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      1 // The template and inlines for the -*- C++ -*- gslice_array class.
      2 
      3 // Copyright (C) 1997-2013 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 (at) 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 */
    219