// ./src/attribute/cfg.md // This function only gets compiled if the target OS is linux #[cfg(target_os = "linux")] fn are_you_on_linux() { println!("You are running linux!"); } // And this function only gets compiled if the target OS is *not* linux #[cfg(not(target_os = "linux"))] fn are_you_on_linux() { println!("You are *not* running linux!"); } fn part0() { are_you_on_linux(); println!("Are you sure?"); if cfg!(target_os = "linux") { println!("Yes. It's definitely linux!"); } else { println!("Yes. It's definitely *not* linux!"); } } pub fn main() { part0(); }