1 // The template and inlines for the -*- C++ -*- gslice_array class.
2
3 // Copyright (C) 1997-2023 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/gslice_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 _GSLICE_ARRAY_H
33 #define _GSLICE_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 Reference to multi-dimensional subset of an array.
48 *
49 * A gslice_array is a reference to the actual elements of an array
50 * specified by a gslice. The way to get a gslice_array is to call
51 * operator[](gslice) on a valarray. The returned gslice_array then
52 * permits carrying operations out on the referenced subset of elements in
53 * the original valarray. For example, operator+=(valarray) will add
54 * values to the subset of elements in the underlying valarray this
55 * gslice_array refers to.
56 *
57 * @param Tp Element type.
58 */
59 template<typename _Tp>
60 class gslice_array
61 {
62 public:
63 typedef _Tp value_type;
64
65 // _GLIBCXX_RESOLVE_LIB_DEFECTS
66 // 253. valarray helper functions are almost entirely useless
67
68 /// Copy constructor. Both slices refer to the same underlying array.
69 gslice_array(const gslice_array&);
70
71 /// Assignment operator. Assigns slice elements to corresponding
72 /// elements of @a a.
73 gslice_array& operator=(const gslice_array&);
74
75 /// Assign slice elements to corresponding elements of @a v.
76 void operator=(const valarray<_Tp>&) const;
77 /// Multiply slice elements by corresponding elements of @a v.
78 void operator*=(const valarray<_Tp>&) const;
79 /// Divide slice elements by corresponding elements of @a v.
80 void operator/=(const valarray<_Tp>&) const;
81 /// Modulo slice elements by corresponding elements of @a v.
82 void operator%=(const valarray<_Tp>&) const;
83 /// Add corresponding elements of @a v to slice elements.
84 void operator+=(const valarray<_Tp>&) const;
85 /// Subtract corresponding elements of @a v from slice elements.
86 void operator-=(const valarray<_Tp>&) const;
87 /// Logical xor slice elements with corresponding elements of @a v.
88 void operator^=(const valarray<_Tp>&) const;
89 /// Logical and slice elements with corresponding elements of @a v.
90 void operator&=(const valarray<_Tp>&) const;
91 /// Logical or slice elements with corresponding elements of @a v.
92 void operator|=(const valarray<_Tp>&) const;
93 /// Left shift slice elements by corresponding elements of @a v.
94 void operator<<=(const valarray<_Tp>&) const;
95 /// Right shift slice elements by corresponding elements of @a v.
96 void operator>>=(const valarray<_Tp>&) const;
97 /// Assign all slice elements to @a t.
98 void operator=(const _Tp&) const;
99
100 template<class _Dom>
101 void operator=(const _Expr<_Dom, _Tp>&) const;
102 template<class _Dom>
103 void operator*=(const _Expr<_Dom, _Tp>&) const;
104 template<class _Dom>
105 void operator/=(const _Expr<_Dom, _Tp>&) const;
106 template<class _Dom>
107 void operator%=(const _Expr<_Dom, _Tp>&) const;
108 template<class _Dom>
109 void operator+=(const _Expr<_Dom, _Tp>&) const;
110 template<class _Dom>
111 void operator-=(const _Expr<_Dom, _Tp>&) const;
112 template<class _Dom>
113 void operator^=(const _Expr<_Dom, _Tp>&) const;
114 template<class _Dom>
115 void operator&=(const _Expr<_Dom, _Tp>&) const;
116 template<class _Dom>
117 void operator|=(const _Expr<_Dom, _Tp>&) const;
118 template<class _Dom>
119 void operator<<=(const _Expr<_Dom, _Tp>&) const;
120 template<class _Dom>
121 void operator>>=(const _Expr<_Dom, _Tp>&) const;
122
123 private:
124 _Array<_Tp> _M_array;
125 const valarray<size_t>& _M_index;
126
127 friend class valarray<_Tp>;
128
129 gslice_array(_Array<_Tp>, const valarray<size_t>&);
130
131 #if __cplusplus < 201103L
132 // not implemented
133 gslice_array();
134 #else
135 public:
136 gslice_array() = delete;
137 #endif
138 };
139
140 template<typename _Tp>
141 inline
142 gslice_array<_Tp>::gslice_array(_Array<_Tp> __a,
143 const valarray<size_t>& __i)
144 : _M_array(__a), _M_index(__i) {}
145
146 template<typename _Tp>
147 inline
148 gslice_array<_Tp>::gslice_array(const gslice_array<_Tp>& __a)
149 : _M_array(__a._M_array), _M_index(__a._M_index) {}
150
151 template<typename _Tp>
152 inline gslice_array<_Tp>&
153 gslice_array<_Tp>::operator=(const gslice_array<_Tp>& __a)
154 {
155 std::__valarray_copy(_Array<_Tp>(__a._M_array),
156 _Array<size_t>(__a._M_index), _M_index.size(),
157 _M_array, _Array<size_t>(_M_index));
158 return *this;
159 }
160
161 template<typename _Tp>
162 inline void
163 gslice_array<_Tp>::operator=(const _Tp& __t) const
164 {
165 std::__valarray_fill(_M_array, _Array<size_t>(_M_index),
166 _M_index.size(), __t);
167 }
168
169 template<typename _Tp>
170 inline void
171 gslice_array<_Tp>::operator=(const valarray<_Tp>& __v) const
172 {
173 std::__valarray_copy(_Array<_Tp>(__v), __v.size(),
174 _M_array, _Array<size_t>(_M_index));
175 }
176
177 template<typename _Tp>
178 template<class _Dom>
179 inline void
180 gslice_array<_Tp>::operator=(const _Expr<_Dom, _Tp>& __e) const
181 {
182 std::__valarray_copy (__e, _M_index.size(), _M_array,
183 _Array<size_t>(_M_index));
184 }
185
186 /// @cond undocumented
187 #undef _DEFINE_VALARRAY_OPERATOR
188 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \
189 template<typename _Tp> \
190 inline void \
191 gslice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \
192 { \
193 _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), \
194 _Array<_Tp>(__v), __v.size()); \
195 } \
196 \
197 template<typename _Tp> \
198 template<class _Dom> \
199 inline void \
200 gslice_array<_Tp>::operator _Op##= (const _Expr<_Dom, _Tp>& __e) const\
201 { \
202 _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), __e,\
203 _M_index.size()); \
204 }
205
206 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
207 _DEFINE_VALARRAY_OPERATOR(/, __divides)
208 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
209 _DEFINE_VALARRAY_OPERATOR(+, __plus)
210 _DEFINE_VALARRAY_OPERATOR(-, __minus)
211 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
212 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
213 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
214 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
215 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
216
217 #undef _DEFINE_VALARRAY_OPERATOR
218 /// @endcond
219
220 /// @} group numeric_arrays
221
222 _GLIBCXX_END_NAMESPACE_VERSION
223 } // namespace
224
225 #endif /* _GSLICE_ARRAY_H */