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// The template and inlines for the -*- C++ -*- mask_array class.
// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005
// 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 2, 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.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
/** @file mask_array.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
// Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>
#ifndef _MASK_ARRAY_H
#define _MASK_ARRAY_H 1
#pragma GCC system_header
_GLIBCXX_BEGIN_NAMESPACE(std)
/**
* @brief Reference to selected subset of an array.
*
* A mask_array is a reference to the actual elements of an array specified
* by a bitmask in the form of an array of bool. The way to get a
* mask_array is to call operator[](valarray<bool>) on a valarray. The
* returned mask_array then permits carrying operations out on the
* referenced subset of elements in the original valarray.
*
* For example, if a mask_array is obtained using the array (false, true,
* false, true) as an argument, the mask array has two elements referring
* to array[1] and array[3] in the underlying array.
*
* @param Tp Element type.
*/
template <class _Tp>
class mask_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.
mask_array (const mask_array&);
/// Assignment operator. Assigns elements to corresponding elements
/// of @a a.
mask_array& operator=(const mask_array&);
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;
// ~mask_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:
mask_array(_Array<_Tp>, size_t, _Array<bool>);
friend class valarray<_Tp>;
const size_t _M_sz;
const _Array<bool> _M_mask;
const _Array<_Tp> _M_array;
// not implemented
mask_array();
};
template<typename _Tp>
inline mask_array<_Tp>::mask_array(const mask_array<_Tp>& a)
: _M_sz(a._M_sz), _M_mask(a._M_mask), _M_array(a._M_array) {}
template<typename _Tp>
inline
mask_array<_Tp>::mask_array(_Array<_Tp> __a, size_t __s, _Array<bool> __m)
: _M_sz(__s), _M_mask(__m), _M_array(__a) {}
template<typename _Tp>
inline mask_array<_Tp>&
mask_array<_Tp>::operator=(const mask_array<_Tp>& __a)
{
std::__valarray_copy(__a._M_array, __a._M_mask,
_M_sz, _M_array, _M_mask);
return *this;
}
template<typename _Tp>
inline void
mask_array<_Tp>::operator=(const _Tp& __t) const
{ std::__valarray_fill(_M_array, _M_sz, _M_mask, __t); }
template<typename _Tp>
inline void
mask_array<_Tp>::operator=(const valarray<_Tp>& __v) const
{ std::__valarray_copy(_Array<_Tp>(__v), __v.size(), _M_array, _M_mask); }
template<typename _Tp>
template<class _Ex>
inline void
mask_array<_Tp>::operator=(const _Expr<_Ex, _Tp>& __e) const
{ std::__valarray_copy(__e, __e.size(), _M_array, _M_mask); }
#undef _DEFINE_VALARRAY_OPERATOR
#define _DEFINE_VALARRAY_OPERATOR(_Op, _Name) \
template<typename _Tp> \
inline void \
mask_array<_Tp>::operator _Op##=(const valarray<_Tp>& __v) const \
{ \
_Array_augmented_##_Name(_M_array, _M_mask, \
_Array<_Tp>(__v), __v.size()); \
} \
\
template<typename _Tp> \
template<class _Dom> \
inline void \
mask_array<_Tp>::operator _Op##=(const _Expr<_Dom, _Tp>& __e) const\
{ \
_Array_augmented_##_Name(_M_array, _M_mask, __e, __e.size()); \
}
_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
_GLIBCXX_END_NAMESPACE
#endif /* _MASK_ARRAY_H */
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