libstdc++-v3/include/bits/mask_array.h

   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 2, 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 // 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,
  20 // USA.
  21
  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
  26 // file does not by itself cause the resulting executable to be covered by
  27 // the GNU General Public License.  This exception does not however
  28 // invalidate any other reasons why the executable file might be covered by
  29 // the GNU General Public License.
  30
  31 /** @file mask_array.h
  32  *  This is an internal header file, included by other library headers.
  33  *  You should not attempt to use it directly.
  34  */
  35
  36 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
  37
  38 #ifndef _MASK_ARRAY_H
  39 #define _MASK_ARRAY_H 1
  40
  41 #pragma GCC system_header
  42
  43 _GLIBCXX_BEGIN_NAMESPACE(std)
  44
  45   /**
  46    * @addtogroup numeric_arrays
  47    * @{
  48    */
  49
  50   /**
  51    *  @brief  Reference to selected subset of an array.
  52    *
  53    *  A mask_array is a reference to the actual elements of an array specified
  54    *  by a bitmask in the form of an array of bool.  The way to get a
  55    *  mask_array is to call operator[](valarray<bool>) on a valarray.  The
  56    *  returned mask_array then permits carrying operations out on the
  57    *  referenced subset of elements in the original valarray.
  58    *
  59    *  For example, if a mask_array is obtained using the array (false, true,
  60    *  false, true) as an argument, the mask array has two elements referring
  61    *  to array[1] and array[3] in the underlying array.
  62    *
  63    *  @param  Tp  Element type.
  64    */
  65   template <class _Tp>
  66     class mask_array
  67     {
  68     public:
  69       typedef _Tp value_type;
  70
  71       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  72       // 253. valarray helper functions are almost entirely useless
  73
  74       ///  Copy constructor.  Both slices refer to the same underlying array.
  75       mask_array (const mask_array&);
  76
  77       ///  Assignment operator.  Assigns elements to corresponding elements
  78       ///  of @a a.
  79       mask_array& operator=(const mask_array&);
  80
  81       void operator=(const valarray<_Tp>&) const;
  82       ///  Multiply slice elements by corresponding elements of @a v.
  83       void operator*=(const valarray<_Tp>&) const;
  84       ///  Divide slice elements by corresponding elements of @a v.
  85       void operator/=(const valarray<_Tp>&) const;
  86       ///  Modulo slice elements by corresponding elements of @a v.
  87       void operator%=(const valarray<_Tp>&) const;
  88       ///  Add corresponding elements of @a v to slice elements.
  89       void operator+=(const valarray<_Tp>&) const;
  90       ///  Subtract corresponding elements of @a v from slice elements.
  91       void operator-=(const valarray<_Tp>&) const;
  92       ///  Logical xor slice elements with corresponding elements of @a v.
  93       void operator^=(const valarray<_Tp>&) const;
  94       ///  Logical and slice elements with corresponding elements of @a v.
  95       void operator&=(const valarray<_Tp>&) const;
  96       ///  Logical or slice elements with corresponding elements of @a v.
  97       void operator|=(const valarray<_Tp>&) const;
  98       ///  Left shift slice elements by corresponding elements of @a v.
  99       void operator<<=(const valarray<_Tp>&) const;
 100       ///  Right shift slice elements by corresponding elements of @a v.
 101       void operator>>=(const valarray<_Tp>&) const;
 102       ///  Assign all slice elements to @a t.
 103       void operator=(const _Tp&) const;
 104
 105         //        ~mask_array ();
 106
 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       template<class _Dom>
 124         void operator|=(const _Expr<_Dom,_Tp>&) const;
 125       template<class _Dom>
 126         void operator<<=(const _Expr<_Dom,_Tp>&) const;
 127       template<class _Dom>
 128         void operator>>=(const _Expr<_Dom,_Tp>&) const;
 129
 130     private:
 131       mask_array(_Array<_Tp>, size_t, _Array<bool>);
 132       friend class valarray<_Tp>;
 133
 134       const size_t       _M_sz;
 135       const _Array<bool> _M_mask;
 136       const _Array<_Tp>  _M_array;
 137
 138       // not implemented
 139       mask_array();
 140     };
 141
 142   template<typename _Tp>
 143     inline mask_array<_Tp>::mask_array(const mask_array<_Tp>& a)
 144     : _M_sz(a._M_sz), _M_mask(a._M_mask), _M_array(a._M_array) {}
 145
 146   template<typename _Tp>
 147     inline
 148     mask_array<_Tp>::mask_array(_Array<_Tp> __a, size_t __s, _Array<bool> __m)
 149     : _M_sz(__s), _M_mask(__m), _M_array(__a) {}
 150
 151   template<typename _Tp>
 152     inline mask_array<_Tp>&
 153     mask_array<_Tp>::operator=(const mask_array<_Tp>& __a)
 154     {
 155       std::__valarray_copy(__a._M_array, __a._M_mask,
 156                            _M_sz, _M_array, _M_mask);
 157       return *this;
 158     }
 159
 160   template<typename _Tp>
 161     inline void
 162     mask_array<_Tp>::operator=(const _Tp& __t) const
 163     { std::__valarray_fill(_M_array, _M_sz, _M_mask, __t); }
 164
 165   template<typename _Tp>
 166     inline void
 167     mask_array<_Tp>::operator=(const valarray<_Tp>& __v) const
 168     { std::__valarray_copy(_Array<_Tp>(__v), __v.size(), _M_array, _M_mask); }
 169
 170   template<typename _Tp>
 171     template<class _Ex>
 172       inline void
 173       mask_array<_Tp>::operator=(const _Expr<_Ex, _Tp>& __e) const
 174       { std::__valarray_copy(__e, __e.size(), _M_array, _M_mask); }
 175
 176 #undef _DEFINE_VALARRAY_OPERATOR
 177 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name)                           \
 178   template<typename _Tp>                                                \
 179     inline void                                                         \
 180     mask_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const    \
 181     {                                                                   \
 182       _Array_augmented_##_Name(_M_array, _M_mask,                       \
 183                                _Array<_Tp>(__v), __v.size());           \
 184     }                                                                   \
 185                                                                         \
 186   template<typename _Tp>                                                \
 187     template<class _Dom>                                                \
 188       inline void                                                       \
 189       mask_array<_Tp>::operator _Op##=(const _Expr<_Dom, _Tp>& __e) const\
 190       {                                                                 \
 191         _Array_augmented_##_Name(_M_array, _M_mask, __e, __e.size());   \
 192       }
 193
 194 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
 195 _DEFINE_VALARRAY_OPERATOR(/, __divides)
 196 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
 197 _DEFINE_VALARRAY_OPERATOR(+, __plus)
 198 _DEFINE_VALARRAY_OPERATOR(-, __minus)
 199 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
 200 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
 201 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
 202 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
 203 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
 204
 205 #undef _DEFINE_VALARRAY_OPERATOR
 206
 207   // @} group numeric_arrays
 208
 209 _GLIBCXX_END_NAMESPACE
 210
 211 #endif /* _MASK_ARRAY_H */