// 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. #[feature(managed_boxes)]; struct r { b: @mut int, } #[unsafe_destructor] impl Drop for r { fn drop(&mut self) { *(self.b) += 1; } } fn r(b: @mut int) -> r { r { b: b } } pub fn main() { let b = @mut 0; { let _p = Some(r(b)); } assert_eq!(*b, 1); }