[Haskell-cafe] Feedback on FFI bindings for C++ library

Hey, I would like to write FII bindings in haskell for cocos2d-x (http://www.cocos2d-x.org/), which is a C++ library. Since I have little experience with this, I would like some feedback before I discover that concept is bad half way. In cocos2d there is a base class with much functionality: CCNode Many classes derive from it (i.E. CCLayer) and use the virtual functions of CCNode (i.E. setPosition). How do I map this to haskell? The general Idea: I have a typeclass, in which everything that is derived from CCNode is an instance: class NodeDerived a where toNode :: a -> Node setPosition :: a -> (Double,Double) -> IO () setPosition a pos = setNodePosition (toNode a) pos instane NodeDerived Layer where toNode = layerToNode and layerToNode :: Layer -> Node would be implemented in C++ as: CCNode* layerToNode(CCLayer* l) { return dynamic_cast(l); } This way I would have only to implement toNode for every class derived from CCNode and get all the functions CCNode defines. What do you think if this Idea? How would you do it? Thanks! Nathan