Assuming I have the following snippet, is it safe to call deleteLater in qto's destructor for other QT objects it might administer?
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MyQTObject qto;
qto.show();
return a.exec();
}
Because I've analyzed similar code like this with a leak detector and all the objects for which deleteLater was called, weren't deallocated correctly unless I replaced the call with a normal delete. If I've understood this correctly, deleteLater only registers a deletion event in the QT message queue. Can this be the problem that qto's destructor is called at the end of main's scope whereas the QT message loop already ends with the return from a.exec? Thus the deletion event will never be processed, in fact not even pushed into a message queue since there is none?
As I understand it, deleteLater is most often used when you require an object to be deleted from within the call to a slot. If delete is used in this case and the object is referenced when returning from the slot, a reference to uninitialised memory occurs.
Therefore, deleteLater requests that object to be deleted by placing a message on the event loop, which is processed at some point, on returning from the slot and it is safe to be deleted.
I expect that using deleteLater in the destructor means there's a likely chance that the object goes out of scope, calls deleteLater on its managed objects, but quits before the event loop has a chance to delete the objects, as exiting from QApplication::exec() will terminate the event loop.