// macros4.rs // Execute `rustlings hint macros4` or use the `hint` watch subcommand for a hint. #[macro_export] macro_rules! my_macro { () => { println!("Check out my macro!"); }; ($val:expr) => { println!("Look at this other macro: {}", $val); }; } fn main() { my_macro!(); my_macro!(7777); }