That problem gets especially harry once you consider every subsystem in the game is going to behave similarly, AI, physics, Sound, etc. It seems like the right

That problem gets especially harry once you consider every subsystem in the game is going to behave similarly, AI, physics, Sound, etc. It seems like the right answer is the same as it is in OO languages favor composition. Grab the Renderable out of the Foos, Bars, and Bazes then pass that list to the render function. It follows the articles suggestion about think about your types more. Why does anyone think the render function needs the entire player state instead of just the part it needs to render something on the screen?