libstdc++
gslice_array.h
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1 // The template and inlines for the -*- C++ -*- gslice_array class.
2 
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004, 2005, 2009, 2010
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 3, or (at your option)
10 // any later version.
11 
12 // This library is distributed in the hope that it will be useful,
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14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
16 
17 // Under Section 7 of GPL version 3, you are granted additional
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19 // 3.1, as published by the Free Software Foundation.
20 
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25 
26 /** @file bits/gslice_array.h
27  * This is an internal header file, included by other library headers.
28  * Do not attempt to use it directly. @headername{valarray}
29  */
30 
31 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
32 
33 #ifndef _GSLICE_ARRAY_H
34 #define _GSLICE_ARRAY_H 1
35 
36 #pragma GCC system_header
37 
38 namespace std _GLIBCXX_VISIBILITY(default)
39 {
40 _GLIBCXX_BEGIN_NAMESPACE_VERSION
41 
42  /**
43  * @addtogroup numeric_arrays
44  * @{
45  */
46 
47  /**
48  * @brief Reference to multi-dimensional subset of an array.
49  *
50  * A gslice_array is a reference to the actual elements of an array
51  * specified by a gslice. The way to get a gslice_array is to call
52  * operator[](gslice) on a valarray. The returned gslice_array then
53  * permits carrying operations out on the referenced subset of elements in
54  * the original valarray. For example, operator+=(valarray) will add
55  * values to the subset of elements in the underlying valarray this
56  * gslice_array refers to.
57  *
58  * @param Tp Element type.
59  */
60  template<typename _Tp>
61  class gslice_array
62  {
63  public:
64  typedef _Tp value_type;
65 
66  // _GLIBCXX_RESOLVE_LIB_DEFECTS
67  // 253. valarray helper functions are almost entirely useless
68 
69  /// Copy constructor. Both slices refer to the same underlying array.
70  gslice_array(const gslice_array&);
71 
72  /// Assignment operator. Assigns slice elements to corresponding
73  /// elements of @a a.
74  gslice_array& operator=(const gslice_array&);
75 
76  /// Assign slice elements to corresponding elements of @a v.
77  void operator=(const valarray<_Tp>&) const;
78  /// Multiply slice elements by corresponding elements of @a v.
79  void operator*=(const valarray<_Tp>&) const;
80  /// Divide slice elements by corresponding elements of @a v.
81  void operator/=(const valarray<_Tp>&) const;
82  /// Modulo slice elements by corresponding elements of @a v.
83  void operator%=(const valarray<_Tp>&) const;
84  /// Add corresponding elements of @a v to slice elements.
85  void operator+=(const valarray<_Tp>&) const;
86  /// Subtract corresponding elements of @a v from slice elements.
87  void operator-=(const valarray<_Tp>&) const;
88  /// Logical xor slice elements with corresponding elements of @a v.
89  void operator^=(const valarray<_Tp>&) const;
90  /// Logical and slice elements with corresponding elements of @a v.
91  void operator&=(const valarray<_Tp>&) const;
92  /// Logical or slice elements with corresponding elements of @a v.
93  void operator|=(const valarray<_Tp>&) const;
94  /// Left shift slice elements by corresponding elements of @a v.
95  void operator<<=(const valarray<_Tp>&) const;
96  /// Right shift slice elements by corresponding elements of @a v.
97  void operator>>=(const valarray<_Tp>&) const;
98  /// Assign all slice elements to @a t.
99  void operator=(const _Tp&) const;
100 
101  template<class _Dom>
102  void operator=(const _Expr<_Dom, _Tp>&) const;
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 
124  private:
125  _Array<_Tp> _M_array;
126  const valarray<size_t>& _M_index;
127 
128  friend class valarray<_Tp>;
129 
130  gslice_array(_Array<_Tp>, const valarray<size_t>&);
131 
132  // not implemented
133  gslice_array();
134  };
135 
136  template<typename _Tp>
137  inline
138  gslice_array<_Tp>::gslice_array(_Array<_Tp> __a,
139  const valarray<size_t>& __i)
140  : _M_array(__a), _M_index(__i) {}
141 
142  template<typename _Tp>
143  inline
145  : _M_array(__a._M_array), _M_index(__a._M_index) {}
146 
147  template<typename _Tp>
148  inline gslice_array<_Tp>&
150  {
151  std::__valarray_copy(_Array<_Tp>(__a._M_array),
152  _Array<size_t>(__a._M_index), _M_index.size(),
153  _M_array, _Array<size_t>(_M_index));
154  return *this;
155  }
156 
157  template<typename _Tp>
158  inline void
159  gslice_array<_Tp>::operator=(const _Tp& __t) const
160  {
161  std::__valarray_fill(_M_array, _Array<size_t>(_M_index),
162  _M_index.size(), __t);
163  }
164 
165  template<typename _Tp>
166  inline void
168  {
169  std::__valarray_copy(_Array<_Tp>(__v), __v.size(),
170  _M_array, _Array<size_t>(_M_index));
171  }
172 
173  template<typename _Tp>
174  template<class _Dom>
175  inline void
176  gslice_array<_Tp>::operator=(const _Expr<_Dom, _Tp>& __e) const
177  {
178  std::__valarray_copy (__e, _M_index.size(), _M_array,
179  _Array<size_t>(_M_index));
180  }
181 
182 #undef _DEFINE_VALARRAY_OPERATOR
183 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \
184  template<typename _Tp> \
185  inline void \
186  gslice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \
187  { \
188  _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), \
189  _Array<_Tp>(__v), __v.size()); \
190  } \
191  \
192  template<typename _Tp> \
193  template<class _Dom> \
194  inline void \
195  gslice_array<_Tp>::operator _Op##= (const _Expr<_Dom, _Tp>& __e) const\
196  { \
197  _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), __e,\
198  _M_index.size()); \
199  }
200 
201 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
202 _DEFINE_VALARRAY_OPERATOR(/, __divides)
203 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
204 _DEFINE_VALARRAY_OPERATOR(+, __plus)
205 _DEFINE_VALARRAY_OPERATOR(-, __minus)
206 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
207 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
208 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
209 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
210 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
211 
212 #undef _DEFINE_VALARRAY_OPERATOR
213 
214  // @} group numeric_arrays
215 
216 _GLIBCXX_END_NAMESPACE_VERSION
217 } // namespace
218 
219 #endif /* _GSLICE_ARRAY_H */