libstdc++
gslice_array.h
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1 // The template and inlines for the -*- C++ -*- gslice_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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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>
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.
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
149  : _M_array(__a._M_array), _M_index(__a._M_index) {}
150 
151  template<typename _Tp>
152  inline gslice_array<_Tp>&
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
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 #undef _DEFINE_VALARRAY_OPERATOR
187 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \
188  template<typename _Tp> \
189  inline void \
190  gslice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \
191  { \
192  _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), \
193  _Array<_Tp>(__v), __v.size()); \
194  } \
195  \
196  template<typename _Tp> \
197  template<class _Dom> \
198  inline void \
199  gslice_array<_Tp>::operator _Op##= (const _Expr<_Dom, _Tp>& __e) const\
200  { \
201  _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), __e,\
202  _M_index.size()); \
203  }
204 
205 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
206 _DEFINE_VALARRAY_OPERATOR(/, __divides)
207 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
208 _DEFINE_VALARRAY_OPERATOR(+, __plus)
209 _DEFINE_VALARRAY_OPERATOR(-, __minus)
210 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
211 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
212 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
213 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
214 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
215 
216 #undef _DEFINE_VALARRAY_OPERATOR
217 
218  /// @} group numeric_arrays
219 
220 _GLIBCXX_END_NAMESPACE_VERSION
221 } // namespace
222 
223 #endif /* _GSLICE_ARRAY_H */
void operator<<=(const valarray< _Tp > &) const
Left shift slice elements by corresponding elements of v.
Definition: gslice_array.h:213
size_t size() const
Return the number of elements in array.
Definition: valarray:937
void operator/=(const valarray< _Tp > &) const
Divide slice elements by corresponding elements of v.
Definition: gslice_array.h:206
void operator%=(const valarray< _Tp > &) const
Modulo slice elements by corresponding elements of v.
Definition: gslice_array.h:207
void operator>>=(const valarray< _Tp > &) const
Right shift slice elements by corresponding elements of v.
Definition: gslice_array.h:214
void operator*=(const valarray< _Tp > &) const
Multiply slice elements by corresponding elements of v.
Definition: gslice_array.h:205
void operator|=(const valarray< _Tp > &) const
Logical or slice elements with corresponding elements of v.
Definition: gslice_array.h:212
void operator^=(const valarray< _Tp > &) const
Logical xor slice elements with corresponding elements of v.
Definition: gslice_array.h:210
void operator-=(const valarray< _Tp > &) const
Subtract corresponding elements of v from slice elements.
Definition: gslice_array.h:209
void operator+=(const valarray< _Tp > &) const
Add corresponding elements of v to slice elements.
Definition: gslice_array.h:208
void operator&=(const valarray< _Tp > &) const
Logical and slice elements with corresponding elements of v.
Definition: gslice_array.h:211
gslice_array & operator=(const gslice_array &)
Assignment operator. Assigns slice elements to corresponding elements of a.
Definition: gslice_array.h:153
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