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


fn main() {
    let a = Rc::new(5);
    println!("Rc strong count: {}", Rc::strong_count(&a));

    let b = Rc::clone(&a);
    println!("Rc strong count: {}", Rc::strong_count(&a));

    let c = Rc::downgrade(&a);
    println!("Rc strong count: {}", Rc::strong_count(&a));
}