Created
December 12, 2021 20:24
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| use std::cell::RefCell; | |
| use std::rc::{Rc, Weak}; | |
| struct Node { | |
| name: String, | |
| } | |
| struct Engine { | |
| selected_node: Option<Weak<RefCell<Node>>>, | |
| } | |
| impl Engine { | |
| fn new() -> Self { | |
| return Engine { selected_node: None }; | |
| } | |
| } | |
| impl Node { | |
| fn new(name: &str) -> Self { | |
| return Node { name: name.to_string() }; | |
| } | |
| } | |
| trait SomeActionMaker<T> { | |
| fn do_some_action(&self, engine: &mut Engine); | |
| } | |
| impl SomeActionMaker<Rc<RefCell<Node>>> for Rc<RefCell<Node>> { | |
| fn do_some_action(&self, engine: &mut Engine) { | |
| engine.selected_node = Some(Rc::downgrade(self)); | |
| } | |
| } | |
| fn main() { | |
| let mut engine = Engine::new(); | |
| let a = Rc::from(RefCell::from(Node::new("sharik"))); | |
| a.do_some_action(&mut engine); | |
| assert_eq!( | |
| engine.selected_node | |
| .expect("none selected") | |
| .upgrade() | |
| .expect("sharik is dead") | |
| .borrow_mut().name, | |
| "sharik" | |
| ); | |
| println!("Ok") | |
| } |
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