Struct async_utils::async_once::Once

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pub struct Once<T> { /* private fields */ }
Expand description

Wrapper presenting an async interface to a OnceCell.

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impl<T> Once<T>

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pub fn new() -> Self

Constructor.

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pub async fn get_or_init<'a, F>(&'a self, fut: F) -> &'a T
where F: Future<Output = T>,

Async wrapper around OnceCell’s get_or_init.

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pub async fn get_or_try_init<'a, F, E>(&'a self, fut: F) -> Result<&'a T, E>
where F: Future<Output = Result<T, E>>,

Async wrapper around OnceCell’s get_or_try_init.

Trait Implementations§

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impl<T: Debug> Debug for Once<T>

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl<T> Default for Once<T>

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fn default() -> Self

Returns the “default value” for a type. Read more

Auto Trait Implementations§

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impl<T> !Freeze for Once<T>

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impl<T> !RefUnwindSafe for Once<T>

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impl<T> Send for Once<T>
where T: Send,

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impl<T> Sync for Once<T>
where T: Sync + Send,

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impl<T> Unpin for Once<T>
where T: Unpin,

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impl<T> UnwindSafe for Once<T>
where T: UnwindSafe,

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T, D> Encode<Ambiguous1, D> for T
where D: ResourceDialect,

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unsafe fn encode( self, _encoder: &mut Encoder<'_, D>, _offset: usize, _depth: Depth, ) -> Result<(), Error>

Encodes the object into the encoder’s buffers. Any handles stored in the object are swapped for Handle::INVALID. Read more
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impl<T, D> Encode<Ambiguous2, D> for T
where D: ResourceDialect,

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unsafe fn encode( self, _encoder: &mut Encoder<'_, D>, _offset: usize, _depth: Depth, ) -> Result<(), Error>

Encodes the object into the encoder’s buffers. Any handles stored in the object are swapped for Handle::INVALID. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a [WithDispatch] wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a [WithDispatch] wrapper. Read more
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impl<St> WithTag for St

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fn tagged<T>(self, tag: T) -> Tagged<T, St>

Produce a new stream from this one which yields item tupled with a constant tag