passing by reference... my darkest enemy
actual reason below:
In your case (without reference) the compiler generates a temporary object (int) for the first argument of your MyApplication constructor. You pass this temporary int to QApplication’s constructor (with int reference), which saves the address of this reference. Once your MyApplication constructor is done the temporary int is destroyed but QApplication still has its address.
/*
* Hedgewars, a free turn based strategy game
* Copyright (c) 2006-2007 Ulyanov Igor <iulyanov@gmail.com>
* Copyright (c) 2007-2011 Andrey Korotaev <unC0Rr@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifndef _HEDGEHOGER_WIDGET
#define _HEDGEHOGER_WIDGET
#include "itemNum.h"
class FrameTeams;
class CHedgehogerWidget : public ItemNum
{
Q_OBJECT
public:
CHedgehogerWidget(const QImage& im, const QImage& img, QWidget * parent);
virtual ~CHedgehogerWidget();
unsigned char getHedgehogsNum() const;
void setHHNum (unsigned int num);
void setNonInteractive();
signals:
void hedgehogsNumChanged();
protected:
virtual void incItems();
virtual void decItems();
private:
CHedgehogerWidget();
FrameTeams* pOurFrameTeams;
};
#endif // _HEDGEHOGER_WIDGET