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 {
30 public:
31 // types
32 typedef _RealType result_type;
33
34 class _LIBCPP_TEMPLATE_VIS param_type
35 {
36 result_type __a_;
37 result_type __b_;
38 public:
39 typedef uniform_real_distribution distribution_type;
40
41 _LIBCPP_INLINE_VISIBILITY
42 explicit param_type(result_type __a = 0,
43 result_type __b = 1)
__a_(__a)44 : __a_(__a), __b_(__b) {}
45
46 _LIBCPP_INLINE_VISIBILITY
a()47 result_type a() const {return __a_;}
48 _LIBCPP_INLINE_VISIBILITY
b()49 result_type b() const {return __b_;}
50
51 friend _LIBCPP_INLINE_VISIBILITY
52 bool operator==(const param_type& __x, const param_type& __y)
53 {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
54 friend _LIBCPP_INLINE_VISIBILITY
55 bool operator!=(const param_type& __x, const param_type& __y)
56 {return !(__x == __y);}
57 };
58
59 private:
60 param_type __p_;
61
62 public:
63 // constructors and reset functions
64 #ifndef _LIBCPP_CXX03_LANG
65 _LIBCPP_INLINE_VISIBILITY
uniform_real_distribution()66 uniform_real_distribution() : uniform_real_distribution(0) {}
67 _LIBCPP_HIDE_FROM_ABI explicit uniform_real_distribution(result_type __a, result_type __b = 1)
__p_(param_type (__a,__b))68 : __p_(param_type(__a, __b)) {}
69 #else
70 _LIBCPP_INLINE_VISIBILITY
71 explicit uniform_real_distribution(result_type __a = 0, result_type __b = 1)
72 : __p_(param_type(__a, __b)) {}
73 #endif
74 _LIBCPP_INLINE_VISIBILITY
uniform_real_distribution(const param_type & __p)75 explicit uniform_real_distribution(const param_type& __p) : __p_(__p) {}
76 _LIBCPP_INLINE_VISIBILITY
reset()77 void reset() {}
78
79 // generating functions
80 template<class _URNG>
81 _LIBCPP_INLINE_VISIBILITY
operator()82 result_type operator()(_URNG& __g)
83 {return (*this)(__g, __p_);}
84 template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
85
86 // property functions
87 _LIBCPP_INLINE_VISIBILITY
a()88 result_type a() const {return __p_.a();}
89 _LIBCPP_INLINE_VISIBILITY
b()90 result_type b() const {return __p_.b();}
91
92 _LIBCPP_INLINE_VISIBILITY
param()93 param_type param() const {return __p_;}
94 _LIBCPP_INLINE_VISIBILITY
param(const param_type & __p)95 void param(const param_type& __p) {__p_ = __p;}
96
97 _LIBCPP_INLINE_VISIBILITY
min()98 result_type min() const {return a();}
99 _LIBCPP_INLINE_VISIBILITY
max()100 result_type max() const {return b();}
101
102 friend _LIBCPP_INLINE_VISIBILITY
103 bool operator==(const uniform_real_distribution& __x,
104 const uniform_real_distribution& __y)
105 {return __x.__p_ == __y.__p_;}
106 friend _LIBCPP_INLINE_VISIBILITY
107 bool operator!=(const uniform_real_distribution& __x,
108 const uniform_real_distribution& __y)
109 {return !(__x == __y);}
110 };
111
112 template<class _RealType>
113 template<class _URNG>
114 inline
115 typename uniform_real_distribution<_RealType>::result_type
operator()116 uniform_real_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
117 {
118 static_assert(__libcpp_random_is_valid_urng<_URNG>::value, "");
119 return (__p.b() - __p.a())
120 * _VSTD::generate_canonical<_RealType, numeric_limits<_RealType>::digits>(__g)
121 + __p.a();
122 }
123
124 template <class _CharT, class _Traits, class _RT>
125 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
126 operator<<(basic_ostream<_CharT, _Traits>& __os,
127 const uniform_real_distribution<_RT>& __x)
128 {
129 __save_flags<_CharT, _Traits> __lx(__os);
130 typedef basic_ostream<_CharT, _Traits> _OStream;
131 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed |
132 _OStream::scientific);
133 _CharT __sp = __os.widen(' ');
134 __os.fill(__sp);
135 return __os << __x.a() << __sp << __x.b();
136 }
137
138 template <class _CharT, class _Traits, class _RT>
139 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
140 operator>>(basic_istream<_CharT, _Traits>& __is,
141 uniform_real_distribution<_RT>& __x)
142 {
143 typedef uniform_real_distribution<_RT> _Eng;
144 typedef typename _Eng::result_type result_type;
145 typedef typename _Eng::param_type param_type;
146 __save_flags<_CharT, _Traits> __lx(__is);
147 typedef basic_istream<_CharT, _Traits> _Istream;
148 __is.flags(_Istream::dec | _Istream::skipws);
149 result_type __a;
150 result_type __b;
151 __is >> __a >> __b;
152 if (!__is.fail())
153 __x.param(param_type(__a, __b));
154 return __is;
155 }
156
157 _LIBCPP_END_NAMESPACE_STD
158
159 _LIBCPP_POP_MACROS
160
161 #endif // _LIBCPP___RANDOM_UNIFORM_REAL_DISTRIBUTION_H
162