1// The template and inlines for the -*- C++ -*- slice_array class. 2 3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005 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 2, 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// You should have received a copy of the GNU General Public License along 18// with this library; see the file COPYING. If not, write to the Free 19// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 20// USA. 21 22// As a special exception, you may use this file as part of a free software 23// library without restriction. Specifically, if other files instantiate 24// templates or use macros or inline functions from this file, or you compile 25// this file and link it with other files to produce an executable, this 26// file does not by itself cause the resulting executable to be covered by 27// the GNU General Public License. This exception does not however 28// invalidate any other reasons why the executable file might be covered by 29// the GNU General Public License. 30 31/** @file slice_array.h 32 * This is an internal header file, included by other library headers. 33 * You should not attempt to use it directly. 34 */ 35 36// Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr> 37 38#ifndef _SLICE_ARRAY_H 39#define _SLICE_ARRAY_H 1 40 41#pragma GCC system_header 42 43_GLIBCXX_BEGIN_NAMESPACE(std) 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 // The default constructor constructor is not required to initialize 87 // data members with any meaningful values, so we choose to do nothing. 88 inline 89 slice::slice() {} 90 91 inline 92 slice::slice(size_t __o, size_t __d, size_t __s) 93 : _M_off(__o), _M_sz(__d), _M_st(__s) {} 94 95 inline size_t 96 slice::start() const 97 { return _M_off; } 98 99 inline size_t 100 slice::size() const 101 { return _M_sz; } 102 103 inline size_t 104 slice::stride() const 105 { return _M_st; } 106 107 /** 108 * @brief Reference to one-dimensional subset of an array. 109 * 110 * A slice_array is a reference to the actual elements of an array 111 * specified by a slice. The way to get a slice_array is to call 112 * operator[](slice) on a valarray. The returned slice_array then permits 113 * carrying operations out on the referenced subset of elements in the 114 * original valarray. For example, operator+=(valarray) will add values 115 * to the subset of elements in the underlying valarray this slice_array 116 * refers to. 117 * 118 * @param Tp Element type. 119 */ 120 template<typename _Tp> 121 class slice_array 122 { 123 public: 124 typedef _Tp value_type; 125 126 // _GLIBCXX_RESOLVE_LIB_DEFECTS 127 // 253. valarray helper functions are almost entirely useless 128 129 /// Copy constructor. Both slices refer to the same underlying array. 130 slice_array(const slice_array&); 131 132 /// Assignment operator. Assigns slice elements to corresponding 133 /// elements of @a a. 134 slice_array& operator=(const slice_array&); 135 136 /// Assign slice elements to corresponding elements of @a v. 137 void operator=(const valarray<_Tp>&) const; 138 /// Multiply slice elements by corresponding elements of @a v. 139 void operator*=(const valarray<_Tp>&) const; 140 /// Divide slice elements by corresponding elements of @a v. 141 void operator/=(const valarray<_Tp>&) const; 142 /// Modulo slice elements by corresponding elements of @a v. 143 void operator%=(const valarray<_Tp>&) const; 144 /// Add corresponding elements of @a v to slice elements. 145 void operator+=(const valarray<_Tp>&) const; 146 /// Subtract corresponding elements of @a v from slice elements. 147 void operator-=(const valarray<_Tp>&) const; 148 /// Logical xor slice elements with corresponding elements of @a v. 149 void operator^=(const valarray<_Tp>&) const; 150 /// Logical and slice elements with corresponding elements of @a v. 151 void operator&=(const valarray<_Tp>&) const; 152 /// Logical or slice elements with corresponding elements of @a v. 153 void operator|=(const valarray<_Tp>&) const; 154 /// Left shift slice elements by corresponding elements of @a v. 155 void operator<<=(const valarray<_Tp>&) const; 156 /// Right shift slice elements by corresponding elements of @a v. 157 void operator>>=(const valarray<_Tp>&) const; 158 /// Assign all slice elements to @a t. 159 void operator=(const _Tp &) const; 160 // ~slice_array (); 161 162 template<class _Dom> 163 void operator=(const _Expr<_Dom, _Tp>&) const; 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; 184 185 private: 186 friend class valarray<_Tp>; 187 slice_array(_Array<_Tp>, const slice&); 188 189 const size_t _M_sz; 190 const size_t _M_stride; 191 const _Array<_Tp> _M_array; 192 193 // not implemented 194 slice_array(); 195 }; 196 197 template<typename _Tp> 198 inline 199 slice_array<_Tp>::slice_array(_Array<_Tp> __a, const slice& __s) 200 : _M_sz(__s.size()), _M_stride(__s.stride()), 201 _M_array(__a.begin() + __s.start()) {} 202 203 template<typename _Tp> 204 inline 205 slice_array<_Tp>::slice_array(const slice_array<_Tp>& a) 206 : _M_sz(a._M_sz), _M_stride(a._M_stride), _M_array(a._M_array) {} 207 208 // template<typename _Tp> 209 // inline slice_array<_Tp>::~slice_array () {} 210 211 template<typename _Tp> 212 inline slice_array<_Tp>& 213 slice_array<_Tp>::operator=(const slice_array<_Tp>& __a) 214 { 215 std::__valarray_copy(__a._M_array, __a._M_sz, __a._M_stride, 216 _M_array, _M_stride); 217 return *this; 218 } 219 220 template<typename _Tp> 221 inline void 222 slice_array<_Tp>::operator=(const _Tp& __t) const 223 { std::__valarray_fill(_M_array, _M_sz, _M_stride, __t); } 224 225 template<typename _Tp> 226 inline void 227 slice_array<_Tp>::operator=(const valarray<_Tp>& __v) const 228 { std::__valarray_copy(_Array<_Tp>(__v), _M_array, _M_sz, _M_stride); } 229 230 template<typename _Tp> 231 template<class _Dom> 232 inline void 233 slice_array<_Tp>::operator=(const _Expr<_Dom,_Tp>& __e) const 234 { std::__valarray_copy(__e, _M_sz, _M_array, _M_stride); } 235 236#undef _DEFINE_VALARRAY_OPERATOR 237#define _DEFINE_VALARRAY_OPERATOR(_Op,_Name) \ 238 template<typename _Tp> \ 239 inline void \ 240 slice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \ 241 { \ 242 _Array_augmented_##_Name(_M_array, _M_sz, _M_stride, _Array<_Tp>(__v));\ 243 } \ 244 \ 245 template<typename _Tp> \ 246 template<class _Dom> \ 247 inline void \ 248 slice_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\ 249 { \ 250 _Array_augmented_##_Name(_M_array, _M_stride, __e, _M_sz); \ 251 } 252 253 254_DEFINE_VALARRAY_OPERATOR(*, __multiplies) 255_DEFINE_VALARRAY_OPERATOR(/, __divides) 256_DEFINE_VALARRAY_OPERATOR(%, __modulus) 257_DEFINE_VALARRAY_OPERATOR(+, __plus) 258_DEFINE_VALARRAY_OPERATOR(-, __minus) 259_DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor) 260_DEFINE_VALARRAY_OPERATOR(&, __bitwise_and) 261_DEFINE_VALARRAY_OPERATOR(|, __bitwise_or) 262_DEFINE_VALARRAY_OPERATOR(<<, __shift_left) 263_DEFINE_VALARRAY_OPERATOR(>>, __shift_right) 264 265#undef _DEFINE_VALARRAY_OPERATOR 266 267_GLIBCXX_END_NAMESPACE 268 269#endif /* _SLICE_ARRAY_H */ 270