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# qpointer.h

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    00001 /****************************************************************************
    00002 **
    00003 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
    00004 ** All rights reserved.
    00005 ** Contact: Nokia Corporation (qt-info@nokia.com)
    00006 **
    00007 ** This file is part of the QtCore module of the Qt Toolkit.
    00008 **
    00009 ** $QT_BEGIN_LICENSE:LGPL$
    00010 ** Commercial Usage
    00011 ** Licensees holding valid Qt Commercial licenses may use this file in
    00012 ** accordance with the Qt Commercial License Agreement provided with the
    00013 ** Software or, alternatively, in accordance with the terms contained in
    00014 ** a written agreement between you and Nokia.
    00015 **
    00016 ** GNU Lesser General Public License Usage
    00017 ** Alternatively, this file may be used under the terms of the GNU Lesser
    00018 ** General Public License version 2.1 as published by the Free Software
    00019 ** Foundation and appearing in the file LICENSE.LGPL included in the
    00020 ** packaging of this file.  Please review the following information to
    00021 ** ensure the GNU Lesser General Public License version 2.1 requirements
    00022 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
    00023 **
    00024 ** In addition, as a special exception, Nokia gives you certain additional
    00025 ** rights.  These rights are described in the Nokia Qt LGPL Exception
    00026 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this module.
    00027 **
    00028 ** GNU General Public License Usage
    00029 ** Alternatively, this file may be used under the terms of the GNU
    00030 ** General Public License version 3.0 as published by the Free Software
    00031 ** Foundation and appearing in the file LICENSE.GPL included in the
    00032 ** packaging of this file.  Please review the following information to
    00033 ** ensure the GNU General Public License version 3.0 requirements will be
    00034 ** met: http://www.gnu.org/copyleft/gpl.html.
    00035 **
    00036 ** If you have questions regarding the use of this file, please contact
    00037 ** Nokia at qt-info@nokia.com.
    00038 ** $QT_END_LICENSE$
    00039 **
    00040 ****************************************************************************/
    00041
    00042 #ifndef QPOINTER_H
    00043 #define QPOINTER_H
    00044
    00045 #include <QtCore/qobject.h>
    00046
    00047 QT_BEGIN_HEADER
    00048
    00049 QT_BEGIN_NAMESPACE
    00050
    00051 QT_MODULE(Core)
    00052
    00053 template <class T>
    00054 class QPointer
    00055 {
    00056     QObject *o;
    00057 public:
    00058     inline QPointer() : o(0) {}
    00059     inline QPointer(T *p) : o(p)
    00060         { QMetaObject::addGuard(&o); }
    00061     inline QPointer(const QPointer<T> &p) : o(p.o)
    00062         { QMetaObject::addGuard(&o); }
    00063     inline ~QPointer()
    00064         { QMetaObject::removeGuard(&o); }
    00065     inline QPointer<T> &operator=(const QPointer<T> &p)
    00066         { if (this != &p) QMetaObject::changeGuard(&o, p.o); return *this; }
    00067     inline QPointer<T> &operator=(T* p)
    00068         { if (o != p) QMetaObject::changeGuard(&o, p); return *this; }
    00069
    00070     inline bool isNull() const
    00071         { return !o; }
    00072
    00073     inline T* operator->() const
    00074         { return static_cast<T*>(const_cast<QObject*>(o)); }
    00075     inline T& operator*() const
    00076         { return *static_cast<T*>(const_cast<QObject*>(o)); }
    00077     inline operator T*() const
    00078         { return static_cast<T*>(const_cast<QObject*>(o)); }
    00079     inline T* data() const
    00080         { return static_cast<T*>(const_cast<QObject*>(o)); }
    00081 };
    00082
    00083
    00084 #if (!defined(Q_CC_SUN) || (__SUNPRO_CC >= 0x580)) // ambiguity between const T * and T *
    00085
    00086 template <class T>
    00087 inline bool operator==(const T *o, const QPointer<T> &p)
    00088 { return o == p.operator->(); }
    00089
    00090 template<class T>
    00091 inline bool operator==(const QPointer<T> &p, const T *o)
    00092 { return p.operator->() == o; }
    00093
    00094 #else
    00095
    00096 template<class T>
    00097 inline bool operator==(const void *o, const QPointer<T> &p)
    00098 { return o == p.operator->(); }
    00099
    00100 template<class T>
    00101 inline bool operator==(const QPointer<T> &p, const void *o)
    00102 { return p.operator->() == o; }
    00103
    00104 #endif
    00105
    00106 template <class T>
    00107 inline bool operator==(T *o, const QPointer<T> &p)
    00108 { return o == p.operator->(); }
    00109
    00110 template<class T>
    00111 inline bool operator==(const QPointer<T> &p, T *o)
    00112 { return p.operator->() == o; }
    00113
    00114 template<class T>
    00115 inline bool operator==(const QPointer<T> &p1, const QPointer<T> &p2)
    00116 { return p1.operator->() == p2.operator->(); }
    00117
    00118
    00119 #if (!defined(Q_CC_SUN) || (__SUNPRO_CC >= 0x580)) // ambiguity between const T * and T *
    00120
    00121 template <class T>
    00122 inline bool operator!=(const T *o, const QPointer<T> &p)
    00123 { return o != p.operator->(); }
    00124
    00125 template<class T>
    00126 inline bool operator!= (const QPointer<T> &p, const T *o)
    00127 { return p.operator->() != o; }
    00128
    00129 #else
    00130
    00131 template<class T>
    00132 inline bool operator!= (const void *o, const QPointer<T> &p)
    00133 { return o != p.operator->(); }
    00134
    00135 template<class T>
    00136 inline bool operator!= (const QPointer<T> &p, const void *o)
    00137 { return p.operator->() != o; }
    00138
    00139 #endif
    00140
    00141 template <class T>
    00142 inline bool operator!=(T *o, const QPointer<T> &p)
    00143 { return o != p.operator->(); }
    00144
    00145 template<class T>
    00146 inline bool operator!= (const QPointer<T> &p, T *o)
    00147 { return p.operator->() != o; }
    00148
    00149 template<class T>
    00150 inline bool operator!= (const QPointer<T> &p1, const QPointer<T> &p2)
    00151 { return p1.operator->() != p2.operator->() ; }
    00152
    00153 // Make MSVC < 1400 (2005) handle "if (NULL == p)" syntax
    00154 #if defined(Q_CC_MSVC) && (_MSC_VER < 1400)
    00155 template<class T>
    00156 inline bool operator== (int i, const QPointer<T> &p)
    00157 { Q_ASSERT(i == 0); return !i && p.isNull(); }
    00158
    00159 template<class T>
    00160 inline bool operator!= (int i, const QPointer<T> &p)
    00161 { Q_ASSERT(i == 0); return !i && !p.isNull(); }
    00162 #endif
    00163
    00164 QT_END_NAMESPACE
    00165
    00166 QT_END_HEADER
    00167
    00168 #endif // QPOINTER_H