Rust constants in different modules?

Question

I have this "main.rs" file which I declare a version constant.

pub const VERSION: &'static str = "v2";
mod game;
fn main() {
   do_stuff();
}

Then I want to access this global constant in a different module "game.rs":

pub fn do_stuff() {
   println!("This is version: {}", VERSION);
}

How do I make the constant available everywhere?

score 31 · Accepted Answer · edited Apr 20 '21 at 06:51

31

As VERSION is declared in main.rs, which is a crate root, you can access it using its absolute path: ::VERSION.

This should work:

pub fn do_stuff() {
    println!("This is version: {}", crate::VERSION);
}

edited Apr 20 '21 at 06:51

Canato

answered May 25 '16 at 07:39

Dogbert

How do we do for a u64 type of field? – Rajeev Ranjan Apr 12 '19 at 06:52
2

Note, in modern Rust you should use "crate::Version" – RandomInsano Feb 02 '20 at 19:35
What @RandomInsano said. This answer needs a little update, it's no longer valid – OctaveL Jan 02 '21 at 10:59
what If I declared it in mod.rs? – collinsmarra Jun 23 '23 at 06:03

score 0 · Answer 2 · answered Nov 17 '22 at 04:17

0

use crate::VERSION
println!("version: {}", VERSION);

will be better.

answered Nov 17 '22 at 04:17

chen Jacky

2 Answers2