reference_count_refcell.rs

use std::cell::RefCell;
use std::rc::Rc;
pub struct MyStruct {
  name: String,
}

fn error_fn() {
  let mut ms = MyStruct {
    name: "Before".to_owned(),
  };
  let mut change1 = || ms.name = "After".to_owned();
  change1();
  // let mut change2 = move || ms.name = "After After".to_owned(); //note: move occurs because `ms` has type `MyStruct`, which does not implement the `Copy` trait
}

fn rs_fn() {
  let rc = Rc::new(RefCell::new(MyStruct {
    name: "Before".to_owned(),
  }));

  let change1 = || rc.borrow_mut().name = "After".to_owned();
  let change2 = || rc.borrow_mut().name = "After".to_owned();
  change1();
  change2();
}

fn main() {
  error_fn();
  rs_fn();
}