pub struct Value<'a, T> { /* private fields */ }
Expand description

Abstraction over some optional value T that is stored in the dispatch context.

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impl<T> Value<'_, T>

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

Get the value as reference.

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pub fn get_mut(&mut self) -> Option<&mut T>

Get the value as mutable reference.

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

Set to the given value.

Self::get and Self::get_mut will return new_value afterwards.

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pub fn or_default(&mut self) -> &mut Twhere T: Default,

Returns a mutable reference to the value.

If the internal value isn’t initialized, this will set it to Default::default() before returning the mutable reference.

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pub fn clear(&mut self)

Clear the internal value.

Self::get and Self::get_mut will return None afterwards.

Auto Trait Implementations§

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impl<'a, T> RefUnwindSafe for Value<'a, T>where T: RefUnwindSafe,

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impl<'a, T> Send for Value<'a, T>where T: Send,

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impl<'a, T> Sync for Value<'a, T>where T: Sync,

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impl<'a, T> Unpin for Value<'a, T>where T: Unpin,

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impl<'a, T> !UnwindSafe for Value<'a, T>

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impl<T> Any for Twhere 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 Twhere T: ?Sized,

const: unstable · source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere 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> CheckedConversion for T

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fn checked_from<T>(t: T) -> Option<Self>where Self: TryFrom<T>,

Convert from a value of T into an equivalent instance of Option<Self>. Read more
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fn checked_into<T>(self) -> Option<T>where Self: TryInto<T>,

Consume self to return Some equivalent value of Option<T>. 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 Twhere U: From<T>,

const: unstable · source§

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, Outer> IsWrappedBy<Outer> for Twhere Outer: AsRef<T> + AsMut<T> + From<T>, T: From<Outer>,

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fn from_ref(outer: &Outer) -> &T

Get a reference to the inner from the outer.

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fn from_mut(outer: &mut Outer) -> &mut T

Get a mutable reference to the inner from the outer.

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impl<T> Pointable for T

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const ALIGN: usize = mem::align_of::<T>()

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> Same<T> for T

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type Output = T

Should always be Self
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impl<T> SaturatedConversion for T

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fn saturated_from<T>(t: T) -> Selfwhere Self: UniqueSaturatedFrom<T>,

Convert from a value of T into an equivalent instance of Self. Read more
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fn saturated_into<T>(self) -> Twhere Self: UniqueSaturatedInto<T>,

Consume self to return an equivalent value of T. Read more
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

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 Twhere 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<S, T> UncheckedInto<T> for Swhere T: UncheckedFrom<S>,

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fn unchecked_into(self) -> T

The counterpart to unchecked_from.
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impl<T, S> UniqueSaturatedInto<T> for Swhere T: Bounded, S: TryInto<T>,

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fn unique_saturated_into(self) -> T

Consume self to return an equivalent value of T.
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impl<V, T> VZip<V> for Twhere V: MultiLane<T>,

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fn vzip(self) -> V

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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<T> JsonSchemaMaybe for T

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impl<T> MaybeRefUnwindSafe for Twhere T: RefUnwindSafe,