// Copyright 2014 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(box_syntax)] struct Foo { x: isize } impl Drop for Foo { fn drop(&mut self) { println!("drop {}", self.x); } } fn main() { let mut ptr = box Foo { x: 0 }; let mut test = |foo: &Foo| { println!("access {}", foo.x); ptr = box Foo { x: ptr.x + 1 }; println!("access {}", foo.x); }; test(&*ptr); //~^ ERROR: cannot borrow `*ptr` as immutable }