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// The template and inlines for the -*- C++ -*- mask_array class.

// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2004

//  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.

// Written by Gabriel Dos Reis <Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr>

/** @file mask_array.h

 *  This is an internal header file, included by other library headers.

 *  You should not attempt to use it directly.

 */

#ifndef _MASK_ARRAY_H

#define _MASK_ARRAY_H 1

#pragma GCC system_header

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

} // std::

#endif /* _MASK_ARRAY_H */

// Local Variables:

// mode:c++

// End: