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use std::cell::Cell;
use std::ops::Deref;
use std::mem::ManuallyDrop;
union Wrap<T> { x: ManuallyDrop<T> }
impl<T> Drop for Wrap<T> {
fn drop(&mut self) {
unsafe { std::ptr::drop_in_place(&mut *self.x as *mut T); }
}
}
impl<T> Wrap<T> {
fn new(x: T) -> Self {
Wrap { x: ManuallyDrop::new(x) }
}
}
impl<T> Deref for Wrap<T> {
type Target = T;
#[inline]
fn deref(&self) -> &Self::Target {
unsafe {
&self.x
}
}
}
struct C<'a>(Cell<Option<&'a C<'a>>>);
impl<'a> Drop for C<'a> {
fn drop(&mut self) {}
}
fn main() {
let v : Wrap<C> = Wrap::new(C(Cell::new(None)));
v.0.set(Some(&v)); //~ ERROR: `v` does not live long enough
}
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