rustbook_learning_guide/
smart_pointers.rs

1//! Smart pointer examples
2
3use std::rc::Rc;
4use std::cell::RefCell;
5
6pub fn smart_pointer_examples() {
7    println!("\n🧠 Smart Pointer Examples");
8    println!("{}", "-".repeat(27));
9    
10    // Box example
11    let boxed = Box::new(5);
12    println!("Boxed value: {}", boxed);
13    
14    // Rc example
15    let rc = Rc::new(10);
16    let rc_clone = Rc::clone(&rc);
17    println!("Rc value: {}, clone: {}", rc, rc_clone);
18    
19    // RefCell example
20    let ref_cell = RefCell::new(20);
21    *ref_cell.borrow_mut() += 5;
22    println!("RefCell value: {}", ref_cell.borrow());
23}
24
25#[derive(Debug)]
26pub struct Shoe {
27    size: u32,
28    style: String,
29}
30
31impl Shoe {
32    pub fn new(size: u32, style: &str) -> Self {
33        Shoe {
34            size,
35            style: style.to_string(),
36        }
37    }
38}
39
40pub fn shoes_in_size(shoes: Vec<Shoe>, shoe_size: u32) -> Vec<Shoe> {
41    shoes.into_iter().filter(|s| s.size == shoe_size).collect()
42}
43
44#[derive(Debug)]
45pub enum List {
46    Cons(i32, Box<List>),
47    Nil,
48}
49
50impl List {
51    pub fn new(values: Vec<i32>) -> Box<List> {
52        let mut result = Box::new(List::Nil);
53        for value in values.into_iter().rev() {
54            result = Box::new(List::Cons(value, result));
55        }
56        result
57    }
58}
59
60
61
rustbook_learning_guide/smart_pointers.rs

rustbook_learning_guide/
smart_pointers.rs
