Can you not use the question mark operator inside the .map() callback to return a Result, something like this answer? https://stackoverflow.com/a/26370894/4948

Can you not use the question mark operator inside the .map() callback to return a Result, something like this answer? https://stackoverflow.com/a/26370894/49485 https://stackoverflow.com/a/26370894/49485 (Not a Rust expert.)