1// The template and inlines for the -*- C++ -*- mask_array class.
2
3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2009
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,
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.
16
17// Under Section 7 of GPL version 3, you are granted additional
18// permissions described in the GCC Runtime Library Exception, version
19// 3.1, as published by the Free Software Foundation.
20
21// You should have received a copy of the GNU General Public License and
22// a copy of the GCC Runtime Library Exception along with this program;
23// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
24// <http://www.gnu.org/licenses/>.
25
26/** @file mask_array.h
27 *  This is an internal header file, included by other library headers.
28 *  You should not attempt to use it directly.
29 */
30
31// Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
32
33#ifndef _MASK_ARRAY_H
34#define _MASK_ARRAY_H 1
35
36#pragma GCC system_header
37
38_GLIBCXX_BEGIN_NAMESPACE(std)
39
40  /**
41   * @addtogroup numeric_arrays
42   * @{
43   */
44
45  /**
46   *  @brief  Reference to selected subset of an array.
47   *
48   *  A mask_array is a reference to the actual elements of an array specified
49   *  by a bitmask in the form of an array of bool.  The way to get a
50   *  mask_array is to call operator[](valarray<bool>) on a valarray.  The
51   *  returned mask_array then permits carrying operations out on the
52   *  referenced subset of elements in the original valarray.
53   *
54   *  For example, if a mask_array is obtained using the array (false, true,
55   *  false, true) as an argument, the mask array has two elements referring
56   *  to array[1] and array[3] in the underlying array.
57   *
58   *  @param  Tp  Element type.
59   */
60  template <class _Tp>
61    class mask_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      mask_array (const mask_array&);
71
72      ///  Assignment operator.  Assigns elements to corresponding elements
73      ///  of @a a.
74      mask_array& operator=(const mask_array&);
75
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        //        ~mask_array ();
101
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      template<class _Dom>
123        void operator>>=(const _Expr<_Dom,_Tp>&) const;
124
125    private:
126      mask_array(_Array<_Tp>, size_t, _Array<bool>);
127      friend class valarray<_Tp>;
128
129      const size_t       _M_sz;
130      const _Array<bool> _M_mask;
131      const _Array<_Tp>  _M_array;
132
133      // not implemented
134      mask_array();
135    };
136
137  template<typename _Tp>
138    inline mask_array<_Tp>::mask_array(const mask_array<_Tp>& a)
139    : _M_sz(a._M_sz), _M_mask(a._M_mask), _M_array(a._M_array) {}
140
141  template<typename _Tp>
142    inline
143    mask_array<_Tp>::mask_array(_Array<_Tp> __a, size_t __s, _Array<bool> __m)
144    : _M_sz(__s), _M_mask(__m), _M_array(__a) {}
145
146  template<typename _Tp>
147    inline mask_array<_Tp>&
148    mask_array<_Tp>::operator=(const mask_array<_Tp>& __a)
149    {
150      std::__valarray_copy(__a._M_array, __a._M_mask,
151			   _M_sz, _M_array, _M_mask);
152      return *this;
153    }
154
155  template<typename _Tp>
156    inline void
157    mask_array<_Tp>::operator=(const _Tp& __t) const
158    { std::__valarray_fill(_M_array, _M_sz, _M_mask, __t); }
159
160  template<typename _Tp>
161    inline void
162    mask_array<_Tp>::operator=(const valarray<_Tp>& __v) const
163    { std::__valarray_copy(_Array<_Tp>(__v), __v.size(), _M_array, _M_mask); }
164
165  template<typename _Tp>
166    template<class _Ex>
167      inline void
168      mask_array<_Tp>::operator=(const _Expr<_Ex, _Tp>& __e) const
169      { std::__valarray_copy(__e, __e.size(), _M_array, _M_mask); }
170
171#undef _DEFINE_VALARRAY_OPERATOR
172#define _DEFINE_VALARRAY_OPERATOR(_Op, _Name)				\
173  template<typename _Tp>						\
174    inline void								\
175    mask_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const	\
176    {									\
177      _Array_augmented_##_Name(_M_array, _M_mask,			\
178			       _Array<_Tp>(__v), __v.size());		\
179    }									\
180									\
181  template<typename _Tp>                                                \
182    template<class _Dom>			                        \
183      inline void							\
184      mask_array<_Tp>::operator _Op##=(const _Expr<_Dom, _Tp>& __e) const\
185      {									\
186	_Array_augmented_##_Name(_M_array, _M_mask, __e, __e.size());   \
187      }
188
189_DEFINE_VALARRAY_OPERATOR(*, __multiplies)
190_DEFINE_VALARRAY_OPERATOR(/, __divides)
191_DEFINE_VALARRAY_OPERATOR(%, __modulus)
192_DEFINE_VALARRAY_OPERATOR(+, __plus)
193_DEFINE_VALARRAY_OPERATOR(-, __minus)
194_DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
195_DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
196_DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
197_DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
198_DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
199
200#undef _DEFINE_VALARRAY_OPERATOR
201
202  // @} group numeric_arrays
203
204_GLIBCXX_END_NAMESPACE
205
206#endif /* _MASK_ARRAY_H */
207