game::actor_ref lua::to_actor(const engine & engine, index_t index) {
return boost::dynamic_pointer_cast<game::actor>(
engine.to_proxy(actor_class, index, actor_empty)
);
}
game::mark_ref lua::to_mark(const engine & engine, index_t index) {
return engine.to_proxy(mark_class, index, mark_empty);
}