Here is some example code:

void * my_callback(void* arg) {
//bla
}
typedef void* (*callback_func)(void *);
void some_caller(callback_func f);

You want my_callback to also get another argument, not passed along by some_caller. Well, in Python you’d do either of the following – pass a functor, an object with a __call__ method, or use functools.partial, or any other equivalent trick.
Turns out, in C++ you could do the same thing, using boost.bind (and other similar libraries), and also, create a functor (an object with operator()).

Besides that, nice one!