228 lines · c
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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___RANDOM_SHUFFLE_ORDER_ENGINE_H10#define _LIBCPP___RANDOM_SHUFFLE_ORDER_ENGINE_H11 12#include <__algorithm/equal.h>13#include <__config>14#include <__cstddef/size_t.h>15#include <__random/is_seed_sequence.h>16#include <__type_traits/enable_if.h>17#include <__type_traits/integral_constant.h>18#include <__type_traits/is_convertible.h>19#include <__utility/move.h>20#include <cstdint>21#include <iosfwd>22 23#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)24# pragma GCC system_header25#endif26 27_LIBCPP_PUSH_MACROS28#include <__undef_macros>29 30_LIBCPP_BEGIN_NAMESPACE_STD31 32template <uint64_t _Xp, uint64_t _Yp>33struct __ugcd {34 static _LIBCPP_CONSTEXPR const uint64_t value = __ugcd<_Yp, _Xp % _Yp>::value;35};36 37template <uint64_t _Xp>38struct __ugcd<_Xp, 0> {39 static _LIBCPP_CONSTEXPR const uint64_t value = _Xp;40};41 42template <uint64_t _Np, uint64_t _Dp>43class __uratio {44 static_assert(_Dp != 0, "__uratio divide by 0");45 static _LIBCPP_CONSTEXPR const uint64_t __gcd = __ugcd<_Np, _Dp>::value;46 47public:48 static _LIBCPP_CONSTEXPR const uint64_t num = _Np / __gcd;49 static _LIBCPP_CONSTEXPR const uint64_t den = _Dp / __gcd;50 51 typedef __uratio<num, den> type;52};53 54template <class _Engine, size_t __k>55class shuffle_order_engine {56 static_assert(0 < __k, "shuffle_order_engine invalid parameters");57 58public:59 // types60 typedef typename _Engine::result_type result_type;61 62private:63 _Engine __e_;64 result_type __v_[__k];65 result_type __y_;66 67public:68 // engine characteristics69 static inline _LIBCPP_CONSTEXPR const size_t table_size = __k;70 71#ifdef _LIBCPP_CXX03_LANG72 static const result_type _Min = _Engine::_Min;73 static const result_type _Max = _Engine::_Max;74#else75 static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();76 static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();77#endif78 static_assert(_Min < _Max, "shuffle_order_engine invalid parameters");79 _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR result_type min() { return _Min; }80 _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR result_type max() { return _Max; }81 82 static _LIBCPP_CONSTEXPR const unsigned long long _Rp = _Max - _Min + 1ull;83 84 // constructors and seeding functions85 _LIBCPP_HIDE_FROM_ABI shuffle_order_engine() { __init(); }86 _LIBCPP_HIDE_FROM_ABI explicit shuffle_order_engine(const _Engine& __e) : __e_(__e) { __init(); }87#ifndef _LIBCPP_CXX03_LANG88 _LIBCPP_HIDE_FROM_ABI explicit shuffle_order_engine(_Engine&& __e) : __e_(std::move(__e)) { __init(); }89#endif // _LIBCPP_CXX03_LANG90 _LIBCPP_HIDE_FROM_ABI explicit shuffle_order_engine(result_type __sd) : __e_(__sd) { __init(); }91 template <92 class _Sseq,93 __enable_if_t<__is_seed_sequence<_Sseq, shuffle_order_engine>::value && !is_convertible<_Sseq, _Engine>::value,94 int> = 0>95 _LIBCPP_HIDE_FROM_ABI explicit shuffle_order_engine(_Sseq& __q) : __e_(__q) {96 __init();97 }98 _LIBCPP_HIDE_FROM_ABI void seed() {99 __e_.seed();100 __init();101 }102 _LIBCPP_HIDE_FROM_ABI void seed(result_type __sd) {103 __e_.seed(__sd);104 __init();105 }106 template <class _Sseq, __enable_if_t<__is_seed_sequence<_Sseq, shuffle_order_engine>::value, int> = 0>107 _LIBCPP_HIDE_FROM_ABI void seed(_Sseq& __q) {108 __e_.seed(__q);109 __init();110 }111 112 // generating functions113 _LIBCPP_HIDE_FROM_ABI result_type operator()() { return __eval(integral_constant<bool, _Rp != 0>()); }114 _LIBCPP_HIDE_FROM_ABI void discard(unsigned long long __z) {115 for (; __z; --__z)116 operator()();117 }118 119 // property functions120 _LIBCPP_HIDE_FROM_ABI const _Engine& base() const _NOEXCEPT { return __e_; }121 122private:123 template <class _Eng, size_t _Kp>124 friend bool operator==(const shuffle_order_engine<_Eng, _Kp>& __x, const shuffle_order_engine<_Eng, _Kp>& __y);125 126 template <class _Eng, size_t _Kp>127 friend bool operator!=(const shuffle_order_engine<_Eng, _Kp>& __x, const shuffle_order_engine<_Eng, _Kp>& __y);128 129 template <class _CharT, class _Traits, class _Eng, size_t _Kp>130 friend basic_ostream<_CharT, _Traits>&131 operator<<(basic_ostream<_CharT, _Traits>& __os, const shuffle_order_engine<_Eng, _Kp>& __x);132 133 template <class _CharT, class _Traits, class _Eng, size_t _Kp>134 friend basic_istream<_CharT, _Traits>&135 operator>>(basic_istream<_CharT, _Traits>& __is, shuffle_order_engine<_Eng, _Kp>& __x);136 137 _LIBCPP_HIDE_FROM_ABI void __init() {138 for (size_t __i = 0; __i < __k; ++__i)139 __v_[__i] = __e_();140 __y_ = __e_();141 }142 143 _LIBCPP_HIDE_FROM_ABI result_type __eval(false_type) { return __eval2(integral_constant<bool, __k & 1>()); }144 _LIBCPP_HIDE_FROM_ABI result_type __eval(true_type) { return __eval(__uratio<__k, _Rp>()); }145 146 _LIBCPP_HIDE_FROM_ABI result_type __eval2(false_type) { return __eval(__uratio<__k / 2, 0x8000000000000000ull>()); }147 _LIBCPP_HIDE_FROM_ABI result_type __eval2(true_type) { return __evalf<__k, 0>(); }148 149 template <uint64_t _Np,150 uint64_t _Dp,151 __enable_if_t<(__uratio<_Np, _Dp>::num > 0xFFFFFFFFFFFFFFFFull / (_Max - _Min)), int> = 0>152 _LIBCPP_HIDE_FROM_ABI result_type __eval(__uratio<_Np, _Dp>) {153 return __evalf<__uratio<_Np, _Dp>::num, __uratio<_Np, _Dp>::den>();154 }155 156 template <uint64_t _Np,157 uint64_t _Dp,158 __enable_if_t<__uratio<_Np, _Dp>::num <= 0xFFFFFFFFFFFFFFFFull / (_Max - _Min), int> = 0>159 _LIBCPP_HIDE_FROM_ABI result_type __eval(__uratio<_Np, _Dp>) {160 const size_t __j = static_cast<size_t>(__uratio<_Np, _Dp>::num * (__y_ - _Min) / __uratio<_Np, _Dp>::den);161 __y_ = __v_[__j];162 __v_[__j] = __e_();163 return __y_;164 }165 166 template <uint64_t __n, uint64_t __d>167 _LIBCPP_HIDE_FROM_ABI result_type __evalf() {168 const double __fp = __d == 0 ? __n / (2. * 0x8000000000000000ull) : __n / (double)__d;169 const size_t __j = static_cast<size_t>(__fp * (__y_ - _Min));170 __y_ = __v_[__j];171 __v_[__j] = __e_();172 return __y_;173 }174};175 176template <class _Eng, size_t _Kp>177_LIBCPP_HIDE_FROM_ABI bool178operator==(const shuffle_order_engine<_Eng, _Kp>& __x, const shuffle_order_engine<_Eng, _Kp>& __y) {179 return __x.__y_ == __y.__y_ && std::equal(__x.__v_, __x.__v_ + _Kp, __y.__v_) && __x.__e_ == __y.__e_;180}181 182template <class _Eng, size_t _Kp>183inline _LIBCPP_HIDE_FROM_ABI bool184operator!=(const shuffle_order_engine<_Eng, _Kp>& __x, const shuffle_order_engine<_Eng, _Kp>& __y) {185 return !(__x == __y);186}187 188template <class _CharT, class _Traits, class _Eng, size_t _Kp>189_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&190operator<<(basic_ostream<_CharT, _Traits>& __os, const shuffle_order_engine<_Eng, _Kp>& __x) {191 __save_flags<_CharT, _Traits> __lx(__os);192 typedef basic_ostream<_CharT, _Traits> _Ostream;193 __os.flags(_Ostream::dec | _Ostream::left);194 _CharT __sp = __os.widen(' ');195 __os.fill(__sp);196 __os << __x.__e_ << __sp << __x.__v_[0];197 for (size_t __i = 1; __i < _Kp; ++__i)198 __os << __sp << __x.__v_[__i];199 return __os << __sp << __x.__y_;200}201 202template <class _CharT, class _Traits, class _Eng, size_t _Kp>203_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&204operator>>(basic_istream<_CharT, _Traits>& __is, shuffle_order_engine<_Eng, _Kp>& __x) {205 typedef typename shuffle_order_engine<_Eng, _Kp>::result_type result_type;206 __save_flags<_CharT, _Traits> __lx(__is);207 typedef basic_istream<_CharT, _Traits> _Istream;208 __is.flags(_Istream::dec | _Istream::skipws);209 _Eng __e;210 result_type __vp[_Kp + 1];211 __is >> __e;212 for (size_t __i = 0; __i < _Kp + 1; ++__i)213 __is >> __vp[__i];214 if (!__is.fail()) {215 __x.__e_ = __e;216 for (size_t __i = 0; __i < _Kp; ++__i)217 __x.__v_[__i] = __vp[__i];218 __x.__y_ = __vp[_Kp];219 }220 return __is;221}222 223_LIBCPP_END_NAMESPACE_STD224 225_LIBCPP_POP_MACROS226 227#endif // _LIBCPP___RANDOM_SHUFFLE_ORDER_ENGINE_H228