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_GEOMETRIC_DISTRIBUTION_H
10#define _LIBCPP___RANDOM_GEOMETRIC_DISTRIBUTION_H
11
12#include <__config>
13#include <__random/is_valid.h>
14#include <__random/negative_binomial_distribution.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
27template <class _IntType = int>
28class geometric_distribution {
29 static_assert(__libcpp_random_is_valid_inttype<_IntType>::value, "IntType must be a supported integer type");
30
31public:
32 // types
33 typedef _IntType result_type;
34
35 class param_type {
36 double __p_;
37
38 public:
39 typedef geometric_distribution distribution_type;
40
41 _LIBCPP_HIDE_FROM_ABI explicit param_type(double __p = 0.5) : __p_(__p) {}
42
43 _LIBCPP_HIDE_FROM_ABI double p() const { return __p_; }
44
45 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) {
46 return __x.__p_ == __y.__p_;
47 }
48 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); }
49 };
50
51private:
52 param_type __p_;
53
54public:
55 // constructors and reset functions
56#ifndef _LIBCPP_CXX03_LANG
57 _LIBCPP_HIDE_FROM_ABI geometric_distribution() : geometric_distribution(0.5) {}
58 _LIBCPP_HIDE_FROM_ABI explicit geometric_distribution(double __p) : __p_(__p) {}
59#else
60 _LIBCPP_HIDE_FROM_ABI explicit geometric_distribution(double __p = 0.5) : __p_(__p) {}
61#endif
62 _LIBCPP_HIDE_FROM_ABI explicit geometric_distribution(const param_type& __p) : __p_(__p) {}
63 _LIBCPP_HIDE_FROM_ABI void reset() {}
64
65 // generating functions
66 template <class _URNG>
67 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) {
68 return (*this)(__g, __p_);
69 }
70 template <class _URNG>
71 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p) {
72 return negative_binomial_distribution<result_type>(1, __p.p())(__g);
73 }
74
75 // property functions
76 _LIBCPP_HIDE_FROM_ABI double p() const { return __p_.p(); }
77
78 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; }
79 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; }
80
81 _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; }
82 _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::max(); }
83
84 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const geometric_distribution& __x, const geometric_distribution& __y) {
85 return __x.__p_ == __y.__p_;
86 }
87 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const geometric_distribution& __x, const geometric_distribution& __y) {
88 return !(__x == __y);
89 }
90};
91
92template <class _CharT, class _Traits, class _IntType>
93_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
94operator<<(basic_ostream<_CharT, _Traits>& __os, const geometric_distribution<_IntType>& __x) {
95 __save_flags<_CharT, _Traits> __lx(__os);
96 typedef basic_ostream<_CharT, _Traits> _OStream;
97 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific);
98 return __os << __x.p();
99}
100
101template <class _CharT, class _Traits, class _IntType>
102_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
103operator>>(basic_istream<_CharT, _Traits>& __is, geometric_distribution<_IntType>& __x) {
104 typedef geometric_distribution<_IntType> _Eng;
105 typedef typename _Eng::param_type param_type;
106 __save_flags<_CharT, _Traits> __lx(__is);
107 typedef basic_istream<_CharT, _Traits> _Istream;
108 __is.flags(_Istream::dec | _Istream::skipws);
109 double __p;
110 __is >> __p;
111 if (!__is.fail())
112 __x.param(param_type(__p));
113 return __is;
114}
115
116_LIBCPP_END_NAMESPACE_STD
117
118_LIBCPP_POP_MACROS
119
120#endif // _LIBCPP___RANDOM_GEOMETRIC_DISTRIBUTION_H
121