| // 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<T>` 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<T>(Vec<T>); |
| impl<T> Drop for Bag<T> { fn drop(&mut self) { } } |
| |
| impl<T> Bag<T> { |
| fn new() -> Self { Bag(Vec::new()) } |
| fn push(&mut self, t: T) { self.0.push(t); } |
| } |