// This test is a simple example of code that violates the dropck // rules: it pushes `&x` and `&y` into a bag (with dtor), but the // referenced data will be dropped before the bag is. fn main() { let mut v = Bag::new(); let x: i8 = 3; let y: i8 = 4; v.push(&x); //~^ ERROR `x` does not live long enough v.push(&y); //~^ ERROR `y` does not live long enough assert_eq!(v.0, [&3, &4]); } //`Vec` is #[may_dangle] w.r.t. `T`; putting a bag over its head // forces borrowck to treat dropping the bag as a potential use. struct Bag(Vec); impl Drop for Bag { fn drop(&mut self) { } } impl Bag { fn new() -> Self { Bag(Vec::new()) } fn push(&mut self, t: T) { self.0.push(t); } }