DataManage/libs/QxOrm/include/QxTraits/qt_meta_object.h

/****************************************************************************
**
** https://www.qxorm.com/
** Copyright (C) 2013 Lionel Marty (contact@qxorm.com)
**
** This file is part of the QxOrm library
**
** This software is provided 'as-is', without any express or implied
** warranty. In no event will the authors be held liable for any
** damages arising from the use of this software
**
** Commercial Usage
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** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Lionel Marty
**
** 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.gpl3.txt' 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
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** If you are unsure which license is appropriate for your use, or
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#ifndef _QX_QT_META_OBJECT_H_
#define _QX_QT_META_OBJECT_H_

#ifdef _MSC_VER
#pragma once
#endif

/*!
 * \file qt_meta_object.h
 * \author Lionel Marty
 * \ingroup QxTraits
 * \brief qx::trait::qt_meta_object<T>::get() : if T is based on QObject class, then return QMetaObject instance of Qt introspection engine, else return NULL
 */

#include <QtCore/qmetaobject.h>
#include <QtCore/qmetatype.h>

namespace qx {
namespace trait {

/*!
 * \ingroup QxTraits
 * \brief qx::trait::qt_meta_object<T>::get() : if T is based on QObject class, then return QMetaObject instance of Qt introspection engine, else return NULL
 */
template <typename T>
class qt_meta_object
{

public:

   enum { is_valid = (std::is_base_of<QObject, T>::value) };

   static const QMetaObject * get()
   { return qtMetaObject<qt_meta_object<T>::is_valid, 0>::get(); }

private:

   template <bool isQObject /* = false */, int dummy>
   struct qtMetaObject
   { static inline const QMetaObject * get() { return NULL; } };

   template <int dummy>
   struct qtMetaObject<true, dummy>
   { static inline const QMetaObject * get() { return (& T::staticMetaObject); } };

};

} // namespace trait
} // namespace qx

#endif // _QX_QT_META_OBJECT_H_