Awesome. Rust's performance is something that impresses me, so I'm certainly not suggesting that it's slow. The point I was making is it's a valid question to ask and a valid thing to measure. Having fought with slow language features (e.g., blocks in Ruby), slow stdlib (e.g., older versions of Scala's collections), and slow techniques adopted by library authors (e.g., ask for forgiveness with exceptions instead of permission) there's just a lot that impacts many if not all apps and if it's outside your own application code, it can be very hard to fix. One of the things I really like about go releases is they indicate exactly what's changed on the performance front, so I have a good idea of what to expect. And since they measure it, they can improve it.