Code shared from the Rust Playground

playground.rs

// use std::cell::RefCell;
// Ownership
use {
    std::ops::Drop
};

#[derive(Debug)]
struct Parent(usize, Child, Child);

#[derive(Debug)]
struct Child(usize);

impl Drop for Parent {
    fn drop(&mut self) {
        println!("Dropping {:?}", self);
    }
}

impl Drop for Child {
    fn drop(&mut self) {
        println!("Dropping {:?}", self);
    }
}



fn main() {
  //let mut rc1 = Rc::new(Child(1));
  let p1 = Parent(1, Child(11), Child(12));
  {
      let p2 = Parent(2, Child(21), Child(22));
      println!("a: p1:{:?}, p2:{:?}", p1,p2);
  }
  
  println!("b p1:{:?}", p1);
  
  let p3 = Parent(3, Child(31), Child(32));
  println!("c: p1:{:?}, p3:{:?}", p1,p3);
// a: p1:Parent(1, Child(11), Child(12)), p2:Parent(2, Child(21), Child(22))
// Dropping Parent(2, Child(21), Child(22))
// Dropping Child(21)
// Dropping Child(22)
// b p1:Parent(1, Child(11), Child(12))
// c: p1:Parent(1, Child(11), Child(12)), p3:Parent(3, Child(31), Child(32))
// Dropping Parent(3, Child(31), Child(32))
// Dropping Child(31)
// Dropping Child(32)
// Dropping Parent(1, Child(11), Child(12))
// Dropping Child(11)
// Dropping Child(12)
}