// 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. // Tests that unary structs can be mutably borrowed. struct Empty; impl Iterator for Empty { fn next(&mut self) -> Option { None } } fn do_something_with(a : &mut Iterator) { println!("{}", a.next()) } pub fn main() { do_something_with(&mut Empty); }