enum Error {
    UserError,
    TokenError,
}

enum Status {
    Ok,
    UnknownUser,
    InternalServerError,
}

fn bar() {
    let _status = match foo() {
        Ok(_) => Status::Ok,
        Err(Error::UserError) => Status::UnknownUser,
        Err(_) => Status::InternalServerError,
    };
    // ...
}

fn foo() -> Result<(), Error> {
    let user = get_user().map_err(|_| Error::UserError)?;
    let _token = get_token(&user).map_err(|_| Error::TokenError)?;
    // ...
    Ok(())
}

struct ErrorX;

fn get_user() -> Result<String, ErrorX> {
    Ok("Jane".into())
}

struct ErrorY;
struct Token;

fn get_token(user: &str) -> Result<Token, ErrorY> {
    Ok(Token)
}