Compilation

& "C:\Program Files\Rust stable 1.1\bin\rustc.EXE" --crate-name messenger --crate-type rlib --emit obj -o buck-out\gen\messenger\messenger\libmessenger.rlib messenger\messenger.rs
& "C:\Program Files\Rust stable 1.1\bin\rustc.EXE" --crate-name hello --crate-type bin -o buck-out\gen\hello\hello --extern messenger=buck-out\gen\messenger\messenger\libmessenger.rlib hello.rs

hello.rs

extern crate messenger;

use messenger::Messenger;

fn main() {
    let messenger = messenger::Messenger::new("Hello, world!");
    messenger.deliver();
}

messenger\messenger.rs

pub struct Messenger {
    message: String,
}

impl Messenger {
    pub fn new(message: &str) -> Messenger {
        Messenger { message: message.to_string(), }
    }

    pub fn deliver(&self) {
        println!("I have a message to deliver to you: {}", &self.message);
    }
}