How do I use a macro across module files?

Question

I have two modules in separate files within the same crate, where the crate has macro_rules enabled. I want to use the macros defined in one module in another m

Answer 1

This answer is outdated as of Rust 1.1.0-stable.

---

You need to add #![macro_escape] at the top of macros.rs and include it using mod macros; as mentioned in the Macros Guide.

$ cat macros.rs
#![macro_escape]

#[macro_export]
macro_rules! my_macro {
    () => { println!("hi"); }
}

$ cat something.rs
#![feature(macro_rules)]
mod macros;

fn main() {
    my_macro!();
}

$ rustc something.rs
$ ./something
hi

For future reference,

$ rustc -v
rustc 0.13.0-dev (2790505c1 2014-11-03 14:17:26 +0000)