1 #![feature(rustc_attrs)]
4 // revisions: migrate nll
5 #![cfg_attr(nll, feature(nll))]
8 let mut x: Box<()> = Box::new(());
13 //[migrate]~^^ WARNING captured variable cannot escape `FnMut` closure body
14 //[migrate]~| WARNING this error has been downgraded to a warning
15 //[migrate]~| WARNING this warning will become a hard error in the future
16 //[nll]~^^^^^ ERROR captured variable cannot escape `FnMut` closure body