1 // The template and inlines for the -*- C++ -*- slice_array class. 2 3 // Copyright (C) 1997-2018 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 3, or (at your option) 9 // any later version. 10 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 16 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /** @file bits/slice_array.h 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. @headername{valarray} 28 */ 29 30 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr> 31 32 #ifndef _SLICE_ARRAY_H 33 #define _SLICE_ARRAY_H 1 34 35 #pragma GCC system_header 36 37 namespace std _GLIBCXX_VISIBILITY(default) 38 { 39 _GLIBCXX_BEGIN_NAMESPACE_VERSION 40 41 /** 42 * @addtogroup numeric_arrays 43 * @{ 44 */ 45 46 /** 47 * @brief Class defining one-dimensional subset of an array. 48 * 49 * The slice class represents a one-dimensional subset of an array, 50 * specified by three parameters: start offset, size, and stride. The 51 * start offset is the index of the first element of the array that is part 52 * of the subset. The size is the total number of elements in the subset. 53 * Stride is the distance between each successive array element to include 54 * in the subset. 55 * 56 * For example, with an array of size 10, and a slice with offset 1, size 3 57 * and stride 2, the subset consists of array elements 1, 3, and 5. 58 */ 59 class slice 60 { 61 public: 62 /// Construct an empty slice. 63 slice(); 64 65 /** 66 * @brief Construct a slice. 67 * 68 * @param __o Offset in array of first element. 69 * @param __d Number of elements in slice. 70 * @param __s Stride between array elements. 71 */ 72 slice(size_t __o, size_t __d, size_t __s); 73 74 /// Return array offset of first slice element. 75 size_t start() const; 76 /// Return size of slice. 77 size_t size() const; 78 /// Return array stride of slice. 79 size_t stride() const; 80 81 private: 82 size_t _M_off; // offset 83 size_t _M_sz; // size 84 size_t _M_st; // stride unit 85 }; 86 87 // _GLIBCXX_RESOLVE_LIB_DEFECTS 88 // 543. valarray slice default constructor 89 inline 90 slice::slice() 91 : _M_off(0), _M_sz(0), _M_st(0) {} 92 93 inline 94 slice::slice(size_t __o, size_t __d, size_t __s) 95 : _M_off(__o), _M_sz(__d), _M_st(__s) {} 96 97 inline size_t 98 slice::start() const 99 { return _M_off; } 100 101 inline size_t 102 slice::size() const 103 { return _M_sz; } 104 105 inline size_t 106 slice::stride() const 107 { return _M_st; } 108 109 /** 110 * @brief Reference to one-dimensional subset of an array. 111 * 112 * A slice_array is a reference to the actual elements of an array 113 * specified by a slice. The way to get a slice_array is to call 114 * operator[](slice) on a valarray. The returned slice_array then permits 115 * carrying operations out on the referenced subset of elements in the 116 * original valarray. For example, operator+=(valarray) will add values 117 * to the subset of elements in the underlying valarray this slice_array 118 * refers to. 119 * 120 * @param Tp Element type. 121 */ 122 template<typename _Tp> 123 class slice_array 124 { 125 public: 126 typedef _Tp value_type; 127 128 // _GLIBCXX_RESOLVE_LIB_DEFECTS 129 // 253. valarray helper functions are almost entirely useless 130 131 /// Copy constructor. Both slices refer to the same underlying array. 132 slice_array(const slice_array&); 133 134 /// Assignment operator. Assigns slice elements to corresponding 135 /// elements of @a a. 136 slice_array& operator=(const slice_array&); 137 138 /// Assign slice elements to corresponding elements of @a v. 139 void operator=(const valarray<_Tp>&) const; 140 /// Multiply slice elements by corresponding elements of @a v. 141 void operator*=(const valarray<_Tp>&) const; 142 /// Divide slice elements by corresponding elements of @a v. 143 void operator/=(const valarray<_Tp>&) const; 144 /// Modulo slice elements by corresponding elements of @a v. 145 void operator%=(const valarray<_Tp>&) const; 146 /// Add corresponding elements of @a v to slice elements. 147 void operator+=(const valarray<_Tp>&) const; 148 /// Subtract corresponding elements of @a v from slice elements. 149 void operator-=(const valarray<_Tp>&) const; 150 /// Logical xor slice elements with corresponding elements of @a v. 151 void operator^=(const valarray<_Tp>&) const; 152 /// Logical and slice elements with corresponding elements of @a v. 153 void operator&=(const valarray<_Tp>&) const; 154 /// Logical or slice elements with corresponding elements of @a v. 155 void operator|=(const valarray<_Tp>&) const; 156 /// Left shift slice elements by corresponding elements of @a v. 157 void operator<<=(const valarray<_Tp>&) const; 158 /// Right shift slice elements by corresponding elements of @a v. 159 void operator>>=(const valarray<_Tp>&) const; 160 /// Assign all slice elements to @a t. 161 void operator=(const _Tp &) const; 162 // ~slice_array (); 163 164 template<class _Dom> 165 void operator=(const _Expr<_Dom, _Tp>&) const; 166 template<class _Dom> 167 void operator*=(const _Expr<_Dom, _Tp>&) const; 168 template<class _Dom> 169 void operator/=(const _Expr<_Dom, _Tp>&) const; 170 template<class _Dom> 171 void operator%=(const _Expr<_Dom, _Tp>&) const; 172 template<class _Dom> 173 void operator+=(const _Expr<_Dom, _Tp>&) const; 174 template<class _Dom> 175 void operator-=(const _Expr<_Dom, _Tp>&) const; 176 template<class _Dom> 177 void operator^=(const _Expr<_Dom, _Tp>&) const; 178 template<class _Dom> 179 void operator&=(const _Expr<_Dom, _Tp>&) const; 180 template<class _Dom> 181 void operator|=(const _Expr<_Dom, _Tp>&) const; 182 template<class _Dom> 183 void operator<<=(const _Expr<_Dom, _Tp>&) const; 184 template<class _Dom> 185 void operator>>=(const _Expr<_Dom, _Tp>&) const; 186 187 private: 188 friend class valarray<_Tp>; 189 slice_array(_Array<_Tp>, const slice&); 190 191 const size_t _M_sz; 192 const size_t _M_stride; 193 const _Array<_Tp> _M_array; 194 195 // not implemented 196 slice_array(); 197 }; 198 199 template<typename _Tp> 200 inline 201 slice_array<_Tp>::slice_array(_Array<_Tp> __a, const slice& __s) 202 : _M_sz(__s.size()), _M_stride(__s.stride()), 203 _M_array(__a.begin() + __s.start()) {} 204 205 template<typename _Tp> 206 inline 207 slice_array<_Tp>::slice_array(const slice_array<_Tp>& __a) 208 : _M_sz(__a._M_sz), _M_stride(__a._M_stride), _M_array(__a._M_array) {} 209 210 // template<typename _Tp> 211 // inline slice_array<_Tp>::~slice_array () {} 212 213 template<typename _Tp> 214 inline slice_array<_Tp>& 215 slice_array<_Tp>::operator=(const slice_array<_Tp>& __a) 216 { 217 std::__valarray_copy(__a._M_array, __a._M_sz, __a._M_stride, 218 _M_array, _M_stride); 219 return *this; 220 } 221 222 template<typename _Tp> 223 inline void 224 slice_array<_Tp>::operator=(const _Tp& __t) const 225 { std::__valarray_fill(_M_array, _M_sz, _M_stride, __t); } 226 227 template<typename _Tp> 228 inline void 229 slice_array<_Tp>::operator=(const valarray<_Tp>& __v) const 230 { std::__valarray_copy(_Array<_Tp>(__v), _M_array, _M_sz, _M_stride); } 231 232 template<typename _Tp> 233 template<class _Dom> 234 inline void 235 slice_array<_Tp>::operator=(const _Expr<_Dom,_Tp>& __e) const 236 { std::__valarray_copy(__e, _M_sz, _M_array, _M_stride); } 237 238 #undef _DEFINE_VALARRAY_OPERATOR 239 #define _DEFINE_VALARRAY_OPERATOR(_Op,_Name) \ 240 template<typename _Tp> \ 241 inline void \ 242 slice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \ 243 { \ 244 _Array_augmented_##_Name(_M_array, _M_sz, _M_stride, _Array<_Tp>(__v));\ 245 } \ 246 \ 247 template<typename _Tp> \ 248 template<class _Dom> \ 249 inline void \ 250 slice_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\ 251 { \ 252 _Array_augmented_##_Name(_M_array, _M_stride, __e, _M_sz); \ 253 } 254 255 256 _DEFINE_VALARRAY_OPERATOR(*, __multiplies) 257 _DEFINE_VALARRAY_OPERATOR(/, __divides) 258 _DEFINE_VALARRAY_OPERATOR(%, __modulus) 259 _DEFINE_VALARRAY_OPERATOR(+, __plus) 260 _DEFINE_VALARRAY_OPERATOR(-, __minus) 261 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor) 262 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and) 263 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or) 264 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left) 265 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right) 266 267 #undef _DEFINE_VALARRAY_OPERATOR 268 269 // @} group numeric_arrays 270 271 _GLIBCXX_END_NAMESPACE_VERSION 272 } // namespace 273 274 #endif /* _SLICE_ARRAY_H */ 275