I believe I may have found a way to create a deadlock in static_visitor, but it may be my own mistake. It seems if I apply one static visitor within another with an extra call to operator() that I use for shared_ptr objects, the program deadlocks in apply_visitor_binary_invoke::internal_visit(). The template in my class below is another static visitor object, so in essence I am creating an effect similar to a java decorator using visitors. Here is a stripped down version of the class with which the deadlock occurs: /** * @class VisitorDecorator * * @brief decorates (wraps) a normal visitor */ template <typename T> class VisitorDecorator : public boost::static_visitor<typename T::result_type> { typedef typename T::result_type t_result_type; public: VisitorDecorator(boost::shared_ptr<T> deviceCommandVisitor, std::string filename): m_visitor(deviceCommandVisitor), m_filename(filename) {} /** * @brief strip shared pointers and handle the object itself */ template <typename U, typename V> inline t_result_type operator()( boost::shared_ptr<U>& deviceP, boost::shared_ptr<V>& commandP){ return operator()(*deviceP,*commandP); } /** * @brief Connect the specified struct types to the log file */ template<typename U, typename V> t_result_type operator()(U& device, V& command){ return (*m_visitor)(device,command); } private: boost::shared_ptr<T> m_visitor; std::string m_filename; }; Does anyone have thoughts or suggestions, be it my fault or a bug in the library? Cheers! Andrew Hundt