// 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. #[derive(Copy)] struct cat { meow: extern "Rust" fn(), } fn meow() { println!("meow") } fn cat() -> cat { cat { meow: meow, } } #[derive(Copy)] struct KittyInfo {kitty: cat} // Code compiles and runs successfully if we add a + before the first arg fn nyan(kitty: cat, _kitty_info: KittyInfo) { (kitty.meow)(); } pub fn main() { let kitty = cat(); nyan(kitty, KittyInfo {kitty: kitty}); }