rustlings-solutions/old_curriculum/macros/macros3.rs

76 lines
588 B
Rust
Raw Normal View History

2018-02-22 06:09:53 +00:00
// macros3.rs
2017-03-17 14:30:29 +00:00
// Make me compile, without taking the macro out of the module! Scroll down for hints :)
mod macros {
macro_rules! my_macro {
() => {
println!("Check out my macro!");
};
}
}
fn main() {
my_macro!();
}
2017-03-19 14:10:48 +00:00
// In order to use a macro outside of its module, you need to do something
// special to the module to lift the macro out into its parent.
2017-03-17 14:30:29 +00:00
2017-03-19 14:10:48 +00:00
// The same trick also works on "extern crate" statements for crates that have
// exported macros, if you've seen any of those around.