1 // The template and inlines for the -*- C++ -*- mask_array class.
3 // Copyright (C) 1997-2024 Free Software Foundation, Inc.
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)
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.
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.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file bits/mask_array.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{valarray}
30 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
33 #define _MASK_ARRAY_H 1
35 #pragma GCC system_header
37 namespace std
_GLIBCXX_VISIBILITY(default)
39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
42 * @addtogroup numeric_arrays
47 * @brief Reference to selected subset of an array.
49 * A mask_array is a reference to the actual elements of an array specified
50 * by a bitmask in the form of an array of bool. The way to get a
51 * mask_array is to call operator[](valarray<bool>) on a valarray. The
52 * returned mask_array then permits carrying operations out on the
53 * referenced subset of elements in the original valarray.
55 * For example, if a mask_array is obtained using the array (false, true,
56 * false, true) as an argument, the mask array has two elements referring
57 * to array[1] and array[3] in the underlying array.
59 * @param Tp Element type.
65 typedef _Tp value_type
;
67 // _GLIBCXX_RESOLVE_LIB_DEFECTS
68 // 253. valarray helper functions are almost entirely useless
70 /// Copy constructor. Both slices refer to the same underlying array.
71 mask_array (const mask_array
&);
73 /// Assignment operator. Assigns elements to corresponding elements
75 mask_array
& operator=(const mask_array
&);
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;
104 void operator=(const _Expr
<_Dom
,_Tp
>&) const;
106 void operator*=(const _Expr
<_Dom
,_Tp
>&) const;
108 void operator/=(const _Expr
<_Dom
,_Tp
>&) const;
110 void operator%=(const _Expr
<_Dom
,_Tp
>&) const;
112 void operator+=(const _Expr
<_Dom
,_Tp
>&) const;
114 void operator-=(const _Expr
<_Dom
,_Tp
>&) const;
116 void operator^=(const _Expr
<_Dom
,_Tp
>&) const;
118 void operator&=(const _Expr
<_Dom
,_Tp
>&) const;
120 void operator|=(const _Expr
<_Dom
,_Tp
>&) const;
122 void operator<<=(const _Expr
<_Dom
,_Tp
>&) const;
124 void operator>>=(const _Expr
<_Dom
,_Tp
>&) const;
127 mask_array(_Array
<_Tp
>, size_t, _Array
<bool>);
128 friend class valarray
<_Tp
>;
131 const _Array
<bool> _M_mask
;
132 const _Array
<_Tp
> _M_array
;
134 #if __cplusplus < 201103L
139 mask_array() = delete;
143 template<typename _Tp
>
144 inline mask_array
<_Tp
>::mask_array(const mask_array
<_Tp
>& __a
)
145 : _M_sz(__a
._M_sz
), _M_mask(__a
._M_mask
), _M_array(__a
._M_array
) {}
147 template<typename _Tp
>
149 mask_array
<_Tp
>::mask_array(_Array
<_Tp
> __a
, size_t __s
, _Array
<bool> __m
)
150 : _M_sz(__s
), _M_mask(__m
), _M_array(__a
) {}
152 template<typename _Tp
>
153 inline mask_array
<_Tp
>&
154 mask_array
<_Tp
>::operator=(const mask_array
<_Tp
>& __a
)
156 __glibcxx_assert(__a
._M_sz
== _M_sz
);
157 std::__valarray_copy(__a
._M_array
, __a
._M_mask
,
158 _M_sz
, _M_array
, _M_mask
);
162 template<typename _Tp
>
164 mask_array
<_Tp
>::operator=(const _Tp
& __t
) const
165 { std::__valarray_fill(_M_array
, _M_sz
, _M_mask
, __t
); }
167 template<typename _Tp
>
169 mask_array
<_Tp
>::operator=(const valarray
<_Tp
>& __v
) const
171 __glibcxx_assert(__v
.size() == _M_sz
);
172 std::__valarray_copy(_Array
<_Tp
>(__v
), __v
.size(), _M_array
, _M_mask
);
175 template<typename _Tp
>
178 mask_array
<_Tp
>::operator=(const _Expr
<_Ex
, _Tp
>& __e
) const
180 __glibcxx_assert(__e
.size() == _M_sz
);
181 std::__valarray_copy(__e
, __e
.size(), _M_array
, _M_mask
);
184 /// @cond undocumented
185 #undef _DEFINE_VALARRAY_OPERATOR
186 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \
187 template<typename _Tp> \
189 mask_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \
191 __glibcxx_assert(__v.size() == _M_sz); \
192 _Array_augmented_##_Name(_M_array, _M_mask, \
193 _Array<_Tp>(__v), __v.size()); \
196 template<typename _Tp> \
197 template<class _Dom> \
199 mask_array<_Tp>::operator _Op##=(const _Expr<_Dom, _Tp>& __e) const\
201 __glibcxx_assert(__e.size() == _M_sz); \
202 _Array_augmented_##_Name(_M_array, _M_mask, __e, __e.size()); \
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
)
216 #undef _DEFINE_VALARRAY_OPERATOR
219 /// @} group numeric_arrays
221 _GLIBCXX_END_NAMESPACE_VERSION
224 #endif /* _MASK_ARRAY_H */