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// 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 slice_array.h 27 * This is an internal header file, included by other library headers. 28 * You should not attempt to use it directly. 29 */ 30 31// Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr> 32 33#ifndef _SLICE_ARRAY_H 34#define _SLICE_ARRAY_H 1 35 36#pragma GCC system_header 37 38_GLIBCXX_BEGIN_NAMESPACE(std) 39 40 /** 41 * @addtogroup numeric_arrays 42 * @{ 43 */ 44 45 /** 46 * @brief Class defining one-dimensional subset of an array. 47 * 48 * The slice class represents a one-dimensional subset of an array, 49 * specified by three parameters: start offset, size, and stride. The 50 * start offset is the index of the first element of the array that is part 51 * of the subset. The size is the total number of elements in the subset. 52 * Stride is the distance between each successive array element to include 53 * in the subset. 54 * 55 * For example, with an array of size 10, and a slice with offset 1, size 3 56 * and stride 2, the subset consists of array elements 1, 3, and 5. 57 */ 58 class slice 59 { 60 public: 61 /// Construct an empty slice. 62 slice(); 63 64 /** 65 * @brief Construct a slice. 66 * 67 * @param o Offset in array of first element. 68 * @param d Number of elements in slice. 69 * @param s Stride between array elements. 70 */ 71 slice(size_t, size_t, size_t); 72 73 /// Return array offset of first slice element. 74 size_t start() const; 75 /// Return size of slice. 76 size_t size() const; 77 /// Return array stride of slice. 78 size_t stride() const; 79 80 private: 81 size_t _M_off; // offset 82 size_t _M_sz; // size 83 size_t _M_st; // stride unit 84 }; 85 86 // _GLIBCXX_RESOLVE_LIB_DEFECTS 87 // 543. valarray slice default constructor 88 inline 89 slice::slice() 90 : _M_off(0), _M_sz(0), _M_st(0) {} 91 92 inline 93 slice::slice(size_t __o, size_t __d, size_t __s) 94 : _M_off(__o), _M_sz(__d), _M_st(__s) {} 95 96 inline size_t 97 slice::start() const 98 { return _M_off; } 99 100 inline size_t 101 slice::size() const 102 { return _M_sz; } 103 104 inline size_t 105 slice::stride() const 106 { return _M_st; } 107 108 /** 109 * @brief Reference to one-dimensional subset of an array. 110 * 111 * A slice_array is a reference to the actual elements of an array 112 * specified by a slice. The way to get a slice_array is to call 113 * operator[](slice) on a valarray. The returned slice_array then permits 114 * carrying operations out on the referenced subset of elements in the 115 * original valarray. For example, operator+=(valarray) will add values 116 * to the subset of elements in the underlying valarray this slice_array 117 * refers to. 118 * 119 * @param Tp Element type. 120 */ 121 template<typename _Tp> 122 class slice_array 123 { 124 public: 125 typedef _Tp value_type; 126 127 // _GLIBCXX_RESOLVE_LIB_DEFECTS 128 // 253. valarray helper functions are almost entirely useless 129 130 /// Copy constructor. Both slices refer to the same underlying array. 131 slice_array(const slice_array&); 132 133 /// Assignment operator. Assigns slice elements to corresponding 134 /// elements of @a a. 135 slice_array& operator=(const slice_array&); 136 137 /// Assign slice elements to corresponding elements of @a v. 138 void operator=(const valarray<_Tp>&) const; 139 /// Multiply slice elements by corresponding elements of @a v. 140 void operator*=(const valarray<_Tp>&) const; 141 /// Divide slice elements by corresponding elements of @a v. 142 void operator/=(const valarray<_Tp>&) const; 143 /// Modulo slice elements by corresponding elements of @a v. 144 void operator%=(const valarray<_Tp>&) const; 145 /// Add corresponding elements of @a v to slice elements. 146 void operator+=(const valarray<_Tp>&) const; 147 /// Subtract corresponding elements of @a v from slice elements. 148 void operator-=(const valarray<_Tp>&) const; 149 /// Logical xor slice elements with corresponding elements of @a v. 150 void operator^=(const valarray<_Tp>&) const; 151 /// Logical and slice elements with corresponding elements of @a v. 152 void operator&=(const valarray<_Tp>&) const; 153 /// Logical or slice elements with corresponding elements of @a v. 154 void operator|=(const valarray<_Tp>&) const; 155 /// Left shift slice elements by corresponding elements of @a v. 156 void operator<<=(const valarray<_Tp>&) const; 157 /// Right shift slice elements by corresponding elements of @a v. 158 void operator>>=(const valarray<_Tp>&) const; 159 /// Assign all slice elements to @a t. 160 void operator=(const _Tp &) const; 161 // ~slice_array (); 162 163 template<class _Dom> 164 void operator=(const _Expr<_Dom, _Tp>&) const; 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; 185 186 private: 187 friend class valarray<_Tp>; 188 slice_array(_Array<_Tp>, const slice&); 189 190 const size_t _M_sz; 191 const size_t _M_stride; 192 const _Array<_Tp> _M_array; 193 194 // not implemented 195 slice_array(); 196 }; 197 198 template<typename _Tp> 199 inline 200 slice_array<_Tp>::slice_array(_Array<_Tp> __a, const slice& __s) 201 : _M_sz(__s.size()), _M_stride(__s.stride()), 202 _M_array(__a.begin() + __s.start()) {} 203 204 template<typename _Tp> 205 inline 206 slice_array<_Tp>::slice_array(const slice_array<_Tp>& a) 207 : _M_sz(a._M_sz), _M_stride(a._M_stride), _M_array(a._M_array) {} 208 209 // template<typename _Tp> 210 // inline slice_array<_Tp>::~slice_array () {} 211 212 template<typename _Tp> 213 inline slice_array<_Tp>& 214 slice_array<_Tp>::operator=(const slice_array<_Tp>& __a) 215 { 216 std::__valarray_copy(__a._M_array, __a._M_sz, __a._M_stride, 217 _M_array, _M_stride); 218 return *this; 219 } 220 221 template<typename _Tp> 222 inline void 223 slice_array<_Tp>::operator=(const _Tp& __t) const 224 { std::__valarray_fill(_M_array, _M_sz, _M_stride, __t); } 225 226 template<typename _Tp> 227 inline void 228 slice_array<_Tp>::operator=(const valarray<_Tp>& __v) const 229 { std::__valarray_copy(_Array<_Tp>(__v), _M_array, _M_sz, _M_stride); } 230 231 template<typename _Tp> 232 template<class _Dom> 233 inline void 234 slice_array<_Tp>::operator=(const _Expr<_Dom,_Tp>& __e) const 235 { std::__valarray_copy(__e, _M_sz, _M_array, _M_stride); } 236 237#undef _DEFINE_VALARRAY_OPERATOR 238#define _DEFINE_VALARRAY_OPERATOR(_Op,_Name) \ 239 template<typename _Tp> \ 240 inline void \ 241 slice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \ 242 { \ 243 _Array_augmented_##_Name(_M_array, _M_sz, _M_stride, _Array<_Tp>(__v));\ 244 } \ 245 \ 246 template<typename _Tp> \ 247 template<class _Dom> \ 248 inline void \ 249 slice_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\ 250 { \ 251 _Array_augmented_##_Name(_M_array, _M_stride, __e, _M_sz); \ 252 } 253 254 255_DEFINE_VALARRAY_OPERATOR(*, __multiplies) 256_DEFINE_VALARRAY_OPERATOR(/, __divides) 257_DEFINE_VALARRAY_OPERATOR(%, __modulus) 258_DEFINE_VALARRAY_OPERATOR(+, __plus) 259_DEFINE_VALARRAY_OPERATOR(-, __minus) 260_DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor) 261_DEFINE_VALARRAY_OPERATOR(&, __bitwise_and) 262_DEFINE_VALARRAY_OPERATOR(|, __bitwise_or) 263_DEFINE_VALARRAY_OPERATOR(<<, __shift_left) 264_DEFINE_VALARRAY_OPERATOR(>>, __shift_right) 265 266#undef _DEFINE_VALARRAY_OPERATOR 267 268 // @} group numeric_arrays 269 270_GLIBCXX_END_NAMESPACE 271 272#endif /* _SLICE_ARRAY_H */ 273