# indirect_array.h

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    00001 // The template and inlines for the -*- C++ -*- indirect_array class.
    00002
    00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004
    00004 //  Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 2, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // You should have received a copy of the GNU General Public License along
    00018 // with this library; see the file COPYING.  If not, write to the Free
    00019 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    00020 // USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
    00032
    00033 /** @file indirect_array.h
    00034  *  This is an internal header file, included by other library headers.
    00035  *  You should not attempt to use it directly.
    00036  */
    00037
    00038 #ifndef _INDIRECT_ARRAY_H
    00039 #define _INDIRECT_ARRAY_H 1
    00040
    00041 #pragma GCC system_header
    00042
    00043 namespace std
    00044 {
    00045   /**
    00046    *  @brief  Reference to arbitrary subset of an array.
    00047    *
    00048    *  An indirect_array is a reference to the actual elements of an array
    00049    *  specified by an ordered array of indices.  The way to get an indirect_array is to
    00050    *  call operator[](valarray<size_t>) on a valarray.  The returned
    00051    *  indirect_array then permits carrying operations out on the referenced
    00052    *  subset of elements in the original valarray.
    00053    *
    00054    *  For example, if an indirect_array is obtained using the array (4,2,0) as
    00055    *  an argument, and then assigned to an array containing (1,2,3), then the
    00056    *  underlying array will have array[0]==3, array[2]==2, and array[4]==1.
    00057    *
    00058    *  @param  Tp  Element type.
    00059    */
    00060   template <class _Tp>
    00061     class indirect_array
    00062     {
    00063     public:
    00064       typedef _Tp value_type;
    00065
    00066       // _GLIBCXX_RESOLVE_LIB_DEFECTS
    00067       // 253. valarray helper functions are almost entirely useless
    00068
    00069       ///  Copy constructor.  Both slices refer to the same underlying array.
    00070       indirect_array(const indirect_array&);
    00071
    00072       ///  Assignment operator.  Assigns elements to corresponding elements
    00073       ///  of @a a.
    00074       indirect_array& operator=(const indirect_array&);
    00075
    00076       ///  Assign slice elements to corresponding elements of @a v.
    00077       void operator=(const valarray<_Tp>&) const;
    00078       ///  Multiply slice elements by corresponding elements of @a v.
    00079       void operator*=(const valarray<_Tp>&) const;
    00080       ///  Divide slice elements by corresponding elements of @a v.
    00081       void operator/=(const valarray<_Tp>&) const;
    00082       ///  Modulo slice elements by corresponding elements of @a v.
    00083       void operator%=(const valarray<_Tp>&) const;
    00084       ///  Add corresponding elements of @a v to slice elements.
    00085       void operator+=(const valarray<_Tp>&) const;
    00086       ///  Subtract corresponding elements of @a v from slice elements.
    00087       void operator-=(const valarray<_Tp>&) const;
    00088       ///  Logical xor slice elements with corresponding elements of @a v.
    00089       void operator^=(const valarray<_Tp>&) const;
    00090       ///  Logical and slice elements with corresponding elements of @a v.
    00091       void operator&=(const valarray<_Tp>&) const;
    00092       ///  Logical or slice elements with corresponding elements of @a v.
    00093       void operator|=(const valarray<_Tp>&) const;
    00094       ///  Left shift slice elements by corresponding elements of @a v.
    00095       void operator<<=(const valarray<_Tp>&) const;
    00096       ///  Right shift slice elements by corresponding elements of @a v.
    00097       void operator>>=(const valarray<_Tp>&) const;
    00098       ///  Assign all slice elements to @a t.
    00099       void operator= (const _Tp&) const;
    00100       //    ~indirect_array();
    00101
    00102       template<class _Dom>
    00103       void operator=(const _Expr<_Dom, _Tp>&) const;
    00104       template<class _Dom>
    00105       void operator*=(const _Expr<_Dom, _Tp>&) const;
    00106       template<class _Dom>
    00107       void operator/=(const _Expr<_Dom, _Tp>&) const;
    00108       template<class _Dom>
    00109       void operator%=(const _Expr<_Dom, _Tp>&) const;
    00110       template<class _Dom>
    00111       void operator+=(const _Expr<_Dom, _Tp>&) const;
    00112       template<class _Dom>
    00113       void operator-=(const _Expr<_Dom, _Tp>&) const;
    00114       template<class _Dom>
    00115       void operator^=(const _Expr<_Dom, _Tp>&) const;
    00116       template<class _Dom>
    00117       void operator&=(const _Expr<_Dom, _Tp>&) const;
    00118       template<class _Dom>
    00119       void operator|=(const _Expr<_Dom, _Tp>&) const;
    00120       template<class _Dom>
    00121       void operator<<=(const _Expr<_Dom, _Tp>&) const;
    00122       template<class _Dom>
    00123       void operator>>=(const _Expr<_Dom, _Tp>&) const;
    00124
    00125     private:
    00126       ///  Copy constructor.  Both slices refer to the same underlying array.
    00127       indirect_array(_Array<_Tp>, size_t, _Array<size_t>);
    00128
    00129       friend class valarray<_Tp>;
    00130       friend class gslice_array<_Tp>;
    00131
    00132       const size_t   _M_sz;
    00133       const _Array<size_t> _M_index;
    00134       const _Array<_Tp>  _M_array;
    00135
    00136       // not implemented
    00137       indirect_array();
    00138     };
    00139
    00140   template<typename _Tp>
    00141     inline
    00142     indirect_array<_Tp>::indirect_array(const indirect_array<_Tp>& __a)
    00143     : _M_sz(__a._M_sz), _M_index(__a._M_index), _M_array(__a._M_array) {}
    00144
    00145   template<typename _Tp>
    00146      inline
    00147      indirect_array<_Tp>::indirect_array(_Array<_Tp> __a, size_t __s,
    00148                      _Array<size_t> __i)
    00149      : _M_sz(__s), _M_index(__i), _M_array(__a) {}
    00150
    00151   template<typename _Tp>
    00152      inline indirect_array<_Tp>&
    00153      indirect_array<_Tp>::operator=(const indirect_array<_Tp>& __a)
    00154      {
    00155        std::__valarray_copy(__a._M_array, _M_sz, __a._M_index, _M_array, _M_index);
    00156        return *this;
    00157      }
    00158
    00159
    00160   template<typename _Tp>
    00161      inline void
    00162      indirect_array<_Tp>::operator=(const _Tp& __t) const
    00163      { std::__valarray_fill(_M_array, _M_index, _M_sz, __t); }
    00164
    00165   template<typename _Tp>
    00166      inline void
    00167      indirect_array<_Tp>::operator=(const valarray<_Tp>& __v) const
    00168      { std::__valarray_copy(_Array<_Tp>(__v), _M_sz, _M_array, _M_index); }
    00169
    00170   template<typename _Tp>
    00171      template<class _Dom>
    00172        inline void
    00173        indirect_array<_Tp>::operator=(const _Expr<_Dom,_Tp>& __e) const
    00174        { std::__valarray_copy(__e, _M_sz, _M_array, _M_index); }
    00175
    00176 #undef _DEFINE_VALARRAY_OPERATOR
    00177 #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name)               \
    00178   template<typename _Tp>                        \
    00179     inline void                             \
    00180     indirect_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const\
    00181     {                                   \
    00182       _Array_augmented_##_Name(_M_array, _M_index, _Array<_Tp>(__v), _M_sz); \
    00183     }                                   \
    00184                                     \
    00185   template<typename _Tp>                                                \
    00186     template<class _Dom>                                \
    00187       inline void                           \
    00188       indirect_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\
    00189       {                                 \
    00190     _Array_augmented_##_Name(_M_array, _M_index, __e, _M_sz);   \
    00191       }
    00192
    00193 _DEFINE_VALARRAY_OPERATOR(*, __multiplies)
    00194 _DEFINE_VALARRAY_OPERATOR(/, __divides)
    00195 _DEFINE_VALARRAY_OPERATOR(%, __modulus)
    00196 _DEFINE_VALARRAY_OPERATOR(+, __plus)
    00197 _DEFINE_VALARRAY_OPERATOR(-, __minus)
    00198 _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor)
    00199 _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and)
    00200 _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
    00201 _DEFINE_VALARRAY_OPERATOR(<<, __shift_left)
    00202 _DEFINE_VALARRAY_OPERATOR(>>, __shift_right)
    00203
    00204 #undef _DEFINE_VALARRAY_OPERATOR
    00205
    00206 } // std::
    00207
    00208 #endif /* _INDIRECT_ARRAY_H */
    00209
    00210 // Local Variables:
    00211 // mode:c++
    00212 // End: