#[export_macro]

macro_rules! foo {

    () => {};

}

​

// You can use it like so:

use my_crate::foo;

// Notice that the macro is exported at the root

macro_rules! say_hello_to {

    ($name:expr) => {

        concat!("Hello, ", $name, "!")

    };

}

​

fn main() {

    println!("{}", say_hello_to!("Alice"));

}

​

#[macro_use]