1 use std::marker::PhantomData;
2 use std::sync::atomic::{AtomicPtr, Ordering};
4 /// This is essentially an `AtomicPtr` but is guaranteed to always be valid
5 pub struct AtomicRef<T: 'static>(AtomicPtr<T>, PhantomData<&'static T>);
7 impl<T: 'static> AtomicRef<T> {
8 pub const fn new(initial: &'static T) -> AtomicRef<T> {
9 AtomicRef(AtomicPtr::new(initial as *const T as *mut T), PhantomData)
12 pub fn swap(&self, new: &'static T) -> &'static T {
13 // We never allow storing anything but a `'static` reference so it's safe to
14 // return it for the same.
15 unsafe { &*self.0.swap(new as *const T as *mut T, Ordering::SeqCst) }
19 impl<T: 'static> std::ops::Deref for AtomicRef<T> {
21 fn deref(&self) -> &Self::Target {
22 // We never allow storing anything but a `'static` reference so it's safe to lend
23 // it out for any amount of time.
24 unsafe { &*self.0.load(Ordering::SeqCst) }