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1 // The template and inlines for the -*- C++ -*- slice_array class.
3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2009
4 // Free Software Foundation, Inc.
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
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12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // You should have received a copy of the GNU General Public License along
18 // with this library; see the file COPYING. If not, write to the Free
19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
22 // As a special exception, you may use this file as part of a free software
23 // library without restriction. Specifically, if other files instantiate
24 // templates or use macros or inline functions from this file, or you compile
25 // this file and link it with other files to produce an executable, this
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27 // the GNU General Public License. This exception does not however
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31 /** @file slice_array.h
32 * This is an internal header file, included by other library headers.
33 * You should not attempt to use it directly.
36 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
38 #ifndef _SLICE_ARRAY_H
39 #define _SLICE_ARRAY_H 1
41 #pragma GCC system_header
43 _GLIBCXX_BEGIN_NAMESPACE(std
)
46 * @addtogroup numeric_arrays
51 * @brief Class defining one-dimensional subset of an array.
53 * The slice class represents a one-dimensional subset of an array,
54 * specified by three parameters: start offset, size, and stride. The
55 * start offset is the index of the first element of the array that is part
56 * of the subset. The size is the total number of elements in the subset.
57 * Stride is the distance between each successive array element to include
60 * For example, with an array of size 10, and a slice with offset 1, size 3
61 * and stride 2, the subset consists of array elements 1, 3, and 5.
66 /// Construct an empty slice.
70 * @brief Construct a slice.
72 * @param o Offset in array of first element.
73 * @param d Number of elements in slice.
74 * @param s Stride between array elements.
76 slice(size_t, size_t, size_t);
78 /// Return array offset of first slice element.
80 /// Return size of slice.
82 /// Return array stride of slice.
83 size_t stride() const;
86 size_t _M_off
; // offset
88 size_t _M_st
; // stride unit
91 // _GLIBCXX_RESOLVE_LIB_DEFECTS
92 // 543. valarray slice default constructor
95 : _M_off(0), _M_sz(0), _M_st(0) {}
98 slice::slice(size_t __o
, size_t __d
, size_t __s
)
99 : _M_off(__o
), _M_sz(__d
), _M_st(__s
) {}
110 slice::stride() const
114 * @brief Reference to one-dimensional subset of an array.
116 * A slice_array is a reference to the actual elements of an array
117 * specified by a slice. The way to get a slice_array is to call
118 * operator[](slice) on a valarray. The returned slice_array then permits
119 * carrying operations out on the referenced subset of elements in the
120 * original valarray. For example, operator+=(valarray) will add values
121 * to the subset of elements in the underlying valarray this slice_array
124 * @param Tp Element type.
126 template<typename _Tp
>
130 typedef _Tp value_type
;
132 // _GLIBCXX_RESOLVE_LIB_DEFECTS
133 // 253. valarray helper functions are almost entirely useless
135 /// Copy constructor. Both slices refer to the same underlying array.
136 slice_array(const slice_array
&);
138 /// Assignment operator. Assigns slice elements to corresponding
139 /// elements of @a a.
140 slice_array
& operator=(const slice_array
&);
142 /// Assign slice elements to corresponding elements of @a v.
143 void operator=(const valarray
<_Tp
>&) const;
144 /// Multiply slice elements by corresponding elements of @a v.
145 void operator*=(const valarray
<_Tp
>&) const;
146 /// Divide slice elements by corresponding elements of @a v.
147 void operator/=(const valarray
<_Tp
>&) const;
148 /// Modulo slice elements by corresponding elements of @a v.
149 void operator%=(const valarray
<_Tp
>&) const;
150 /// Add corresponding elements of @a v to slice elements.
151 void operator+=(const valarray
<_Tp
>&) const;
152 /// Subtract corresponding elements of @a v from slice elements.
153 void operator-=(const valarray
<_Tp
>&) const;
154 /// Logical xor slice elements with corresponding elements of @a v.
155 void operator^=(const valarray
<_Tp
>&) const;
156 /// Logical and slice elements with corresponding elements of @a v.
157 void operator&=(const valarray
<_Tp
>&) const;
158 /// Logical or slice elements with corresponding elements of @a v.
159 void operator|=(const valarray
<_Tp
>&) const;
160 /// Left shift slice elements by corresponding elements of @a v.
161 void operator<<=(const valarray
<_Tp
>&) const;
162 /// Right shift slice elements by corresponding elements of @a v.
163 void operator>>=(const valarray
<_Tp
>&) const;
164 /// Assign all slice elements to @a t.
165 void operator=(const _Tp
&) const;
169 void operator=(const _Expr
<_Dom
, _Tp
>&) const;
171 void operator*=(const _Expr
<_Dom
, _Tp
>&) const;
173 void operator/=(const _Expr
<_Dom
, _Tp
>&) const;
175 void operator%=(const _Expr
<_Dom
, _Tp
>&) const;
177 void operator+=(const _Expr
<_Dom
, _Tp
>&) const;
179 void operator-=(const _Expr
<_Dom
, _Tp
>&) const;
181 void operator^=(const _Expr
<_Dom
, _Tp
>&) const;
183 void operator&=(const _Expr
<_Dom
, _Tp
>&) const;
185 void operator|=(const _Expr
<_Dom
, _Tp
>&) const;
187 void operator<<=(const _Expr
<_Dom
, _Tp
>&) const;
189 void operator>>=(const _Expr
<_Dom
, _Tp
>&) const;
192 friend class valarray
<_Tp
>;
193 slice_array(_Array
<_Tp
>, const slice
&);
196 const size_t _M_stride
;
197 const _Array
<_Tp
> _M_array
;
203 template<typename _Tp
>
205 slice_array
<_Tp
>::slice_array(_Array
<_Tp
> __a
, const slice
& __s
)
206 : _M_sz(__s
.size()), _M_stride(__s
.stride()),
207 _M_array(__a
.begin() + __s
.start()) {}
209 template<typename _Tp
>
211 slice_array
<_Tp
>::slice_array(const slice_array
<_Tp
>& a
)
212 : _M_sz(a
._M_sz
), _M_stride(a
._M_stride
), _M_array(a
._M_array
) {}
214 // template<typename _Tp>
215 // inline slice_array<_Tp>::~slice_array () {}
217 template<typename _Tp
>
218 inline slice_array
<_Tp
>&
219 slice_array
<_Tp
>::operator=(const slice_array
<_Tp
>& __a
)
221 std::__valarray_copy(__a
._M_array
, __a
._M_sz
, __a
._M_stride
,
222 _M_array
, _M_stride
);
226 template<typename _Tp
>
228 slice_array
<_Tp
>::operator=(const _Tp
& __t
) const
229 { std::__valarray_fill(_M_array
, _M_sz
, _M_stride
, __t
); }
231 template<typename _Tp
>
233 slice_array
<_Tp
>::operator=(const valarray
<_Tp
>& __v
) const
234 { std::__valarray_copy(_Array
<_Tp
>(__v
), _M_array
, _M_sz
, _M_stride
); }
236 template<typename _Tp
>
239 slice_array
<_Tp
>::operator=(const _Expr
<_Dom
,_Tp
>& __e
) const
240 { std::__valarray_copy(__e
, _M_sz
, _M_array
, _M_stride
); }
242 #undef _DEFINE_VALARRAY_OPERATOR
243 #define _DEFINE_VALARRAY_OPERATOR(_Op,_Name) \
244 template<typename _Tp> \
246 slice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \
248 _Array_augmented_##_Name(_M_array, _M_sz, _M_stride, _Array<_Tp>(__v));\
251 template<typename _Tp> \
252 template<class _Dom> \
254 slice_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\
256 _Array_augmented_##_Name(_M_array, _M_stride, __e, _M_sz); \
260 _DEFINE_VALARRAY_OPERATOR(*, __multiplies
)
261 _DEFINE_VALARRAY_OPERATOR(/, __divides
)
262 _DEFINE_VALARRAY_OPERATOR(%, __modulus
)
263 _DEFINE_VALARRAY_OPERATOR(+, __plus
)
264 _DEFINE_VALARRAY_OPERATOR(-, __minus
)
265 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor
)
266 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and
)
267 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or
)
268 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left
)
269 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right
)
271 #undef _DEFINE_VALARRAY_OPERATOR
273 // @} group numeric_arrays
275 _GLIBCXX_END_NAMESPACE
277 #endif /* _SLICE_ARRAY_H */