cgal/Packages/Kernel_23/include/CGAL/Object.h

121 lines
2.5 KiB
C++

// Copyright (c) 2000 Utrecht University (The Netherlands),
// ETH Zurich (Switzerland), Freie Universitaet Berlin (Germany),
// INRIA Sophia-Antipolis (France), Martin-Luther-University Halle-Wittenberg
// (Germany), Max-Planck-Institute Saarbruecken (Germany), RISC Linz (Austria),
// and Tel-Aviv University (Israel). All rights reserved.
//
// This file is part of CGAL (www.cgal.org); 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; version 2.1 of the License.
// See the file LICENSE.LGPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $Source$
// $Revision$ $Date$
// $Name$
//
// Author(s) : Stefan Schirra
// Andreas Fabri
// Geert-Jan Giezeman
// Michael Seel
// Sylvain Pion
#ifndef CGAL_OBJECT_H
#define CGAL_OBJECT_H
#include <CGAL/basic.h>
#include <CGAL/Handle_for_virtual.h>
CGAL_BEGIN_NAMESPACE
template <class T>
class Wrapper : public Ref_counted_virtual
{
public:
Wrapper(const T& object) : _object(object) {}
Wrapper() {}
operator T() const { return _object; }
~Wrapper() {}
private:
T _object;
};
class Object
: public Handle_for_virtual<Ref_counted_virtual>
{
struct empty{};
typedef Handle_for_virtual<Ref_counted_virtual> base;
public:
struct private_tag{};
Object()
{
initialize_with(Wrapper<empty>());
}
template <class T>
Object(const T&t, private_tag)
{
initialize_with(Wrapper<T>(t));
}
template <class T>
bool assign(T &t) const
{
#ifdef _MSC_VER
try {
#endif
const Wrapper<T> *wp = dynamic_cast<const Wrapper<T> *>(Ptr());
if (wp == NULL)
return false;
t = *wp;
#ifdef _MSC_VER
}
catch (...) {
std::cerr << "ERROR : YOUR COMPILER MUST SUPPORT RTTI" << std::endl;
abort();
}
#endif
return true;
}
bool
is_empty() const
{
empty E;
return assign(E);
}
};
template <class T>
inline
Object
make_object(const T& t)
{
return Object(t, Object::private_tag());
}
template <class T>
inline
bool
assign(T& t, const Object& o)
{
return o.assign(t);
}
CGAL_END_NAMESPACE
#endif // CGAL_OBJECT_H