1 // The template and inlines for the -*- C++ -*- slice_array class. 2 3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2009, 4 // 2010 Free Software Foundation, Inc. 5 // 6 // This file is part of the GNU ISO C++ Library. This library is free 7 // software; you can redistribute it and/or modify it under the 8 // terms of the GNU General Public License as published by the 9 // Free Software Foundation; either version 3, or (at your option) 10 // any later version. 11 12 // This library is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 17 // Under Section 7 of GPL version 3, you are granted additional 18 // permissions described in the GCC Runtime Library Exception, version 19 // 3.1, as published by the Free Software Foundation. 20 21 // You should have received a copy of the GNU General Public License and 22 // a copy of the GCC Runtime Library Exception along with this program; 23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 // <http://www.gnu.org/licenses/>. 25 26 /** @file bits/slice_array.h 27 * This is an internal header file, included by other library headers. 28 * Do not attempt to use it directly. @headername{valarray} 29 */ 30 31 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis (at) DPTMaths.ENS-Cachan.Fr> 32 33 #ifndef _SLICE_ARRAY_H 34 #define _SLICE_ARRAY_H 1 35 36 #pragma GCC system_header 37 38 namespace std _GLIBCXX_VISIBILITY(default) 39 { 40 _GLIBCXX_BEGIN_NAMESPACE_VERSION 41 42 /** 43 * @addtogroup numeric_arrays 44 * @{ 45 */ 46 47 /** 48 * @brief Class defining one-dimensional subset of an array. 49 * 50 * The slice class represents a one-dimensional subset of an array, 51 * specified by three parameters: start offset, size, and stride. The 52 * start offset is the index of the first element of the array that is part 53 * of the subset. The size is the total number of elements in the subset. 54 * Stride is the distance between each successive array element to include 55 * in the subset. 56 * 57 * For example, with an array of size 10, and a slice with offset 1, size 3 58 * and stride 2, the subset consists of array elements 1, 3, and 5. 59 */ 60 class slice 61 { 62 public: 63 /// Construct an empty slice. 64 slice(); 65 66 /** 67 * @brief Construct a slice. 68 * 69 * @param o Offset in array of first element. 70 * @param d Number of elements in slice. 71 * @param s Stride between array elements. 72 */ 73 slice(size_t, size_t, size_t); 74 75 /// Return array offset of first slice element. 76 size_t start() const; 77 /// Return size of slice. 78 size_t size() const; 79 /// Return array stride of slice. 80 size_t stride() const; 81 82 private: 83 size_t _M_off; // offset 84 size_t _M_sz; // size 85 size_t _M_st; // stride unit 86 }; 87 88 // _GLIBCXX_RESOLVE_LIB_DEFECTS 89 // 543. valarray slice default constructor 90 inline 91 slice::slice() 92 : _M_off(0), _M_sz(0), _M_st(0) {} 93 94 inline 95 slice::slice(size_t __o, size_t __d, size_t __s) 96 : _M_off(__o), _M_sz(__d), _M_st(__s) {} 97 98 inline size_t 99 slice::start() const 100 { return _M_off; } 101 102 inline size_t 103 slice::size() const 104 { return _M_sz; } 105 106 inline size_t 107 slice::stride() const 108 { return _M_st; } 109 110 /** 111 * @brief Reference to one-dimensional subset of an array. 112 * 113 * A slice_array is a reference to the actual elements of an array 114 * specified by a slice. The way to get a slice_array is to call 115 * operator[](slice) on a valarray. The returned slice_array then permits 116 * carrying operations out on the referenced subset of elements in the 117 * original valarray. For example, operator+=(valarray) will add values 118 * to the subset of elements in the underlying valarray this slice_array 119 * refers to. 120 * 121 * @param Tp Element type. 122 */ 123 template<typename _Tp> 124 class slice_array 125 { 126 public: 127 typedef _Tp value_type; 128 129 // _GLIBCXX_RESOLVE_LIB_DEFECTS 130 // 253. valarray helper functions are almost entirely useless 131 132 /// Copy constructor. Both slices refer to the same underlying array. 133 slice_array(const slice_array&); 134 135 /// Assignment operator. Assigns slice elements to corresponding 136 /// elements of @a a. 137 slice_array& operator=(const slice_array&); 138 139 /// Assign slice elements to corresponding elements of @a v. 140 void operator=(const valarray<_Tp>&) const; 141 /// Multiply slice elements by corresponding elements of @a v. 142 void operator*=(const valarray<_Tp>&) const; 143 /// Divide slice elements by corresponding elements of @a v. 144 void operator/=(const valarray<_Tp>&) const; 145 /// Modulo slice elements by corresponding elements of @a v. 146 void operator%=(const valarray<_Tp>&) const; 147 /// Add corresponding elements of @a v to slice elements. 148 void operator+=(const valarray<_Tp>&) const; 149 /// Subtract corresponding elements of @a v from slice elements. 150 void operator-=(const valarray<_Tp>&) const; 151 /// Logical xor slice elements with corresponding elements of @a v. 152 void operator^=(const valarray<_Tp>&) const; 153 /// Logical and slice elements with corresponding elements of @a v. 154 void operator&=(const valarray<_Tp>&) const; 155 /// Logical or slice elements with corresponding elements of @a v. 156 void operator|=(const valarray<_Tp>&) const; 157 /// Left shift slice elements by corresponding elements of @a v. 158 void operator<<=(const valarray<_Tp>&) const; 159 /// Right shift slice elements by corresponding elements of @a v. 160 void operator>>=(const valarray<_Tp>&) const; 161 /// Assign all slice elements to @a t. 162 void operator=(const _Tp &) const; 163 // ~slice_array (); 164 165 template<class _Dom> 166 void operator=(const _Expr<_Dom, _Tp>&) const; 167 template<class _Dom> 168 void operator*=(const _Expr<_Dom, _Tp>&) const; 169 template<class _Dom> 170 void operator/=(const _Expr<_Dom, _Tp>&) const; 171 template<class _Dom> 172 void operator%=(const _Expr<_Dom, _Tp>&) const; 173 template<class _Dom> 174 void operator+=(const _Expr<_Dom, _Tp>&) const; 175 template<class _Dom> 176 void operator-=(const _Expr<_Dom, _Tp>&) const; 177 template<class _Dom> 178 void operator^=(const _Expr<_Dom, _Tp>&) const; 179 template<class _Dom> 180 void operator&=(const _Expr<_Dom, _Tp>&) const; 181 template<class _Dom> 182 void operator|=(const _Expr<_Dom, _Tp>&) const; 183 template<class _Dom> 184 void operator<<=(const _Expr<_Dom, _Tp>&) const; 185 template<class _Dom> 186 void operator>>=(const _Expr<_Dom, _Tp>&) const; 187 188 private: 189 friend class valarray<_Tp>; 190 slice_array(_Array<_Tp>, const slice&); 191 192 const size_t _M_sz; 193 const size_t _M_stride; 194 const _Array<_Tp> _M_array; 195 196 // not implemented 197 slice_array(); 198 }; 199 200 template<typename _Tp> 201 inline 202 slice_array<_Tp>::slice_array(_Array<_Tp> __a, const slice& __s) 203 : _M_sz(__s.size()), _M_stride(__s.stride()), 204 _M_array(__a.begin() + __s.start()) {} 205 206 template<typename _Tp> 207 inline 208 slice_array<_Tp>::slice_array(const slice_array<_Tp>& a) 209 : _M_sz(a._M_sz), _M_stride(a._M_stride), _M_array(a._M_array) {} 210 211 // template<typename _Tp> 212 // inline slice_array<_Tp>::~slice_array () {} 213 214 template<typename _Tp> 215 inline slice_array<_Tp>& 216 slice_array<_Tp>::operator=(const slice_array<_Tp>& __a) 217 { 218 std::__valarray_copy(__a._M_array, __a._M_sz, __a._M_stride, 219 _M_array, _M_stride); 220 return *this; 221 } 222 223 template<typename _Tp> 224 inline void 225 slice_array<_Tp>::operator=(const _Tp& __t) const 226 { std::__valarray_fill(_M_array, _M_sz, _M_stride, __t); } 227 228 template<typename _Tp> 229 inline void 230 slice_array<_Tp>::operator=(const valarray<_Tp>& __v) const 231 { std::__valarray_copy(_Array<_Tp>(__v), _M_array, _M_sz, _M_stride); } 232 233 template<typename _Tp> 234 template<class _Dom> 235 inline void 236 slice_array<_Tp>::operator=(const _Expr<_Dom,_Tp>& __e) const 237 { std::__valarray_copy(__e, _M_sz, _M_array, _M_stride); } 238 239 #undef _DEFINE_VALARRAY_OPERATOR 240 #define _DEFINE_VALARRAY_OPERATOR(_Op,_Name) \ 241 template<typename _Tp> \ 242 inline void \ 243 slice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \ 244 { \ 245 _Array_augmented_##_Name(_M_array, _M_sz, _M_stride, _Array<_Tp>(__v));\ 246 } \ 247 \ 248 template<typename _Tp> \ 249 template<class _Dom> \ 250 inline void \ 251 slice_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\ 252 { \ 253 _Array_augmented_##_Name(_M_array, _M_stride, __e, _M_sz); \ 254 } 255 256 257 _DEFINE_VALARRAY_OPERATOR(*, __multiplies) 258 _DEFINE_VALARRAY_OPERATOR(/, __divides) 259 _DEFINE_VALARRAY_OPERATOR(%, __modulus) 260 _DEFINE_VALARRAY_OPERATOR(+, __plus) 261 _DEFINE_VALARRAY_OPERATOR(-, __minus) 262 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor) 263 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and) 264 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or) 265 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left) 266 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right) 267 268 #undef _DEFINE_VALARRAY_OPERATOR 269 270 // @} group numeric_arrays 271 272 _GLIBCXX_END_NAMESPACE_VERSION 273 } // namespace 274 275 #endif /* _SLICE_ARRAY_H */ 276
