hello rust mutations / published by https://github.com/dacr/code-examples-manager #1a97069e-facd-4c5a-a52c-56dada02659e/53873e7d990ccc338d7259237d16fc4e5acef0e9

hello-mutations.rs

#!/usr/bin/env rust-script
// summary : hello rust mutations
// keywords : rust, mutations, @testable
// publish : gist
// authors : David Crosson
// license : Apache License Version 2.0 (https://www.apache.org/licenses/LICENSE-2.0.txt)
// id : 1a97069e-facd-4c5a-a52c-56dada02659e
// created-on : 2024-10-12T21:24:30+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : ./$file

fn main() {
    // -------------------------------------
    {
        let immutable_by_default = 32;
        let mut made_mutable = 42;
        made_mutable = 24;
        assert_eq!(immutable_by_default, 32);
        assert_eq!(made_mutable, 24);
        println!("{}", made_mutable);
    }
    // -------------------------------------
    {
        let mut hello = "hello".to_string();
        hello.push_str(" world"); // won't work without mut :
        hello = "world".to_string(); // won't work without mut :
        println!("`mut` mean both the reference AND the referenced content can be modified")
    }
}