// 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 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. struct dtor { x: @mut int, } impl dtor : Drop { fn finalize(&self) { // abuse access to shared mutable state to write this code *self.x -= 1; } } fn unwrap(+o: Option) -> T { match move o { Some(move v) => move v, None => fail } } fn main() { let x = @mut 1; { let b = Some(dtor { x:x }); let c = unwrap(move b); } assert *x == 0; }