nullObject.H

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License
    This file is part of OpenFOAM.
 
    OpenFOAM 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 of the License, or
    (at your option) any later version.
 
    OpenFOAM 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.
 
    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::NullObject
 
Description
    Singleton null-object class and instance
 
SourceFiles
    nullObjectI.H
    nullObject.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef nullObject_H
#define nullObject_H
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                         Class nullObject Declaration
\*---------------------------------------------------------------------------*/
 
class NullObject
{
    //- Private constructor
    NullObject()
    {}
 
public:
 
    //- The unique null object
    static const NullObject nullObject;
 
    //- Disallow default bitwise copy construction
    NullObject(const NullObject&) = delete;
 
    //- Disallow default bitwise assignment
    void operator=(const NullObject&) = delete;
};
 
 
//- Pointer to the unique nullObject
extern const NullObject* nullObjectPtr;
 
 
//- Return const reference to the nullObject of type T
template<class T>
inline const T& NullObjectRef();
 
//- Return const pointer to the nullObject of type T
template<class T>
inline const T* NullObjectConstPtr();
 
//- Return pointer to the nullObject of type T
template<class T>
inline T* NullObjectPtr();
 
//- Return reference to the nullObject of type T
template<class T>
inline T&& NullObjectMove();
 
 
//- Return true if t is a reference to the nullObject of type T
template<class T>
inline bool isNull(const T& t);
 
//- Return true if t is not a reference to the nullObject of type T
template<class T>
inline bool notNull(const T& t);
 
 
//- Return true if t is a pointer to the nullObject of type T
template<class T>
inline bool isNull(const T* t);
 
//- Return true if t is not a pointer to the nullObject of type T
template<class T>
inline bool notNull(const T* t);
 
 
//- Return true if t is a pointer to the nullObject of type T
template<class T>
inline bool isNull(T* t);
 
//- Return true if t is not a pointer to the nullObject of type T
template<class T>
inline bool notNull(T* t);
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#include "nullObjectI.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //