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Diffstat (limited to 'src/corelib/kernel/qvariant_p.h')
-rw-r--r-- | src/corelib/kernel/qvariant_p.h | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/src/corelib/kernel/qvariant_p.h b/src/corelib/kernel/qvariant_p.h new file mode 100644 index 0000000000..a30d2df5f7 --- /dev/null +++ b/src/corelib/kernel/qvariant_p.h @@ -0,0 +1,153 @@ +/**************************************************************************** +** +** Copyright (C) 2011 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 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> +#include <QtCore/qvariant.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(); + } + +} + +Q_CORE_EXPORT const QVariant::Handler *qcoreVariantHandler(); + +QT_END_NAMESPACE + +#endif // QVARIANT_P_H |