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//@ run-pass
#![allow(non_snake_case)]
use std::rc::Rc;
use std::cell::Cell;
struct Field {
number: usize,
state: Rc<Cell<usize>>
}
impl Field {
fn new(number: usize, state: Rc<Cell<usize>>) -> Field {
Field {
number: number,
state: state
}
}
}
impl Drop for Field {
fn drop(&mut self) {
println!("Dropping field {}", self.number);
assert_eq!(self.state.get(), self.number);
self.state.set(self.state.get()+1);
}
}
struct NoDropImpl {
_one: Field,
_two: Field,
_three: Field
}
struct HasDropImpl {
_one: Field,
_two: Field,
_three: Field
}
impl Drop for HasDropImpl {
fn drop(&mut self) {
println!("HasDropImpl.drop()");
assert_eq!(self._one.state.get(), 0);
self._one.state.set(1);
}
}
pub fn main() {
let state = Rc::new(Cell::new(1));
let noImpl = NoDropImpl {
_one: Field::new(1, state.clone()),
_two: Field::new(2, state.clone()),
_three: Field::new(3, state.clone())
};
drop(noImpl);
assert_eq!(state.get(), 4);
state.set(0);
let hasImpl = HasDropImpl {
_one: Field::new(1, state.clone()),
_two: Field::new(2, state.clone()),
_three: Field::new(3, state.clone())
};
drop(hasImpl);
assert_eq!(state.get(), 4);
}
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