// This would previously leak the Box because we wouldn't // schedule cleanups when auto borrowing trait objects. // This program should be valgrind clean. static mut DROP_RAN: bool = false; struct Foo; impl Drop for Foo { fn drop(&mut self) { unsafe { DROP_RAN = true; } } } trait Trait { fn dummy(&self) { } } impl Trait for Foo {} pub fn main() { { let _x: &Trait = &*(Box::new(Foo) as Box); } unsafe { assert!(DROP_RAN); } }