use std::cell::Cell;

struct DropCell<'a>(&'a Cell<i32>);

impl<'a> DropCell<'a> {
    /// A method on the struct that lets us use it in a match expression
    fn get_matchable(&self) -> Option<()> {
        Some(())
    }
}

impl<'a> Drop for DropCell<'a> {
    fn drop(&mut self) {
        println!("{}", self.0.get())
    }
}

fn main() {
    let cell = Cell::new(0);

    // prints "0"
    let _ = DropCell(&cell).get_matchable();

    // prints "2"
    match DropCell(&cell).get_matchable() {
        Some(()) => {
            cell.set(2);
        },
        _ => (),
    }; // semicolon necessary to prevent borrow-check error
}