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_UNIFORM_REAL_DISTRIBUTION_H 10 #define _LIBCPP___RANDOM_UNIFORM_REAL_DISTRIBUTION_H 11 12 #include <__config> 13 #include <__random/generate_canonical.h> 14 #include <__random/is_valid.h> 15 #include <iosfwd> 16 #include <limits> 17 18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19 # pragma GCC system_header 20 #endif 21 22 _LIBCPP_PUSH_MACROS 23 #include <__undef_macros> 24 25 _LIBCPP_BEGIN_NAMESPACE_STD 26 27 template <class _RealType = double> 28 class _LIBCPP_TEMPLATE_VIS uniform_real_distribution { 29 static_assert(__libcpp_random_is_valid_realtype<_RealType>::value, 30 "RealType must be a supported floating-point type"); 31 32 public: 33 // types 34 typedef _RealType result_type; 35 36 class _LIBCPP_TEMPLATE_VIS param_type { 37 result_type __a_; 38 result_type __b_; 39 40 public: 41 typedef uniform_real_distribution distribution_type; 42 43 _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __a = 0, result_type __b = 1) : __a_(__a), __b_(__b) {} 44 45 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __a_; } 46 _LIBCPP_HIDE_FROM_ABI result_type b() const { return __b_; } 47 48 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) { 49 return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_; 50 } 51 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); } 52 }; 53 54 private: 55 param_type __p_; 56 57 public: 58 // constructors and reset functions 59 #ifndef _LIBCPP_CXX03_LANG 60 _LIBCPP_HIDE_FROM_ABI uniform_real_distribution() : uniform_real_distribution(0) {} 61 _LIBCPP_HIDE_FROM_ABI explicit uniform_real_distribution(result_type __a, result_type __b = 1) 62 : __p_(param_type(__a, __b)) {} 63 #else 64 _LIBCPP_HIDE_FROM_ABI explicit uniform_real_distribution(result_type __a = 0, result_type __b = 1) 65 : __p_(param_type(__a, __b)) {} 66 #endif 67 _LIBCPP_HIDE_FROM_ABI explicit uniform_real_distribution(const param_type& __p) : __p_(__p) {} 68 _LIBCPP_HIDE_FROM_ABI void reset() {} 69 70 // generating functions 71 template <class _URNG> 72 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) { 73 return (*this)(__g, __p_); 74 } 75 template <class _URNG> 76 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p); 77 78 // property functions 79 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __p_.a(); } 80 _LIBCPP_HIDE_FROM_ABI result_type b() const { return __p_.b(); } 81 82 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; } 83 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; } 84 85 _LIBCPP_HIDE_FROM_ABI result_type min() const { return a(); } 86 _LIBCPP_HIDE_FROM_ABI result_type max() const { return b(); } 87 88 friend _LIBCPP_HIDE_FROM_ABI bool 89 operator==(const uniform_real_distribution& __x, const uniform_real_distribution& __y) { 90 return __x.__p_ == __y.__p_; 91 } 92 friend _LIBCPP_HIDE_FROM_ABI bool 93 operator!=(const uniform_real_distribution& __x, const uniform_real_distribution& __y) { 94 return !(__x == __y); 95 } 96 }; 97 98 template <class _RealType> 99 template <class _URNG> 100 inline typename uniform_real_distribution<_RealType>::result_type 101 uniform_real_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p) { 102 static_assert(__libcpp_random_is_valid_urng<_URNG>::value, ""); 103 return (__p.b() - __p.a()) * std::generate_canonical<_RealType, numeric_limits<_RealType>::digits>(__g) + __p.a(); 104 } 105 106 template <class _CharT, class _Traits, class _RT> 107 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 108 operator<<(basic_ostream<_CharT, _Traits>& __os, const uniform_real_distribution<_RT>& __x) { 109 __save_flags<_CharT, _Traits> __lx(__os); 110 typedef basic_ostream<_CharT, _Traits> _OStream; 111 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific); 112 _CharT __sp = __os.widen(' '); 113 __os.fill(__sp); 114 return __os << __x.a() << __sp << __x.b(); 115 } 116 117 template <class _CharT, class _Traits, class _RT> 118 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 119 operator>>(basic_istream<_CharT, _Traits>& __is, uniform_real_distribution<_RT>& __x) { 120 typedef uniform_real_distribution<_RT> _Eng; 121 typedef typename _Eng::result_type result_type; 122 typedef typename _Eng::param_type param_type; 123 __save_flags<_CharT, _Traits> __lx(__is); 124 typedef basic_istream<_CharT, _Traits> _Istream; 125 __is.flags(_Istream::dec | _Istream::skipws); 126 result_type __a; 127 result_type __b; 128 __is >> __a >> __b; 129 if (!__is.fail()) 130 __x.param(param_type(__a, __b)); 131 return __is; 132 } 133 134 _LIBCPP_END_NAMESPACE_STD 135 136 _LIBCPP_POP_MACROS 137 138 #endif // _LIBCPP___RANDOM_UNIFORM_REAL_DISTRIBUTION_H 139