Your operators are likely not being called because they are of the incorrect signature. The type of a member equality operator should be as shown: struct Foo { bool operator==(const Foo& f) const;
// this is the incorrect equivalent of your operator // bool operator==(Foo f); }
The const parameter is the correct way to do it, but it is most likely the method not being const that prevents your operators from being invoked.
Actually, the reason the operator< is not being invoked is because the way it's defined, it compares a Node object to a NodePtr: class Node { ... bool operator<(NodePtr otherNode) { return (id < otherNode->id); } }; What you want is an operator< that compares a NodePtr to a NodePtr, because this is what set<NodePtr>::find() will call. This needs to be defined as a non-member function: bool operator<(NodePtr a, NodePtr b) { return a->getID() < b->getID(); } Having said that, Rob is right that using ptr_container is a better approach. Regards, Nate