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___CXX03___RANDOM_GEOMETRIC_DISTRIBUTION_H 10 #define _LIBCPP___CXX03___RANDOM_GEOMETRIC_DISTRIBUTION_H 11 12 #include <__cxx03/__config> 13 #include <__cxx03/__random/is_valid.h> 14 #include <__cxx03/__random/negative_binomial_distribution.h> 15 #include <__cxx03/iosfwd> 16 #include <__cxx03/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 <__cxx03/__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 __p_(__p)41 _LIBCPP_HIDE_FROM_ABI explicit param_type(double __p = 0.5) : __p_(__p) {} 42 p()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 __p_(__p)56 _LIBCPP_HIDE_FROM_ABI explicit geometric_distribution(double __p = 0.5) : __p_(__p) {} geometric_distribution(const param_type & __p)57 _LIBCPP_HIDE_FROM_ABI explicit geometric_distribution(const param_type& __p) : __p_(__p) {} reset()58 _LIBCPP_HIDE_FROM_ABI void reset() {} 59 60 // generating functions 61 template <class _URNG> operator()62 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) { 63 return (*this)(__g, __p_); 64 } 65 template <class _URNG> operator()66 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p) { 67 return negative_binomial_distribution<result_type>(1, __p.p())(__g); 68 } 69 70 // property functions p()71 _LIBCPP_HIDE_FROM_ABI double p() const { return __p_.p(); } 72 param()73 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; } param(const param_type & __p)74 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; } 75 min()76 _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; } max()77 _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::max(); } 78 79 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const geometric_distribution& __x, const geometric_distribution& __y) { 80 return __x.__p_ == __y.__p_; 81 } 82 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const geometric_distribution& __x, const geometric_distribution& __y) { 83 return !(__x == __y); 84 } 85 }; 86 87 template <class _CharT, class _Traits, class _IntType> 88 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 89 operator<<(basic_ostream<_CharT, _Traits>& __os, const geometric_distribution<_IntType>& __x) { 90 __save_flags<_CharT, _Traits> __lx(__os); 91 typedef basic_ostream<_CharT, _Traits> _OStream; 92 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific); 93 return __os << __x.p(); 94 } 95 96 template <class _CharT, class _Traits, class _IntType> 97 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 98 operator>>(basic_istream<_CharT, _Traits>& __is, geometric_distribution<_IntType>& __x) { 99 typedef geometric_distribution<_IntType> _Eng; 100 typedef typename _Eng::param_type param_type; 101 __save_flags<_CharT, _Traits> __lx(__is); 102 typedef basic_istream<_CharT, _Traits> _Istream; 103 __is.flags(_Istream::dec | _Istream::skipws); 104 double __p; 105 __is >> __p; 106 if (!__is.fail()) 107 __x.param(param_type(__p)); 108 return __is; 109 } 110 111 _LIBCPP_END_NAMESPACE_STD 112 113 _LIBCPP_POP_MACROS 114 115 #endif // _LIBCPP___CXX03___RANDOM_GEOMETRIC_DISTRIBUTION_H 116