I have an interpreter that uses a visitor pattern while performing a reduction of the program tree. As part of the visitor pattern, each class that can be a node in the tree must respond to: virtual void accept(Visitor& v); where each node then implements by calling visitor with itself using the proper type. The function calls in visitor are like: void visit(shared_ptr<Node> node); void visit(shared_ptr<Type> node); etc. (where Type is a descendant of node BTW). Normally with the visitor pattern (GOF style in this case), the implementation of accept is simply: void Node::accept(Visitor &v) { v.visit(this); } I've tried adding enable_shared_from_this<...> as a superclass of my nodes, and returning shared_from_this(), which works in some cases, but in others just seems to hang. These occur in classes that are a little more complex. For example, I have a TypeTemplate<T> class that wraps to underlying types TypeTemplate<int>, TypeTemplate<float>, TypeTemplate<etc>. I've tried adding enable_shared_from_this<TypeTemplate<T> >, and then having an implmentation void TypeTemplate<T>::accept(Visitor &v) { v.visit(enable_shared_from_this<TypeTemplate<T> >::shared_from_this()); } but it just hangs on both vc7.1 on windows and Xcode on OS X. (I had to add the extra scoping because I got complaints that "shared_from_this() was ambiguous in multiple inheritance.") I read in some past postings that the shared_from_this template doesn't work so well for complex class hierarchies, and I am wondering if I am running into that. I was thinking of putting my own internal_weak_ptr into the classes, but was confused by some of the examples I have seen. Most of them seem to reference a static function create() which instantiates the weak_ptr, and returns a shared_ptr<X>. When I consider my situation: shared_ptr<Node> aNode(new Node(...)); Visitor v; aNode->accept(v); How does the accept implementation return a shared_ptr that is linked with aNode? I've looked through the enable_shared_from_this implementation, and can't figure out how it is supposed to work. even if I return shared_from_this(), I'm not sure now that is linked to aNode. Does everything have to go through a factory like create()? Sorry for the long rambling e-mail. I hope it makes sense what I am trying to do. Cheers, tim