fn borrowed_proc<'a>(x: &'a isize) -> Box<dyn FnMut()->(isize) + 'a> { // This is legal, because the region bound on `proc` // states that it captures `x`. Box::new(move|| { *x }) } fn static_proc(x: &isize) -> Box<dyn FnMut() -> (isize) + 'static> { // This is illegal, because the region bound on `proc` is 'static. Box::new(move || { *x }) //~^ ERROR lifetime may not live long enough } fn main() { }