real_distribution<_RealType>::result_type
3774uniform_real_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
3775{
3776    return (__p.b() - __p.a())
3777        * _VSTD::generate_canonical<_RealType, numeric_limits<_RealType>::digits>(__g)
3778        + __p.a();
3779}
3780
3781template <class _CharT, class _Traits, class _RT>
3782basic_ostream<_CharT, _Traits>&
3783operator<<(basic_ostream<_CharT, _Traits>& __os,
3784           const uniform_real_distribution<_RT>& __x)
3785{
3786    __save_flags<_CharT, _Traits> __lx(__os);
3787    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
3788               ios_base::scientific);
3789    _CharT __sp = __os.widen(' ');
3790    __os.fill(__sp);
3791    return __os << __x.a() << __sp << __x.b();
3792}
3793
3794template <class _CharT, class _Traits, class _RT>
3795basic_istream<_CharT, _Traits>&
3796operator>>(basic_istream<_CharT, _Traits>& __is,
3797           uniform_real_distribution<_RT>& __x)
3798{
3799    typedef uniform_real_distribution<_RT> _Eng;
3800    typedef typename _Eng::result_type result_type;
3801    typedef typename _Eng::param_type param_type;
3802    __save_flags<_CharT, _Traits> __lx(__is);
3803    __is.flags(ios_base::dec | ios_base::skipws);
3804    result_type __a;
3805    result_type __b;
3806    __is >> __a >> __b;
3807    if (!__is.fail())
3808        __x.param(param_type(__a, __b));
3809    return __is;
3810}
3811
3812// bernoulli_distribution
3813
3814class _LIBCPP_TEMPLATE_VIS bernoulli_distribution
3815{
3816public:
3817    // types
3818    typedef bool result_type;
3819
3820    class _LIBCPP_TEMPLATE_VIS param_type
3821    {
3822        double __p_;
3823    public:
3824        typedef bernoulli_distribution distribution_type;
3825
3826        _LIBCPP_INLINE_VISIBILITY
3827        explicit param_type(double __p = 0.5) : __p_(__p) {}
3828
3829        _LIBCPP_INLINE_VISIBILITY
3830        double p() const {return __p_;}
3831
3832        friend _LIBCPP_INLINE_VISIBILITY
3833            bool operator==(const param_type& __x, const param_type& __y)
3834            {return __x.__p_ == __y.__p_;}
3835        friend _LIBCPP_INLINE_VISIBILITY
3836            bool operator!=(const param_type& __x, const param_type& __y)
3837            {return !(__x == __y);}
3838    };
3839
3840private:
3841    param_type __p_;
3842
3843public:
3844    // constructors and reset functions
3845    _LIBCPP_INLINE_VISIBILITY
3846    explicit bernoulli_distribution(double __p = 0.5)
3847        : __p_(param_type(__p)) {}
3848    _LIBCPP_INLINE_VISIBILITY
3849    explicit bernoulli_distribution(const param_type& __p) : __p_(__p) {}
3850    _LIBCPP_INLINE_VISIBILITY
3851    void reset() {}
3852
3853    // generating functions
3854    template<class _URNG>
3855        _LIBCPP_INLINE_VISIBILITY
3856        result_type operator()(_URNG& __g)
3857        {return (*this)(__g, __p_);}
3858    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
3859
3860    // property functions
3861    _LIBCPP_INLINE_VISIBILITY
3862    double p() const {return __p_.p();}
3863
3864    _LIBCPP_INLINE_VISIBILITY
3865    param_type param() const {return __p_;}
3866    _LIBCPP_INLINE_VISIBILITY
3867    void param(const param_type& __p) {__p_ = __p;}
3868
3869    _LIBCPP_INLINE_VISIBILITY
3870    result_type min() const {return false;}
3871    _LIBCPP_INLINE_VISIBILITY
3872    result_type max() const {return true;}
3873
3874    friend _LIBCPP_INLINE_VISIBILITY
3875        bool operator==(const bernoulli_distribution& __x,
3876                        const bernoulli_distribution& __y)
3877        {return __x.__p_ == __y.__p_;}
3878    friend _LIBCPP_INLINE_VISIBILITY
3879        bool operator!=(const bernoulli_distribution& __x,
3880                        const bernoulli_distribution& __y)
3881        {return !(__x == __y);}
3882};
3883
3884template<class _URNG>
3885inline
3886bernoulli_distribution::result_type
3887bernoulli_distribution::operator()(_URNG& __g, const param_type& __p)
3888{
3889    uniform_real_distribution<double> __gen;
3890    return __gen(__g) < __p.p();
3891}
3892
3893template <class _CharT, class _Traits>
3894basic_ostream<_CharT, _Traits>&
3895operator<<(basic_ostream<_CharT, _Traits>& __os, const bernoulli_distribution& __x)
3896{
3897    __save_flags<_CharT, _Traits> __lx(__os);
3898    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
3899               ios_base::scientific);
3900    _CharT __sp = __os.widen(' ');
3901    __os.fill(__sp);
3902    return __os << __x.p();
3903}
3904
3905template <class _CharT, class _Traits>
3906basic_istream<_CharT, _Traits>&
3907operator>>(basic_istream<_CharT, _Traits>& __is, bernoulli_distribution& __x)
3908{
3909    typedef bernoulli_distribution _Eng;
3910    typedef typename _Eng::param_type param_type;
3911    __save_flags<_CharT, _Traits> __lx(__is);
3912    __is.flags(ios_base::dec | ios_base::skipws);
3913    double __p;
3914    __is >> __p;
3915    if (!__is.fail())
3916        __x.param(param_type(__p));
3917    return __is;
3918}
3919
3920// binomial_distribution
3921
3922template<class _IntType = int>
3923class _LIBCPP_TEMPLATE_VIS binomial_distribution
3924{
3925public:
3926    // types
3927    typedef _IntType result_type;
3928
3929    class _LIBCPP_TEMPLATE_VIS param_type
3930    {
3931        result_type __t_;
3932        double __p_;
3933        double __pr_;
3934        double __odds_ratio_;
3935        result_type __r0_;
3936    public:
3937        typedef binomial_distribution distribution_type;
3938
3939        explicit param_type(result_type __t = 1, double __p = 0.5);
3940
3941        _LIBCPP_INLINE_VISIBILITY
3942        result_type t() const {return __t_;}
3943        _LIBCPP_INLINE_VISIBILITY
3944        double p() const {return __p_;}
3945
3946        friend _LIBCPP_INLINE_VISIBILITY
3947            bool operator==(const param_type& __x, const param_type& __y)
3948            {return __x.__t_ == __y.__t_ && __x.__p_ == __y.__p_;}
3949        friend _LIBCPP_INLINE_VISIBILITY
3950            bool operator!=(const param_type& __x, const param_type& __y)
3951            {return !(__x == __y);}
3952
3953        friend class binomial_distribution;
3954    };
3955
3956private:
3957    param_type __p_;
3958
3959public:
3960    // constructors and reset functions
3961    _LIBCPP_INLINE_VISIBILITY
3962    explicit binomial_distribution(result_type __t = 1, double __p = 0.5)
3963        : __p_(param_type(__t, __p)) {}
3964    _LIBCPP_INLINE_VISIBILITY
3965    explicit binomial_distribution(const param_type& __p) : __p_(__p) {}
3966    _LIBCPP_INLINE_VISIBILITY
3967    void reset() {}
3968
3969    // generating functions
3970    template<class _URNG>
3971        _LIBCPP_INLINE_VISIBILITY
3972        result_type operator()(_URNG& __g)
3973        {return (*this)(__g, __p_);}
3974    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
3975
3976    // property functions
3977    _LIBCPP_INLINE_VISIBILITY
3978    result_type t() const {return __p_.t();}
3979    _LIBCPP_INLINE_VISIBILITY
3980    double p() const {return __p_.p();}
3981
3982    _LIBCPP_INLINE_VISIBILITY
3983    param_type param() const {return __p_;}
3984    _LIBCPP_INLINE_VISIBILITY
3985    void param(const param_type& __p) {__p_ = __p;}
3986
3987    _LIBCPP_INLINE_VISIBILITY
3988    result_type min() const {return 0;}
3989    _LIBCPP_INLINE_VISIBILITY
3990    result_type max() const {return t();}
3991
3992    friend _LIBCPP_INLINE_VISIBILITY
3993        bool operator==(const binomial_distribution& __x,
3994                        const binomial_distribution& __y)
3995        {return __x.__p_ == __y.__p_;}
3996    friend _LIBCPP_INLINE_VISIBILITY
3997        bool operator!=(const binomial_distribution& __x,
3998                        const binomial_distribution& __y)
3999        {return !(__x == __y);}
4000};
4001
4002#ifndef _LIBCPP_MSVCRT
4003extern "C" double lgamma_r(double, int *);
4004#endif
4005
4006inline _LIBCPP_INLINE_VISIBILITY double __libcpp_lgamma(double __d) {
4007#if defined(_LIBCPP_MSVCRT)
4008  return lgamma(__d);
4009#else
4010  int __sign;
4011  return lgamma_r(__d, &__sign);
4012#endif
4013}
4014
4015template<class _IntType>
4016binomial_distribution<_IntType>::param_type::param_type(const result_type __t, const double __p)
4017    : __t_(__t), __p_(__p)
4018{
4019    if (0 < __p_ && __p_ < 1)
4020    {
4021        __r0_ = static_cast<result_type>((__t_ + 1) * __p_);
4022        __pr_ = _VSTD::exp(__libcpp_lgamma(__t_ + 1.) -
4023                           __libcpp_lgamma(__r0_ + 1.) -
4024                           __libcpp_lgamma(__t_ - __r0_ + 1.) + __r0_ * _VSTD::log(__p_) +
4025                           (__t_ - __r0_) * _VSTD::log(1 - __p_));
4026        __odds_ratio_ = __p_ / (1 - __p_);
4027    }
4028}
4029
4030// Reference: Kemp, C.D. (1986). `A modal method for generating binomial
4031//           variables', Commun. Statist. - Theor. Meth. 15(3), 805-813.
4032template<class _IntType>
4033template<class _URNG>
4034_IntType
4035binomial_distribution<_IntType>::operator()(_URNG& __g, const param_type& __pr)
4036{
4037    if (__pr.__t_ == 0 || __pr.__p_ == 0)
4038        return 0;
4039    if (__pr.__p_ == 1)
4040        return __pr.__t_;
4041    uniform_real_distribution<double> __gen;
4042    double __u = __gen(__g) - __pr.__pr_;
4043    if (__u < 0)
4044        return __pr.__r0_;
4045    double __pu = __pr.__pr_;
4046    double __pd = __pu;
4047    result_type __ru = __pr.__r0_;
4048    result_type __rd = __ru;
4049    while (true)
4050    {
4051        if (__rd >= 1)
4052        {
4053            __pd *= __rd / (__pr.__odds_ratio_ * (__pr.__t_ - __rd + 1));
4054            __u -= __pd;
4055            if (__u < 0)
4056                return __rd - 1;
4057        }
4058        if ( __rd != 0 )
4059            --__rd;
4060        ++__ru;
4061        if (__ru <= __pr.__t_)
4062        {
4063            __pu *= (__pr.__t_ - __ru + 1) * __pr.__odds_ratio_ / __ru;
4064            __u -= __pu;
4065            if (__u < 0)
4066                return __ru;
4067        }
4068    }
4069}
4070
4071template <class _CharT, class _Traits, class _IntType>
4072basic_ostream<_CharT, _Traits>&
4073operator<<(basic_ostream<_CharT, _Traits>& __os,
4074           const binomial_distribution<_IntType>& __x)
4075{
4076    __save_flags<_CharT, _Traits> __lx(__os);
4077    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4078               ios_base::scientific);
4079    _CharT __sp = __os.widen(' ');
4080    __os.fill(__sp);
4081    return __os << __x.t() << __sp << __x.p();
4082}
4083
4084template <class _CharT, class _Traits, class _IntType>
4085basic_istream<_CharT, _Traits>&
4086operator>>(basic_istream<_CharT, _Traits>& __is,
4087           binomial_distribution<_IntType>& __x)
4088{
4089    typedef binomial_distribution<_IntType> _Eng;
4090    typedef typename _Eng::result_type result_type;
4091    typedef typename _Eng::param_type param_type;
4092    __save_flags<_CharT, _Traits> __lx(__is);
4093    __is.flags(ios_base::dec | ios_base::skipws);
4094    result_type __t;
4095    double __p;
4096    __is >> __t >> __p;
4097    if (!__is.fail())
4098        __x.param(param_type(__t, __p));
4099    return __is;
4100}
4101
4102// exponential_distribution
4103
4104template<class _RealType = double>
4105class _LIBCPP_TEMPLATE_VIS exponential_distribution
4106{
4107public:
4108    // types
4109    typedef _RealType result_type;
4110
4111    class _LIBCPP_TEMPLATE_VIS param_type
4112    {
4113        result_type __lambda_;
4114    public:
4115        typedef exponential_distribution distribution_type;
4116
4117        _LIBCPP_INLINE_VISIBILITY
4118        explicit param_type(result_type __lambda = 1) : __lambda_(__lambda) {}
4119
4120        _LIBCPP_INLINE_VISIBILITY
4121        result_type lambda() const {return __lambda_;}
4122
4123        friend _LIBCPP_INLINE_VISIBILITY
4124            bool operator==(const param_type& __x, const param_type& __y)
4125            {return __x.__lambda_ == __y.__lambda_;}
4126        friend _LIBCPP_INLINE_VISIBILITY
4127            bool operator!=(const param_type& __x, const param_type& __y)
4128            {return !(__x == __y);}
4129    };
4130
4131private:
4132    param_type __p_;
4133
4134public:
4135    // constructors and reset functions
4136    _LIBCPP_INLINE_VISIBILITY
4137    explicit exponential_distribution(result_type __lambda = 1)
4138        : __p_(param_type(__lambda)) {}
4139    _LIBCPP_INLINE_VISIBILITY
4140    explicit exponential_distribution(const param_type& __p) : __p_(__p) {}
4141    _LIBCPP_INLINE_VISIBILITY
4142    void reset() {}
4143
4144    // generating functions
4145    template<class _URNG>
4146        _LIBCPP_INLINE_VISIBILITY
4147        result_type operator()(_URNG& __g)
4148        {return (*this)(__g, __p_);}
4149    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4150
4151    // property functions
4152    _LIBCPP_INLINE_VISIBILITY
4153    result_type lambda() const {return __p_.lambda();}
4154
4155    _LIBCPP_INLINE_VISIBILITY
4156    param_type param() const {return __p_;}
4157    _LIBCPP_INLINE_VISIBILITY
4158    void param(const param_type& __p) {__p_ = __p;}
4159
4160    _LIBCPP_INLINE_VISIBILITY
4161    result_type min() const {return 0;}
4162    _LIBCPP_INLINE_VISIBILITY
4163    result_type max() const {return numeric_limits<result_type>::infinity();}
4164
4165    friend _LIBCPP_INLINE_VISIBILITY
4166        bool operator==(const exponential_distribution& __x,
4167                        const exponential_distribution& __y)
4168        {return __x.__p_ == __y.__p_;}
4169    friend _LIBCPP_INLINE_VISIBILITY
4170        bool operator!=(const exponential_distribution& __x,
4171                        const exponential_distribution& __y)
4172        {return !(__x == __y);}
4173};
4174
4175template <class _RealType>
4176template<class _URNG>
4177_RealType
4178exponential_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4179{
4180    return -_VSTD::log
4181                  (
4182                      result_type(1) -
4183                      _VSTD::generate_canonical<result_type,
4184                                       numeric_limits<result_type>::digits>(__g)
4185                  )
4186                  / __p.lambda();
4187}
4188
4189template <class _CharT, class _Traits, class _RealType>
4190basic_ostream<_CharT, _Traits>&
4191operator<<(basic_ostream<_CharT, _Traits>& __os,
4192           const exponential_distribution<_RealType>& __x)
4193{
4194    __save_flags<_CharT, _Traits> __lx(__os);
4195    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4196               ios_base::scientific);
4197    return __os << __x.lambda();
4198}
4199
4200template <class _CharT, class _Traits, class _RealType>
4201basic_istream<_CharT, _Traits>&
4202operator>>(basic_istream<_CharT, _Traits>& __is,
4203           exponential_distribution<_RealType>& __x)
4204{
4205    typedef exponential_distribution<_RealType> _Eng;
4206    typedef typename _Eng::result_type result_type;
4207    typedef typename _Eng::param_type param_type;
4208    __save_flags<_CharT, _Traits> __lx(__is);
4209    __is.flags(ios_base::dec | ios_base::skipws);
4210    result_type __lambda;
4211    __is >> __lambda;
4212    if (!__is.fail())
4213        __x.param(param_type(__lambda));
4214    return __is;
4215}
4216
4217// normal_distribution
4218
4219template<class _RealType = double>
4220class _LIBCPP_TEMPLATE_VIS normal_distribution
4221{
4222public:
4223    // types
4224    typedef _RealType result_type;
4225
4226    class _LIBCPP_TEMPLATE_VIS param_type
4227    {
4228        result_type __mean_;
4229        result_type __stddev_;
4230    public:
4231        typedef normal_distribution distribution_type;
4232
4233        _LIBCPP_INLINE_VISIBILITY
4234        explicit param_type(result_type __mean = 0, result_type __stddev = 1)
4235            : __mean_(__mean), __stddev_(__stddev) {}
4236
4237        _LIBCPP_INLINE_VISIBILITY
4238        result_type mean() const {return __mean_;}
4239        _LIBCPP_INLINE_VISIBILITY
4240        result_type stddev() const {return __stddev_;}
4241
4242        friend _LIBCPP_INLINE_VISIBILITY
4243            bool operator==(const param_type& __x, const param_type& __y)
4244            {return __x.__mean_ == __y.__mean_ && __x.__stddev_ == __y.__stddev_;}
4245        friend _LIBCPP_INLINE_VISIBILITY
4246            bool operator!=(const param_type& __x, const param_type& __y)
4247            {return !(__x == __y);}
4248    };
4249
4250private:
4251    param_type __p_;
4252    result_type _V_;
4253    bool _V_hot_;
4254
4255public:
4256    // constructors and reset functions
4257    _LIBCPP_INLINE_VISIBILITY
4258    explicit normal_distribution(result_type __mean = 0, result_type __stddev = 1)
4259        : __p_(param_type(__mean, __stddev)), _V_hot_(false) {}
4260    _LIBCPP_INLINE_VISIBILITY
4261    explicit normal_distribution(const param_type& __p)
4262        : __p_(__p), _V_hot_(false) {}
4263    _LIBCPP_INLINE_VISIBILITY
4264    void reset() {_V_hot_ = false;}
4265
4266    // generating functions
4267    template<class _URNG>
4268        _LIBCPP_INLINE_VISIBILITY
4269        result_type operator()(_URNG& __g)
4270        {return (*this)(__g, __p_);}
4271    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4272
4273    // property functions
4274    _LIBCPP_INLINE_VISIBILITY
4275    result_type mean() const {return __p_.mean();}
4276    _LIBCPP_INLINE_VISIBILITY
4277    result_type stddev() const {return __p_.stddev();}
4278
4279    _LIBCPP_INLINE_VISIBILITY
4280    param_type param() const {return __p_;}
4281    _LIBCPP_INLINE_VISIBILITY
4282    void param(const param_type& __p) {__p_ = __p;}
4283
4284    _LIBCPP_INLINE_VISIBILITY
4285    result_type min() const {return -numeric_limits<result_type>::infinity();}
4286    _LIBCPP_INLINE_VISIBILITY
4287    result_type max() const {return numeric_limits<result_type>::infinity();}
4288
4289    friend _LIBCPP_INLINE_VISIBILITY
4290        bool operator==(const normal_distribution& __x,
4291                        const normal_distribution& __y)
4292        {return __x.__p_ == __y.__p_ && __x._V_hot_ == __y._V_hot_ &&
4293                (!__x._V_hot_ || __x._V_ == __y._V_);}
4294    friend _LIBCPP_INLINE_VISIBILITY
4295        bool operator!=(const normal_distribution& __x,
4296                        const normal_distribution& __y)
4297        {return !(__x == __y);}
4298
4299    template <class _CharT, class _Traits, class _RT>
4300    friend
4301    basic_ostream<_CharT, _Traits>&
4302    operator<<(basic_ostream<_CharT, _Traits>& __os,
4303               const normal_distribution<_RT>& __x);
4304
4305    template <class _CharT, class _Traits, class _RT>
4306    friend
4307    basic_istream<_CharT, _Traits>&
4308    operator>>(basic_istream<_CharT, _Traits>& __is,
4309               normal_distribution<_RT>& __x);
4310};
4311
4312template <class _RealType>
4313template<class _URNG>
4314_RealType
4315normal_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4316{
4317    result_type _Up;
4318    if (_V_hot_)
4319    {
4320        _V_hot_ = false;
4321        _Up = _V_;
4322    }
4323    else
4324    {
4325        uniform_real_distribution<result_type> _Uni(-1, 1);
4326        result_type __u;
4327        result_type __v;
4328        result_type __s;
4329        do
4330        {
4331            __u = _Uni(__g);
4332            __v = _Uni(__g);
4333            __s = __u * __u + __v * __v;
4334        } while (__s > 1 || __s == 0);
4335        result_type _Fp = _VSTD::sqrt(-2 * _VSTD::log(__s) / __s);
4336        _V_ = __v * _Fp;
4337        _V_hot_ = true;
4338        _Up = __u * _Fp;
4339    }
4340    return _Up * __p.stddev() + __p.mean();
4341}
4342
4343template <class _CharT, class _Traits, class _RT>
4344basic_ostream<_CharT, _Traits>&
4345operator<<(basic_ostream<_CharT, _Traits>& __os,
4346           const normal_distribution<_RT>& __x)
4347{
4348    __save_flags<_CharT, _Traits> __lx(__os);
4349    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4350               ios_base::scientific);
4351    _CharT __sp = __os.widen(' ');
4352    __os.fill(__sp);
4353    __os << __x.mean() << __sp << __x.stddev() << __sp << __x._V_hot_;
4354    if (__x._V_hot_)
4355        __os << __sp << __x._V_;
4356    return __os;
4357}
4358
4359template <class _CharT, class _Traits, class _RT>
4360basic_istream<_CharT, _Traits>&
4361operator>>(basic_istream<_CharT, _Traits>& __is,
4362           normal_distribution<_RT>& __x)
4363{
4364    typedef normal_distribution<_RT> _Eng;
4365    typedef typename _Eng::result_type result_type;
4366    typedef typename _Eng::param_type param_type;
4367    __save_flags<_CharT, _Traits> __lx(__is);
4368    __is.flags(ios_base::dec | ios_base::skipws);
4369    result_type __mean;
4370    result_type __stddev;
4371    result_type _Vp = 0;
4372    bool _V_hot = false;
4373    __is >> __mean >> __stddev >> _V_hot;
4374    if (_V_hot)
4375        __is >> _Vp;
4376    if (!__is.fail())
4377    {
4378        __x.param(param_type(__mean, __stddev));
4379        __x._V_hot_ = _V_hot;
4380        __x._V_ = _Vp;
4381    }
4382    return __is;
4383}
4384
4385// lognormal_distribution
4386
4387template<class _RealType = double>
4388class _LIBCPP_TEMPLATE_VIS lognormal_distribution
4389{
4390public:
4391    // types
4392    typedef _RealType result_type;
4393
4394    class _LIBCPP_TEMPLATE_VIS param_type
4395    {
4396        normal_distribution<result_type> __nd_;
4397    public:
4398        typedef lognormal_distribution distribution_type;
4399
4400        _LIBCPP_INLINE_VISIBILITY
4401        explicit param_type(result_type __m = 0, result_type __s = 1)
4402            : __nd_(__m, __s) {}
4403
4404        _LIBCPP_INLINE_VISIBILITY
4405        result_type m() const {return __nd_.mean();}
4406        _LIBCPP_INLINE_VISIBILITY
4407        result_type s() const {return __nd_.stddev();}
4408
4409        friend _LIBCPP_INLINE_VISIBILITY
4410            bool operator==(const param_type& __x, const param_type& __y)
4411            {return __x.__nd_ == __y.__nd_;}
4412        friend _LIBCPP_INLINE_VISIBILITY
4413            bool operator!=(const param_type& __x, const param_type& __y)
4414            {return !(__x == __y);}
4415        friend class lognormal_distribution;
4416
4417        template <class _CharT, class _Traits, class _RT>
4418        friend
4419        basic_ostream<_CharT, _Traits>&
4420        operator<<(basic_ostream<_CharT, _Traits>& __os,
4421                   const lognormal_distribution<_RT>& __x);
4422
4423        template <class _CharT, class _Traits, class _RT>
4424        friend
4425        basic_istream<_CharT, _Traits>&
4426        operator>>(basic_istream<_CharT, _Traits>& __is,
4427                   lognormal_distribution<_RT>& __x);
4428    };
4429
4430private:
4431    param_type __p_;
4432
4433public:
4434    // constructor and reset functions
4435    _LIBCPP_INLINE_VISIBILITY
4436    explicit lognormal_distribution(result_type __m = 0, result_type __s = 1)
4437        : __p_(param_type(__m, __s)) {}
4438    _LIBCPP_INLINE_VISIBILITY
4439    explicit lognormal_distribution(const param_type& __p)
4440        : __p_(__p) {}
4441    _LIBCPP_INLINE_VISIBILITY
4442    void reset() {__p_.__nd_.reset();}
4443
4444    // generating functions
4445    template<class _URNG>
4446        _LIBCPP_INLINE_VISIBILITY
4447        result_type operator()(_URNG& __g)
4448        {return (*this)(__g, __p_);}
4449    template<class _URNG>
4450        _LIBCPP_INLINE_VISIBILITY
4451        result_type operator()(_URNG& __g, const param_type& __p)
4452        {return _VSTD::exp(const_cast<normal_distribution<result_type>&>(__p.__nd_)(__g));}
4453
4454    // property functions
4455    _LIBCPP_INLINE_VISIBILITY
4456    result_type m() const {return __p_.m();}
4457    _LIBCPP_INLINE_VISIBILITY
4458    result_type s() const {return __p_.s();}
4459
4460    _LIBCPP_INLINE_VISIBILITY
4461    param_type param() const {return __p_;}
4462    _LIBCPP_INLINE_VISIBILITY
4463    void param(const param_type& __p) {__p_ = __p;}
4464
4465    _LIBCPP_INLINE_VISIBILITY
4466    result_type min() const {return 0;}
4467    _LIBCPP_INLINE_VISIBILITY
4468    result_type max() const {return numeric_limits<result_type>::infinity();}
4469
4470    friend _LIBCPP_INLINE_VISIBILITY
4471        bool operator==(const lognormal_distribution& __x,
4472                        const lognormal_distribution& __y)
4473        {return __x.__p_ == __y.__p_;}
4474    friend _LIBCPP_INLINE_VISIBILITY
4475        bool operator!=(const lognormal_distribution& __x,
4476                        const lognormal_distribution& __y)
4477        {return !(__x == __y);}
4478
4479    template <class _CharT, class _Traits, class _RT>
4480    friend
4481    basic_ostream<_CharT, _Traits>&
4482    operator<<(basic_ostream<_CharT, _Traits>& __os,
4483               const lognormal_distribution<_RT>& __x);
4484
4485    template <class _CharT, class _Traits, class _RT>
4486    friend
4487    basic_istream<_CharT, _Traits>&
4488    operator>>(basic_istream<_CharT, _Traits>& __is,
4489               lognormal_distribution<_RT>& __x);
4490};
4491
4492template <class _CharT, class _Traits, class _RT>
4493inline _LIBCPP_INLINE_VISIBILITY
4494basic_ostream<_CharT, _Traits>&
4495operator<<(basic_ostream<_CharT, _Traits>& __os,
4496           const lognormal_distribution<_RT>& __x)
4497{
4498    return __os << __x.__p_.__nd_;
4499}
4500
4501template <class _CharT, class _Traits, class _RT>
4502inline _LIBCPP_INLINE_VISIBILITY
4503basic_istream<_CharT, _Traits>&
4504operator>>(basic_istream<_CharT, _Traits>& __is,
4505           lognormal_distribution<_RT>& __x)
4506{
4507    return __is >> __x.__p_.__nd_;
4508}
4509
4510// poisson_distribution
4511
4512template<class _IntType = int>
4513class _LIBCPP_TEMPLATE_VIS poisson_distribution
4514{
4515public:
4516    // types
4517    typedef _IntType result_type;
4518
4519    class _LIBCPP_TEMPLATE_VIS param_type
4520    {
4521        double __mean_;
4522        double __s_;
4523        double __d_;
4524        double __l_;
4525        double __omega_;
4526        double __c0_;
4527        double __c1_;
4528        double __c2_;
4529        double __c3_;
4530        double __c_;
4531
4532    public:
4533        typedef poisson_distribution distribution_type;
4534
4535        explicit param_type(double __mean = 1.0);
4536
4537        _LIBCPP_INLINE_VISIBILITY
4538        double mean() const {return __mean_;}
4539
4540        friend _LIBCPP_INLINE_VISIBILITY
4541            bool operator==(const param_type& __x, const param_type& __y)
4542            {return __x.__mean_ == __y.__mean_;}
4543        friend _LIBCPP_INLINE_VISIBILITY
4544            bool operator!=(const param_type& __x, const param_type& __y)
4545            {return !(__x == __y);}
4546
4547        friend class poisson_distribution;
4548    };
4549
4550private:
4551    param_type __p_;
4552
4553public:
4554    // constructors and reset functions
4555    _LIBCPP_INLINE_VISIBILITY
4556    explicit poisson_distribution(double __mean = 1.0) : __p_(__mean) {}
4557    _LIBCPP_INLINE_VISIBILITY
4558    explicit poisson_distribution(const param_type& __p) : __p_(__p) {}
4559    _LIBCPP_INLINE_VISIBILITY
4560    void reset() {}
4561
4562    // generating functions
4563    template<class _URNG>
4564        _LIBCPP_INLINE_VISIBILITY
4565        result_type operator()(_URNG& __g)
4566        {return (*this)(__g, __p_);}
4567    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4568
4569    // property functions
4570    _LIBCPP_INLINE_VISIBILITY
4571    double mean() const {return __p_.mean();}
4572
4573    _LIBCPP_INLINE_VISIBILITY
4574    param_type param() const {return __p_;}
4575    _LIBCPP_INLINE_VISIBILITY
4576    void param(const param_type& __p) {__p_ = __p;}
4577
4578    _LIBCPP_INLINE_VISIBILITY
4579    result_type min() const {return 0;}
4580    _LIBCPP_INLINE_VISIBILITY
4581    result_type max() const {return numeric_limits<result_type>::max();}
4582
4583    friend _LIBCPP_INLINE_VISIBILITY
4584        bool operator==(const poisson_distribution& __x,
4585                        const poisson_distribution& __y)
4586        {return __x.__p_ == __y.__p_;}
4587    friend _LIBCPP_INLINE_VISIBILITY
4588        bool operator!=(const poisson_distribution& __x,
4589                        const poisson_distribution& __y)
4590        {return !(__x == __y);}
4591};
4592
4593template<class _IntType>
4594poisson_distribution<_IntType>::param_type::param_type(double __mean)
4595    : __mean_(__mean)
4596{
4597    if (__mean_ < 10)
4598    {
4599        __s_ = 0;
4600        __d_ = 0;
4601        __l_ = _VSTD::exp(-__mean_);
4602        __omega_ = 0;
4603        __c3_ = 0;
4604        __c2_ = 0;
4605        __c1_ = 0;
4606        __c0_ = 0;
4607        __c_ = 0;
4608    }
4609    else
4610    {
4611        __s_ = _VSTD::sqrt(__mean_);
4612        __d_ = 6 * __mean_ * __mean_;
4613        __l_ = static_cast<result_type>(__mean_ - 1.1484);
4614        __omega_ = .3989423 / __s_;
4615        double __b1_ = .4166667E-1 / __mean_;
4616        double __b2_ = .3 * __b1_ * __b1_;
4617        __c3_ = .1428571 * __b1_ * __b2_;
4618        __c2_ = __b2_ - 15. * __c3_;
4619        __c1_ = __b1_ - 6. * __b2_ + 45. * __c3_;
4620        __c0_ = 1. - __b1_ + 3. * __b2_ - 15. * __c3_;
4621        __c_ = .1069 / __mean_;
4622    }
4623}
4624
4625template <class _IntType>
4626template<class _URNG>
4627_IntType
4628poisson_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
4629{
4630    result_type __x;
4631    uniform_real_distribution<double> __urd;
4632    if (__pr.__mean_ < 10)
4633    {
4634         __x = 0;
4635        for (double __p = __urd(__urng); __p > __pr.__l_; ++__x)
4636            __p *= __urd(__urng);
4637    }
4638    else
4639    {
4640        double __difmuk;
4641        double __g = __pr.__mean_ + __pr.__s_ * normal_distribution<double>()(__urng);
4642        double __u;
4643        if (__g > 0)
4644        {
4645            __x = static_cast<result_type>(__g);
4646            if (__x >= __pr.__l_)
4647                return __x;
4648            __difmuk = __pr.__mean_ - __x;
4649            __u = __urd(__urng);
4650            if (__pr.__d_ * __u >= __difmuk * __difmuk * __difmuk)
4651                return __x;
4652        }
4653        exponential_distribution<double> __edist;
4654        for (bool __using_exp_dist = false; true; __using_exp_dist = true)
4655        {
4656            double __e;
4657            if (__using_exp_dist || __g < 0)
4658            {
4659                double __t;
4660                do
4661                {
4662                    __e = __edist(__urng);
4663                    __u = __urd(__urng);
4664                    __u += __u - 1;
4665                    __t = 1.8 + (__u < 0 ? -__e : __e);
4666                } while (__t <= -.6744);
4667                __x = __pr.__mean_ + __pr.__s_ * __t;
4668                __difmuk = __pr.__mean_ - __x;
4669                __using_exp_dist = true;
4670            }
4671            double __px;
4672            double __py;
4673            if (__x < 10)
4674            {
4675                const result_type __fac[] = {1, 1, 2, 6, 24, 120, 720, 5040,
4676                                             40320, 362880};
4677                __px = -__pr.__mean_;
4678                __py = _VSTD::pow(__pr.__mean_, (double)__x) / __fac[__x];
4679            }
4680            else
4681            {
4682                double __del = .8333333E-1 / __x;
4683                __del -= 4.8 * __del * __del * __del;
4684                double __v = __difmuk / __x;
4685                if (_VSTD::abs(__v) > 0.25)
4686                    __px = __x * _VSTD::log(1 + __v) - __difmuk - __del;
4687                else
4688                    __px = __x * __v * __v * (((((((.1250060 * __v + -.1384794) *
4689                           __v + .1421878) * __v + -.1661269) * __v + .2000118) *
4690                           __v + -.2500068) * __v + .3333333) * __v + -.5) - __del;
4691                __py = .3989423 / _VSTD::sqrt(__x);
4692            }
4693            double __r = (0.5 - __difmuk) / __pr.__s_;
4694            double __r2 = __r * __r;
4695            double __fx = -0.5 * __r2;
4696            double __fy = __pr.__omega_ * (((__pr.__c3_ * __r2 + __pr.__c2_) *
4697                                        __r2 + __pr.__c1_) * __r2 + __pr.__c0_);
4698            if (__using_exp_dist)
4699            {
4700                if (__pr.__c_ * _VSTD::abs(__u) <= __py * _VSTD::exp(__px + __e) -
4701                                                   __fy * _VSTD::exp(__fx + __e))
4702                    break;
4703            }
4704            else
4705            {
4706                if (__fy - __u * __fy <= __py * _VSTD::exp(__px - __fx))
4707                    break;
4708            }
4709        }
4710    }
4711    return __x;
4712}
4713
4714template <class _CharT, class _Traits, class _IntType>
4715basic_ostream<_CharT, _Traits>&
4716operator<<(basic_ostream<_CharT, _Traits>& __os,
4717           const poisson_distribution<_IntType>& __x)
4718{
4719    __save_flags<_CharT, _Traits> __lx(__os);
4720    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4721               ios_base::scientific);
4722    return __os << __x.mean();
4723}
4724
4725template <class _CharT, class _Traits, class _IntType>
4726basic_istream<_CharT, _Traits>&
4727operator>>(basic_istream<_CharT, _Traits>& __is,
4728           poisson_distribution<_IntType>& __x)
4729{
4730    typedef poisson_distribution<_IntType> _Eng;
4731    typedef typename _Eng::param_type param_type;
4732    __save_flags<_CharT, _Traits> __lx(__is);
4733    __is.flags(ios_base::dec | ios_base::skipws);
4734    double __mean;
4735    __is >> __mean;
4736    if (!__is.fail())
4737        __x.param(param_type(__mean));
4738    return __is;
4739}
4740
4741// weibull_distribution
4742
4743template<class _RealType = double>
4744class _LIBCPP_TEMPLATE_VIS weibull_distribution
4745{
4746public:
4747    // types
4748    typedef _RealType result_type;
4749
4750    class _LIBCPP_TEMPLATE_VIS param_type
4751    {
4752        result_type __a_;
4753        result_type __b_;
4754    public:
4755        typedef weibull_distribution distribution_type;
4756
4757        _LIBCPP_INLINE_VISIBILITY
4758        explicit param_type(result_type __a = 1, result_type __b = 1)
4759            : __a_(__a), __b_(__b) {}
4760
4761        _LIBCPP_INLINE_VISIBILITY
4762        result_type a() const {return __a_;}
4763        _LIBCPP_INLINE_VISIBILITY
4764        result_type b() const {return __b_;}
4765
4766        friend _LIBCPP_INLINE_VISIBILITY
4767            bool operator==(const param_type& __x, const param_type& __y)
4768            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
4769        friend _LIBCPP_INLINE_VISIBILITY
4770            bool operator!=(const param_type& __x, const param_type& __y)
4771            {return !(__x == __y);}
4772    };
4773
4774private:
4775    param_type __p_;
4776
4777public:
4778    // constructor and reset functions
4779    _LIBCPP_INLINE_VISIBILITY
4780    explicit weibull_distribution(result_type __a = 1, result_type __b = 1)
4781        : __p_(param_type(__a, __b)) {}
4782    _LIBCPP_INLINE_VISIBILITY
4783    explicit weibull_distribution(const param_type& __p)
4784        : __p_(__p) {}
4785    _LIBCPP_INLINE_VISIBILITY
4786    void reset() {}
4787
4788    // generating functions
4789    template<class _URNG>
4790        _LIBCPP_INLINE_VISIBILITY
4791        result_type operator()(_URNG& __g)
4792        {return (*this)(__g, __p_);}
4793    template<class _URNG>
4794        _LIBCPP_INLINE_VISIBILITY
4795        result_type operator()(_URNG& __g, const param_type& __p)
4796        {return __p.b() *
4797            _VSTD::pow(exponential_distribution<result_type>()(__g), 1/__p.a());}
4798
4799    // property functions
4800    _LIBCPP_INLINE_VISIBILITY
4801    result_type a() const {return __p_.a();}
4802    _LIBCPP_INLINE_VISIBILITY
4803    result_type b() const {return __p_.b();}
4804
4805    _LIBCPP_INLINE_VISIBILITY
4806    param_type param() const {return __p_;}
4807    _LIBCPP_INLINE_VISIBILITY
4808    void param(const param_type& __p) {__p_ = __p;}
4809
4810    _LIBCPP_INLINE_VISIBILITY
4811    result_type min() const {return 0;}
4812    _LIBCPP_INLINE_VISIBILITY
4813    result_type max() const {return numeric_limits<result_type>::infinity();}
4814
4815    friend _LIBCPP_INLINE_VISIBILITY
4816        bool operator==(const weibull_distribution& __x,
4817                        const weibull_distribution& __y)
4818        {return __x.__p_ == __y.__p_;}
4819    friend _LIBCPP_INLINE_VISIBILITY
4820        bool operator!=(const weibull_distribution& __x,
4821                        const weibull_distribution& __y)
4822        {return !(__x == __y);}
4823};
4824
4825template <class _CharT, class _Traits, class _RT>
4826basic_ostream<_CharT, _Traits>&
4827operator<<(basic_ostream<_CharT, _Traits>& __os,
4828           const weibull_distribution<_RT>& __x)
4829{
4830    __save_flags<_CharT, _Traits> __lx(__os);
4831    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4832               ios_base::scientific);
4833    _CharT __sp = __os.widen(' ');
4834    __os.fill(__sp);
4835    __os << __x.a() << __sp << __x.b();
4836    return __os;
4837}
4838
4839template <class _CharT, class _Traits, class _RT>
4840basic_istream<_CharT, _Traits>&
4841operator>>(basic_istream<_CharT, _Traits>& __is,
4842           weibull_distribution<_RT>& __x)
4843{
4844    typedef weibull_distribution<_RT> _Eng;
4845    typedef typename _Eng::result_type result_type;
4846    typedef typename _Eng::param_type param_type;
4847    __save_flags<_CharT, _Traits> __lx(__is);
4848    __is.flags(ios_base::dec | ios_base::skipws);
4849    result_type __a;
4850    result_type __b;
4851    __is >> __a >> __b;
4852    if (!__is.fail())
4853        __x.param(param_type(__a, __b));
4854    return __is;
4855}
4856
4857template<class _RealType = double>
4858class _LIBCPP_TEMPLATE_VIS extreme_value_distribution
4859{
4860public:
4861    // types
4862    typedef _RealType result_type;
4863
4864    class _LIBCPP_TEMPLATE_VIS param_type
4865    {
4866        result_type __a_;
4867        result_type __b_;
4868    public:
4869        typedef extreme_value_distribution distribution_type;
4870
4871        _LIBCPP_INLINE_VISIBILITY
4872        explicit param_type(result_type __a = 0, result_type __b = 1)
4873            : __a_(__a), __b_(__b) {}
4874
4875        _LIBCPP_INLINE_VISIBILITY
4876        result_type a() const {return __a_;}
4877        _LIBCPP_INLINE_VISIBILITY
4878        result_type b() const {return __b_;}
4879
4880        friend _LIBCPP_INLINE_VISIBILITY
4881            bool operator==(const param_type& __x, const param_type& __y)
4882            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
4883        friend _LIBCPP_INLINE_VISIBILITY
4884            bool operator!=(const param_type& __x, const param_type& __y)
4885            {return !(__x == __y);}
4886    };
4887
4888private:
4889    param_type __p_;
4890
4891public:
4892    // constructor and reset functions
4893    _LIBCPP_INLINE_VISIBILITY
4894    explicit extreme_value_distribution(result_type __a = 0, result_type __b = 1)
4895        : __p_(param_type(__a, __b)) {}
4896    _LIBCPP_INLINE_VISIBILITY
4897    explicit extreme_value_distribution(const param_type& __p)
4898        : __p_(__p) {}
4899    _LIBCPP_INLINE_VISIBILITY
4900    void reset() {}
4901
4902    // generating functions
4903    template<class _URNG>
4904        _LIBCPP_INLINE_VISIBILITY
4905        result_type operator()(_URNG& __g)
4906        {return (*this)(__g, __p_);}
4907    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
4908
4909    // property functions
4910    _LIBCPP_INLINE_VISIBILITY
4911    result_type a() const {return __p_.a();}
4912    _LIBCPP_INLINE_VISIBILITY
4913    result_type b() const {return __p_.b();}
4914
4915    _LIBCPP_INLINE_VISIBILITY
4916    param_type param() const {return __p_;}
4917    _LIBCPP_INLINE_VISIBILITY
4918    void param(const param_type& __p) {__p_ = __p;}
4919
4920    _LIBCPP_INLINE_VISIBILITY
4921    result_type min() const {return -numeric_limits<result_type>::infinity();}
4922    _LIBCPP_INLINE_VISIBILITY
4923    result_type max() const {return numeric_limits<result_type>::infinity();}
4924
4925    friend _LIBCPP_INLINE_VISIBILITY
4926        bool operator==(const extreme_value_distribution& __x,
4927                        const extreme_value_distribution& __y)
4928        {return __x.__p_ == __y.__p_;}
4929    friend _LIBCPP_INLINE_VISIBILITY
4930        bool operator!=(const extreme_value_distribution& __x,
4931                        const extreme_value_distribution& __y)
4932        {return !(__x == __y);}
4933};
4934
4935template<class _RealType>
4936template<class _URNG>
4937_RealType
4938extreme_value_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
4939{
4940    return __p.a() - __p.b() *
4941         _VSTD::log(-_VSTD::log(1-uniform_real_distribution<result_type>()(__g)));
4942}
4943
4944template <class _CharT, class _Traits, class _RT>
4945basic_ostream<_CharT, _Traits>&
4946operator<<(basic_ostream<_CharT, _Traits>& __os,
4947           const extreme_value_distribution<_RT>& __x)
4948{
4949    __save_flags<_CharT, _Traits> __lx(__os);
4950    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
4951               ios_base::scientific);
4952    _CharT __sp = __os.widen(' ');
4953    __os.fill(__sp);
4954    __os << __x.a() << __sp << __x.b();
4955    return __os;
4956}
4957
4958template <class _CharT, class _Traits, class _RT>
4959basic_istream<_CharT, _Traits>&
4960operator>>(basic_istream<_CharT, _Traits>& __is,
4961           extreme_value_distribution<_RT>& __x)
4962{
4963    typedef extreme_value_distribution<_RT> _Eng;
4964    typedef typename _Eng::result_type result_type;
4965    typedef typename _Eng::param_type param_type;
4966    __save_flags<_CharT, _Traits> __lx(__is);
4967    __is.flags(ios_base::dec | ios_base::skipws);
4968    result_type __a;
4969    result_type __b;
4970    __is >> __a >> __b;
4971    if (!__is.fail())
4972        __x.param(param_type(__a, __b));
4973    return __is;
4974}
4975
4976// gamma_distribution
4977
4978template<class _RealType = double>
4979class _LIBCPP_TEMPLATE_VIS gamma_distribution
4980{
4981public:
4982    // types
4983    typedef _RealType result_type;
4984
4985    class _LIBCPP_TEMPLATE_VIS param_type
4986    {
4987        result_type __alpha_;
4988        result_type __beta_;
4989    public:
4990        typedef gamma_distribution distribution_type;
4991
4992        _LIBCPP_INLINE_VISIBILITY
4993        explicit param_type(result_type __alpha = 1, result_type __beta = 1)
4994            : __alpha_(__alpha), __beta_(__beta) {}
4995
4996        _LIBCPP_INLINE_VISIBILITY
4997        result_type alpha() const {return __alpha_;}
4998        _LIBCPP_INLINE_VISIBILITY
4999        result_type beta() const {return __beta_;}
5000
5001        friend _LIBCPP_INLINE_VISIBILITY
5002            bool operator==(const param_type& __x, const param_type& __y)
5003            {return __x.__alpha_ == __y.__alpha_ && __x.__beta_ == __y.__beta_;}
5004        friend _LIBCPP_INLINE_VISIBILITY
5005            bool operator!=(const param_type& __x, const param_type& __y)
5006            {return !(__x == __y);}
5007    };
5008
5009private:
5010    param_type __p_;
5011
5012public:
5013    // constructors and reset functions
5014    _LIBCPP_INLINE_VISIBILITY
5015    explicit gamma_distribution(result_type __alpha = 1, result_type __beta = 1)
5016        : __p_(param_type(__alpha, __beta)) {}
5017    _LIBCPP_INLINE_VISIBILITY
5018    explicit gamma_distribution(const param_type& __p)
5019        : __p_(__p) {}
5020    _LIBCPP_INLINE_VISIBILITY
5021    void reset() {}
5022
5023    // generating functions
5024    template<class _URNG>
5025        _LIBCPP_INLINE_VISIBILITY
5026        result_type operator()(_URNG& __g)
5027        {return (*this)(__g, __p_);}
5028    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5029
5030    // property functions
5031    _LIBCPP_INLINE_VISIBILITY
5032    result_type alpha() const {return __p_.alpha();}
5033    _LIBCPP_INLINE_VISIBILITY
5034    result_type beta() const {return __p_.beta();}
5035
5036    _LIBCPP_INLINE_VISIBILITY
5037    param_type param() const {return __p_;}
5038    _LIBCPP_INLINE_VISIBILITY
5039    void param(const param_type& __p) {__p_ = __p;}
5040
5041    _LIBCPP_INLINE_VISIBILITY
5042    result_type min() const {return 0;}
5043    _LIBCPP_INLINE_VISIBILITY
5044    result_type max() const {return numeric_limits<result_type>::infinity();}
5045
5046    friend _LIBCPP_INLINE_VISIBILITY
5047        bool operator==(const gamma_distribution& __x,
5048                        const gamma_distribution& __y)
5049        {return __x.__p_ == __y.__p_;}
5050    friend _LIBCPP_INLINE_VISIBILITY
5051        bool operator!=(const gamma_distribution& __x,
5052                        const gamma_distribution& __y)
5053        {return !(__x == __y);}
5054};
5055
5056template <class _RealType>
5057template<class _URNG>
5058_RealType
5059gamma_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5060{
5061    result_type __a = __p.alpha();
5062    uniform_real_distribution<result_type> __gen(0, 1);
5063    exponential_distribution<result_type> __egen;
5064    result_type __x;
5065    if (__a == 1)
5066        __x = __egen(__g);
5067    else if (__a > 1)
5068    {
5069        const result_type __b = __a - 1;
5070        const result_type __c = 3 * __a - result_type(0.75);
5071        while (true)
5072        {
5073            const result_type __u = __gen(__g);
5074            const result_type __v = __gen(__g);
5075            const result_type __w = __u * (1 - __u);
5076            if (__w != 0)
5077            {
5078                const result_type __y = _VSTD::sqrt(__c / __w) *
5079                                        (__u - result_type(0.5));
5080                __x = __b + __y;
5081                if (__x >= 0)
5082                {
5083                    const result_type __z = 64 * __w * __w * __w * __v * __v;
5084                    if (__z <= 1 - 2 * __y * __y / __x)
5085                        break;
5086                    if (_VSTD::log(__z) <= 2 * (__b * _VSTD::log(__x / __b) - __y))
5087                        break;
5088                }
5089            }
5090        }
5091    }
5092    else  // __a < 1
5093    {
5094        while (true)
5095        {
5096            const result_type __u = __gen(__g);
5097            const result_type __es = __egen(__g);
5098            if (__u <= 1 - __a)
5099            {
5100                __x = _VSTD::pow(__u, 1 / __a);
5101                if (__x <= __es)
5102                    break;
5103            }
5104            else
5105            {
5106                const result_type __e = -_VSTD::log((1-__u)/__a);
5107                __x = _VSTD::pow(1 - __a + __a * __e, 1 / __a);
5108                if (__x <= __e + __es)
5109                    break;
5110            }
5111        }
5112    }
5113    return __x * __p.beta();
5114}
5115
5116template <class _CharT, class _Traits, class _RT>
5117basic_ostream<_CharT, _Traits>&
5118operator<<(basic_ostream<_CharT, _Traits>& __os,
5119           const gamma_distribution<_RT>& __x)
5120{
5121    __save_flags<_CharT, _Traits> __lx(__os);
5122    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5123               ios_base::scientific);
5124    _CharT __sp = __os.widen(' ');
5125    __os.fill(__sp);
5126    __os << __x.alpha() << __sp << __x.beta();
5127    return __os;
5128}
5129
5130template <class _CharT, class _Traits, class _RT>
5131basic_istream<_CharT, _Traits>&
5132operator>>(basic_istream<_CharT, _Traits>& __is,
5133           gamma_distribution<_RT>& __x)
5134{
5135    typedef gamma_distribution<_RT> _Eng;
5136    typedef typename _Eng::result_type result_type;
5137    typedef typename _Eng::param_type param_type;
5138    __save_flags<_CharT, _Traits> __lx(__is);
5139    __is.flags(ios_base::dec | ios_base::skipws);
5140    result_type __alpha;
5141    result_type __beta;
5142    __is >> __alpha >> __beta;
5143    if (!__is.fail())
5144        __x.param(param_type(__alpha, __beta));
5145    return __is;
5146}
5147
5148// negative_binomial_distribution
5149
5150template<class _IntType = int>
5151class _LIBCPP_TEMPLATE_VIS negative_binomial_distribution
5152{
5153public:
5154    // types
5155    typedef _IntType result_type;
5156
5157    class _LIBCPP_TEMPLATE_VIS param_type
5158    {
5159        result_type __k_;
5160        double __p_;
5161    public:
5162        typedef negative_binomial_distribution distribution_type;
5163
5164        _LIBCPP_INLINE_VISIBILITY
5165        explicit param_type(result_type __k = 1, double __p = 0.5)
5166            : __k_(__k), __p_(__p) {}
5167
5168        _LIBCPP_INLINE_VISIBILITY
5169        result_type k() const {return __k_;}
5170        _LIBCPP_INLINE_VISIBILITY
5171        double p() const {return __p_;}
5172
5173        friend _LIBCPP_INLINE_VISIBILITY
5174            bool operator==(const param_type& __x, const param_type& __y)
5175            {return __x.__k_ == __y.__k_ && __x.__p_ == __y.__p_;}
5176        friend _LIBCPP_INLINE_VISIBILITY
5177            bool operator!=(const param_type& __x, const param_type& __y)
5178            {return !(__x == __y);}
5179    };
5180
5181private:
5182    param_type __p_;
5183
5184public:
5185    // constructor and reset functions
5186    _LIBCPP_INLINE_VISIBILITY
5187    explicit negative_binomial_distribution(result_type __k = 1, double __p = 0.5)
5188        : __p_(__k, __p) {}
5189    _LIBCPP_INLINE_VISIBILITY
5190    explicit negative_binomial_distribution(const param_type& __p) : __p_(__p) {}
5191    _LIBCPP_INLINE_VISIBILITY
5192    void reset() {}
5193
5194    // generating functions
5195    template<class _URNG>
5196        _LIBCPP_INLINE_VISIBILITY
5197        result_type operator()(_URNG& __g)
5198        {return (*this)(__g, __p_);}
5199    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5200
5201    // property functions
5202    _LIBCPP_INLINE_VISIBILITY
5203    result_type k() const {return __p_.k();}
5204    _LIBCPP_INLINE_VISIBILITY
5205    double p() const {return __p_.p();}
5206
5207    _LIBCPP_INLINE_VISIBILITY
5208    param_type param() const {return __p_;}
5209    _LIBCPP_INLINE_VISIBILITY
5210    void param(const param_type& __p) {__p_ = __p;}
5211
5212    _LIBCPP_INLINE_VISIBILITY
5213    result_type min() const {return 0;}
5214    _LIBCPP_INLINE_VISIBILITY
5215    result_type max() const {return numeric_limits<result_type>::max();}
5216
5217    friend _LIBCPP_INLINE_VISIBILITY
5218        bool operator==(const negative_binomial_distribution& __x,
5219                        const negative_binomial_distribution& __y)
5220        {return __x.__p_ == __y.__p_;}
5221    friend _LIBCPP_INLINE_VISIBILITY
5222        bool operator!=(const negative_binomial_distribution& __x,
5223                        const negative_binomial_distribution& __y)
5224        {return !(__x == __y);}
5225};
5226
5227template <class _IntType>
5228template<class _URNG>
5229_IntType
5230negative_binomial_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
5231{
5232    result_type __k = __pr.k();
5233    double __p = __pr.p();
5234    if (__k <= 21 * __p)
5235    {
5236        bernoulli_distribution __gen(__p);
5237        result_type __f = 0;
5238        result_type __s = 0;
5239        while (__s < __k)
5240        {
5241            if (__gen(__urng))
5242                ++__s;
5243            else
5244                ++__f;
5245        }
5246        return __f;
5247    }
5248    return poisson_distribution<result_type>(gamma_distribution<double>
5249                                            (__k, (1-__p)/__p)(__urng))(__urng);
5250}
5251
5252template <class _CharT, class _Traits, class _IntType>
5253basic_ostream<_CharT, _Traits>&
5254operator<<(basic_ostream<_CharT, _Traits>& __os,
5255           const negative_binomial_distribution<_IntType>& __x)
5256{
5257    __save_flags<_CharT, _Traits> __lx(__os);
5258    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5259               ios_base::scientific);
5260    _CharT __sp = __os.widen(' ');
5261    __os.fill(__sp);
5262    return __os << __x.k() << __sp << __x.p();
5263}
5264
5265template <class _CharT, class _Traits, class _IntType>
5266basic_istream<_CharT, _Traits>&
5267operator>>(basic_istream<_CharT, _Traits>& __is,
5268           negative_binomial_distribution<_IntType>& __x)
5269{
5270    typedef negative_binomial_distribution<_IntType> _Eng;
5271    typedef typename _Eng::result_type result_type;
5272    typedef typename _Eng::param_type param_type;
5273    __save_flags<_CharT, _Traits> __lx(__is);
5274    __is.flags(ios_base::dec | ios_base::skipws);
5275    result_type __k;
5276    double __p;
5277    __is >> __k >> __p;
5278    if (!__is.fail())
5279        __x.param(param_type(__k, __p));
5280    return __is;
5281}
5282
5283// geometric_distribution
5284
5285template<class _IntType = int>
5286class _LIBCPP_TEMPLATE_VIS geometric_distribution
5287{
5288public:
5289    // types
5290    typedef _IntType result_type;
5291
5292    class _LIBCPP_TEMPLATE_VIS param_type
5293    {
5294        double __p_;
5295    public:
5296        typedef geometric_distribution distribution_type;
5297
5298        _LIBCPP_INLINE_VISIBILITY
5299        explicit param_type(double __p = 0.5) : __p_(__p) {}
5300
5301        _LIBCPP_INLINE_VISIBILITY
5302        double p() const {return __p_;}
5303
5304        friend _LIBCPP_INLINE_VISIBILITY
5305            bool operator==(const param_type& __x, const param_type& __y)
5306            {return __x.__p_ == __y.__p_;}
5307        friend _LIBCPP_INLINE_VISIBILITY
5308            bool operator!=(const param_type& __x, const param_type& __y)
5309            {return !(__x == __y);}
5310    };
5311
5312private:
5313    param_type __p_;
5314
5315public:
5316    // constructors and reset functions
5317    _LIBCPP_INLINE_VISIBILITY
5318    explicit geometric_distribution(double __p = 0.5) : __p_(__p) {}
5319    _LIBCPP_INLINE_VISIBILITY
5320    explicit geometric_distribution(const param_type& __p) : __p_(__p) {}
5321    _LIBCPP_INLINE_VISIBILITY
5322    void reset() {}
5323
5324    // generating functions
5325    template<class _URNG>
5326        _LIBCPP_INLINE_VISIBILITY
5327        result_type operator()(_URNG& __g)
5328        {return (*this)(__g, __p_);}
5329    template<class _URNG>
5330        _LIBCPP_INLINE_VISIBILITY
5331        result_type operator()(_URNG& __g, const param_type& __p)
5332        {return negative_binomial_distribution<result_type>(1, __p.p())(__g);}
5333
5334    // property functions
5335    _LIBCPP_INLINE_VISIBILITY
5336    double p() const {return __p_.p();}
5337
5338    _LIBCPP_INLINE_VISIBILITY
5339    param_type param() const {return __p_;}
5340    _LIBCPP_INLINE_VISIBILITY
5341    void param(const param_type& __p) {__p_ = __p;}
5342
5343    _LIBCPP_INLINE_VISIBILITY
5344    result_type min() const {return 0;}
5345    _LIBCPP_INLINE_VISIBILITY
5346    result_type max() const {return numeric_limits<result_type>::max();}
5347
5348    friend _LIBCPP_INLINE_VISIBILITY
5349        bool operator==(const geometric_distribution& __x,
5350                        const geometric_distribution& __y)
5351        {return __x.__p_ == __y.__p_;}
5352    friend _LIBCPP_INLINE_VISIBILITY
5353        bool operator!=(const geometric_distribution& __x,
5354                        const geometric_distribution& __y)
5355        {return !(__x == __y);}
5356};
5357
5358template <class _CharT, class _Traits, class _IntType>
5359basic_ostream<_CharT, _Traits>&
5360operator<<(basic_ostream<_CharT, _Traits>& __os,
5361           const geometric_distribution<_IntType>& __x)
5362{
5363    __save_flags<_CharT, _Traits> __lx(__os);
5364    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5365               ios_base::scientific);
5366    return __os << __x.p();
5367}
5368
5369template <class _CharT, class _Traits, class _IntType>
5370basic_istream<_CharT, _Traits>&
5371operator>>(basic_istream<_CharT, _Traits>& __is,
5372           geometric_distribution<_IntType>& __x)
5373{
5374    typedef geometric_distribution<_IntType> _Eng;
5375    typedef typename _Eng::param_type param_type;
5376    __save_flags<_CharT, _Traits> __lx(__is);
5377    __is.flags(ios_base::dec | ios_base::skipws);
5378    double __p;
5379    __is >> __p;
5380    if (!__is.fail())
5381        __x.param(param_type(__p));
5382    return __is;
5383}
5384
5385// chi_squared_distribution
5386
5387template<class _RealType = double>
5388class _LIBCPP_TEMPLATE_VIS chi_squared_distribution
5389{
5390public:
5391    // types
5392    typedef _RealType result_type;
5393
5394    class _LIBCPP_TEMPLATE_VIS param_type
5395    {
5396        result_type __n_;
5397    public:
5398        typedef chi_squared_distribution distribution_type;
5399
5400        _LIBCPP_INLINE_VISIBILITY
5401        explicit param_type(result_type __n = 1) : __n_(__n) {}
5402
5403        _LIBCPP_INLINE_VISIBILITY
5404        result_type n() const {return __n_;}
5405
5406        friend _LIBCPP_INLINE_VISIBILITY
5407            bool operator==(const param_type& __x, const param_type& __y)
5408            {return __x.__n_ == __y.__n_;}
5409        friend _LIBCPP_INLINE_VISIBILITY
5410            bool operator!=(const param_type& __x, const param_type& __y)
5411            {return !(__x == __y);}
5412    };
5413
5414private:
5415    param_type __p_;
5416
5417public:
5418    // constructor and reset functions
5419    _LIBCPP_INLINE_VISIBILITY
5420    explicit chi_squared_distribution(result_type __n = 1)
5421        : __p_(param_type(__n)) {}
5422    _LIBCPP_INLINE_VISIBILITY
5423    explicit chi_squared_distribution(const param_type& __p)
5424        : __p_(__p) {}
5425    _LIBCPP_INLINE_VISIBILITY
5426    void reset() {}
5427
5428    // generating functions
5429    template<class _URNG>
5430        _LIBCPP_INLINE_VISIBILITY
5431        result_type operator()(_URNG& __g)
5432        {return (*this)(__g, __p_);}
5433    template<class _URNG>
5434        _LIBCPP_INLINE_VISIBILITY
5435        result_type operator()(_URNG& __g, const param_type& __p)
5436        {return gamma_distribution<result_type>(__p.n() / 2, 2)(__g);}
5437
5438    // property functions
5439    _LIBCPP_INLINE_VISIBILITY
5440    result_type n() const {return __p_.n();}
5441
5442    _LIBCPP_INLINE_VISIBILITY
5443    param_type param() const {return __p_;}
5444    _LIBCPP_INLINE_VISIBILITY
5445    void param(const param_type& __p) {__p_ = __p;}
5446
5447    _LIBCPP_INLINE_VISIBILITY
5448    result_type min() const {return 0;}
5449    _LIBCPP_INLINE_VISIBILITY
5450    result_type max() const {return numeric_limits<result_type>::infinity();}
5451
5452    friend _LIBCPP_INLINE_VISIBILITY
5453        bool operator==(const chi_squared_distribution& __x,
5454                        const chi_squared_distribution& __y)
5455        {return __x.__p_ == __y.__p_;}
5456    friend _LIBCPP_INLINE_VISIBILITY
5457        bool operator!=(const chi_squared_distribution& __x,
5458                        const chi_squared_distribution& __y)
5459        {return !(__x == __y);}
5460};
5461
5462template <class _CharT, class _Traits, class _RT>
5463basic_ostream<_CharT, _Traits>&
5464operator<<(basic_ostream<_CharT, _Traits>& __os,
5465           const chi_squared_distribution<_RT>& __x)
5466{
5467    __save_flags<_CharT, _Traits> __lx(__os);
5468    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5469               ios_base::scientific);
5470    __os << __x.n();
5471    return __os;
5472}
5473
5474template <class _CharT, class _Traits, class _RT>
5475basic_istream<_CharT, _Traits>&
5476operator>>(basic_istream<_CharT, _Traits>& __is,
5477           chi_squared_distribution<_RT>& __x)
5478{
5479    typedef chi_squared_distribution<_RT> _Eng;
5480    typedef typename _Eng::result_type result_type;
5481    typedef typename _Eng::param_type param_type;
5482    __save_flags<_CharT, _Traits> __lx(__is);
5483    __is.flags(ios_base::dec | ios_base::skipws);
5484    result_type __n;
5485    __is >> __n;
5486    if (!__is.fail())
5487        __x.param(param_type(__n));
5488    return __is;
5489}
5490
5491// cauchy_distribution
5492
5493template<class _RealType = double>
5494class _LIBCPP_TEMPLATE_VIS cauchy_distribution
5495{
5496public:
5497    // types
5498    typedef _RealType result_type;
5499
5500    class _LIBCPP_TEMPLATE_VIS param_type
5501    {
5502        result_type __a_;
5503        result_type __b_;
5504    public:
5505        typedef cauchy_distribution distribution_type;
5506
5507        _LIBCPP_INLINE_VISIBILITY
5508        explicit param_type(result_type __a = 0, result_type __b = 1)
5509            : __a_(__a), __b_(__b) {}
5510
5511        _LIBCPP_INLINE_VISIBILITY
5512        result_type a() const {return __a_;}
5513        _LIBCPP_INLINE_VISIBILITY
5514        result_type b() const {return __b_;}
5515
5516        friend _LIBCPP_INLINE_VISIBILITY
5517            bool operator==(const param_type& __x, const param_type& __y)
5518            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
5519        friend _LIBCPP_INLINE_VISIBILITY
5520            bool operator!=(const param_type& __x, const param_type& __y)
5521            {return !(__x == __y);}
5522    };
5523
5524private:
5525    param_type __p_;
5526
5527public:
5528    // constructor and reset functions
5529    _LIBCPP_INLINE_VISIBILITY
5530    explicit cauchy_distribution(result_type __a = 0, result_type __b = 1)
5531        : __p_(param_type(__a, __b)) {}
5532    _LIBCPP_INLINE_VISIBILITY
5533    explicit cauchy_distribution(const param_type& __p)
5534        : __p_(__p) {}
5535    _LIBCPP_INLINE_VISIBILITY
5536    void reset() {}
5537
5538    // generating functions
5539    template<class _URNG>
5540        _LIBCPP_INLINE_VISIBILITY
5541        result_type operator()(_URNG& __g)
5542        {return (*this)(__g, __p_);}
5543    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
5544
5545    // property functions
5546    _LIBCPP_INLINE_VISIBILITY
5547    result_type a() const {return __p_.a();}
5548    _LIBCPP_INLINE_VISIBILITY
5549    result_type b() const {return __p_.b();}
5550
5551    _LIBCPP_INLINE_VISIBILITY
5552    param_type param() const {return __p_;}
5553    _LIBCPP_INLINE_VISIBILITY
5554    void param(const param_type& __p) {__p_ = __p;}
5555
5556    _LIBCPP_INLINE_VISIBILITY
5557    result_type min() const {return -numeric_limits<result_type>::infinity();}
5558    _LIBCPP_INLINE_VISIBILITY
5559    result_type max() const {return numeric_limits<result_type>::infinity();}
5560
5561    friend _LIBCPP_INLINE_VISIBILITY
5562        bool operator==(const cauchy_distribution& __x,
5563                        const cauchy_distribution& __y)
5564        {return __x.__p_ == __y.__p_;}
5565    friend _LIBCPP_INLINE_VISIBILITY
5566        bool operator!=(const cauchy_distribution& __x,
5567                        const cauchy_distribution& __y)
5568        {return !(__x == __y);}
5569};
5570
5571template <class _RealType>
5572template<class _URNG>
5573inline
5574_RealType
5575cauchy_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5576{
5577    uniform_real_distribution<result_type> __gen;
5578    // purposefully let tan arg get as close to pi/2 as it wants, tan will return a finite
5579    return __p.a() + __p.b() * _VSTD::tan(3.1415926535897932384626433832795 * __gen(__g));
5580}
5581
5582template <class _CharT, class _Traits, class _RT>
5583basic_ostream<_CharT, _Traits>&
5584operator<<(basic_ostream<_CharT, _Traits>& __os,
5585           const cauchy_distribution<_RT>& __x)
5586{
5587    __save_flags<_CharT, _Traits> __lx(__os);
5588    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5589               ios_base::scientific);
5590    _CharT __sp = __os.widen(' ');
5591    __os.fill(__sp);
5592    __os << __x.a() << __sp << __x.b();
5593    return __os;
5594}
5595
5596template <class _CharT, class _Traits, class _RT>
5597basic_istream<_CharT, _Traits>&
5598operator>>(basic_istream<_CharT, _Traits>& __is,
5599           cauchy_distribution<_RT>& __x)
5600{
5601    typedef cauchy_distribution<_RT> _Eng;
5602    typedef typename _Eng::result_type result_type;
5603    typedef typename _Eng::param_type param_type;
5604    __save_flags<_CharT, _Traits> __lx(__is);
5605    __is.flags(ios_base::dec | ios_base::skipws);
5606    result_type __a;
5607    result_type __b;
5608    __is >> __a >> __b;
5609    if (!__is.fail())
5610        __x.param(param_type(__a, __b));
5611    return __is;
5612}
5613
5614// fisher_f_distribution
5615
5616template<class _RealType = double>
5617class _LIBCPP_TEMPLATE_VIS fisher_f_distribution
5618{
5619public:
5620    // types
5621    typedef _RealType result_type;
5622
5623    class _LIBCPP_TEMPLATE_VIS param_type
5624    {
5625        result_type __m_;
5626        result_type __n_;
5627    public:
5628        typedef fisher_f_distribution distribution_type;
5629
5630        _LIBCPP_INLINE_VISIBILITY
5631        explicit param_type(result_type __m = 1, result_type __n = 1)
5632            : __m_(__m), __n_(__n) {}
5633
5634        _LIBCPP_INLINE_VISIBILITY
5635        result_type m() const {return __m_;}
5636        _LIBCPP_INLINE_VISIBILITY
5637        result_type n() const {return __n_;}
5638
5639        friend _LIBCPP_INLINE_VISIBILITY
5640            bool operator==(const param_type& __x, const param_type& __y)
5641            {return __x.__m_ == __y.__m_ && __x.__n_ == __y.__n_;}
5642        friend _LIBCPP_INLINE_VISIBILITY
5643            bool operator!=(const param_type& __x, const param_type& __y)
5644            {return !(__x == __y);}
5645    };
5646
5647private:
5648    param_type __p_;
5649
5650public:
5651    // constructor and reset functions
5652    _LIBCPP_INLINE_VISIBILITY
5653    explicit fisher_f_distribution(result_type __m = 1, result_type __n = 1)
5654        : __p_(param_type(__m, __n)) {}
5655    _LIBCPP_INLINE_VISIBILITY
5656    explicit fisher_f_distribution(const param_type& __p)
5657        : __p_(__p) {}
5658    _LIBCPP_INLINE_VISIBILITY
5659    void reset() {}
5660
5661    // generating functions
5662    template<class _URNG>
5663        _LIBCPP_INLINE_VISIBILITY
5664        result_type operator()(_URNG& __g)
5665        {return (*this)(__g, __p_);}
5666    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5667
5668    // property functions
5669    _LIBCPP_INLINE_VISIBILITY
5670    result_type m() const {return __p_.m();}
5671    _LIBCPP_INLINE_VISIBILITY
5672    result_type n() const {return __p_.n();}
5673
5674    _LIBCPP_INLINE_VISIBILITY
5675    param_type param() const {return __p_;}
5676    _LIBCPP_INLINE_VISIBILITY
5677    void param(const param_type& __p) {__p_ = __p;}
5678
5679    _LIBCPP_INLINE_VISIBILITY
5680    result_type min() const {return 0;}
5681    _LIBCPP_INLINE_VISIBILITY
5682    result_type max() const {return numeric_limits<result_type>::infinity();}
5683
5684    friend _LIBCPP_INLINE_VISIBILITY
5685        bool operator==(const fisher_f_distribution& __x,
5686                        const fisher_f_distribution& __y)
5687        {return __x.__p_ == __y.__p_;}
5688    friend _LIBCPP_INLINE_VISIBILITY
5689        bool operator!=(const fisher_f_distribution& __x,
5690                        const fisher_f_distribution& __y)
5691        {return !(__x == __y);}
5692};
5693
5694template <class _RealType>
5695template<class _URNG>
5696_RealType
5697fisher_f_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5698{
5699    gamma_distribution<result_type> __gdm(__p.m() * result_type(.5));
5700    gamma_distribution<result_type> __gdn(__p.n() * result_type(.5));
5701    return __p.n() * __gdm(__g) / (__p.m() * __gdn(__g));
5702}
5703
5704template <class _CharT, class _Traits, class _RT>
5705basic_ostream<_CharT, _Traits>&
5706operator<<(basic_ostream<_CharT, _Traits>& __os,
5707           const fisher_f_distribution<_RT>& __x)
5708{
5709    __save_flags<_CharT, _Traits> __lx(__os);
5710    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5711               ios_base::scientific);
5712    _CharT __sp = __os.widen(' ');
5713    __os.fill(__sp);
5714    __os << __x.m() << __sp << __x.n();
5715    return __os;
5716}
5717
5718template <class _CharT, class _Traits, class _RT>
5719basic_istream<_CharT, _Traits>&
5720operator>>(basic_istream<_CharT, _Traits>& __is,
5721           fisher_f_distribution<_RT>& __x)
5722{
5723    typedef fisher_f_distribution<_RT> _Eng;
5724    typedef typename _Eng::result_type result_type;
5725    typedef typename _Eng::param_type param_type;
5726    __save_flags<_CharT, _Traits> __lx(__is);
5727    __is.flags(ios_base::dec | ios_base::skipws);
5728    result_type __m;
5729    result_type __n;
5730    __is >> __m >> __n;
5731    if (!__is.fail())
5732        __x.param(param_type(__m, __n));
5733    return __is;
5734}
5735
5736// student_t_distribution
5737
5738template<class _RealType = double>
5739class _LIBCPP_TEMPLATE_VIS student_t_distribution
5740{
5741public:
5742    // types
5743    typedef _RealType result_type;
5744
5745    class _LIBCPP_TEMPLATE_VIS param_type
5746    {
5747        result_type __n_;
5748    public:
5749        typedef student_t_distribution distribution_type;
5750
5751        _LIBCPP_INLINE_VISIBILITY
5752        explicit param_type(result_type __n = 1) : __n_(__n) {}
5753
5754        _LIBCPP_INLINE_VISIBILITY
5755        result_type n() const {return __n_;}
5756
5757        friend _LIBCPP_INLINE_VISIBILITY
5758            bool operator==(const param_type& __x, const param_type& __y)
5759            {return __x.__n_ == __y.__n_;}
5760        friend _LIBCPP_INLINE_VISIBILITY
5761            bool operator!=(const param_type& __x, const param_type& __y)
5762            {return !(__x == __y);}
5763    };
5764
5765private:
5766    param_type __p_;
5767    normal_distribution<result_type> __nd_;
5768
5769public:
5770    // constructor and reset functions
5771    _LIBCPP_INLINE_VISIBILITY
5772    explicit student_t_distribution(result_type __n = 1)
5773        : __p_(param_type(__n)) {}
5774    _LIBCPP_INLINE_VISIBILITY
5775    explicit student_t_distribution(const param_type& __p)
5776        : __p_(__p) {}
5777    _LIBCPP_INLINE_VISIBILITY
5778    void reset() {__nd_.reset();}
5779
5780    // generating functions
5781    template<class _URNG>
5782        _LIBCPP_INLINE_VISIBILITY
5783        result_type operator()(_URNG& __g)
5784        {return (*this)(__g, __p_);}
5785    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5786
5787    // property functions
5788    _LIBCPP_INLINE_VISIBILITY
5789    result_type n() const {return __p_.n();}
5790
5791    _LIBCPP_INLINE_VISIBILITY
5792    param_type param() const {return __p_;}
5793    _LIBCPP_INLINE_VISIBILITY
5794    void param(const param_type& __p) {__p_ = __p;}
5795
5796    _LIBCPP_INLINE_VISIBILITY
5797    result_type min() const {return -numeric_limits<result_type>::infinity();}
5798    _LIBCPP_INLINE_VISIBILITY
5799    result_type max() const {return numeric_limits<result_type>::infinity();}
5800
5801    friend _LIBCPP_INLINE_VISIBILITY
5802        bool operator==(const student_t_distribution& __x,
5803                        const student_t_distribution& __y)
5804        {return __x.__p_ == __y.__p_;}
5805    friend _LIBCPP_INLINE_VISIBILITY
5806        bool operator!=(const student_t_distribution& __x,
5807                        const student_t_distribution& __y)
5808        {return !(__x == __y);}
5809};
5810
5811template <class _RealType>
5812template<class _URNG>
5813_RealType
5814student_t_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
5815{
5816    gamma_distribution<result_type> __gd(__p.n() * .5, 2);
5817    return __nd_(__g) * _VSTD::sqrt(__p.n()/__gd(__g));
5818}
5819
5820template <class _CharT, class _Traits, class _RT>
5821basic_ostream<_CharT, _Traits>&
5822operator<<(basic_ostream<_CharT, _Traits>& __os,
5823           const student_t_distribution<_RT>& __x)
5824{
5825    __save_flags<_CharT, _Traits> __lx(__os);
5826    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
5827               ios_base::scientific);
5828    __os << __x.n();
5829    return __os;
5830}
5831
5832template <class _CharT, class _Traits, class _RT>
5833basic_istream<_CharT, _Traits>&
5834operator>>(basic_istream<_CharT, _Traits>& __is,
5835           student_t_distribution<_RT>& __x)
5836{
5837    typedef student_t_distribution<_RT> _Eng;
5838    typedef typename _Eng::result_type result_type;
5839    typedef typename _Eng::param_type param_type;
5840    __save_flags<_CharT, _Traits> __lx(__is);
5841    __is.flags(ios_base::dec | ios_base::skipws);
5842    result_type __n;
5843    __is >> __n;
5844    if (!__is.fail())
5845        __x.param(param_type(__n));
5846    return __is;
5847}
5848
5849// discrete_distribution
5850
5851template<class _IntType = int>
5852class _LIBCPP_TEMPLATE_VIS discrete_distribution
5853{
5854public:
5855    // types
5856    typedef _IntType result_type;
5857
5858    class _LIBCPP_TEMPLATE_VIS param_type
5859    {
5860        vector<double> __p_;
5861    public:
5862        typedef discrete_distribution distribution_type;
5863
5864        _LIBCPP_INLINE_VISIBILITY
5865        param_type() {}
5866        template<class _InputIterator>
5867            _LIBCPP_INLINE_VISIBILITY
5868            param_type(_InputIterator __f, _InputIterator __l)
5869            : __p_(__f, __l) {__init();}
5870#ifndef _LIBCPP_CXX03_LANG
5871        _LIBCPP_INLINE_VISIBILITY
5872        param_type(initializer_list<double> __wl)
5873            : __p_(__wl.begin(), __wl.end()) {__init();}
5874#endif  // _LIBCPP_CXX03_LANG
5875        template<class _UnaryOperation>
5876            param_type(size_t __nw, double __xmin, double __xmax,
5877                       _UnaryOperation __fw);
5878
5879        vector<double> probabilities() const;
5880
5881        friend _LIBCPP_INLINE_VISIBILITY
5882            bool operator==(const param_type& __x, const param_type& __y)
5883            {return __x.__p_ == __y.__p_;}
5884        friend _LIBCPP_INLINE_VISIBILITY
5885            bool operator!=(const param_type& __x, const param_type& __y)
5886            {return !(__x == __y);}
5887
5888    private:
5889        void __init();
5890
5891        friend class discrete_distribution;
5892
5893        template <class _CharT, class _Traits, class _IT>
5894        friend
5895        basic_ostream<_CharT, _Traits>&
5896        operator<<(basic_ostream<_CharT, _Traits>& __os,
5897                   const discrete_distribution<_IT>& __x);
5898
5899        template <class _CharT, class _Traits, class _IT>
5900        friend
5901        basic_istream<_CharT, _Traits>&
5902        operator>>(basic_istream<_CharT, _Traits>& __is,
5903                   discrete_distribution<_IT>& __x);
5904    };
5905
5906private:
5907    param_type __p_;
5908
5909public:
5910    // constructor and reset functions
5911    _LIBCPP_INLINE_VISIBILITY
5912    discrete_distribution() {}
5913    template<class _InputIterator>
5914        _LIBCPP_INLINE_VISIBILITY
5915        discrete_distribution(_InputIterator __f, _InputIterator __l)
5916            : __p_(__f, __l) {}
5917#ifndef _LIBCPP_CXX03_LANG
5918    _LIBCPP_INLINE_VISIBILITY
5919    discrete_distribution(initializer_list<double> __wl)
5920        : __p_(__wl) {}
5921#endif  // _LIBCPP_CXX03_LANG
5922    template<class _UnaryOperation>
5923        _LIBCPP_INLINE_VISIBILITY
5924        discrete_distribution(size_t __nw, double __xmin, double __xmax,
5925                              _UnaryOperation __fw)
5926        : __p_(__nw, __xmin, __xmax, __fw) {}
5927    _LIBCPP_INLINE_VISIBILITY
5928    explicit discrete_distribution(const param_type& __p)
5929        : __p_(__p) {}
5930    _LIBCPP_INLINE_VISIBILITY
5931    void reset() {}
5932
5933    // generating functions
5934    template<class _URNG>
5935        _LIBCPP_INLINE_VISIBILITY
5936        result_type operator()(_URNG& __g)
5937        {return (*this)(__g, __p_);}
5938    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
5939
5940    // property functions
5941    _LIBCPP_INLINE_VISIBILITY
5942    vector<double> probabilities() const {return __p_.probabilities();}
5943
5944    _LIBCPP_INLINE_VISIBILITY
5945    param_type param() const {return __p_;}
5946    _LIBCPP_INLINE_VISIBILITY
5947    void param(const param_type& __p) {__p_ = __p;}
5948
5949    _LIBCPP_INLINE_VISIBILITY
5950    result_type min() const {return 0;}
5951    _LIBCPP_INLINE_VISIBILITY
5952    result_type max() const {return __p_.__p_.size();}
5953
5954    friend _LIBCPP_INLINE_VISIBILITY
5955        bool operator==(const discrete_distribution& __x,
5956                        const discrete_distribution& __y)
5957        {return __x.__p_ == __y.__p_;}
5958    friend _LIBCPP_INLINE_VISIBILITY
5959        bool operator!=(const discrete_distribution& __x,
5960                        const discrete_distribution& __y)
5961        {return !(__x == __y);}
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
5976template<class _IntType>
5977template<class _UnaryOperation>
5978discrete_distribution<_IntType>::param_type::param_type(size_t __nw,
5979                                                        double __xmin,
5980                                                        double __xmax,
5981                                                        _UnaryOperation __fw)
5982{
5983    if (__nw > 1)
5984    {
5985        __p_.reserve(__nw - 1);
5986        double __d = (__xmax - __xmin) / __nw;
5987        double __d2 = __d / 2;
5988        for (size_t __k = 0; __k < __nw; ++__k)
5989            __p_.push_back(__fw(__xmin + __k * __d + __d2));
5990        __init();
5991    }
5992}
5993
5994template<class _IntType>
5995void
5996discrete_distribution<_IntType>::param_type::__init()
5997{
5998    if (!__p_.empty())
5999    {
6000        if (__p_.size() > 1)
6001        {
6002            double __s = _VSTD::accumulate(__p_.begin(), __p_.end(), 0.0);
6003            for (_VSTD::vector<double>::iterator __i = __p_.begin(), __e = __p_.end();
6004                                                                       __i < __e; ++__i)
6005                *__i /= __s;
6006            vector<double> __t(__p_.size() - 1);
6007            _VSTD::partial_sum(__p_.begin(), __p_.end() - 1, __t.begin());
6008            swap(__p_, __t);
6009        }
6010        else
6011        {
6012            __p_.clear();
6013            __p_.shrink_to_fit();
6014        }
6015    }
6016}
6017
6018template<class _IntType>
6019vector<double>
6020discrete_distribution<_IntType>::param_type::probabilities() const
6021{
6022    size_t __n = __p_.size();
6023    _VSTD::vector<double> __p(__n+1);
6024    _VSTD::adjacent_difference(__p_.begin(), __p_.end(), __p.begin());
6025    if (__n > 0)
6026        __p[__n] = 1 - __p_[__n-1];
6027    else
6028        __p[0] = 1;
6029    return __p;
6030}
6031
6032template<class _IntType>
6033template<class _URNG>
6034_IntType
6035discrete_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
6036{
6037    uniform_real_distribution<double> __gen;
6038    return static_cast<_IntType>(
6039           _VSTD::upper_bound(__p.__p_.begin(), __p.__p_.end(), __gen(__g)) -
6040                                                              __p.__p_.begin());
6041}
6042
6043template <class _CharT, class _Traits, class _IT>
6044basic_ostream<_CharT, _Traits>&
6045operator<<(basic_ostream<_CharT, _Traits>& __os,
6046           const discrete_distribution<_IT>& __x)
6047{
6048    __save_flags<_CharT, _Traits> __lx(__os);
6049    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
6050               ios_base::scientific);
6051    _CharT __sp = __os.widen(' ');
6052    __os.fill(__sp);
6053    size_t __n = __x.__p_.__p_.size();
6054    __os << __n;
6055    for (size_t __i = 0; __i < __n; ++__i)
6056        __os << __sp << __x.__p_.__p_[__i];
6057    return __os;
6058}
6059
6060template <class _CharT, class _Traits, class _IT>
6061basic_istream<_CharT, _Traits>&
6062operator>>(basic_istream<_CharT, _Traits>& __is,
6063           discrete_distribution<_IT>& __x)
6064{
6065    __save_flags<_CharT, _Traits> __lx(__is);
6066    __is.flags(ios_base::dec | ios_base::skipws);
6067    size_t __n;
6068    __is >> __n;
6069    vector<double> __p(__n);
6070    for (size_t __i = 0; __i < __n; ++__i)
6071        __is >> __p[__i];
6072    if (!__is.fail())
6073        swap(__x.__p_.__p_, __p);
6074    return __is;
6075}
6076
6077// piecewise_constant_distribution
6078
6079template<class _RealType = double>
6080class _LIBCPP_TEMPLATE_VIS piecewise_constant_distribution
6081{
6082public:
6083    // types
6084    typedef _RealType result_type;
6085
6086    class _LIBCPP_TEMPLATE_VIS param_type
6087    {
6088        vector<result_type> __b_;
6089        vector<result_type> __densities_;
6090        vector<result_type> __areas_;
6091    public:
6092        typedef piecewise_constant_distribution distribution_type;
6093
6094        param_type();
6095        template<class _InputIteratorB, class _InputIteratorW>
6096            param_type(_InputIteratorB __fB, _InputIteratorB __lB,
6097                       _InputIteratorW __fW);
6098#ifndef _LIBCPP_CXX03_LANG
6099        template<class _UnaryOperation>
6100            param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
6101#endif  // _LIBCPP_CXX03_LANG
6102        template<class _UnaryOperation>
6103            param_type(size_t __nw, result_type __xmin, result_type __xmax,
6104                       _UnaryOperation __fw);
6105        param_type & operator=(const param_type& __rhs);
6106
6107        _LIBCPP_INLINE_VISIBILITY
6108        vector<result_type> intervals() const {return __b_;}
6109        _LIBCPP_INLINE_VISIBILITY
6110        vector<result_type> densities() const {return __densities_;}
6111
6112        friend _LIBCPP_INLINE_VISIBILITY
6113            bool operator==(const param_type& __x, const param_type& __y)
6114            {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
6115        friend _LIBCPP_INLINE_VISIBILITY
6116            bool operator!=(const param_type& __x, const param_type& __y)
6117            {return !(__x == __y);}
6118
6119    private:
6120        void __init();
6121
6122        friend class piecewise_constant_distribution;
6123
6124        template <class _CharT, class _Traits, class _RT>
6125        friend
6126        basic_ostream<_CharT, _Traits>&
6127        operator<<(basic_ostream<_CharT, _Traits>& __os,
6128                   const piecewise_constant_distribution<_RT>& __x);
6129
6130        template <class _CharT, class _Traits, class _RT>
6131        friend
6132        basic_istream<_CharT, _Traits>&
6133        operator>>(basic_istream<_CharT, _Traits>& __is,
6134                   piecewise_constant_distribution<_RT>& __x);
6135    };
6136
6137private:
6138    param_type __p_;
6139
6140public:
6141    // constructor and reset functions
6142    _LIBCPP_INLINE_VISIBILITY
6143    piecewise_constant_distribution() {}
6144    template<class _InputIteratorB, class _InputIteratorW>
6145        _LIBCPP_INLINE_VISIBILITY
6146        piecewise_constant_distribution(_InputIteratorB __fB,
6147                                        _InputIteratorB __lB,
6148                                        _InputIteratorW __fW)
6149        : __p_(__fB, __lB, __fW) {}
6150
6151#ifndef _LIBCPP_CXX03_LANG
6152    template<class _UnaryOperation>
6153        _LIBCPP_INLINE_VISIBILITY
6154        piecewise_constant_distribution(initializer_list<result_type> __bl,
6155                                        _UnaryOperation __fw)
6156        : __p_(__bl, __fw) {}
6157#endif  // _LIBCPP_CXX03_LANG
6158
6159    template<class _UnaryOperation>
6160        _LIBCPP_INLINE_VISIBILITY
6161        piecewise_constant_distribution(size_t __nw, result_type __xmin,
6162                                        result_type __xmax, _UnaryOperation __fw)
6163        : __p_(__nw, __xmin, __xmax, __fw) {}
6164
6165    _LIBCPP_INLINE_VISIBILITY
6166    explicit piecewise_constant_distribution(const param_type& __p)
6167        : __p_(__p) {}
6168
6169    _LIBCPP_INLINE_VISIBILITY
6170    void reset() {}
6171
6172    // generating functions
6173    template<class _URNG>
6174        _LIBCPP_INLINE_VISIBILITY
6175        result_type operator()(_URNG& __g)
6176        {return (*this)(__g, __p_);}
6177    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
6178
6179    // property functions
6180    _LIBCPP_INLINE_VISIBILITY
6181    vector<result_type> intervals() const {return __p_.intervals();}
6182    _LIBCPP_INLINE_VISIBILITY
6183    vector<result_type> densities() const {return __p_.densities();}
6184
6185    _LIBCPP_INLINE_VISIBILITY
6186    param_type param() const {return __p_;}
6187    _LIBCPP_INLINE_VISIBILITY
6188    void param(const param_type& __p) {__p_ = __p;}
6189
6190    _LIBCPP_INLINE_VISIBILITY
6191    result_type min() const {return __p_.__b_.front();}
6192    _LIBCPP_INLINE_VISIBILITY
6193    result_type max() const {return __p_.__b_.back();}
6194
6195    friend _LIBCPP_INLINE_VISIBILITY
6196        bool operator==(const piecewise_constant_distribution& __x,
6197                        const piecewise_constant_distribution& __y)
6198        {return __x.__p_ == __y.__p_;}
6199    friend _LIBCPP_INLINE_VISIBILITY
6200        bool operator!=(const piecewise_constant_distribution& __x,
6201                           const piecewise_constant_distribution& __y)
6202        {return !(__x == __y);}
6203
6204    template <class _CharT, class _Traits, class _RT>
6205    friend
6206    basic_ostream<_CharT, _Traits>&
6207    operator<<(basic_ostream<_CharT, _Traits>& __os,
6208               const piecewise_constant_distribution<_RT>& __x);
6209
6210    template <class _CharT, class _Traits, class _RT>
6211    friend
6212    basic_istream<_CharT, _Traits>&
6213    operator>>(basic_istream<_CharT, _Traits>& __is,
6214               piecewise_constant_distribution<_RT>& __x);
6215};
6216
6217template<class _RealType>
6218typename piecewise_constant_distribution<_RealType>::param_type &
6219piecewise_constant_distribution<_RealType>::param_type::operator=
6220                                                       (const param_type& __rhs)
6221{
6222//  These can throw
6223    __b_.reserve        (__rhs.__b_.size ());
6224    __densities_.reserve(__rhs.__densities_.size());
6225    __areas_.reserve    (__rhs.__areas_.size());
6226
6227//  These can not throw
6228    __b_         = __rhs.__b_;
6229    __densities_ = __rhs.__densities_;
6230    __areas_     =  __rhs.__areas_;
6231    return *this;
6232}
6233
6234template<class _RealType>
6235void
6236piecewise_constant_distribution<_RealType>::param_type::__init()
6237{
6238    // __densities_ contains non-normalized areas
6239    result_type __total_area = _VSTD::accumulate(__densities_.begin(),
6240                                                __densities_.end(),
6241                                                result_type());
6242    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6243        __densities_[__i] /= __total_area;
6244    // __densities_ contains normalized areas
6245    __areas_.assign(__densities_.size(), result_type());
6246    _VSTD::partial_sum(__densities_.begin(), __densities_.end() - 1,
6247                                                          __areas_.begin() + 1);
6248    // __areas_ contains partial sums of normalized areas: [0, __densities_ - 1]
6249    __densities_.back() = 1 - __areas_.back();  // correct round off error
6250    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6251        __densities_[__i] /= (__b_[__i+1] - __b_[__i]);
6252    // __densities_ now contains __densities_
6253}
6254
6255template<class _RealType>
6256piecewise_constant_distribution<_RealType>::param_type::param_type()
6257    : __b_(2),
6258      __densities_(1, 1.0),
6259      __areas_(1, 0.0)
6260{
6261    __b_[1] = 1;
6262}
6263
6264template<class _RealType>
6265template<class _InputIteratorB, class _InputIteratorW>
6266piecewise_constant_distribution<_RealType>::param_type::param_type(
6267        _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
6268    : __b_(__fB, __lB)
6269{
6270    if (__b_.size() < 2)
6271    {
6272        __b_.resize(2);
6273        __b_[0] = 0;
6274        __b_[1] = 1;
6275        __densities_.assign(1, 1.0);
6276        __areas_.assign(1, 0.0);
6277    }
6278    else
6279    {
6280        __densities_.reserve(__b_.size() - 1);
6281        for (size_t __i = 0; __i < __b_.size() - 1; ++__i, ++__fW)
6282            __densities_.push_back(*__fW);
6283        __init();
6284    }
6285}
6286
6287#ifndef _LIBCPP_CXX03_LANG
6288
6289template<class _RealType>
6290template<class _UnaryOperation>
6291piecewise_constant_distribution<_RealType>::param_type::param_type(
6292        initializer_list<result_type> __bl, _UnaryOperation __fw)
6293    : __b_(__bl.begin(), __bl.end())
6294{
6295    if (__b_.size() < 2)
6296    {
6297        __b_.resize(2);
6298        __b_[0] = 0;
6299        __b_[1] = 1;
6300        __densities_.assign(1, 1.0);
6301        __areas_.assign(1, 0.0);
6302    }
6303    else
6304    {
6305        __densities_.reserve(__b_.size() - 1);
6306        for (size_t __i = 0; __i < __b_.size() - 1; ++__i)
6307            __densities_.push_back(__fw((__b_[__i+1] + __b_[__i])*.5));
6308        __init();
6309    }
6310}
6311
6312#endif  // _LIBCPP_CXX03_LANG
6313
6314template<class _RealType>
6315template<class _UnaryOperation>
6316piecewise_constant_distribution<_RealType>::param_type::param_type(
6317        size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
6318    : __b_(__nw == 0 ? 2 : __nw + 1)
6319{
6320    size_t __n = __b_.size() - 1;
6321    result_type __d = (__xmax - __xmin) / __n;
6322    __densities_.reserve(__n);
6323    for (size_t __i = 0; __i < __n; ++__i)
6324    {
6325        __b_[__i] = __xmin + __i * __d;
6326        __densities_.push_back(__fw(__b_[__i] + __d*.5));
6327    }
6328    __b_[__n] = __xmax;
6329    __init();
6330}
6331
6332template<class _RealType>
6333template<class _URNG>
6334_RealType
6335piecewise_constant_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
6336{
6337    typedef uniform_real_distribution<result_type> _Gen;
6338    result_type __u = _Gen()(__g);
6339    ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
6340                                      __u) - __p.__areas_.begin() - 1;
6341    return (__u - __p.__areas_[__k]) / __p.__densities_[__k] + __p.__b_[__k];
6342}
6343
6344template <class _CharT, class _Traits, class _RT>
6345basic_ostream<_CharT, _Traits>&
6346operator<<(basic_ostream<_CharT, _Traits>& __os,
6347           const piecewise_constant_distribution<_RT>& __x)
6348{
6349    __save_flags<_CharT, _Traits> __lx(__os);
6350    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
6351               ios_base::scientific);
6352    _CharT __sp = __os.widen(' ');
6353    __os.fill(__sp);
6354    size_t __n = __x.__p_.__b_.size();
6355    __os << __n;
6356    for (size_t __i = 0; __i < __n; ++__i)
6357        __os << __sp << __x.__p_.__b_[__i];
6358    __n = __x.__p_.__densities_.size();
6359    __os << __sp << __n;
6360    for (size_t __i = 0; __i < __n; ++__i)
6361        __os << __sp << __x.__p_.__densities_[__i];
6362    __n = __x.__p_.__areas_.size();
6363    __os << __sp << __n;
6364    for (size_t __i = 0; __i < __n; ++__i)
6365        __os << __sp << __x.__p_.__areas_[__i];
6366    return __os;
6367}
6368
6369template <class _CharT, class _Traits, class _RT>
6370basic_istream<_CharT, _Traits>&
6371operator>>(basic_istream<_CharT, _Traits>& __is,
6372           piecewise_constant_distribution<_RT>& __x)
6373{
6374    typedef piecewise_constant_distribution<_RT> _Eng;
6375    typedef typename _Eng::result_type result_type;
6376    __save_flags<_CharT, _Traits> __lx(__is);
6377    __is.flags(ios_base::dec | ios_base::skipws);
6378    size_t __n;
6379    __is >> __n;
6380    vector<result_type> __b(__n);
6381    for (size_t __i = 0; __i < __n; ++__i)
6382        __is >> __b[__i];
6383    __is >> __n;
6384    vector<result_type> __densities(__n);
6385    for (size_t __i = 0; __i < __n; ++__i)
6386        __is >> __densities[__i];
6387    __is >> __n;
6388    vector<result_type> __areas(__n);
6389    for (size_t __i = 0; __i < __n; ++__i)
6390        __is >> __areas[__i];
6391    if (!__is.fail())
6392    {
6393        swap(__x.__p_.__b_, __b);
6394        swap(__x.__p_.__densities_, __densities);
6395        swap(__x.__p_.__areas_, __areas);
6396    }
6397    return __is;
6398}
6399
6400// piecewise_linear_distribution
6401
6402template<class _RealType = double>
6403class _LIBCPP_TEMPLATE_VIS piecewise_linear_distribution
6404{
6405public:
6406    // types
6407    typedef _RealType result_type;
6408
6409    class _LIBCPP_TEMPLATE_VIS param_type
6410    {
6411        vector<result_type> __b_;
6412        vector<result_type> __densities_;
6413        vector<result_type> __areas_;
6414    public:
6415        typedef piecewise_linear_distribution distribution_type;
6416
6417        param_type();
6418        template<class _InputIteratorB, class _InputIteratorW>
6419            param_type(_InputIteratorB __fB, _InputIteratorB __lB,
6420                       _InputIteratorW __fW);
6421#ifndef _LIBCPP_CXX03_LANG
6422        template<class _UnaryOperation>
6423            param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
6424#endif  // _LIBCPP_CXX03_LANG
6425        template<class _UnaryOperation>
6426            param_type(size_t __nw, result_type __xmin, result_type __xmax,
6427                       _UnaryOperation __fw);
6428        param_type & operator=(const param_type& __rhs);
6429
6430        _LIBCPP_INLINE_VISIBILITY
6431        vector<result_type> intervals() const {return __b_;}
6432        _LIBCPP_INLINE_VISIBILITY
6433        vector<result_type> densities() const {return __densities_;}
6434
6435        friend _LIBCPP_INLINE_VISIBILITY
6436            bool operator==(const param_type& __x, const param_type& __y)
6437            {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
6438        friend _LIBCPP_INLINE_VISIBILITY
6439            bool operator!=(const param_type& __x, const param_type& __y)
6440            {return !(__x == __y);}
6441
6442    private:
6443        void __init();
6444
6445        friend class piecewise_linear_distribution;
6446
6447        template <class _CharT, class _Traits, class _RT>
6448        friend
6449        basic_ostream<_CharT, _Traits>&
6450        operator<<(basic_ostream<_CharT, _Traits>& __os,
6451                   const piecewise_linear_distribution<_RT>& __x);
6452
6453        template <class _CharT, class _Traits, class _RT>
6454        friend
6455        basic_istream<_CharT, _Traits>&
6456        operator>>(basic_istream<_CharT, _Traits>& __is,
6457                   piecewise_linear_distribution<_RT>& __x);
6458    };
6459
6460private:
6461    param_type __p_;
6462
6463public:
6464    // constructor and reset functions
6465    _LIBCPP_INLINE_VISIBILITY
6466    piecewise_linear_distribution() {}
6467    template<class _InputIteratorB, class _InputIteratorW>
6468        _LIBCPP_INLINE_VISIBILITY
6469        piecewise_linear_distribution(_InputIteratorB __fB,
6470                                      _InputIteratorB __lB,
6471                                      _InputIteratorW __fW)
6472        : __p_(__fB, __lB, __fW) {}
6473
6474#ifndef _LIBCPP_CXX03_LANG
6475    template<class _UnaryOperation>
6476        _LIBCPP_INLINE_VISIBILITY
6477        piecewise_linear_distribution(initializer_list<result_type> __bl,
6478                                      _UnaryOperation __fw)
6479        : __p_(__bl, __fw) {}
6480#endif  // _LIBCPP_CXX03_LANG
6481
6482    template<class _UnaryOperation>
6483        _LIBCPP_INLINE_VISIBILITY
6484        piecewise_linear_distribution(size_t __nw, result_type __xmin,
6485                                      result_type __xmax, _UnaryOperation __fw)
6486        : __p_(__nw, __xmin, __xmax, __fw) {}
6487
6488    _LIBCPP_INLINE_VISIBILITY
6489    explicit piecewise_linear_distribution(const param_type& __p)
6490        : __p_(__p) {}
6491
6492    _LIBCPP_INLINE_VISIBILITY
6493    void reset() {}
6494
6495    // generating functions
6496    template<class _URNG>
6497        _LIBCPP_INLINE_VISIBILITY
6498        result_type operator()(_URNG& __g)
6499        {return (*this)(__g, __p_);}
6500    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
6501
6502    // property functions
6503    _LIBCPP_INLINE_VISIBILITY
6504    vector<result_type> intervals() const {return __p_.intervals();}
6505    _LIBCPP_INLINE_VISIBILITY
6506    vector<result_type> densities() const {return __p_.densities();}
6507
6508    _LIBCPP_INLINE_VISIBILITY
6509    param_type param() const {return __p_;}
6510    _LIBCPP_INLINE_VISIBILITY
6511    void param(const param_type& __p) {__p_ = __p;}
6512
6513    _LIBCPP_INLINE_VISIBILITY
6514    result_type min() const {return __p_.__b_.front();}
6515    _LIBCPP_INLINE_VISIBILITY
6516    result_type max() const {return __p_.__b_.back();}
6517
6518    friend _LIBCPP_INLINE_VISIBILITY
6519        bool operator==(const piecewise_linear_distribution& __x,
6520                        const piecewise_linear_distribution& __y)
6521        {return __x.__p_ == __y.__p_;}
6522    friend _LIBCPP_INLINE_VISIBILITY
6523        bool operator!=(const piecewise_linear_distribution& __x,
6524                        const piecewise_linear_distribution& __y)
6525        {return !(__x == __y);}
6526
6527    template <class _CharT, class _Traits, class _RT>
6528    friend
6529    basic_ostream<_CharT, _Traits>&
6530    operator<<(basic_ostream<_CharT, _Traits>& __os,
6531               const piecewise_linear_distribution<_RT>& __x);
6532
6533    template <class _CharT, class _Traits, class _RT>
6534    friend
6535    basic_istream<_CharT, _Traits>&
6536    operator>>(basic_istream<_CharT, _Traits>& __is,
6537               piecewise_linear_distribution<_RT>& __x);
6538};
6539
6540template<class _RealType>
6541typename piecewise_linear_distribution<_RealType>::param_type &
6542piecewise_linear_distribution<_RealType>::param_type::operator=
6543                                                       (const param_type& __rhs)
6544{
6545//  These can throw
6546    __b_.reserve        (__rhs.__b_.size ());
6547    __densities_.reserve(__rhs.__densities_.size());
6548    __areas_.reserve    (__rhs.__areas_.size());
6549
6550//  These can not throw
6551    __b_         = __rhs.__b_;
6552    __densities_ = __rhs.__densities_;
6553    __areas_     =  __rhs.__areas_;
6554    return *this;
6555}
6556
6557
6558template<class _RealType>
6559void
6560piecewise_linear_distribution<_RealType>::param_type::__init()
6561{
6562    __areas_.assign(__densities_.size() - 1, result_type());
6563    result_type _Sp = 0;
6564    for (size_t __i = 0; __i < __areas_.size(); ++__i)
6565    {
6566        __areas_[__i] = (__densities_[__i+1] + __densities_[__i]) *
6567                        (__b_[__i+1] - __b_[__i]) * .5;
6568        _Sp += __areas_[__i];
6569    }
6570    for (size_t __i = __areas_.size(); __i > 1;)
6571    {
6572        --__i;
6573        __areas_[__i] = __areas_[__i-1] / _Sp;
6574    }
6575    __areas_[0] = 0;
6576    for (size_t __i = 1; __i < __areas_.size(); ++__i)
6577        __areas_[__i] += __areas_[__i-1];
6578    for (size_t __i = 0; __i < __densities_.size(); ++__i)
6579        __densities_[__i] /= _Sp;
6580}
6581
6582template<class _RealType>
6583piecewise_linear_distribution<_RealType>::param_type::param_type()
6584    : __b_(2),
6585      __densities_(2, 1.0),
6586      __areas_(1, 0.0)
6587{
6588    __b_[1] = 1;
6589}
6590
6591template<class _RealType>
6592template<class _InputIteratorB, class _InputIteratorW>
6593piecewise_linear_distribution<_RealType>::param_type::param_type(
6594        _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
6595    : __b_(__fB, __lB)
6596{
6597    if (__b_.size() < 2)
6598    {
6599        __b_.resize(2);
6600        __b_[0] = 0;
6601        __b_[1] = 1;
6602        __densities_.assign(2, 1.0);
6603        __areas_.assign(1, 0.0);
6604    }
6605    else
6606    {
6607        __densities_.reserve(__b_.size());
6608        for (size_t __i = 0; __i < __b_.size(); ++__i, ++__fW)
6609            __densities_.push_back(*__fW);
6610        __init();
6611    }
6612}
6613
6614#ifndef _LIBCPP_CXX03_LANG
6615
6616template<class _RealType>
6617template<class _UnaryOperation>
6618piecewise_linear_distribution<_RealType>::param_type::param_type(
6619        initializer_list<result_type> __bl, _UnaryOperation __fw)
6620    : __b_(__bl.begin(), __bl.end())
6621{
6622    if (__b_.size() < 2)
6623    {
6624        __b_.resize(2);
6625        __b_[0] = 0;
6626        __b_[1] = 1;
6627        __densities_.assign(2, 1.0);
6628        __areas_.assign(1, 0.0);
6629    }
6630    else
6631    {
6632        __densities_.reserve(__b_.size());
6633        for (size_t __i = 0; __i < __b_.size(); ++__i)
6634            __densities_.push_back(__fw(__b_[__i]));
6635        __init();
6636    }
6637}
6638
6639#endif  // _LIBCPP_CXX03_LANG
6640
6641template<class _RealType>
6642template<class _UnaryOperation>
6643piecewise_linear_distribution<_RealType>::param_type::param_type(
6644        size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
6645    : __b_(__nw == 0 ? 2 : __nw + 1)
6646{
6647    size_t __n = __b_.size() - 1;
6648    result_type __d = (__xmax - __xmin) / __n;
6649    __densities_.reserve(__b_.size());
6650    for (size_t __i = 0; __i < __n; ++__i)
6651    {
6652        __b_[__i] = __xmin + __i * __d;
6653        __densities_.push_back(__fw(__b_[__i]));
6654    }
6655    __b_[__n] = __xmax;
6656    __densities_.push_back(__fw(__b_[__n]));
6657    __init();
6658}
6659
6660template<class _RealType>
6661template<class _URNG>
6662_RealType
6663piecewise_linear_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
6664{
6665    typedef uniform_real_distribution<result_type> _Gen;
6666    result_type __u = _Gen()(__g);
6667    ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
6668                                      __u) - __p.__areas_.begin() - 1;
6669    __u -= __p.__areas_[__k];
6670    const result_type __dk = __p.__densities_[__k];
6671    const result_type __dk1 = __p.__densities_[__k+1];
6672    const result_type __deltad = __dk1 - __dk;
6673    const result_type __bk = __p.__b_[__k];
6674    if (__deltad == 0)
6675        return __u / __dk + __bk;
6676    const result_type __bk1 = __p.__b_[__k+1];
6677    const result_type __deltab = __bk1 - __bk;
6678    return (__bk * __dk1 - __bk1 * __dk +
6679        _VSTD::sqrt(__deltab * (__deltab * __dk * __dk + 2 * __deltad * __u))) /
6680        __deltad;
6681}
6682
6683template <class _CharT, class _Traits, class _RT>
6684basic_ostream<_CharT, _Traits>&
6685operator<<(basic_ostream<_CharT, _Traits>& __os,
6686           const piecewise_linear_distribution<_RT>& __x)
6687{
6688    __save_flags<_CharT, _Traits> __lx(__os);
6689    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
6690               ios_base::scientific);
6691    _CharT __sp = __os.widen(' ');
6692    __os.fill(__sp);
6693    size_t __n = __x.__p_.__b_.size();
6694    __os << __n;
6695    for (size_t __i = 0; __i < __n; ++__i)
6696        __os << __sp << __x.__p_.__b_[__i];
6697    __n = __x.__p_.__densities_.size();
6698    __os << __sp << __n;
6699    for (size_t __i = 0; __i < __n; ++__i)
6700        __os << __sp << __x.__p_.__densities_[__i];
6701    __n = __x.__p_.__areas_.size();
6702    __os << __sp << __n;
6703    for (size_t __i = 0; __i < __n; ++__i)
6704        __os << __sp << __x.__p_.__areas_[__i];
6705    return __os;
6706}
6707
6708template <class _CharT, class _Traits, class _RT>
6709basic_istream<_CharT, _Traits>&
6710operator>>(basic_istream<_CharT, _Traits>& __is,
6711           piecewise_linear_distribution<_RT>& __x)
6712{
6713    typedef piecewise_linear_distribution<_RT> _Eng;
6714    typedef typename _Eng::result_type result_type;
6715    __save_flags<_CharT, _Traits> __lx(__is);
6716    __is.flags(ios_base::dec | ios_base::skipws);
6717    size_t __n;
6718    __is >> __n;
6719    vector<result_type> __b(__n);
6720    for (size_t __i = 0; __i < __n; ++__i)
6721        __is >> __b[__i];
6722    __is >> __n;
6723    vector<result_type> __densities(__n);
6724    for (size_t __i = 0; __i < __n; ++__i)
6725        __is >> __densities[__i];
6726    __is >> __n;
6727    vector<result_type> __areas(__n);
6728    for (size_t __i = 0; __i < __n; ++__i)
6729        __is >> __areas[__i];
6730    if (!__is.fail())
6731    {
6732        swap(__x.__p_.__b_, __b);
6733        swap(__x.__p_.__densities_, __densities);
6734        swap(__x.__p_.__areas_, __areas);
6735    }
6736    return __is;
6737}
6738
6739_LIBCPP_END_NAMESPACE_STD
6740
6741_LIBCPP_POP_MACROS
6742
6743#endif  // _LIBCPP_RANDOM
6744