| //@ run-pass |
| |
| // Example taken from RFC 1238 text |
| |
| // https://github.com/rust-lang/rfcs/blob/master/text/1238-nonparametric-dropck.md |
| // #example-of-the-unguarded-escape-hatch |
| |
| #![feature(dropck_eyepatch)] |
| use std::cell::Cell; |
| |
| struct Concrete<'a>(#[allow(dead_code)] u32, Cell<Option<&'a Concrete<'a>>>); |
| |
| struct Foo<T> { data: Vec<T> } |
| |
| // Below is the UGEH attribute |
| unsafe impl<#[may_dangle] T> Drop for Foo<T> { |
| fn drop(&mut self) { } |
| } |
| |
| fn main() { |
| let mut foo = Foo { data: Vec::new() }; |
| foo.data.push(Concrete(0, Cell::new(None))); |
| foo.data.push(Concrete(0, Cell::new(None))); |
| |
| foo.data[0].1.set(Some(&foo.data[1])); |
| foo.data[1].1.set(Some(&foo.data[0])); |
| } |
