libstdc++
indirect_array.h
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1 // The template and inlines for the -*- C++ -*- indirect_array class.
2 
3 // Copyright (C) 1997-2021 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
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22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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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 
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 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>
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.
72 
73  /// Assignment operator. Assigns elements to corresponding elements
74  /// of @a a.
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
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>&
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
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 #undef _DEFINE_VALARRAY_OPERATOR
178 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \
179  template<typename _Tp> \
180  inline void \
181  indirect_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const\
182  { \
183  _Array_augmented_##_Name(_M_array, _M_index, _Array<_Tp>(__v), _M_sz); \
184  } \
185  \
186  template<typename _Tp> \
187  template<class _Dom> \
188  inline void \
189  indirect_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\
190  { \
191  _Array_augmented_##_Name(_M_array, _M_index, __e, _M_sz); \
192  }
193 
194 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
195 _DEFINE_VALARRAY_OPERATOR(/, __divides)
196 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
197 _DEFINE_VALARRAY_OPERATOR(+, __plus)
198 _DEFINE_VALARRAY_OPERATOR(-, __minus)
199 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
200 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
201 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
202 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
203 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
204 
205 #undef _DEFINE_VALARRAY_OPERATOR
206 
207  /// @} group numeric_arrays
208 
209 _GLIBCXX_END_NAMESPACE_VERSION
210 } // namespace
211 
212 #endif /* _INDIRECT_ARRAY_H */
void operator/=(const valarray< _Tp > &) const
Divide slice elements by corresponding elements of v.
void operator^=(const valarray< _Tp > &) const
Logical xor slice elements with corresponding elements of v.
void operator|=(const valarray< _Tp > &) const
Logical or slice elements with corresponding elements of v.
void operator<<=(const valarray< _Tp > &) const
Left shift slice elements by corresponding elements of v.
void operator>>=(const valarray< _Tp > &) const
Right shift slice elements by corresponding elements of v.
indirect_array & operator=(const indirect_array &)
Assignment operator. Assigns elements to corresponding elements of a.
void operator-=(const valarray< _Tp > &) const
Subtract corresponding elements of v from slice elements.
void operator*=(const valarray< _Tp > &) const
Multiply slice elements by corresponding elements of v.
void operator&=(const valarray< _Tp > &) const
Logical and slice elements with corresponding elements of v.
void operator+=(const valarray< _Tp > &) const
Add corresponding elements of v to slice elements.
void operator%=(const valarray< _Tp > &) const
Modulo slice elements by corresponding elements of v.
ISO C++ entities toplevel namespace is std.
Smart array designed to support numeric processing.
Definition: valarray:128
Reference to multi-dimensional subset of an array.
Definition: gslice_array.h:61
Reference to arbitrary subset of an array.