> A special “I would never write Rust like that” variant that returns the value in a Box on the heap. This is because a friend of mine, after seeing my results,

> A special “I would never write Rust like that” variant that returns the value in a Box on the heap. This is because a friend of mine, after seeing my results, told me I was cheating, because all Rust versions so far used registers/stack to return the value, and Java was at a disadvantage due to returning on the heap (by default). Uhh, okay? This sounds a bit silly to me. It's good to add the additional comparison, sure, but "cheating" is just not the right word. The point of this article is ostensibly to compare the built-in Option types, not heap allocation. The fact that Java allocates any Options on the heap is part of that comparison (and reflects badly on Java, fwiw). Either way, glad to see that Rust is doing a good job eliminating the overhead. I'm not sure if arithmetic is the right kind of benchmark here, but it'd probably be difficult to measure the performance overhead across "real" codebases, so focusing on a tight loop microbenchmark is probably fine.