[Boost-users] mpl for_each copies function object (bug?)

Hi there! I'm currently struggling with mpl::for_each: It copies my function object no matter what I do. Here is some dummy code: worker_t workit; // the worker object which recieves the different types and has an internal state mpl::for_each< mpl::vector<bool, double>, worker_t& >(workit); Now, the workit object becomes copied which is clear from the sources. However, I explicitly requested it not to be copied by the hint of giving the reference worker_t& as a template parameter. Maybe this behaviour is wanted, but I do not see the reason. In the fusion-world this is the way to go if one wants to prevent copying of function objects. Is this now a bug or a feature and how can I fix it (quick). Greetings, Sebastian