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
__a_(__a)43 _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __a = 0, result_type __b = 1) : __a_(__a), __b_(__b) {}
44
a()45 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __a_; }
b()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
uniform_real_distribution()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)
__p_(param_type (__a,__b))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
uniform_real_distribution(const param_type & __p)67 _LIBCPP_HIDE_FROM_ABI explicit uniform_real_distribution(const param_type& __p) : __p_(__p) {}
reset()68 _LIBCPP_HIDE_FROM_ABI void reset() {}
69
70 // generating functions
71 template <class _URNG>
operator()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
a()79 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __p_.a(); }
b()80 _LIBCPP_HIDE_FROM_ABI result_type b() const { return __p_.b(); }
81
param()82 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; }
param(const param_type & __p)83 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; }
84
min()85 _LIBCPP_HIDE_FROM_ABI result_type min() const { return a(); }
max()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
operator()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