Rust Reference and Ownership Challenges

e1.rs

#[derive(Copy, Clone, Debug)]
struct Label<'a> {
    number: u32,
    check: u32,
    name:  &'a str

}

fn main() {
    let _args: Vec<String> = std::env::args().collect();


    let l1 = Label { number: 3 , check: 100_u32, name: "Garry"};
    let l2 = l1;

    let mut l3 = l1;
    l3.check = 900;
    l3.name = "Larry Lux";

    println!("{:?} {:?} {:?}", l1, l2, l3);
}

e2.rs

use std::collections::HashMap;

type Table = HashMap<String, Vec<String>>;

fn main() {
    let _args: Vec<String> = std::env::args().collect();



    let mut t1 : Table = Table::new();

    t1.insert( String::from("item1"), vec!{"b".to_string(), "a".to_string(),});
    t1.insert( String::from("item2"), vec!{"e".to_string(), "e".to_string(),});
    t1.insert( String::from("item3"), vec!{"f".to_string(), "h".to_string(),"a".to_string()});

    sort_list(&mut t1);


    for (i, l) in t1 {
        print!("{} -> ", i);

        for x in l {
            print!("{},", x);
        }

        println!()
    }
}

fn sort_list ( p: &mut Table) {

    for (_item, list) in p {
        list.sort();
    }
}

e3.rs

fn main() {
    let _args: Vec<String> = std::env::args().collect();

    let x : &str = "Hello";

    let xx : &&str = &x;

    let xxx : &&&str = &&x;

    let y : String = x.to_string();

  
    assert!(xx == &"Hello");
  
    assert!(*xx == "Hello");
  
    assert_eq!(xx , &"Hello");
  
    assert_eq!(xxx , &"Hello");

    assert_eq!(y , "Hello".to_string());

}