37 /// let mut guard = xa.lock();
39 /// assert_eq!(guard.get(0), None);
41 /// assert_eq!(guard.store(0, dead, GFP_KERNEL)?.as_deref(), None);
42 /// assert_eq!(guard.get(0).copied(), Some(0xdead));
44 /// *guard.get_mut(0).unwrap() = 0xffff;
45 /// assert_eq!(guard.get(0).copied(), Some(0xffff));
47 /// assert_eq!(guard.store(0, beef, GFP_KERNEL)?.as_deref().copied(), Some(0xffff));
48 /// assert_eq!(guard.get(0).copied(), Some(0xbeef));
50 /// guard.remove(0);
51 /// assert_eq!(guard.get(0), None);
122     pub fn try_lock(&self) -> Option<Guard<'_, T>> {  in try_lock()
125             Some(Guard {  in try_lock()
135     pub fn lock(&self) -> Guard<'_, T> {  in lock()
139         Guard {  in lock()
146 /// A lock guard.
148 /// The lock is unlocked when the guard goes out of scope.
149 #[must_use = "the lock unlocks immediately when the guard is unused"]
150 pub struct Guard<'a, T: ForeignOwnable> {  struct
155 impl<T: ForeignOwnable> Drop for Guard<'_, T> {  implementation
164 /// The error returned by [`store`](Guard::store).
180 impl<'a, T: ForeignOwnable> Guard<'a, T> {  impl