Struct zng_var::ContextInitHandle

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pub struct ContextInitHandle(/* private fields */);
Expand description

Identifies the unique context a ContextualizedVar is in.

Each node that sets context-vars have an unique ID, it is different after each (re)init. The ContextualizedVar records this ID, and rebuilds when it has changed. The contextualized inner vars are retained when the ID has at least one clone.

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impl ContextInitHandle

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pub fn new() -> Self

Generates a new unique handle.

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pub fn current() -> Self

Gets the current context handle.

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pub fn with_context<R>(&self, action: impl FnOnce() -> R) -> R

Runs action with self as the current context ID.

Note that ContextVar::with_context already calls this method.

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pub fn downgrade(&self) -> WeakContextInitHandle

Create a weak handle that can be used to monitor self, but does not hold it.

Trait Implementations§

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impl Clone for ContextInitHandle

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fn clone(&self) -> ContextInitHandle

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for ContextInitHandle

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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 Default for ContextInitHandle

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fn default() -> ContextInitHandle

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

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fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl PartialEq for ContextInitHandle

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fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl Eq for ContextInitHandle

Auto Trait 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> AnyVarValue for T
where T: VarValue,

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fn as_any(&self) -> &(dyn Any + 'static)

Access to dyn Any methods.
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fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Access to mut dyn Any methods.
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fn clone_boxed(&self) -> Box<dyn AnyVarValue>

Clone the value.
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fn clone_boxed_var(&self) -> Box<dyn AnyVar>

Clone the value into a new boxed LocalVar<Self>.
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fn into_any(self: Box<T>) -> Box<dyn Any>

Access to Box<dyn Any> methods.
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fn eq_any(&self, other: &(dyn AnyVarValue + 'static)) -> bool

Gets if self equals other.
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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> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

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fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
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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>

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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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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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where T: VarValue,

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type Var = LocalVar<T>

Variable type that will wrap the T value. Read more
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fn into_var(self) -> <T as IntoVar<T>>::Var

Converts the source value into a var.
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fn into_boxed_var(self) -> BoxedVar<T>
where Self: Sized,

Converts into BoxedVar<T>. Read more
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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)

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where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. 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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where S: Into<Dispatch>,

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