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Diffstat (limited to 'libcxx/include/__random/geometric_distribution.h')
-rw-r--r-- | libcxx/include/__random/geometric_distribution.h | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/libcxx/include/__random/geometric_distribution.h b/libcxx/include/__random/geometric_distribution.h new file mode 100644 index 000000000000..174914eaed2e --- /dev/null +++ b/libcxx/include/__random/geometric_distribution.h @@ -0,0 +1,141 @@ +//===----------------------------------------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// + +#ifndef _LIBCPP___RANDOM_GEOMETRIC_DISTRIBUTION_H +#define _LIBCPP___RANDOM_GEOMETRIC_DISTRIBUTION_H + +#include <__config> +#include <__random/negative_binomial_distribution.h> +#include <iosfwd> +#include <limits> + +#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) +#pragma GCC system_header +#endif + +_LIBCPP_PUSH_MACROS +#include <__undef_macros> + +_LIBCPP_BEGIN_NAMESPACE_STD + +template<class _IntType = int> +class _LIBCPP_TEMPLATE_VIS geometric_distribution +{ +public: + // types + typedef _IntType result_type; + + class _LIBCPP_TEMPLATE_VIS param_type + { + double __p_; + public: + typedef geometric_distribution distribution_type; + + _LIBCPP_INLINE_VISIBILITY + explicit param_type(double __p = 0.5) : __p_(__p) {} + + _LIBCPP_INLINE_VISIBILITY + double p() const {return __p_;} + + friend _LIBCPP_INLINE_VISIBILITY + bool operator==(const param_type& __x, const param_type& __y) + {return __x.__p_ == __y.__p_;} + friend _LIBCPP_INLINE_VISIBILITY + bool operator!=(const param_type& __x, const param_type& __y) + {return !(__x == __y);} + }; + +private: + param_type __p_; + +public: + // constructors and reset functions +#ifndef _LIBCPP_CXX03_LANG + _LIBCPP_INLINE_VISIBILITY + geometric_distribution() : geometric_distribution(0.5) {} + _LIBCPP_INLINE_VISIBILITY + explicit geometric_distribution(double __p) + : __p_(__p) {} +#else + _LIBCPP_INLINE_VISIBILITY + explicit geometric_distribution(double __p = 0.5) + : __p_(__p) {} +#endif + _LIBCPP_INLINE_VISIBILITY + explicit geometric_distribution(const param_type& __p) : __p_(__p) {} + _LIBCPP_INLINE_VISIBILITY + void reset() {} + + // generating functions + template<class _URNG> + _LIBCPP_INLINE_VISIBILITY + result_type operator()(_URNG& __g) + {return (*this)(__g, __p_);} + template<class _URNG> + _LIBCPP_INLINE_VISIBILITY + result_type operator()(_URNG& __g, const param_type& __p) + {return negative_binomial_distribution<result_type>(1, __p.p())(__g);} + + // property functions + _LIBCPP_INLINE_VISIBILITY + double p() const {return __p_.p();} + + _LIBCPP_INLINE_VISIBILITY + param_type param() const {return __p_;} + _LIBCPP_INLINE_VISIBILITY + void param(const param_type& __p) {__p_ = __p;} + + _LIBCPP_INLINE_VISIBILITY + result_type min() const {return 0;} + _LIBCPP_INLINE_VISIBILITY + result_type max() const {return numeric_limits<result_type>::max();} + + friend _LIBCPP_INLINE_VISIBILITY + bool operator==(const geometric_distribution& __x, + const geometric_distribution& __y) + {return __x.__p_ == __y.__p_;} + friend _LIBCPP_INLINE_VISIBILITY + bool operator!=(const geometric_distribution& __x, + const geometric_distribution& __y) + {return !(__x == __y);} +}; + +template <class _CharT, class _Traits, class _IntType> +basic_ostream<_CharT, _Traits>& +operator<<(basic_ostream<_CharT, _Traits>& __os, + const geometric_distribution<_IntType>& __x) +{ + __save_flags<_CharT, _Traits> __lx(__os); + typedef basic_ostream<_CharT, _Traits> _OStream; + __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | + _OStream::scientific); + return __os << __x.p(); +} + +template <class _CharT, class _Traits, class _IntType> +basic_istream<_CharT, _Traits>& +operator>>(basic_istream<_CharT, _Traits>& __is, + geometric_distribution<_IntType>& __x) +{ + typedef geometric_distribution<_IntType> _Eng; + typedef typename _Eng::param_type param_type; + __save_flags<_CharT, _Traits> __lx(__is); + typedef basic_istream<_CharT, _Traits> _Istream; + __is.flags(_Istream::dec | _Istream::skipws); + double __p; + __is >> __p; + if (!__is.fail()) + __x.param(param_type(__p)); + return __is; +} + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___RANDOM_GEOMETRIC_DISTRIBUTION_H |