/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtCore module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#ifndef QPOINTER_H

#define QPOINTER_H

#include <QtCore/qobject.h>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Core)

template <class T>

class QPointer

{

    QObject *o;

public:

    inline QPointer() : o(0) {}

    inline QPointer(T *p) : o(p)

        { QMetaObject::addGuard(&o); }

    inline QPointer(const QPointer<T> &p) : o(p.o)

        { QMetaObject::addGuard(&o); }

    inline ~QPointer()

        { QMetaObject::removeGuard(&o); }

    inline QPointer<T> &operator=(const QPointer<T> &p)

        { if (this != &p) QMetaObject::changeGuard(&o, p.o); return *this; }

    inline QPointer<T> &operator=(T* p)

        { if (o != p) QMetaObject::changeGuard(&o, p); return *this; }

    inline bool isNull() const

        { return !o; }

    inline T* operator->() const

        { return static_cast<T*>(const_cast<QObject*>(o)); }

    inline T& operator*() const

        { return *static_cast<T*>(const_cast<QObject*>(o)); }

    inline operator T*() const

        { return static_cast<T*>(const_cast<QObject*>(o)); }

    inline T* data() const

        { return static_cast<T*>(const_cast<QObject*>(o)); }

};

#if (!defined(Q_CC_SUN) || (__SUNPRO_CC >= 0x580)) // ambiguity between const T * and T *

template <class T>

inline bool operator==(const T *o, const QPointer<T> &p)

{ return o == p.operator->(); }

template<class T>

inline bool operator==(const QPointer<T> &p, const T *o)

{ return p.operator->() == o; }

#else

template<class T>

inline bool operator==(const void *o, const QPointer<T> &p)

{ return o == p.operator->(); }

template<class T>

inline bool operator==(const QPointer<T> &p, const void *o)

{ return p.operator->() == o; }

#endif

template <class T>

inline bool operator==(T *o, const QPointer<T> &p)

{ return o == p.operator->(); }

template<class T>

inline bool operator==(const QPointer<T> &p, T *o)

{ return p.operator->() == o; }

template<class T>

inline bool operator==(const QPointer<T> &p1, const QPointer<T> &p2)

{ return p1.operator->() == p2.operator->(); }

#if (!defined(Q_CC_SUN) || (__SUNPRO_CC >= 0x580)) // ambiguity between const T * and T *

template <class T>

inline bool operator!=(const T *o, const QPointer<T> &p)

{ return o != p.operator->(); }

template<class T>

inline bool operator!= (const QPointer<T> &p, const T *o)

{ return p.operator->() != o; }

#else

template<class T>

inline bool operator!= (const void *o, const QPointer<T> &p)

{ return o != p.operator->(); }

template<class T>

inline bool operator!= (const QPointer<T> &p, const void *o)

{ return p.operator->() != o; }

#endif

template <class T>

inline bool operator!=(T *o, const QPointer<T> &p)

{ return o != p.operator->(); }

template<class T>

inline bool operator!= (const QPointer<T> &p, T *o)

{ return p.operator->() != o; }

template<class T>

inline bool operator!= (const QPointer<T> &p1, const QPointer<T> &p2)

{ return p1.operator->() != p2.operator->() ; }

// Make MSVC < 1400 (2005) handle "if (NULL == p)" syntax

#if defined(Q_CC_MSVC) && (_MSC_VER < 1400)

template<class T>

inline bool operator== (int i, const QPointer<T> &p)

{ Q_ASSERT(i == 0); return !i && p.isNull(); }

template<class T>

inline bool operator!= (int i, const QPointer<T> &p)

{ Q_ASSERT(i == 0); return !i && !p.isNull(); }

#endif

QT_END_NAMESPACE

QT_END_HEADER

#endif // QPOINTER_H