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Edit File: indirect_array.h

// The template and inlines for the -*- C++ -*- indirect_array class. // Copyright (C) 1997-2021 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file bits/indirect_array.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{valarray} */ // Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr> #ifndef _INDIRECT_ARRAY_H #define _INDIRECT_ARRAY_H 1 #pragma GCC system_header namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /** * @addtogroup numeric_arrays * @{ */ /** * @brief Reference to arbitrary subset of an array. * * An indirect_array is a reference to the actual elements of an array * specified by an ordered array of indices. The way to get an * indirect_array is to call operator[](valarray<size_t>) on a valarray. * The returned indirect_array then permits carrying operations out on the * referenced subset of elements in the original valarray. * * For example, if an indirect_array is obtained using the array (4,2,0) as * an argument, and then assigned to an array containing (1,2,3), then the * underlying array will have array[0]==3, array[2]==2, and array[4]==1. * * @param Tp Element type. */ template <class _Tp> class indirect_array { public: typedef _Tp value_type; // _GLIBCXX_RESOLVE_LIB_DEFECTS // 253. valarray helper functions are almost entirely useless /// Copy constructor. Both slices refer to the same underlying array. indirect_array(const indirect_array&); /// Assignment operator. Assigns elements to corresponding elements /// of @a a. indirect_array& operator=(const indirect_array&); /// Assign slice elements to corresponding elements of @a v. void operator=(const valarray<_Tp>&) const; /// Multiply slice elements by corresponding elements of @a v. void operator*=(const valarray<_Tp>&) const; /// Divide slice elements by corresponding elements of @a v. void operator/=(const valarray<_Tp>&) const; /// Modulo slice elements by corresponding elements of @a v. void operator%=(const valarray<_Tp>&) const; /// Add corresponding elements of @a v to slice elements. void operator+=(const valarray<_Tp>&) const; /// Subtract corresponding elements of @a v from slice elements. void operator-=(const valarray<_Tp>&) const; /// Logical xor slice elements with corresponding elements of @a v. void operator^=(const valarray<_Tp>&) const; /// Logical and slice elements with corresponding elements of @a v. void operator&=(const valarray<_Tp>&) const; /// Logical or slice elements with corresponding elements of @a v. void operator|=(const valarray<_Tp>&) const; /// Left shift slice elements by corresponding elements of @a v. void operator<<=(const valarray<_Tp>&) const; /// Right shift slice elements by corresponding elements of @a v. void operator>>=(const valarray<_Tp>&) const; /// Assign all slice elements to @a t. void operator= (const _Tp&) const; // ~indirect_array(); template<class _Dom> void operator=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator*=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator/=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator%=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator+=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator-=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator^=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator&=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator|=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator<<=(const _Expr<_Dom, _Tp>&) const; template<class _Dom> void operator>>=(const _Expr<_Dom, _Tp>&) const; private: /// Copy constructor. Both slices refer to the same underlying array. indirect_array(_Array<_Tp>, size_t, _Array<size_t>); friend class valarray<_Tp>; friend class gslice_array<_Tp>; const size_t _M_sz; const _Array<size_t> _M_index; const _Array<_Tp> _M_array; // not implemented indirect_array(); }; template<typename _Tp> inline indirect_array<_Tp>::indirect_array(const indirect_array<_Tp>& __a) : _M_sz(__a._M_sz), _M_index(__a._M_index), _M_array(__a._M_array) {} template<typename _Tp> inline indirect_array<_Tp>::indirect_array(_Array<_Tp> __a, size_t __s, _Array<size_t> __i) : _M_sz(__s), _M_index(__i), _M_array(__a) {} template<typename _Tp> inline indirect_array<_Tp>& indirect_array<_Tp>::operator=(const indirect_array<_Tp>& __a) { std::__valarray_copy(__a._M_array, _M_sz, __a._M_index, _M_array, _M_index); return *this; } template<typename _Tp> inline void indirect_array<_Tp>::operator=(const _Tp& __t) const { std::__valarray_fill(_M_array, _M_index, _M_sz, __t); } template<typename _Tp> inline void indirect_array<_Tp>::operator=(const valarray<_Tp>& __v) const { std::__valarray_copy(_Array<_Tp>(__v), _M_sz, _M_array, _M_index); } template<typename _Tp> template<class _Dom> inline void indirect_array<_Tp>::operator=(const _Expr<_Dom, _Tp>& __e) const { std::__valarray_copy(__e, _M_sz, _M_array, _M_index); } /// @cond undocumented #undef _DEFINE_VALARRAY_OPERATOR #define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \ template<typename _Tp> \ inline void \ indirect_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const\ { \ _Array_augmented_##_Name(_M_array, _M_index, _Array<_Tp>(__v), _M_sz); \ } \ \ template<typename _Tp> \ template<class _Dom> \ inline void \ indirect_array<_Tp>::operator _Op##=(const _Expr<_Dom,_Tp>& __e) const\ { \ _Array_augmented_##_Name(_M_array, _M_index, __e, _M_sz); \ } _DEFINE_VALARRAY_OPERATOR(*, __multiplies) _DEFINE_VALARRAY_OPERATOR(/, __divides) _DEFINE_VALARRAY_OPERATOR(%, __modulus) _DEFINE_VALARRAY_OPERATOR(+, __plus) _DEFINE_VALARRAY_OPERATOR(-, __minus) _DEFINE_VALARRAY_OPERATOR(^, __bitwise_xor) _DEFINE_VALARRAY_OPERATOR(&, __bitwise_and) _DEFINE_VALARRAY_OPERATOR(|, __bitwise_or) _DEFINE_VALARRAY_OPERATOR(<<, __shift_left) _DEFINE_VALARRAY_OPERATOR(>>, __shift_right) #undef _DEFINE_VALARRAY_OPERATOR /// @endcond /// @} group numeric_arrays _GLIBCXX_END_NAMESPACE_VERSION } // namespace #endif /* _INDIRECT_ARRAY_H */