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 27 template <class _IntType = int> 28 class _LIBCPP_TEMPLATE_VIS geometric_distribution { 29 static_assert(__libcpp_random_is_valid_inttype<_IntType>::value, "IntType must be a supported integer type"); 30 31 public: 32 // types 33 typedef _IntType result_type; 34 35 class _LIBCPP_TEMPLATE_VIS 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 51 private: 52 param_type __p_; 53 54 public: 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 92 template <class _CharT, class _Traits, class _IntType> 93 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 94 operator<<(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 } 100 101 template <class _CharT, class _Traits, class _IntType> 102 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 103 operator>>(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