QSharedPointer reset()

Redman

qDebug() << "START";
for (int i = 0; i < 5; i++) {
   if (list.length() >= 1)
      qDebug() << list.last().data()->objectName();

   QSharedPointer<QObject> tmp = QSharedPointer<QObject>(new QObject());
   tmp.data()->setObjectName("Test");

   list.append(QSharedPointer<QObject>(new QObject()));
   list.last().reset(tmp.data());
}
qDebug() << "END";

Please explain to me, why the objectName 'Test' is lost on the list entry. When tmp is destructed the name gets lost, even though I set the list entry to point to the same QObject

Btw, when qDebug() is called, the program crashes

jsulm

@Redman The problem is that after reset you have two different shared pointers pointing to same data. As soon as tmp is deleted (on next loop iteration) it deletes the data it points to. Instead of reset use swap(...).

Asperamanca

@Redman
Not sure about the object name. But the code is suspicious in any case: Both tmp and list.last() are now owners of the same object. I think what you want is list.last() = tmp, no?

jsulm

@Redman The problem is that after reset you have two different shared pointers pointing to same data. As soon as tmp is deleted (on next loop iteration) it deletes the data it points to. Instead of reset use swap(...).