Enum ContextValue

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pub enum ContextValue<T>where
    T: 'static + Clone + PartialEq,{
    Some(T, ContextHandle<T>),
    None,
}

Expand description

A helper which holds both value and handle in a way that it can easily be updated if it is present.

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Some(T, ContextHandle<T>)

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None

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impl<T> ContextValue<T>
where T: 'static + Clone + PartialEq,

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pub fn set(&mut self, new_value: T)

Set a new value, only if the handle is present.

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pub fn get(&self) -> Option<&T>

Get the current value.

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pub fn as_ref(&self) -> Option<&T>

Trait Implementations§

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impl<T> From<Option<(T, ContextHandle<T>)>> for ContextValue<T>
where T: 'static + Clone + PartialEq,

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fn from(value: Option<(T, ContextHandle<T>)>) -> Self

Converts to this type from the input type.

Auto Trait Implementations§

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impl<T> !UnwindSafe for ContextValue<T>

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> 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 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> IntoEither for T

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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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