vector_view.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2009 - 2018 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, redistribute
// it, and/or modify it under the terms of the GNU Lesser General
// Public License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
// The full text of the license can be found in the file LICENSE.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------

#ifndef dealii_vector_view_h
#define dealii_vector_view_h


#include <deal.II/base/config.h>

#include <deal.II/base/exceptions.h>
#include <deal.II/base/subscriptor.h>

#include <deal.II/lac/vector.h>

#include <cstdio>

DEAL_II_NAMESPACE_OPEN


template <typename Number>
class DEAL_II_DEPRECATED VectorView : public Vector<Number>
{
public:
  using size_type = types::global_dof_index;

  VectorView(const size_type new_size, Number *ptr);

  VectorView(const size_type new_size, const Number *ptr);

  ~VectorView() override;

  virtual void
  reinit(const size_type N, const bool omit_zeroing_entries = false) override;

  void
  reinit(const size_type N, Number *ptr);

  void
  reinit(const size_type N, const Number *ptr);

  virtual void
  swap(Vector<Number> &v) override;
};



/*----------------------- Inline functions ----------------------------------*/

#ifndef DOXYGEN

template <typename Number>
inline VectorView<Number>::VectorView(const size_type new_size, Number *ptr)
{
  this->vec_size     = new_size;
  this->max_vec_size = new_size;
  // release the pointer, but do not delete the object pointed to
  this->values.release();
  this->values.reset(ptr);
}



template <typename Number>
inline VectorView<Number>::VectorView(const size_type new_size,
                                      const Number *  ptr)
{
  this->vec_size     = new_size;
  this->max_vec_size = new_size;
  this->values.reset(const_cast<Number *>(ptr));
}



template <typename Number>
inline VectorView<Number>::~VectorView()
{
  // avoid that the base class releases
  // memory it doesn't own
  this->vec_size     = 0;
  this->max_vec_size = 0;

  // release the pointer, but do not delete the object pointed to
  this->values.release();
}


template <typename Number>
inline void
VectorView<Number>::reinit(const size_type N, const bool omit_zeroing_entries)
{
  this->vec_size     = N;
  this->max_vec_size = N;
  if (omit_zeroing_entries == false)
    Vector<Number>::operator=(static_cast<Number>(0));
}


template <typename Number>
inline void
VectorView<Number>::reinit(const size_type new_size, Number *ptr)
{
  this->vec_size     = new_size;
  this->max_vec_size = new_size;
  // release the pointer, but do not delete the object pointed to
  this->values.release();
  this->values.reset(ptr);
}


template <typename Number>
inline void
VectorView<Number>::reinit(const size_type new_size, const Number *ptr)
{
  this->vec_size     = new_size;
  this->max_vec_size = new_size;
  // release the pointer, but do not delete the object pointed to
  this->values.release();
  this->values.reset(const_cast<Number *>(ptr));
}


template <typename Number>
inline void
VectorView<Number>::swap(Vector<Number> &)
{
  AssertThrow(false, ExcMessage("Can't swap a VectorView with a Vector!"));
}

#endif

DEAL_II_NAMESPACE_CLOSE

#endif