[stickfigure]

Yeah, mapToInt is annoying because the primitive/object dichotomy in Java is annoying. No question about it, it's a wart on the language. Though it does offer some optimization abilities, so the dichotomy is not completely meritless - it's easy to understand why the language designers did it this way. Maybe project valhalla will fix this someday, I don't know. In the mean time, it's not a fatal flaw.