// 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. use std::cell::RefCell; // FIXME (#22405): Replace `Box::new` with `box` here when/if possible. fn main() { let mut y = 1; let c = RefCell::new(vec![]); c.push(Box::new(|| y = 0)); c.push(Box::new(|| y = 0)); //~^ ERROR cannot borrow `y` as mutable more than once at a time } fn ufcs() { let mut y = 1; let c = RefCell::new(vec![]); Push::push(&c, Box::new(|| y = 0)); Push::push(&c, Box::new(|| y = 0)); //~^ ERROR cannot borrow `y` as mutable more than once at a time } trait Push<'c> { fn push<'f: 'c>(&self, push: Box); } impl<'c> Push<'c> for RefCell>> { fn push<'f: 'c>(&self, fun: Box) { self.borrow_mut().push(fun) } }