It'd be `()` and make it so that every side effecting function would be at minimum two lines long, and be a visible wart. It's pretty easy to tell that if the f

It'd be `()` and make it so that every side effecting function would be at minimum two lines long, and be a visible wart. It's pretty easy to tell that if the function returns something, the last line evaluates to that expression even if there's no `return` since if it didn't, it wouldn't compile (or there'd be a dead code warning).