libstdc++
gslice_array.h
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1 // The template and inlines for the -*- C++ -*- gslice_array class.
2 
3 // Copyright (C) 1997-2018 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
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 <[email protected]>
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  // not implemented
132  gslice_array();
133  };
134 
135  template<typename _Tp>
136  inline
137  gslice_array<_Tp>::gslice_array(_Array<_Tp> __a,
138  const valarray<size_t>& __i)
139  : _M_array(__a), _M_index(__i) {}
140 
141  template<typename _Tp>
142  inline
144  : _M_array(__a._M_array), _M_index(__a._M_index) {}
145 
146  template<typename _Tp>
147  inline gslice_array<_Tp>&
149  {
150  std::__valarray_copy(_Array<_Tp>(__a._M_array),
151  _Array<size_t>(__a._M_index), _M_index.size(),
152  _M_array, _Array<size_t>(_M_index));
153  return *this;
154  }
155 
156  template<typename _Tp>
157  inline void
158  gslice_array<_Tp>::operator=(const _Tp& __t) const
159  {
160  std::__valarray_fill(_M_array, _Array<size_t>(_M_index),
161  _M_index.size(), __t);
162  }
163 
164  template<typename _Tp>
165  inline void
167  {
168  std::__valarray_copy(_Array<_Tp>(__v), __v.size(),
169  _M_array, _Array<size_t>(_M_index));
170  }
171 
172  template<typename _Tp>
173  template<class _Dom>
174  inline void
175  gslice_array<_Tp>::operator=(const _Expr<_Dom, _Tp>& __e) const
176  {
177  std::__valarray_copy (__e, _M_index.size(), _M_array,
178  _Array<size_t>(_M_index));
179  }
180 
181 #undef _DEFINE_VALARRAY_OPERATOR
182 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \
183  template<typename _Tp> \
184  inline void \
185  gslice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \
186  { \
187  _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), \
188  _Array<_Tp>(__v), __v.size()); \
189  } \
190  \
191  template<typename _Tp> \
192  template<class _Dom> \
193  inline void \
194  gslice_array<_Tp>::operator _Op##= (const _Expr<_Dom, _Tp>& __e) const\
195  { \
196  _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), __e,\
197  _M_index.size()); \
198  }
199 
200 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
201 _DEFINE_VALARRAY_OPERATOR(/, __divides)
202 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
203 _DEFINE_VALARRAY_OPERATOR(+, __plus)
204 _DEFINE_VALARRAY_OPERATOR(-, __minus)
205 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
206 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
207 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
208 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
209 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
210 
211 #undef _DEFINE_VALARRAY_OPERATOR
212 
213  // @} group numeric_arrays
214 
215 _GLIBCXX_END_NAMESPACE_VERSION
216 } // namespace
217 
218 #endif /* _GSLICE_ARRAY_H */
void operator-=(const valarray< _Tp > &) const
Subtract corresponding elements of v from slice elements.
Definition: gslice_array.h:204
void operator+=(const valarray< _Tp > &) const
Add corresponding elements of v to slice elements.
Definition: gslice_array.h:203
Reference to multi-dimensional subset of an array.
Definition: valarray:82
void operator*=(const valarray< _Tp > &) const
Multiply slice elements by corresponding elements of v.
Definition: gslice_array.h:200
void operator^=(const valarray< _Tp > &) const
Logical xor slice elements with corresponding elements of v.
Definition: gslice_array.h:205
void operator&=(const valarray< _Tp > &) const
Logical and slice elements with corresponding elements of v.
Definition: gslice_array.h:206
size_t size() const
Return the number of elements in array.
Definition: valarray:926
void operator/=(const valarray< _Tp > &) const
Divide slice elements by corresponding elements of v.
Definition: gslice_array.h:201
void operator%=(const valarray< _Tp > &) const
Modulo slice elements by corresponding elements of v.
Definition: gslice_array.h:202
Smart array designed to support numeric processing.
Definition: valarray:78
ISO C++ entities toplevel namespace is std.
void operator<<=(const valarray< _Tp > &) const
Left shift slice elements by corresponding elements of v.
Definition: gslice_array.h:208
void operator>>=(const valarray< _Tp > &) const
Right shift slice elements by corresponding elements of v.
Definition: gslice_array.h:209
gslice_array(const gslice_array &)
Copy constructor. Both slices refer to the same underlying array.
Definition: gslice_array.h:143
gslice_array & operator=(const gslice_array &)
Assignment operator. Assigns slice elements to corresponding elements of a.
Definition: gslice_array.h:148
void operator|=(const valarray< _Tp > &) const
Logical or slice elements with corresponding elements of v.
Definition: gslice_array.h:207