How to do it...

1. In the bin folder, create a file called shared.rs

2. Add the following code and run it with cargo run --bin shared:

1    use std::rc::Rc;
2 
3    // The ball will survive until all kids are done playing with 
        it
4    struct Kid {
5      ball: Rc<Ball>,
6    }
7    struct Ball;
8 
9    fn main() {
10     {
11       // rc is created and count is at 1
12       let foo = Rc::new("foo");
13       // foo goes out of scope; count decreases
14       // count is zero; the object gets destroyed
15     }
16 
17     {
18       // rc is created and count is at 1
19       let bar = Rc::new("bar");
20       // rc is cloned; count increases to 2
21       let second_bar = Rc::clone(&bar);
22       // bar goes out of scode; count decreases to 1
23       // bar goes out of scode; count decreases to 0
24     }
25 
26     {
27       // rc is created and count is at 1
28       let baz = Rc::new("baz");
29       {
30         // rc is cloned; count increases to...