Struct OnceBox
pub(crate) struct OnceBox<T> { pub(in ::sys::sync::once_box) ptr: Atomic<*mut T> }Fields
ptr: Atomic<*mut T>
Implementations
impl<T> OnceBox<T>
const fn new() -> Selfunsafe fn get_unchecked(&self) -> Pin<&T>Gets access to the value, assuming it is already initialized and this initialization has been observed by the current thread.
Since all modifications to the pointer have already been observed, the pointer load in this function can be performed with relaxed ordering, potentially allowing the optimizer to turn code like this:
once_box.get_or_init; unsafeinto
once_box.get_or_initSafety
This causes undefined behavior if the assumption above is violated.
fn get_or_init(&self, f: impl FnOnce() -> Pin<Box<T>>) -> Pin<&T>fn take(&mut self) -> Option<Pin<Box<T>>>fn initialize(&self, f: impl FnOnce() -> Pin<Box<T>>) -> Pin<&T>
Trait Implementations
impl<T> Drop for OnceBox<T>
fn drop(&mut self)
impl<T: Send + Sync> Sync for OnceBox<T>
impl<T: Send> Send for OnceBox<T>
Auto Trait Implementations
impl<T> !Freeze for OnceBox<T>
impl<T> RefUnwindSafe for OnceBox<T>
where
Atomic<*mut T>: RefUnwindSafe,
impl<T> Unpin for OnceBox<T>
where
Atomic<*mut T>: Unpin,
impl<T> UnsafeUnpin for OnceBox<T>
where
Atomic<*mut T>: UnsafeUnpin,
impl<T> UnwindSafe for OnceBox<T>
where
Atomic<*mut T>: UnwindSafe,
Blanket Implementations
impl<T> Any for OnceBox<T>
where
T: 'static + ?Sized,
fn type_id(&self) -> TypeId
impl<T> Borrow<T> for OnceBox<T>
where
T: ?Sized,
fn borrow(&self) -> &T
impl<T> BorrowMut<T> for OnceBox<T>
where
T: ?Sized,
fn borrow_mut(&mut self) -> &mut T
impl<T> From<T> for OnceBox<T>
fn from(t: T) -> TReturns the argument unchanged.
impl<T> SizeHint for OnceBox<T>
where
T: ?Sized,
fn lower_bound(&self) -> usizefn upper_bound(&self) -> Option<usize>
impl<T> SizedTypeProperties for OnceBox<T>
impl<T, U> Into<U> for OnceBox<T>
where
U: From<T>,
fn into(self) -> UCalls
U::from(self).That is, this conversion is whatever the implementation of
[From]<T> for Uchooses to do.
impl<T, U> TryFrom<U> for OnceBox<T>
where
U: Into<T>,
type Error = Infallible;fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
impl<T, U> TryInto<U> for OnceBox<T>
where
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error;fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>