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___RANDOM_BERNOULLI_DISTRIBUTION_H 10 #define _LIBCPP___RANDOM_BERNOULLI_DISTRIBUTION_H 11 12 #include <__config> 13 #include <__random/uniform_real_distribution.h> 14 #include <iosfwd> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 #pragma GCC system_header 18 #endif 19 20 _LIBCPP_PUSH_MACROS 21 #include <__undef_macros> 22 23 _LIBCPP_BEGIN_NAMESPACE_STD 24 25 class _LIBCPP_TEMPLATE_VIS bernoulli_distribution 26 { 27 public: 28 // types 29 typedef bool result_type; 30 31 class _LIBCPP_TEMPLATE_VIS param_type 32 { 33 double __p_; 34 public: 35 typedef bernoulli_distribution distribution_type; 36 37 _LIBCPP_INLINE_VISIBILITY 38 explicit param_type(double __p = 0.5) : __p_(__p) {} 39 40 _LIBCPP_INLINE_VISIBILITY 41 double p() const {return __p_;} 42 43 friend _LIBCPP_INLINE_VISIBILITY 44 bool operator==(const param_type& __x, const param_type& __y) 45 {return __x.__p_ == __y.__p_;} 46 friend _LIBCPP_INLINE_VISIBILITY 47 bool operator!=(const param_type& __x, const param_type& __y) 48 {return !(__x == __y);} 49 }; 50 51 private: 52 param_type __p_; 53 54 public: 55 // constructors and reset functions 56 #ifndef _LIBCPP_CXX03_LANG 57 _LIBCPP_INLINE_VISIBILITY 58 bernoulli_distribution() : bernoulli_distribution(0.5) {} 59 _LIBCPP_INLINE_VISIBILITY 60 explicit bernoulli_distribution(double __p) : __p_(param_type(__p)) {} 61 #else 62 _LIBCPP_INLINE_VISIBILITY 63 explicit bernoulli_distribution(double __p = 0.5) : __p_(param_type(__p)) {} 64 #endif 65 _LIBCPP_INLINE_VISIBILITY 66 explicit bernoulli_distribution(const param_type& __p) : __p_(__p) {} 67 _LIBCPP_INLINE_VISIBILITY 68 void reset() {} 69 70 // generating functions 71 template<class _URNG> 72 _LIBCPP_INLINE_VISIBILITY 73 result_type operator()(_URNG& __g) 74 {return (*this)(__g, __p_);} 75 template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p); 76 77 // property functions 78 _LIBCPP_INLINE_VISIBILITY 79 double p() const {return __p_.p();} 80 81 _LIBCPP_INLINE_VISIBILITY 82 param_type param() const {return __p_;} 83 _LIBCPP_INLINE_VISIBILITY 84 void param(const param_type& __p) {__p_ = __p;} 85 86 _LIBCPP_INLINE_VISIBILITY 87 result_type min() const {return false;} 88 _LIBCPP_INLINE_VISIBILITY 89 result_type max() const {return true;} 90 91 friend _LIBCPP_INLINE_VISIBILITY 92 bool operator==(const bernoulli_distribution& __x, 93 const bernoulli_distribution& __y) 94 {return __x.__p_ == __y.__p_;} 95 friend _LIBCPP_INLINE_VISIBILITY 96 bool operator!=(const bernoulli_distribution& __x, 97 const bernoulli_distribution& __y) 98 {return !(__x == __y);} 99 }; 100 101 template<class _URNG> 102 inline 103 bernoulli_distribution::result_type 104 bernoulli_distribution::operator()(_URNG& __g, const param_type& __p) 105 { 106 uniform_real_distribution<double> __gen; 107 return __gen(__g) < __p.p(); 108 } 109 110 template <class _CharT, class _Traits> 111 basic_ostream<_CharT, _Traits>& 112 operator<<(basic_ostream<_CharT, _Traits>& __os, const bernoulli_distribution& __x) 113 { 114 __save_flags<_CharT, _Traits> __lx(__os); 115 typedef basic_ostream<_CharT, _Traits> _OStream; 116 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | 117 _OStream::scientific); 118 _CharT __sp = __os.widen(' '); 119 __os.fill(__sp); 120 return __os << __x.p(); 121 } 122 123 template <class _CharT, class _Traits> 124 basic_istream<_CharT, _Traits>& 125 operator>>(basic_istream<_CharT, _Traits>& __is, bernoulli_distribution& __x) 126 { 127 typedef bernoulli_distribution _Eng; 128 typedef typename _Eng::param_type param_type; 129 __save_flags<_CharT, _Traits> __lx(__is); 130 typedef basic_istream<_CharT, _Traits> _Istream; 131 __is.flags(_Istream::dec | _Istream::skipws); 132 double __p; 133 __is >> __p; 134 if (!__is.fail()) 135 __x.param(param_type(__p)); 136 return __is; 137 } 138 139 _LIBCPP_END_NAMESPACE_STD 140 141 _LIBCPP_POP_MACROS 142 143 #endif // _LIBCPP___RANDOM_BERNOULLI_DISTRIBUTION_H 144