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

   1 // The template and inlines for the -*- C++ -*- indirect_array class.
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2009, 2010
   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 bits/indirect_array.h
  27  *  This is an internal header file, included by other library headers.
  28  *  Do not attempt to use it directly. @headername{valarray}
  29  */
  30
  31 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
  32
  33 #ifndef _INDIRECT_ARRAY_H
  34 #define _INDIRECT_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 arbitrary subset of an array.
  47    *
  48    *  An indirect_array is a reference to the actual elements of an array
  49    *  specified by an ordered array of indices.  The way to get an
  50    *  indirect_array is to call operator[](valarray<size_t>) on a valarray.
  51    *  The returned indirect_array then permits carrying operations out on the
  52    *  referenced subset of elements in the original valarray.
  53    *
  54    *  For example, if an indirect_array is obtained using the array (4,2,0) as
  55    *  an argument, and then assigned to an array containing (1,2,3), then the
  56    *  underlying array will have array[0]==3, array[2]==2, and array[4]==1.
  57    *
  58    *  @param  Tp  Element type.
  59    */
  60   template <class _Tp>
  61     class indirect_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       indirect_array(const indirect_array&);
  71
  72       ///  Assignment operator.  Assigns elements to corresponding elements
  73       ///  of @a a.
  74       indirect_array& operator=(const indirect_array&);
  75
  76       ///  Assign slice elements to corresponding elements of @a v.
  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;
 100       //    ~indirect_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       ///  Copy constructor.  Both slices refer to the same underlying array.
 127       indirect_array(_Array<_Tp>, size_t, _Array<size_t>);
 128
 129       friend class valarray<_Tp>;
 130       friend class gslice_array<_Tp>;
 131
 132       const size_t       _M_sz;
 133       const _Array<size_t> _M_index;
 134       const _Array<_Tp>  _M_array;
 135
 136       // not implemented
 137       indirect_array();
 138     };
 139
 140   template<typename _Tp>
 141     inline
 142     indirect_array<_Tp>::indirect_array(const indirect_array<_Tp>& __a)
 143     : _M_sz(__a._M_sz), _M_index(__a._M_index), _M_array(__a._M_array) {}
 144
 145   template<typename _Tp>
 146     inline
 147     indirect_array<_Tp>::indirect_array(_Array<_Tp> __a, size_t __s,
 148                                         _Array<size_t> __i)
 149     : _M_sz(__s), _M_index(__i), _M_array(__a) {}
 150
 151   template<typename _Tp>
 152     inline indirect_array<_Tp>&
 153     indirect_array<_Tp>::operator=(const indirect_array<_Tp>& __a)
 154     {
 155       std::__valarray_copy(__a._M_array, _M_sz, __a._M_index, _M_array,
 156                            _M_index);
 157       return *this;
 158     }
 159
 160   template<typename _Tp>
 161     inline void
 162     indirect_array<_Tp>::operator=(const _Tp& __t) const
 163     { std::__valarray_fill(_M_array, _M_index, _M_sz, __t); }
 164
 165   template<typename _Tp>
 166     inline void
 167     indirect_array<_Tp>::operator=(const valarray<_Tp>& __v) const
 168     { std::__valarray_copy(_Array<_Tp>(__v), _M_sz, _M_array, _M_index); }
 169
 170   template<typename _Tp>
 171     template<class _Dom>
 172       inline void
 173       indirect_array<_Tp>::operator=(const _Expr<_Dom, _Tp>& __e) const
 174       { std::__valarray_copy(__e, _M_sz, _M_array, _M_index); }
 175
 176 #undef _DEFINE_VALARRAY_OPERATOR
 177 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name)                           \
 178   template<typename _Tp>                                                \
 179     inline void                                                         \
 180     indirect_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const\
 181     {                                                                   \
 182       _Array_augmented_##_Name(_M_array, _M_index, _Array<_Tp>(__v), _M_sz); \
 183     }                                                                   \
 184                                                                         \
 185   template<typename _Tp>                                                \
 186     template<class _Dom>                                                \
 187       inline void                                                       \
 188       indirect_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\
 189       {                                                                 \
 190         _Array_augmented_##_Name(_M_array, _M_index, __e, _M_sz);       \
 191       }
 192
 193 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
 194 _DEFINE_VALARRAY_OPERATOR(/, __divides)
 195 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
 196 _DEFINE_VALARRAY_OPERATOR(+, __plus)
 197 _DEFINE_VALARRAY_OPERATOR(-, __minus)
 198 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
 199 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
 200 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
 201 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
 202 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
 203
 204 #undef _DEFINE_VALARRAY_OPERATOR
 205
 206   // @} group numeric_arrays
 207
 208 _GLIBCXX_END_NAMESPACE
 209
 210 #endif /* _INDIRECT_ARRAY_H */