a final (?) version of boost.coroutine is available at http://ok73.ok.funpic.de/boost-coroutine.zip In contrast to the original concept coroutine<> is not similar to a function/functor. 1.) the coroutine-fn is started at construction of coroutine<> - helps to solve some problems related to the last 'yield'-operation - similar to the behaviour of boost::thread - arguments which have to be the first arguments of coroutine-fn must be applied to coroutine<>-ctor (arguments()) 2.) coroutine<>::operator() returns a reference to the coroutine instead the return-value 3.) return-values must be accessed via coroutine<>::get() regards, Oliver