fn main() {
    if cfg!(target_os = "windows") {
        println!("Hello Windows");
    }else if cfg!(target_os = "linux"){
        println!("Hello Linux");
    }else{
        println!("Unknown os");
    }
}

fn main() {
    if cfg!(target_os = "windows") {
        println!("Hello Windows");
    }else if cfg!(target_os = "linux"){
        println!("Hello Linux");
    }else{
        println!("Unknown os");
    }
}