auto_ptr.h

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// The libMesh Finite Element Library.
// Copyright (C) 2002-2014 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner

// This library is free software; you can 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.

// 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
// Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#ifndef LIBMESH_AUTO_PTR_H
#define LIBMESH_AUTO_PTR_H

#include "libmesh/libmesh_config.h"
#include "libmesh_common.h" // for libmesh_deprecated()

// LibMesh's AutoPtr is now libmesh_deprecated(), just like the
// std::auto_ptr it is based on.
//
// New library code should use the UniquePtr typedef (which will
// eventually be a C++11 alias declaration).  LibMesh's UniquePtr is
// one of:
// 1.) std::unique_ptr
// 2.) Howard Hinnant's C++03 compatible boost::unique_ptr
// 3.) The deprecated libMesh AutoPtr
// in that order, depending on what your compiler supports.  If you
// are using a compiler that cannot compile Howard Hinnant's
// unique_ptr implementation, you should probably think about
// upgrading.
#ifdef LIBMESH_ENABLE_UNIQUE_PTR
  #ifdef LIBMESH_HAVE_CXX11_UNIQUE_PTR
  #  include <memory>
  #  define UniquePtr std::unique_ptr
  #elif LIBMESH_HAVE_HINNANT_UNIQUE_PTR
  #  include "libmesh/unique_ptr.hpp"
  #  define UniquePtr boost::unique_ptr
  #else
  #  define UniquePtr libMesh::AutoPtr
  #endif
#else
  // libMesh was configured with --disable-unique-ptr, so we'll use
  // libMesh's AutoPtr class instead.
  #define UniquePtr libMesh::AutoPtr
#endif

namespace libMesh
{

template<typename Tp1>
struct AutoPtrRef
{
  Tp1* _ptr;

  explicit
  AutoPtrRef(Tp1* p)
    : _ptr(p) {}
};


template<typename Tp>
class AutoPtr
{
private:

  Tp* _ptr;

public:
  typedef Tp element_type;

  explicit
  AutoPtr(element_type* p = 0)
    : _ptr(p)
  {
    // Note: we can't call libmesh_deprecated() here, since global
    // AutoPtr variables are sometimes created before the libMesh::out
    // stream is ready.
  }

  AutoPtr(AutoPtr& a)
    : _ptr(a.release())
  {
  }

  template<typename Tp1>
  AutoPtr(AutoPtr<Tp1>& a)
    : _ptr(a.release())
  {
  }

  AutoPtr&
  operator=(AutoPtr& a)
  {
    reset(a.release());
    return *this;
  }

  template <typename Tp1>
  AutoPtr&
  operator=(AutoPtr<Tp1>& a)
  {
    reset(a.release());
    return *this;
  }

  ~AutoPtr()
  {
    if (!libMesh::warned_about_auto_ptr)
      {
        libMesh::warned_about_auto_ptr = true;
        libMesh::out << "*** Warning, AutoPtr is deprecated and will be removed in a future library version! "
                     << __FILE__ << ", line " << __LINE__ << ", compiled " << __DATE__ << " at " << __TIME__ << " ***" << std::endl;
      }
    delete _ptr;
  }

  element_type&
  operator*() const  { return *_ptr; }

  element_type*
  operator->() const  { return _ptr; }

  element_type*
  get() const  { return _ptr; }

  element_type*
  release()
  {
    element_type* tmp = _ptr;
    _ptr = 0;
    return tmp;
  }

  void
  reset(element_type* p = 0)
  {
    if (p != _ptr)
      {
        delete _ptr;
        _ptr = p;
      }
  }

  AutoPtr(AutoPtrRef<element_type> ref)
    : _ptr(ref._ptr) {}

  AutoPtr&
  operator=(AutoPtrRef<element_type> ref)
  {
    if (ref._ptr != this->get())
      {
        delete _ptr;
        _ptr = ref._ptr;
      }
    return *this;
  }

  template<typename Tp1>
  operator AutoPtrRef<Tp1>()
  { return AutoPtrRef<Tp1>(this->release()); }

  template<typename Tp1>
  operator AutoPtr<Tp1>()
  { return AutoPtr<Tp1>(this->release()); }
};



} // namespace libMesh

#endif // LIBMESH_AUTO_PTR_H