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_EXTREME_VALUE_DISTRIBUTION_H
10 #define _LIBCPP___RANDOM_EXTREME_VALUE_DISTRIBUTION_H
11
12 #include <__config>
13 #include <__random/is_valid.h>
14 #include <__random/uniform_real_distribution.h>
15 #include <cmath>
16 #include <iosfwd>
17 #include <limits>
18
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 # pragma GCC system_header
21 #endif
22
23 _LIBCPP_PUSH_MACROS
24 #include <__undef_macros>
25
26 _LIBCPP_BEGIN_NAMESPACE_STD
27
28 template <class _RealType = double>
29 class _LIBCPP_TEMPLATE_VIS extreme_value_distribution {
30 static_assert(__libcpp_random_is_valid_realtype<_RealType>::value,
31 "RealType must be a supported floating-point type");
32
33 public:
34 // types
35 typedef _RealType result_type;
36
37 class _LIBCPP_TEMPLATE_VIS param_type {
38 result_type __a_;
39 result_type __b_;
40
41 public:
42 typedef extreme_value_distribution distribution_type;
43
__a_(__a)44 _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __a = 0, result_type __b = 1) : __a_(__a), __b_(__b) {}
45
a()46 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __a_; }
b()47 _LIBCPP_HIDE_FROM_ABI result_type b() const { return __b_; }
48
49 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) {
50 return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;
51 }
52 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); }
53 };
54
55 private:
56 param_type __p_;
57
58 public:
59 // constructor and reset functions
60 #ifndef _LIBCPP_CXX03_LANG
extreme_value_distribution()61 _LIBCPP_HIDE_FROM_ABI extreme_value_distribution() : extreme_value_distribution(0) {}
62 _LIBCPP_HIDE_FROM_ABI explicit extreme_value_distribution(result_type __a, result_type __b = 1)
__p_(param_type (__a,__b))63 : __p_(param_type(__a, __b)) {}
64 #else
65 _LIBCPP_HIDE_FROM_ABI explicit extreme_value_distribution(result_type __a = 0, result_type __b = 1)
66 : __p_(param_type(__a, __b)) {}
67 #endif
extreme_value_distribution(const param_type & __p)68 _LIBCPP_HIDE_FROM_ABI explicit extreme_value_distribution(const param_type& __p) : __p_(__p) {}
reset()69 _LIBCPP_HIDE_FROM_ABI void reset() {}
70
71 // generating functions
72 template <class _URNG>
operator()73 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) {
74 return (*this)(__g, __p_);
75 }
76 template <class _URNG>
77 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p);
78
79 // property functions
a()80 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __p_.a(); }
b()81 _LIBCPP_HIDE_FROM_ABI result_type b() const { return __p_.b(); }
82
param()83 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; }
param(const param_type & __p)84 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; }
85
min()86 _LIBCPP_HIDE_FROM_ABI result_type min() const { return -numeric_limits<result_type>::infinity(); }
max()87 _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::infinity(); }
88
89 friend _LIBCPP_HIDE_FROM_ABI bool
90 operator==(const extreme_value_distribution& __x, const extreme_value_distribution& __y) {
91 return __x.__p_ == __y.__p_;
92 }
93 friend _LIBCPP_HIDE_FROM_ABI bool
94 operator!=(const extreme_value_distribution& __x, const extreme_value_distribution& __y) {
95 return !(__x == __y);
96 }
97 };
98
99 template <class _RealType>
100 template <class _URNG>
operator()101 _RealType extreme_value_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p) {
102 static_assert(__libcpp_random_is_valid_urng<_URNG>::value, "");
103 return __p.a() - __p.b() * std::log(-std::log(1 - uniform_real_distribution<result_type>()(__g)));
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 extreme_value_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 __os << __x.a() << __sp << __x.b();
115 return __os;
116 }
117
118 template <class _CharT, class _Traits, class _RT>
119 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
120 operator>>(basic_istream<_CharT, _Traits>& __is, extreme_value_distribution<_RT>& __x) {
121 typedef extreme_value_distribution<_RT> _Eng;
122 typedef typename _Eng::result_type result_type;
123 typedef typename _Eng::param_type param_type;
124 __save_flags<_CharT, _Traits> __lx(__is);
125 typedef basic_istream<_CharT, _Traits> _Istream;
126 __is.flags(_Istream::dec | _Istream::skipws);
127 result_type __a;
128 result_type __b;
129 __is >> __a >> __b;
130 if (!__is.fail())
131 __x.param(param_type(__a, __b));
132 return __is;
133 }
134
135 _LIBCPP_END_NAMESPACE_STD
136
137 _LIBCPP_POP_MACROS
138
139 #endif // _LIBCPP___RANDOM_EXTREME_VALUE_DISTRIBUTION_H
140