On Sat, Aug 18, 2012 at 09:29:53PM +0300, Nikos Chantziaras wrote: > On 18/08/12 20:46, K. Frank wrote: > > [...] > > This does raise one c++ / Qt question for me: When an automatic > > variable goes out of scope, its destructor is called (and, at some > > point, the stack is popped, but not by the destructor nor by any > > explicit user code). When a heap variable is deleted, its destructor > > is called, and the equivalent of free is called. The point is delete > > is not called (in correct code) on automatic variables. > > > > How can the Qt parent-child system work with both automatic and > > heap variables as children? When a child object registers itself > > with its parent (e.g., by being passed a pointer to its parent in its > > constructor), neither the child object nor the parent knows whether > > the child is an automatic or heap variable (and, using portable > > standard c++, can't know). So how can the parent know (when the > > parent is destroyed) whether to call the child's destructor directly or > > to call delete on the child? > > Qt doesn't detect this. Your application will crash. So don't do it :-) > > On a similar note, don't delete QObject instances manually. Call their > deleteLater() member function instead.
There are only rare cases where deleteLater is needed. Otherwise, using it is unneeded overhead. Andre' _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
