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

// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// 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 slice_array.h
 *  This is an internal header file, included by other library headers.
 *  You should not attempt to use it directly.
 */

#ifndef _CPP_BITS_SLICE_ARRAY_H
#define _CPP_BITS_SLICE_ARRAY_H 1

#pragma GCC system_header

namespace std
{
  class slice
  {
  public:
    slice();
    slice(size_t, size_t, size_t);
    
    size_t start() const;
    size_t size() const;
    size_t stride() const;
    
  private:
    size_t _M_off;                      // offset
    size_t _M_sz;			// size
    size_t _M_st;			// stride unit
  };

  // The default constructor constructor is not required to initialize
  // data members with any meaningful values, so we choose to do nothing.
  inline 
  slice::slice() {}
  
  inline 
  slice::slice(size_t __o, size_t __d, size_t __s)
    : _M_off(__o), _M_sz(__d), _M_st(__s) {}
  
  inline size_t
  slice::start() const
  { return _M_off; }
  
  inline size_t
  slice::size() const
  { return _M_sz; }
  
  inline size_t
  slice::stride() const
  { return _M_st; }

  template<typename _Tp>
    class slice_array
    {
    public:
      typedef _Tp value_type;

      // This constructor is implemented since we need to return a value.
      slice_array(const slice_array&);

      // This operator must be public.  See DR-253.
      slice_array& operator=(const slice_array&);

      void operator=(const valarray<_Tp>&) const;
      void operator*=(const valarray<_Tp>&) const;
      void operator/=(const valarray<_Tp>&) const;
      void operator%=(const valarray<_Tp>&) const;
      void operator+=(const valarray<_Tp>&) const;
      void operator-=(const valarray<_Tp>&) const;
      void operator^=(const valarray<_Tp>&) const;
      void operator&=(const valarray<_Tp>&) const;
      void operator|=(const valarray<_Tp>&) const;
      void operator<<=(const valarray<_Tp>&) const;
      void operator>>=(const valarray<_Tp>&) const;
      void operator=(const _Tp &) const;
      //        ~slice_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:
      friend class valarray<_Tp>;
      slice_array(_Array<_Tp>, const slice&);

      const size_t     _M_sz;
      const size_t     _M_stride;
      const _Array<_Tp> _M_array;

      // not implemented
      slice_array();
    };

  template<typename _Tp>
    inline 
    slice_array<_Tp>::slice_array(_Array<_Tp> __a, const slice& __s)
      : _M_sz(__s.size()), _M_stride(__s.stride()),
	_M_array(__a.begin() + __s.start()) {}

  template<typename _Tp>
    inline 
    slice_array<_Tp>::slice_array(const slice_array<_Tp>& a)
      : _M_sz(a._M_sz), _M_stride(a._M_stride), _M_array(a._M_array) {}
    
  //    template<typename _Tp>
  //    inline slice_array<_Tp>::~slice_array () {}

  template<typename _Tp>
    inline slice_array<_Tp>&
    slice_array<_Tp>::operator=(const slice_array<_Tp>& __a)
    {
      __valarray_copy(_M_array, _M_sz, _M_stride, __a._M_array, __a._M_stride);
      return *this;
    }

  template<typename _Tp>
    inline void
    slice_array<_Tp>::operator=(const _Tp& __t) const
    { __valarray_fill(_M_array, _M_sz, _M_stride, __t); }
    
  template<typename _Tp>
    inline void
    slice_array<_Tp>::operator=(const valarray<_Tp>& __v) const
    { __valarray_copy (_Array<_Tp> (__v), _M_array, _M_sz, _M_stride); }
    
  template<typename _Tp>
  template<class _Dom>
    inline void
    slice_array<_Tp>::operator=(const _Expr<_Dom,_Tp>& __e) const
    { __valarray_copy (__e, _M_sz, _M_array, _M_stride); }

#undef _DEFINE_VALARRAY_OPERATOR
#define _DEFINE_VALARRAY_OPERATOR(_Op,_Name)				\
template<typename _Tp>							\
inline void								\
slice_array<_Tp>::operator _Op##= (const valarray<_Tp>& __v) const	\
{									\
  _Array_augmented_##_Name (_M_array, _M_sz, _M_stride, _Array<_Tp> (__v));\
}									\
									\
template<typename _Tp> template<class _Dom>				\
inline void								\
slice_array<_Tp>::operator _Op##= (const _Expr<_Dom,_Tp>& __e) const	\
{									\
    _Array_augmented_##_Name (_M_array, _M_stride, __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(^, xor)
_DEFINE_VALARRAY_OPERATOR(&, and)
_DEFINE_VALARRAY_OPERATOR(|, or)
_DEFINE_VALARRAY_OPERATOR(<<, shift_left)
_DEFINE_VALARRAY_OPERATOR(>>, shift_right)

#undef _DEFINE_VALARRAY_OPERATOR

} // std::

#endif /* _CPP_BITS_SLICE_ARRAY_H */

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