[ztcfegzgf]

you can make sync IO calls in Rust if i'm not mistaken. be it reading a file or doing a remote HTTP request.

and with this being true, the article's argument does not work, there is no types-mark-io happening there.

the argument applies better to Haskell, where you cannot do any IO without the types saying so.

interestingly, it also applies somewhat to Javascript, where because of backward-compat and history, it's not possible to do sync IO (mostly :) welcome to javascript), so if you do not see an "async" annotation, you can be mostly sure that this is pure cpu-work.