vector_view.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2009 - 2016 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 at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------

#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 VectorView : public Vector<Number>
{
public:

  typedef types::global_dof_index size_type;

  VectorView(const size_type new_size, Number *ptr);

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

  ~VectorView();

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

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

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

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



/*----------------------- 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;
  this->val           = 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->val           = 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;
  this->val = 0;
}


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;
  this->val           = 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;
  this->val           = const_cast<Number *>(ptr);
}


template<typename Number>
inline
void VectorView<Number>::swap(Vector<Number> &)
{
  AssertThrow(false, ExcMessage("Cant' swap a VectorView with a Vector!"));
}

#endif

DEAL_II_NAMESPACE_CLOSE

#endif