rustlings/exercises/macros/macros3.rs
2019-07-18 12:59:46 +02:00

77 lines
601 B
Rust
Executable file

// macros3.rs
// Make me compile, without taking the macro out of the module! Scroll down for hints :)
#[macro_use]
mod macros {
macro_rules! my_macro {
() => {
println!("Check out my macro!");
};
}
}
fn main() {
my_macro!();
}
// 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.
// The same trick also works on "extern crate" statements for crates that have
// exported macros, if you've seen any of those around.