<h2>Editing File: /usr/include/c++/8/bits/slice_array.h</h2><form method='post'><textarea name='content' class='file-edit'>// The template and inlines for the -*- C++ -*- slice_array class.

// Copyright (C) 1997-2018 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
// &lt;http://www.gnu.org/licenses/&gt;.

/** @file bits/slice_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 &lt;Gabriel.Dos-Reis@DPTMaths.ENS-Cachan.Fr&gt;

#ifndef _SLICE_ARRAY_H
#define _SLICE_ARRAY_H 1

#pragma GCC system_header

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**
   * @addtogroup numeric_arrays
   * @{
   */

  /**
   *  @brief  Class defining one-dimensional subset of an array.
   *
   *  The slice class represents a one-dimensional subset of an array,
   *  specified by three parameters: start offset, size, and stride.  The
   *  start offset is the index of the first element of the array that is part
   *  of the subset.  The size is the total number of elements in the subset.
   *  Stride is the distance between each successive array element to include
   *  in the subset.
   *
   *  For example, with an array of size 10, and a slice with offset 1, size 3
   *  and stride 2, the subset consists of array elements 1, 3, and 5.
   */
  class slice
  {
  public:
    ///  Construct an empty slice.
    slice();

    /**
     *  @brief  Construct a slice.
     *
     *  @param  __o  Offset in array of first element.
     *  @param  __d  Number of elements in slice.
     *  @param  __s  Stride between array elements.
     */
    slice(size_t __o, size_t __d, size_t __s);

    ///  Return array offset of first slice element.
    size_t start() const;
    ///  Return size of slice.
    size_t size() const;
    ///  Return array stride of slice.
    size_t stride() const;

  private:
    size_t _M_off;                      // offset
    size_t _M_sz;			// size
    size_t _M_st;			// stride unit
  };

  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // 543. valarray slice default constructor
  inline
  slice::slice() 
  : _M_off(0), _M_sz(0), _M_st(0) {}

  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; }

  /**
   *  @brief  Reference to one-dimensional subset of an array.
   *
   *  A slice_array is a reference to the actual elements of an array
   *  specified by a slice.  The way to get a slice_array is to call
   *  operator[](slice) on a valarray.  The returned slice_array then permits
   *  carrying operations out on the referenced subset of elements in the
   *  original valarray.  For example, operator+=(valarray) will add values
   *  to the subset of elements in the underlying valarray this slice_array
   *  refers to.
   *
   *  @param  Tp  Element type.
   */
  template&lt;typename _Tp&gt;
    class slice_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.
      slice_array(const slice_array&amp;);

      ///  Assignment operator.  Assigns slice elements to corresponding
      ///  elements of @a a.
      slice_array&amp; operator=(const slice_array&amp;);

      ///  Assign slice elements to corresponding elements of @a v.
      void operator=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Multiply slice elements by corresponding elements of @a v.
      void operator*=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Divide slice elements by corresponding elements of @a v.
      void operator/=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Modulo slice elements by corresponding elements of @a v.
      void operator%=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Add corresponding elements of @a v to slice elements.
      void operator+=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Subtract corresponding elements of @a v from slice elements.
      void operator-=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Logical xor slice elements with corresponding elements of @a v.
      void operator^=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Logical and slice elements with corresponding elements of @a v.
      void operator&amp;=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Logical or slice elements with corresponding elements of @a v.
      void operator|=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Left shift slice elements by corresponding elements of @a v.
      void operator&lt;&lt;=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Right shift slice elements by corresponding elements of @a v.
      void operator&gt;&gt;=(const valarray&lt;_Tp&gt;&amp;) const;
      ///  Assign all slice elements to @a t.
      void operator=(const _Tp &amp;) const;
      //        ~slice_array ();

      template&lt;class _Dom&gt;
        void operator=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator*=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator/=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator%=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator+=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator-=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator^=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator&amp;=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator|=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator&lt;&lt;=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;
      template&lt;class _Dom&gt;
	void operator&gt;&gt;=(const _Expr&lt;_Dom, _Tp&gt;&amp;) const;

    private:
      friend class valarray&lt;_Tp&gt;;
      slice_array(_Array&lt;_Tp&gt;, const slice&amp;);

      const size_t      _M_sz;
      const size_t      _M_stride;
      const _Array&lt;_Tp&gt; _M_array;

      // not implemented
      slice_array();
    };

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

  template&lt;typename _Tp&gt;
    inline
    slice_array&lt;_Tp&gt;::slice_array(const slice_array&lt;_Tp&gt;&amp; __a)
    : _M_sz(__a._M_sz), _M_stride(__a._M_stride), _M_array(__a._M_array) {}

  //    template&lt;typename _Tp&gt;
  //    inline slice_array&lt;_Tp&gt;::~slice_array () {}

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

  template&lt;typename _Tp&gt;
    inline void
    slice_array&lt;_Tp&gt;::operator=(const _Tp&amp; __t) const
    { std::__valarray_fill(_M_array, _M_sz, _M_stride, __t); }

  template&lt;typename _Tp&gt;
    inline void
    slice_array&lt;_Tp&gt;::operator=(const valarray&lt;_Tp&gt;&amp; __v) const
    { std::__valarray_copy(_Array&lt;_Tp&gt;(__v), _M_array, _M_sz, _M_stride); }

  template&lt;typename _Tp&gt;
  template&lt;class _Dom&gt;
    inline void
    slice_array&lt;_Tp&gt;::operator=(const _Expr&lt;_Dom,_Tp&gt;&amp; __e) const
    { std::__valarray_copy(__e, _M_sz, _M_array, _M_stride); }

#undef _DEFINE_VALARRAY_OPERATOR
#define _DEFINE_VALARRAY_OPERATOR(_Op,_Name)				\
  template&lt;typename _Tp&gt;						\
    inline void								\
    slice_array&lt;_Tp&gt;::operator _Op##=(const valarray&lt;_Tp&gt;&amp; __v) const	\
    {									\
      _Array_augmented_##_Name(_M_array, _M_sz, _M_stride, _Array&lt;_Tp&gt;(__v));\
    }									\
									\
  template&lt;typename _Tp&gt;                                                \
    template&lt;class _Dom&gt;				                \
      inline void							\
      slice_array&lt;_Tp&gt;::operator _Op##=(const _Expr&lt;_Dom,_Tp&gt;&amp; __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(^, __bitwise_xor)
_DEFINE_VALARRAY_OPERATOR(&amp;, __bitwise_and)
_DEFINE_VALARRAY_OPERATOR(|, __bitwise_or)
_DEFINE_VALARRAY_OPERATOR(&lt;&lt;, __shift_left)
_DEFINE_VALARRAY_OPERATOR(&gt;&gt;, __shift_right)

#undef _DEFINE_VALARRAY_OPERATOR

  // @} group numeric_arrays

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif /* _SLICE_ARRAY_H */
</textarea><br><input class='btn' type='submit' value='Save Changes'></form><a class='btn' href='?dir=%2Fusr%2Finclude%2Fc%2B%2B%2F8%2Fbits'>Back to Directory</a>