ups, sorry, my fault.. the example seems to work, but I run into that problem because I tried to perform an dynamic_cast on that weak_ptr. How this should be done in this simple example? class Base { public: boost::weak_ptr<Base> neigh; }; class Derived : public Base { }; int main() { { boost::shared_ptr<Base> a(new Base); boost::shared_ptr<Derived> d(new Derived); a->neigh = d; d->neigh = a; //like that? boost::shared_ptr<Derived> pD2 = boost::shared_dynamic_cast< Derived

( a->neigh.lock()); } }

-----Ursprüngliche Nachricht----- Von: Sören Freudiger [mailto:muffmolch@gmx.de] Gesendet: Montag, 24. November 2008 21:03 An: boost@lists.boost.org Betreff: dynamic_cast with WeakPtr? Hi @all Maybe you can help me. I tried to use weak_ptr for breaking circular references, but I found out that this pointers can't handle derived classes. But in my classes I have some neighbor relations that I want to tore with shared_ptr: class Base { public: boost::shared_ptr<Base> neigh; }; class Derived : public Base { }; int main() { { boost::shared_ptr<Base> a(new Base); boost::shared_ptr<Derived> d(new Derived) a.neigh = d; d.neigh = a; } //both objects are in memory because of circular references, but weak pointer doesn't work, //becaus eit seems to be unable handling derived classes... and there's no dynamic cast } How do you solve problems like that with boost pointers avoiding circular references? Best reagrds, SirAnn