// This test should never pass! use std::cell::RefCell; use std::rc::Rc; trait Swap: Sized { fn swap(self, other: Self); } impl Swap for Rc> { fn swap(self, other: Self) { >::swap(&self, &other); } } fn hide<'a, 'b: 'a, T: 'static>(x: Rc>) -> impl Swap + 'a { x //~^ ERROR hidden type for `impl Swap + 'a` captures lifetime that does not appear in bounds } fn dangle() -> &'static [i32; 3] { let long = Rc::new(RefCell::new(&[4, 5, 6])); let x = [1, 2, 3]; let short = Rc::new(RefCell::new(&x)); hide(long.clone()).swap(hide(short)); let res: &'static [i32; 3] = *long.borrow(); res } fn main() { println!("{:?}", dangle()); }