| // Copyright 2012 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use std::cell::Cell; |
| |
| struct dtor<'a> { |
| x: &'a Cell<isize>, |
| } |
| |
| impl<'a> Drop for dtor<'a> { |
| fn drop(&mut self) { |
| self.x.set(self.x.get() - 1); |
| } |
| } |
| |
| fn unwrap<T>(o: Option<T>) -> T { |
| match o { |
| Some(v) => v, |
| None => panic!() |
| } |
| } |
| |
| pub fn main() { |
| let x = &Cell::new(1); |
| |
| { |
| let b = Some(dtor { x:x }); |
| let _c = unwrap(b); |
| } |
| |
| assert_eq!(x.get(), 0); |
| } |