Rust-Interior-Mutability.rs

use std::rc::Rc;
use std::cell::RefCell;

#[derive(Debug)]
struct MyType {
    num: i32
}

impl MyType {
    pub fn add(&mut self, amount: i32) {
        self.num += amount;
    }
}

fn main() {
    let my_type = MyType { num: 10 };
    println!("{:?}", my_type);

    let rfc_my_type: RefCell<MyType> = RefCell::new(my_type);
    rfc_my_type.borrow_mut().add(1);
    println!("{:?}", rfc_my_type.borrow());
    
    let rc1_my_type: Rc<&RefCell<MyType>> = Rc::new(&rfc_my_type);
    rc1_my_type.borrow_mut().add(1);
    println!("{:?}", rc1_my_type.borrow());
    
    let rc2_my_type: Rc<&RefCell<MyType>> = Rc::new(&rfc_my_type);
    rc2_my_type.borrow_mut().add(1);
    println!("{:?}", rc2_my_type.borrow());
}