1// The template and inlines for the -*- C++ -*- indirect_array class. 2 3// Copyright (C) 1997-2022 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/indirect_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 _INDIRECT_ARRAY_H 33#define _INDIRECT_ARRAY_H 1 34 35#pragma GCC system_header 36 37namespace std _GLIBCXX_VISIBILITY(default) 38{ 39_GLIBCXX_BEGIN_NAMESPACE_VERSION 40 41 /** 42 * @addtogroup numeric_arrays 43 * @{ 44 */ 45 46 /** 47 * @brief Reference to arbitrary subset of an array. 48 * 49 * An indirect_array is a reference to the actual elements of an array 50 * specified by an ordered array of indices. The way to get an 51 * indirect_array is to call operator[](valarray<size_t>) on a valarray. 52 * The returned indirect_array then permits carrying operations out on the 53 * referenced subset of elements in the original valarray. 54 * 55 * For example, if an indirect_array is obtained using the array (4,2,0) as 56 * an argument, and then assigned to an array containing (1,2,3), then the 57 * underlying array will have array[0]==3, array[2]==2, and array[4]==1. 58 * 59 * @param Tp Element type. 60 */ 61 template <class _Tp> 62 class indirect_array 63 { 64 public: 65 typedef _Tp value_type; 66 67 // _GLIBCXX_RESOLVE_LIB_DEFECTS 68 // 253. valarray helper functions are almost entirely useless 69 70 /// Copy constructor. Both slices refer to the same underlying array. 71 indirect_array(const indirect_array&); 72 73 /// Assignment operator. Assigns elements to corresponding elements 74 /// of @a a. 75 indirect_array& operator=(const indirect_array&); 76 77 /// Assign slice elements to corresponding elements of @a v. 78 void operator=(const valarray<_Tp>&) const; 79 /// Multiply slice elements by corresponding elements of @a v. 80 void operator*=(const valarray<_Tp>&) const; 81 /// Divide slice elements by corresponding elements of @a v. 82 void operator/=(const valarray<_Tp>&) const; 83 /// Modulo slice elements by corresponding elements of @a v. 84 void operator%=(const valarray<_Tp>&) const; 85 /// Add corresponding elements of @a v to slice elements. 86 void operator+=(const valarray<_Tp>&) const; 87 /// Subtract corresponding elements of @a v from slice elements. 88 void operator-=(const valarray<_Tp>&) const; 89 /// Logical xor slice elements with corresponding elements of @a v. 90 void operator^=(const valarray<_Tp>&) const; 91 /// Logical and slice elements with corresponding elements of @a v. 92 void operator&=(const valarray<_Tp>&) const; 93 /// Logical or slice elements with corresponding elements of @a v. 94 void operator|=(const valarray<_Tp>&) const; 95 /// Left shift slice elements by corresponding elements of @a v. 96 void operator<<=(const valarray<_Tp>&) const; 97 /// Right shift slice elements by corresponding elements of @a v. 98 void operator>>=(const valarray<_Tp>&) const; 99 /// Assign all slice elements to @a t. 100 void operator= (const _Tp&) const; 101 // ~indirect_array(); 102 103 template<class _Dom> 104 void operator=(const _Expr<_Dom, _Tp>&) const; 105 template<class _Dom> 106 void operator*=(const _Expr<_Dom, _Tp>&) const; 107 template<class _Dom> 108 void operator/=(const _Expr<_Dom, _Tp>&) const; 109 template<class _Dom> 110 void operator%=(const _Expr<_Dom, _Tp>&) const; 111 template<class _Dom> 112 void operator+=(const _Expr<_Dom, _Tp>&) const; 113 template<class _Dom> 114 void operator-=(const _Expr<_Dom, _Tp>&) const; 115 template<class _Dom> 116 void operator^=(const _Expr<_Dom, _Tp>&) const; 117 template<class _Dom> 118 void operator&=(const _Expr<_Dom, _Tp>&) const; 119 template<class _Dom> 120 void operator|=(const _Expr<_Dom, _Tp>&) const; 121 template<class _Dom> 122 void operator<<=(const _Expr<_Dom, _Tp>&) const; 123 template<class _Dom> 124 void operator>>=(const _Expr<_Dom, _Tp>&) const; 125 126 private: 127 /// Copy constructor. Both slices refer to the same underlying array. 128 indirect_array(_Array<_Tp>, size_t, _Array<size_t>); 129 130 friend class valarray<_Tp>; 131 friend class gslice_array<_Tp>; 132 133 const size_t _M_sz; 134 const _Array<size_t> _M_index; 135 const _Array<_Tp> _M_array; 136 137 // not implemented 138 indirect_array(); 139 }; 140 141 template<typename _Tp> 142 inline 143 indirect_array<_Tp>::indirect_array(const indirect_array<_Tp>& __a) 144 : _M_sz(__a._M_sz), _M_index(__a._M_index), _M_array(__a._M_array) {} 145 146 template<typename _Tp> 147 inline 148 indirect_array<_Tp>::indirect_array(_Array<_Tp> __a, size_t __s, 149 _Array<size_t> __i) 150 : _M_sz(__s), _M_index(__i), _M_array(__a) {} 151 152 template<typename _Tp> 153 inline indirect_array<_Tp>& 154 indirect_array<_Tp>::operator=(const indirect_array<_Tp>& __a) 155 { 156 std::__valarray_copy(__a._M_array, _M_sz, __a._M_index, _M_array, 157 _M_index); 158 return *this; 159 } 160 161 template<typename _Tp> 162 inline void 163 indirect_array<_Tp>::operator=(const _Tp& __t) const 164 { std::__valarray_fill(_M_array, _M_index, _M_sz, __t); } 165 166 template<typename _Tp> 167 inline void 168 indirect_array<_Tp>::operator=(const valarray<_Tp>& __v) const 169 { std::__valarray_copy(_Array<_Tp>(__v), _M_sz, _M_array, _M_index); } 170 171 template<typename _Tp> 172 template<class _Dom> 173 inline void 174 indirect_array<_Tp>::operator=(const _Expr<_Dom, _Tp>& __e) const 175 { std::__valarray_copy(__e, _M_sz, _M_array, _M_index); } 176 177 /// @cond undocumented 178#undef _DEFINE_VALARRAY_OPERATOR 179#define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \ 180 template<typename _Tp> \ 181 inline void \ 182 indirect_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const\ 183 { \ 184 _Array_augmented_##_Name(_M_array, _M_index, _Array<_Tp>(__v), _M_sz); \ 185 } \ 186 \ 187 template<typename _Tp> \ 188 template<class _Dom> \ 189 inline void \ 190 indirect_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\ 191 { \ 192 _Array_augmented_##_Name(_M_array, _M_index, __e, _M_sz); \ 193 } 194 195_DEFINE_VALARRAY_OPERATOR(*, __multiplies) 196_DEFINE_VALARRAY_OPERATOR(/, __divides) 197_DEFINE_VALARRAY_OPERATOR(%, __modulus) 198_DEFINE_VALARRAY_OPERATOR(+, __plus) 199_DEFINE_VALARRAY_OPERATOR(-, __minus) 200_DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor) 201_DEFINE_VALARRAY_OPERATOR(&, __bitwise_and) 202_DEFINE_VALARRAY_OPERATOR(|, __bitwise_or) 203_DEFINE_VALARRAY_OPERATOR(<<, __shift_left) 204_DEFINE_VALARRAY_OPERATOR(>>, __shift_right) 205 206#undef _DEFINE_VALARRAY_OPERATOR 207 /// @endcond 208 209 /// @} group numeric_arrays 210 211_GLIBCXX_END_NAMESPACE_VERSION 212} // namespace 213 214#endif /* _INDIRECT_ARRAY_H */ 215