1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #ifndef _LIBCPP___CXX03___RANDOM_BERNOULLI_DISTRIBUTION_H
10 #define _LIBCPP___CXX03___RANDOM_BERNOULLI_DISTRIBUTION_H
11
12 #include <__cxx03/__config>
13 #include <__cxx03/__random/is_valid.h>
14 #include <__cxx03/__random/uniform_real_distribution.h>
15 #include <__cxx03/iosfwd>
16
17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18 # pragma GCC system_header
19 #endif
20
21 _LIBCPP_PUSH_MACROS
22 #include <__cxx03/__undef_macros>
23
24 _LIBCPP_BEGIN_NAMESPACE_STD
25
26 class _LIBCPP_TEMPLATE_VIS bernoulli_distribution {
27 public:
28 // types
29 typedef bool result_type;
30
31 class _LIBCPP_TEMPLATE_VIS param_type {
32 double __p_;
33
34 public:
35 typedef bernoulli_distribution distribution_type;
36
__p_(__p)37 _LIBCPP_HIDE_FROM_ABI explicit param_type(double __p = 0.5) : __p_(__p) {}
38
p()39 _LIBCPP_HIDE_FROM_ABI double p() const { return __p_; }
40
41 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) {
42 return __x.__p_ == __y.__p_;
43 }
44 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); }
45 };
46
47 private:
48 param_type __p_;
49
50 public:
51 // constructors and reset functions
__p_(param_type (__p))52 _LIBCPP_HIDE_FROM_ABI explicit bernoulli_distribution(double __p = 0.5) : __p_(param_type(__p)) {}
bernoulli_distribution(const param_type & __p)53 _LIBCPP_HIDE_FROM_ABI explicit bernoulli_distribution(const param_type& __p) : __p_(__p) {}
reset()54 _LIBCPP_HIDE_FROM_ABI void reset() {}
55
56 // generating functions
57 template <class _URNG>
operator()58 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) {
59 return (*this)(__g, __p_);
60 }
61 template <class _URNG>
62 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p);
63
64 // property functions
p()65 _LIBCPP_HIDE_FROM_ABI double p() const { return __p_.p(); }
66
param()67 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; }
param(const param_type & __p)68 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; }
69
min()70 _LIBCPP_HIDE_FROM_ABI result_type min() const { return false; }
max()71 _LIBCPP_HIDE_FROM_ABI result_type max() const { return true; }
72
73 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const bernoulli_distribution& __x, const bernoulli_distribution& __y) {
74 return __x.__p_ == __y.__p_;
75 }
76 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const bernoulli_distribution& __x, const bernoulli_distribution& __y) {
77 return !(__x == __y);
78 }
79 };
80
81 template <class _URNG>
operator()82 inline bernoulli_distribution::result_type bernoulli_distribution::operator()(_URNG& __g, const param_type& __p) {
83 static_assert(__libcpp_random_is_valid_urng<_URNG>::value, "");
84 uniform_real_distribution<double> __gen;
85 return __gen(__g) < __p.p();
86 }
87
88 template <class _CharT, class _Traits>
89 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
90 operator<<(basic_ostream<_CharT, _Traits>& __os, const bernoulli_distribution& __x) {
91 __save_flags<_CharT, _Traits> __lx(__os);
92 typedef basic_ostream<_CharT, _Traits> _OStream;
93 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific);
94 _CharT __sp = __os.widen(' ');
95 __os.fill(__sp);
96 return __os << __x.p();
97 }
98
99 template <class _CharT, class _Traits>
100 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
101 operator>>(basic_istream<_CharT, _Traits>& __is, bernoulli_distribution& __x) {
102 typedef bernoulli_distribution _Eng;
103 typedef typename _Eng::param_type param_type;
104 __save_flags<_CharT, _Traits> __lx(__is);
105 typedef basic_istream<_CharT, _Traits> _Istream;
106 __is.flags(_Istream::dec | _Istream::skipws);
107 double __p;
108 __is >> __p;
109 if (!__is.fail())
110 __x.param(param_type(__p));
111 return __is;
112 }
113
114 _LIBCPP_END_NAMESPACE_STD
115
116 _LIBCPP_POP_MACROS
117
118 #endif // _LIBCPP___CXX03___RANDOM_BERNOULLI_DISTRIBUTION_H
119