Using our library

To use our library, we need to modify our main.rs file to look like this.

main.rs

extern crate hello_world;

use hello_world::{generate_greeting, generate_custom_greeting};

fn main() {
    println!("{}", generate_greeting());
    println!("{}", generate_custom_greeting("Robert"));
}

On the first line we declare that we will be using an external library with extern crate [package_name]; at that point we can use the two functions we defined in our library.

Next we want to bring them into scope directly so we add the line use hello_world::{generate_greeting, generate_custom_greeting}; If we didn't add that line we could still use them like this hello_world::generate_greeting() which is a little less nice.

When we run our program, we should now get the following output

$ cargo run
...
Hello, world!
Hello, Robert!