XdlOrm/include/QxTraits/construct_ptr.h

/****************************************************************************
**
** https://www.qxorm.com/
** Copyright (C) 2013 XDL Team (ic-east.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
**
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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 XDL Team
**
** 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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#ifndef _QX_CONSTRUCT_PTR_H_
#define _QX_CONSTRUCT_PTR_H_

#ifdef _MSC_VER
#pragma once
#endif

/*!
 * \file construct_ptr.h
 * \author XDL Team
 * \ingroup QxTraits
 * \brief qx::trait::construct_ptr<T>::get(T & t, bool bReset = false) : instantiate (or reset) a new pointer, support both nude-pointer and smart-pointer of boost, Qt and QxOrm libraries
 */

#include <QtCore/qsharedpointer.h>

#if (QT_VERSION >= QT_VERSION_CHECK(4, 6, 0))
#include <QtCore/qscopedpointer.h>
#endif // (QT_VERSION >= QT_VERSION_CHECK(4, 6, 0))

#include <QxDao/QxDaoPointer.h>

namespace qx
{
   namespace trait
   {

      /*!
       * \ingroup QxTraits
       * \brief qx::trait::construct_ptr<T>::get(T & t, bool bReset = false) : instantiate (or reset) a new pointer, support both nude-pointer and smart-pointer of boost, Qt and QxOrm libraries
       */
      template <typename T>
      struct construct_ptr
      {

      private:
         typedef typename std::remove_pointer<T>::type type_ptr;

      public:
         static inline void get(T &t, bool bReset = false)
         {
            new_ptr<std::is_abstract<type_ptr>::value, 0>::get(t, bReset);
         }

      private:
         template <bool isAbstract /* = false */, int dummy>
         struct new_ptr
         {
            static inline void get(T &t, bool bReset)
            {
               if (bReset)
               {
                  t = NULL;
               }
               else
               {
                  t = new type_ptr();
               }
            }
         };

         template <int dummy>
         struct new_ptr<true, dummy>
         {
            static inline void get(T &t, bool bReset)
            {
               Q_UNUSED(t);
               Q_UNUSED(bReset);
               qDebug("[QxOrm] qx::trait::construct_ptr<T> : %s", "cannot instantiate abstract class");
            }
         };
      };

#ifdef _QX_ENABLE_BOOST

      template <typename T>
      struct construct_ptr<boost::scoped_ptr<T>>
      {
         static inline void get(boost::scoped_ptr<T> &t, bool bReset = false)
         {
            if (bReset)
            {
               t.reset();
            }
            else
            {
               t.reset(new T());
            }
         }
      };

      template <typename T>
      struct construct_ptr<boost::shared_ptr<T>>
      {
         static inline void get(boost::shared_ptr<T> &t, bool bReset = false)
         {
            if (bReset)
            {
               t.reset();
            }
            else
            {
               t.reset(new T());
            }
         }
      };

      template <typename T>
      struct construct_ptr<boost::intrusive_ptr<T>>
      {
         static inline void get(boost::intrusive_ptr<T> &t, bool bReset = false)
         {
            if (bReset)
            {
               t.reset();
            }
            else
            {
               t.reset(new T());
            }
         }
      };

#endif // _QX_ENABLE_BOOST

      template <typename T>
      struct construct_ptr<QSharedPointer<T>>
      {
         static inline void get(QSharedPointer<T> &t, bool bReset = false)
         {
            if (bReset)
            {
               t = QSharedPointer<T>();
            }
            else
            {
               t = QSharedPointer<T>(new T());
            }
         }
      };

#if (QT_VERSION >= QT_VERSION_CHECK(4, 6, 0))
      template <typename T>
      struct construct_ptr<QScopedPointer<T>>
      {
         static inline void get(QScopedPointer<T> &t, bool bReset = false)
         {
            if (bReset)
            {
               t = QScopedPointer<T>();
            }
            else
            {
               t = QScopedPointer<T>(new T());
            }
         }
      };
#endif // (QT_VERSION >= QT_VERSION_CHECK(4, 6, 0))

      template <typename T>
      struct construct_ptr<qx::dao::ptr<T>>
      {
         static inline void get(qx::dao::ptr<T> &t, bool bReset = false)
         {
            if (bReset)
            {
               t = qx::dao::ptr<T>();
            }
            else
            {
               t = qx::dao::ptr<T>(new T());
            }
         }
      };

      template <typename T>
      struct construct_ptr<std::unique_ptr<T>>
      {
         static inline void get(std::unique_ptr<T> &t, bool bReset = false)
         {
            if (bReset)
            {
               t.reset();
            }
            else
            {
               t.reset(new T());
            }
         }
      };

      template <typename T>
      struct construct_ptr<std::shared_ptr<T>>
      {
         static inline void get(std::shared_ptr<T> &t, bool bReset = false)
         {
            if (bReset)
            {
               t.reset();
            }
            else
            {
               t = std::make_shared<T>();
            }
         }
      };

   } // namespace trait
} // namespace qx

#endif // _QX_CONSTRUCT_PTR_H_