On Wed, Jun 13, 2012 at 11:35:16PM +0200, Jan Kundrát wrote: > Hi Jochen, > > On 06/13/12 22:50, Jochen Becher wrote: > > Of course it is not a bad idea to access siblings in a destructor. Why > > should it? If destruction follows in a known and reliable way there is > > no reason to avoid it. I do it to check some post-conditions using > > Q_ASSERT() to ensure all resources were freed and that involves some > > checks in siblings. > > QObject's children are destroyed in an order which is not specified, > hence it's a bad idea to access "siblings" in a QObject's destructor. > > In certain circumstances, a solution which uses QPointer can be handy, > ie. when you just want to take an optional cleanup like "hey buddy, if > you're still here, I'd like to let you know that I'm gone so that you > don't count on me being around anymore". However, it has big drawbacks > -- because you cannot affect the order of destruction reliably, you > cannot test both ways and it can be very easy to suddenly rely on one > particular order.
If deterministic order of destruction is needed one can always do it "manually" in the destructor body of the QObject-derived parent class instead of waiting for the parent's base class desctructor with it's "non-deterministic order of destruction" kicks in. Andre' _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
