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Diffstat (limited to 'contrib/llvm-project/libcxx/include/__random/cauchy_distribution.h')
-rw-r--r-- | contrib/llvm-project/libcxx/include/__random/cauchy_distribution.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__random/cauchy_distribution.h b/contrib/llvm-project/libcxx/include/__random/cauchy_distribution.h new file mode 100644 index 000000000000..bd341427a152 --- /dev/null +++ b/contrib/llvm-project/libcxx/include/__random/cauchy_distribution.h @@ -0,0 +1,139 @@ +//===----------------------------------------------------------------------===// +// +// 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_CAUCHY_DISTRIBUTION_H +#define _LIBCPP___RANDOM_CAUCHY_DISTRIBUTION_H + +#include <__config> +#include <__random/is_valid.h> +#include <__random/uniform_real_distribution.h> +#include <cmath> +#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 _RealType = double> +class _LIBCPP_TEMPLATE_VIS cauchy_distribution { + static_assert(__libcpp_random_is_valid_realtype<_RealType>::value, + "RealType must be a supported floating-point type"); + +public: + // types + typedef _RealType result_type; + + class _LIBCPP_TEMPLATE_VIS param_type { + result_type __a_; + result_type __b_; + + public: + typedef cauchy_distribution distribution_type; + + _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __a = 0, result_type __b = 1) : __a_(__a), __b_(__b) {} + + _LIBCPP_HIDE_FROM_ABI result_type a() const { return __a_; } + _LIBCPP_HIDE_FROM_ABI result_type b() const { return __b_; } + + friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) { + return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_; + } + friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); } + }; + +private: + param_type __p_; + +public: + // constructor and reset functions +#ifndef _LIBCPP_CXX03_LANG + _LIBCPP_HIDE_FROM_ABI cauchy_distribution() : cauchy_distribution(0) {} + _LIBCPP_HIDE_FROM_ABI explicit cauchy_distribution(result_type __a, result_type __b = 1) + : __p_(param_type(__a, __b)) {} +#else + _LIBCPP_HIDE_FROM_ABI explicit cauchy_distribution(result_type __a = 0, result_type __b = 1) + : __p_(param_type(__a, __b)) {} +#endif + _LIBCPP_HIDE_FROM_ABI explicit cauchy_distribution(const param_type& __p) : __p_(__p) {} + _LIBCPP_HIDE_FROM_ABI void reset() {} + + // generating functions + template <class _URNG> + _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) { + return (*this)(__g, __p_); + } + template <class _URNG> + _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p); + + // property functions + _LIBCPP_HIDE_FROM_ABI result_type a() const { return __p_.a(); } + _LIBCPP_HIDE_FROM_ABI result_type b() const { return __p_.b(); } + + _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; } + _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; } + + _LIBCPP_HIDE_FROM_ABI result_type min() const { return -numeric_limits<result_type>::infinity(); } + _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::infinity(); } + + friend _LIBCPP_HIDE_FROM_ABI bool operator==(const cauchy_distribution& __x, const cauchy_distribution& __y) { + return __x.__p_ == __y.__p_; + } + friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const cauchy_distribution& __x, const cauchy_distribution& __y) { + return !(__x == __y); + } +}; + +template <class _RealType> +template <class _URNG> +inline _RealType cauchy_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p) { + static_assert(__libcpp_random_is_valid_urng<_URNG>::value, ""); + uniform_real_distribution<result_type> __gen; + // purposefully let tan arg get as close to pi/2 as it wants, tan will return a finite + return __p.a() + __p.b() * std::tan(3.1415926535897932384626433832795 * __gen(__g)); +} + +template <class _CharT, class _Traits, class _RT> +_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& +operator<<(basic_ostream<_CharT, _Traits>& __os, const cauchy_distribution<_RT>& __x) { + __save_flags<_CharT, _Traits> __lx(__os); + typedef basic_ostream<_CharT, _Traits> _OStream; + __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific); + _CharT __sp = __os.widen(' '); + __os.fill(__sp); + __os << __x.a() << __sp << __x.b(); + return __os; +} + +template <class _CharT, class _Traits, class _RT> +_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& +operator>>(basic_istream<_CharT, _Traits>& __is, cauchy_distribution<_RT>& __x) { + typedef cauchy_distribution<_RT> _Eng; + typedef typename _Eng::result_type result_type; + 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); + result_type __a; + result_type __b; + __is >> __a >> __b; + if (!__is.fail()) + __x.param(param_type(__a, __b)); + return __is; +} + +_LIBCPP_END_NAMESPACE_STD + +_LIBCPP_POP_MACROS + +#endif // _LIBCPP___RANDOM_CAUCHY_DISTRIBUTION_H |