Hello all! I am in the process of re-designing some libraries I wrote a while back as a pet-project. I want to update the mostly "C-style" code to safer, more extensible "C++ style" code. Anyway, now I'm trying to tackle a basic scheduler module. The idea is simple: the scheduler (lets call it class Scheduler) iterates over a list of Entity <smart>pointers, calling Entity->DoSomething() each time. DoSomething() returns a value (a "cost") representing how long the action took (conceptually in game time, not actual time). Entities such as characters, an input handler, a game clock, spell timers, etc. can be added to Schedule, and the game loop basically becomes: Scheduler.AddEntities(); do { Scheduler.Run(); } while !GameState.quit The whole purpose of this was written for a turn-based game, although I don't see why it couldn't be used in a real-time scenario. The possible problem as I see it, is that this is intrusive. That is, any object that wants to be part of the scheduler must inherit Entity interface. Basically, I don't want to lock myself into a design consideration that I might regret later. One alternative I considered was to just pass a member function pointer to the Scheduler, but that seems dangerous to me: if the Entity has been destructed without removing it from Scheduler, bad things would undoubtedly ensue. So: anyone have any other/better suggestions on doing something like this? I feel like I may be missing something fundamental here, due to my inexperience. Of course, using Entity inheritance may be the perfect solution, and maybe I just need some reassurance [embarrass] Thanks for any advice (and sorry if I was too long-winded!)