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/is_valid.h> 14 #include <__random/uniform_real_distribution.h> 15 #include <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 <__undef_macros> 23 24 _LIBCPP_BEGIN_NAMESPACE_STD 25 26 class _LIBCPP_TEMPLATE_VIS bernoulli_distribution 27 { 28 public: 29 // types 30 typedef bool result_type; 31 32 class _LIBCPP_TEMPLATE_VIS param_type 33 { 34 double __p_; 35 public: 36 typedef bernoulli_distribution distribution_type; 37 38 _LIBCPP_INLINE_VISIBILITY 39 explicit param_type(double __p = 0.5) : __p_(__p) {} 40 41 _LIBCPP_INLINE_VISIBILITY 42 double p() const {return __p_;} 43 44 friend _LIBCPP_INLINE_VISIBILITY 45 bool operator==(const param_type& __x, const param_type& __y) 46 {return __x.__p_ == __y.__p_;} 47 friend _LIBCPP_INLINE_VISIBILITY 48 bool operator!=(const param_type& __x, const param_type& __y) 49 {return !(__x == __y);} 50 }; 51 52 private: 53 param_type __p_; 54 55 public: 56 // constructors and reset functions 57 #ifndef _LIBCPP_CXX03_LANG 58 _LIBCPP_INLINE_VISIBILITY 59 bernoulli_distribution() : bernoulli_distribution(0.5) {} 60 _LIBCPP_INLINE_VISIBILITY 61 explicit bernoulli_distribution(double __p) : __p_(param_type(__p)) {} 62 #else 63 _LIBCPP_INLINE_VISIBILITY 64 explicit bernoulli_distribution(double __p = 0.5) : __p_(param_type(__p)) {} 65 #endif 66 _LIBCPP_INLINE_VISIBILITY 67 explicit bernoulli_distribution(const param_type& __p) : __p_(__p) {} 68 _LIBCPP_INLINE_VISIBILITY 69 void reset() {} 70 71 // generating functions 72 template<class _URNG> 73 _LIBCPP_INLINE_VISIBILITY 74 result_type operator()(_URNG& __g) 75 {return (*this)(__g, __p_);} 76 template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p); 77 78 // property functions 79 _LIBCPP_INLINE_VISIBILITY 80 double p() const {return __p_.p();} 81 82 _LIBCPP_INLINE_VISIBILITY 83 param_type param() const {return __p_;} 84 _LIBCPP_INLINE_VISIBILITY 85 void param(const param_type& __p) {__p_ = __p;} 86 87 _LIBCPP_INLINE_VISIBILITY 88 result_type min() const {return false;} 89 _LIBCPP_INLINE_VISIBILITY 90 result_type max() const {return true;} 91 92 friend _LIBCPP_INLINE_VISIBILITY 93 bool operator==(const bernoulli_distribution& __x, 94 const bernoulli_distribution& __y) 95 {return __x.__p_ == __y.__p_;} 96 friend _LIBCPP_INLINE_VISIBILITY 97 bool operator!=(const bernoulli_distribution& __x, 98 const bernoulli_distribution& __y) 99 {return !(__x == __y);} 100 }; 101 102 template<class _URNG> 103 inline 104 bernoulli_distribution::result_type 105 bernoulli_distribution::operator()(_URNG& __g, const param_type& __p) 106 { 107 static_assert(__libcpp_random_is_valid_urng<_URNG>::value, ""); 108 uniform_real_distribution<double> __gen; 109 return __gen(__g) < __p.p(); 110 } 111 112 template <class _CharT, class _Traits> 113 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 114 operator<<(basic_ostream<_CharT, _Traits>& __os, const bernoulli_distribution& __x) 115 { 116 __save_flags<_CharT, _Traits> __lx(__os); 117 typedef basic_ostream<_CharT, _Traits> _OStream; 118 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | 119 _OStream::scientific); 120 _CharT __sp = __os.widen(' '); 121 __os.fill(__sp); 122 return __os << __x.p(); 123 } 124 125 template <class _CharT, class _Traits> 126 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 127 operator>>(basic_istream<_CharT, _Traits>& __is, bernoulli_distribution& __x) 128 { 129 typedef bernoulli_distribution _Eng; 130 typedef typename _Eng::param_type param_type; 131 __save_flags<_CharT, _Traits> __lx(__is); 132 typedef basic_istream<_CharT, _Traits> _Istream; 133 __is.flags(_Istream::dec | _Istream::skipws); 134 double __p; 135 __is >> __p; 136 if (!__is.fail()) 137 __x.param(param_type(__p)); 138 return __is; 139 } 140 141 _LIBCPP_END_NAMESPACE_STD 142 143 _LIBCPP_POP_MACROS 144 145 #endif // _LIBCPP___RANDOM_BERNOULLI_DISTRIBUTION_H 146