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

   1 // The template and inlines for the -*- C++ -*- gslice_array class.
   2
   3 // Copyright (C) 1997-2017 Free Software Foundation, Inc.
   4 //
   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)
   9 // any later version.
  10
  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.
  15
  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.
  19
  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/>.
  24
  25 /** @file bits/gslice_array.h
  26  *  This is an internal header file, included by other library headers.
  27  *  Do not attempt to use it directly. @headername{valarray}
  28  */
  29
  30 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
  31
  32 #ifndef _GSLICE_ARRAY_H
  33 #define _GSLICE_ARRAY_H 1
  34
  35 #pragma GCC system_header
  36
  37 namespace std _GLIBCXX_VISIBILITY(default)
  38 {
  39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  40
  41   /**
  42    * @addtogroup numeric_arrays
  43    * @{
  44    */
  45
  46   /**
  47    *  @brief  Reference to multi-dimensional subset of an array.
  48    *
  49    *  A gslice_array is a reference to the actual elements of an array
  50    *  specified by a gslice.  The way to get a gslice_array is to call
  51    *  operator[](gslice) on a valarray.  The returned gslice_array then
  52    *  permits carrying operations out on the referenced subset of elements in
  53    *  the original valarray.  For example, operator+=(valarray) will add
  54    *  values to the subset of elements in the underlying valarray this
  55    *  gslice_array refers to.
  56    *
  57    *  @param  Tp  Element type.
  58    */
  59   template<typename _Tp>
  60     class gslice_array
  61     {
  62     public:
  63       typedef _Tp value_type;
  64
  65       // _GLIBCXX_RESOLVE_LIB_DEFECTS
  66       // 253. valarray helper functions are almost entirely useless
  67
  68       ///  Copy constructor.  Both slices refer to the same underlying array.
  69       gslice_array(const gslice_array&);
  70
  71       ///  Assignment operator.  Assigns slice elements to corresponding
  72       ///  elements of @a a.
  73       gslice_array& operator=(const gslice_array&);
  74
  75       ///  Assign slice elements to corresponding elements of @a v.
  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       template<class _Dom>
 101         void operator=(const _Expr<_Dom, _Tp>&) const;
 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
 123     private:
 124       _Array<_Tp>    _M_array;
 125       const valarray<size_t>& _M_index;
 126
 127       friend class valarray<_Tp>;
 128
 129       gslice_array(_Array<_Tp>, const valarray<size_t>&);
 130
 131       // not implemented
 132       gslice_array();
 133     };
 134
 135   template<typename _Tp>
 136     inline
 137     gslice_array<_Tp>::gslice_array(_Array<_Tp> __a,
 138                                     const valarray<size_t>& __i)
 139     : _M_array(__a), _M_index(__i) {}
 140
 141   template<typename _Tp>
 142     inline
 143     gslice_array<_Tp>::gslice_array(const gslice_array<_Tp>& __a)
 144     : _M_array(__a._M_array), _M_index(__a._M_index) {}
 145
 146   template<typename _Tp>
 147     inline gslice_array<_Tp>&
 148     gslice_array<_Tp>::operator=(const gslice_array<_Tp>& __a)
 149     {
 150       std::__valarray_copy(_Array<_Tp>(__a._M_array),
 151                            _Array<size_t>(__a._M_index), _M_index.size(),
 152                            _M_array, _Array<size_t>(_M_index));
 153       return *this;
 154     }
 155
 156   template<typename _Tp>
 157     inline void
 158     gslice_array<_Tp>::operator=(const _Tp& __t) const
 159     {
 160       std::__valarray_fill(_M_array, _Array<size_t>(_M_index),
 161                            _M_index.size(), __t);
 162     }
 163
 164   template<typename _Tp>
 165     inline void
 166     gslice_array<_Tp>::operator=(const valarray<_Tp>& __v) const
 167     {
 168       std::__valarray_copy(_Array<_Tp>(__v), __v.size(),
 169                            _M_array, _Array<size_t>(_M_index));
 170     }
 171
 172   template<typename _Tp>
 173     template<class _Dom>
 174       inline void
 175       gslice_array<_Tp>::operator=(const _Expr<_Dom, _Tp>& __e) const
 176       {
 177         std::__valarray_copy (__e, _M_index.size(), _M_array,
 178                               _Array<size_t>(_M_index));
 179       }
 180
 181 #undef _DEFINE_VALARRAY_OPERATOR
 182 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name)                           \
 183   template<typename _Tp>                                                \
 184     inline void                                                         \
 185     gslice_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const  \
 186     {                                                                   \
 187       _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index),      \
 188                                _Array<_Tp>(__v), __v.size());           \
 189     }                                                                   \
 190                                                                         \
 191   template<typename _Tp>                                                \
 192     template<class _Dom>                                                \
 193       inline void                                                       \
 194       gslice_array<_Tp>::operator _Op##= (const _Expr<_Dom, _Tp>& __e) const\
 195       {                                                                 \
 196         _Array_augmented_##_Name(_M_array, _Array<size_t>(_M_index), __e,\
 197                                  _M_index.size());                      \
 198       }
 199
 200 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
 201 _DEFINE_VALARRAY_OPERATOR(/, __divides)
 202 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
 203 _DEFINE_VALARRAY_OPERATOR(+, __plus)
 204 _DEFINE_VALARRAY_OPERATOR(-, __minus)
 205 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
 206 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
 207 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
 208 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
 209 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
 210
 211 #undef _DEFINE_VALARRAY_OPERATOR
 212
 213   // @} group numeric_arrays
 214
 215 _GLIBCXX_END_NAMESPACE_VERSION
 216 } // namespace
 217
 218 #endif /* _GSLICE_ARRAY_H */