#include <QtCore/QSharedPointer>
#include <QtCore/QDebug>

struct A
{
	A() { qDebug() << "\tA()"; }
	virtual ~A() { qDebug() << "\t~A()"; }
};

struct B { virtual ~B() { } };

int main(int argc, char * argv[])
{
	Q_UNUSED(argc);
	Q_UNUSED(argv);
	
	qDebug() << "Failed dynamic cast from a into b; destroy b before a:";
	qDebug() << "{";
	{
		QSharedPointer<A> a(new A);
		QSharedPointer<B> b = a.dynamicCast<B>(); // failed dynamic cast
		b.clear();
		a.clear();
	}
	qDebug() << "}";
	
	qDebug() << "\nFailed dynamic cast from a into b; destroy a before b:";
	qDebug() << "{";
	{
		QSharedPointer<A> a(new A);
		QSharedPointer<B> b = a.dynamicCast<B>(); // failed dynamic cast
		a.clear();
		b.clear();
	}
	qDebug() << "}";
	
	return 0;
}