// 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. fn destructure(x: Option) -> int { match x { None => 0, Some(ref mut v) => *v //~ ERROR cannot borrow } } fn main() { assert_eq!(destructure(Some(22)), 22); }