Macros

Rust’s macro system is very powerful, but also kind of difficult to wrap your head around. We’re not going to teach you how to write your own fully-featured macros. Instead, we’ll show you how to use and create them.

If you’d like to learn more about writing your own macros, the macrokata project has a similar style of exercises to Rustlings, but is all about learning to write Macros.

Further information

Rustlings

macros1

 
// macros1.rs
// Execute `rustlings hint macros1` or use the `hint` watch subcommand for a hint.

// I AM NOT DONE

macro_rules! my_macro {
    () => {
        println!("Check out my macro!");
    };
}

fn main() {
    my_macro();
}

macros2

 
// macros2.rs
// Execute `rustlings hint macros2` or use the `hint` watch subcommand for a hint.

// I AM NOT DONE

fn main() {
    my_macro!();
}

macro_rules! my_macro {
    () => {
        println!("Check out my macro!");
    };
}

macros3

 
// macros3.rs
// Make me compile, without taking the macro out of the module!
// Execute `rustlings hint macros3` or use the `hint` watch subcommand for a hint.

// I AM NOT DONE

mod macros {
    macro_rules! my_macro {
        () => {
            println!("Check out my macro!");
        };
    }
}

fn main() {
    my_macro!();
}

macros4

 
// macros4.rs
// Execute `rustlings hint macros4` or use the `hint` watch subcommand for a hint.

// I AM NOT DONE

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);
}