some_expression? // is the same as: match some_expression { Ok(value) => value, Err(err) => return Err(err), }..= ..=expr, expr..=expr Right-inclusive range literal PartialOrd ..= is an operator that is used to generate ranges// The () type, also called “unit”. // The () type has exactly one value (), // and is used when there is no other meaningful value that could be returned: fn long() -> () {} fn short() {}