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_SHUFFLE_ORDER_ENGINE_H 10 #define _LIBCPP___RANDOM_SHUFFLE_ORDER_ENGINE_H 11 12 #include <__algorithm/equal.h> 13 #include <__config> 14 #include <__random/is_seed_sequence.h> 15 #include <__type_traits/enable_if.h> 16 #include <__type_traits/integral_constant.h> 17 #include <__type_traits/is_convertible.h> 18 #include <__utility/move.h> 19 #include <cstddef> 20 #include <cstdint> 21 #include <iosfwd> 22 23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 24 # pragma GCC system_header 25 #endif 26 27 _LIBCPP_PUSH_MACROS 28 #include <__undef_macros> 29 30 _LIBCPP_BEGIN_NAMESPACE_STD 31 32 template <uint64_t _Xp, uint64_t _Yp> 33 struct __ugcd { 34 static _LIBCPP_CONSTEXPR const uint64_t value = __ugcd<_Yp, _Xp % _Yp>::value; 35 }; 36 37 template <uint64_t _Xp> 38 struct __ugcd<_Xp, 0> { 39 static _LIBCPP_CONSTEXPR const uint64_t value = _Xp; 40 }; 41 42 template <uint64_t _Np, uint64_t _Dp> 43 class __uratio { 44 static_assert(_Dp != 0, "__uratio divide by 0"); 45 static _LIBCPP_CONSTEXPR const uint64_t __gcd = __ugcd<_Np, _Dp>::value; 46 47 public: 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 54 template <class _Engine, size_t __k> 55 class _LIBCPP_TEMPLATE_VIS shuffle_order_engine { 56 static_assert(0 < __k, "shuffle_order_engine invalid parameters"); 57 58 public: 59 // types 60 typedef typename _Engine::result_type result_type; 61 62 private: 63 _Engine __e_; 64 result_type __v_[__k]; 65 result_type __y_; 66 67 public: 68 // engine characteristics 69 static _LIBCPP_CONSTEXPR const size_t table_size = __k; 70 71 #ifdef _LIBCPP_CXX03_LANG 72 static const result_type _Min = _Engine::_Min; 73 static const result_type _Max = _Engine::_Max; 74 #else 75 static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min(); 76 static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max(); 77 #endif 78 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 functions 85 _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_LANG 88 _LIBCPP_HIDE_FROM_ABI explicit shuffle_order_engine(_Engine&& __e) : __e_(std::move(__e)) { __init(); } 89 #endif // _LIBCPP_CXX03_LANG 90 _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 functions 113 _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 functions 120 _LIBCPP_HIDE_FROM_ABI const _Engine& base() const _NOEXCEPT { return __e_; } 121 122 private: 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 }; 175 176 template <class _Engine, size_t __k> 177 _LIBCPP_CONSTEXPR const size_t shuffle_order_engine<_Engine, __k>::table_size; 178 179 template <class _Eng, size_t _Kp> 180 _LIBCPP_HIDE_FROM_ABI bool 181 operator==(const shuffle_order_engine<_Eng, _Kp>& __x, const shuffle_order_engine<_Eng, _Kp>& __y) { 182 return __x.__y_ == __y.__y_ && std::equal(__x.__v_, __x.__v_ + _Kp, __y.__v_) && __x.__e_ == __y.__e_; 183 } 184 185 template <class _Eng, size_t _Kp> 186 inline _LIBCPP_HIDE_FROM_ABI bool 187 operator!=(const shuffle_order_engine<_Eng, _Kp>& __x, const shuffle_order_engine<_Eng, _Kp>& __y) { 188 return !(__x == __y); 189 } 190 191 template <class _CharT, class _Traits, class _Eng, size_t _Kp> 192 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 193 operator<<(basic_ostream<_CharT, _Traits>& __os, const shuffle_order_engine<_Eng, _Kp>& __x) { 194 __save_flags<_CharT, _Traits> __lx(__os); 195 typedef basic_ostream<_CharT, _Traits> _Ostream; 196 __os.flags(_Ostream::dec | _Ostream::left); 197 _CharT __sp = __os.widen(' '); 198 __os.fill(__sp); 199 __os << __x.__e_ << __sp << __x.__v_[0]; 200 for (size_t __i = 1; __i < _Kp; ++__i) 201 __os << __sp << __x.__v_[__i]; 202 return __os << __sp << __x.__y_; 203 } 204 205 template <class _CharT, class _Traits, class _Eng, size_t _Kp> 206 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 207 operator>>(basic_istream<_CharT, _Traits>& __is, shuffle_order_engine<_Eng, _Kp>& __x) { 208 typedef typename shuffle_order_engine<_Eng, _Kp>::result_type result_type; 209 __save_flags<_CharT, _Traits> __lx(__is); 210 typedef basic_istream<_CharT, _Traits> _Istream; 211 __is.flags(_Istream::dec | _Istream::skipws); 212 _Eng __e; 213 result_type __vp[_Kp + 1]; 214 __is >> __e; 215 for (size_t __i = 0; __i < _Kp + 1; ++__i) 216 __is >> __vp[__i]; 217 if (!__is.fail()) { 218 __x.__e_ = __e; 219 for (size_t __i = 0; __i < _Kp; ++__i) 220 __x.__v_[__i] = __vp[__i]; 221 __x.__y_ = __vp[_Kp]; 222 } 223 return __is; 224 } 225 226 _LIBCPP_END_NAMESPACE_STD 227 228 _LIBCPP_POP_MACROS 229 230 #endif // _LIBCPP___RANDOM_SHUFFLE_ORDER_ENGINE_H 231