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/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** 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 either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** 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 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://www.qtsoftware.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QVARIANT_P_H
#define QVARIANT_P_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
// takes a type, returns the internal void* pointer cast
// to a pointer of the input type
#include <QtCore/qglobal.h>
QT_BEGIN_NAMESPACE
#ifdef Q_CC_SUN // Sun CC picks the wrong overload, so introduce awful hack
template <typename T>
inline T *v_cast(const QVariant::Private *nd, T * = 0)
{
QVariant::Private *d = const_cast<QVariant::Private *>(nd);
return ((sizeof(T) > sizeof(QVariant::Private::Data))
? static_cast<T *>(d->data.shared->ptr)
: static_cast<T *>(static_cast<void *>(&d->data.c)));
}
#else // every other compiler in this world
template <typename T>
inline const T *v_cast(const QVariant::Private *d, T * = 0)
{
return ((sizeof(T) > sizeof(QVariant::Private::Data))
? static_cast<const T *>(d->data.shared->ptr)
: static_cast<const T *>(static_cast<const void *>(&d->data.c)));
}
template <typename T>
inline T *v_cast(QVariant::Private *d, T * = 0)
{
return ((sizeof(T) > sizeof(QVariant::Private::Data))
? static_cast<T *>(d->data.shared->ptr)
: static_cast<T *>(static_cast<void *>(&d->data.c)));
}
#endif
//a simple template that avoids to allocate 2 memory chunks when creating a QVariant
template <class T> class QVariantPrivateSharedEx : public QVariant::PrivateShared
{
public:
QVariantPrivateSharedEx() : QVariant::PrivateShared(&m_t) { }
QVariantPrivateSharedEx(const T&t) : QVariant::PrivateShared(&m_t), m_t(t) { }
private:
T m_t;
};
// constructs a new variant if copy is 0, otherwise copy-constructs
template <class T>
inline void v_construct(QVariant::Private *x, const void *copy, T * = 0)
{
if (sizeof(T) > sizeof(QVariant::Private::Data)) {
x->data.shared = copy ? new QVariantPrivateSharedEx<T>(*static_cast<const T *>(copy))
: new QVariantPrivateSharedEx<T>;
x->is_shared = true;
} else {
if (copy)
new (&x->data.ptr) T(*static_cast<const T *>(copy));
else
new (&x->data.ptr) T;
}
}
template <class T>
inline void v_construct(QVariant::Private *x, const T &t)
{
if (sizeof(T) > sizeof(QVariant::Private::Data)) {
x->data.shared = new QVariantPrivateSharedEx<T>(t);
x->is_shared = true;
} else {
new (&x->data.ptr) T(t);
}
}
// deletes the internal structures
template <class T>
inline void v_clear(QVariant::Private *d, T* = 0)
{
if (sizeof(T) > sizeof(QVariant::Private::Data)) {
//now we need to cast
//because QVariant::PrivateShared doesn't have a virtual destructor
delete static_cast<QVariantPrivateSharedEx<T>*>(d->data.shared);
} else {
v_cast<T>(d)->~T();
}
}
QT_END_NAMESPACE
#endif // QVARIANT_P_H
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