pub enum JsOption<T> {
    Some(T),
    Null,
    Undefined,
}
Expand description

An Option-like type with two data-less variants in addition to Some: Null and Undefined.

Variants§

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Some(T)

Some value T

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Null

Explicit absence of a value

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Undefined

Implicit absence of a value

Implementations§

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impl<T> JsOption<T>

pub fn from_option(opt: Option<T>) -> JsOption<T>

Construct a JsOption from a regular Option.

None will be converted to to Null.

pub fn from_implicit_option(opt: Option<T>) -> JsOption<T>

Construct a JsOption from a regular Option.

None will be converted to Undefined.

pub fn into_option(self) -> Option<T>

Convert a JsOption to Option.

pub fn into_nested_option(self) -> Option<Option<T>>

Convert a JsOption<T> to Option<Option<T>>.

Null is represented as Some(None) while Undefined is represented as None.

pub const fn is_some(&self) -> bool

Returns true if the JsOption contains a value.

pub const fn is_null(&self) -> bool

Returns true if the JsOption is Null.

pub const fn is_undefined(&self) -> bool

Returns true if the JsOption is Undefined.

pub fn unwrap(self) -> T

Returns the contained Some value, consuming the self value.

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Panics if the self value equals Null or Undefined.

pub fn unwrap_or(self, default: T) -> T

Returns the contained Some value or a provided default.

pub fn unwrap_or_else<F>(self, f: F) -> T
where F: FnOnce() -> T,

Returns the contained Some value computes is from a closure.

pub fn map<U, F>(self, f: F) -> JsOption<U>
where F: FnOnce(T) -> U,

Maps a JsOption<T> to JsOption<U> by applying a function to a contained value.

pub const fn as_ref(&self) -> JsOption<&T>

Converts from &Option<T> to Option<&T>.

pub fn as_mut(&mut self) -> JsOption<&mut T>

Converts from &mut Option<T> to Option<&mut T>.

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impl<T> JsOption<T>
where T: Default,

pub fn unwrap_or_default(self) -> T

Returns the contained Some value or a default.

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impl<T> JsOption<T>
where T: Deref,

pub fn as_deref(&self) -> JsOption<&<T as Deref>::Target>

Converts from &JsOption<T> to JsOption<&T::Target>.

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impl<T> JsOption<T>
where T: DerefMut,

pub fn as_deref_mut(&mut self) -> JsOption<&mut <T as Deref>::Target>

Converts from &mut JsOption<T> to JsOption<&mut T::Target>.

Trait Implementations§

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impl<T> Clone for JsOption<T>
where T: Clone,

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fn clone(&self) -> JsOption<T>

Returns a copy of the value. Read more
1.0.0 · source§

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl<T> Debug for JsOption<T>
where T: Debug,

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

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

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fn default() -> JsOption<T>

Returns the default value, JsOption::Undefined.

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impl<'de, T> Deserialize<'de> for JsOption<T>
where T: Deserialize<'de>,

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fn deserialize<D>( deserializer: D ) -> Result<JsOption<T>, <D as Deserializer<'de>>::Error>
where D: Deserializer<'de>,

Deserialize a JsOption.

This implementation will never return Undefined. You need to use #[serde(default)] to get Undefined when the field is not present.

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impl<T> Hash for JsOption<T>
where T: Hash,

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

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<T> Ord for JsOption<T>
where T: Ord,

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fn cmp(&self, other: &JsOption<T>) -> Ordering

This method returns an Ordering between self and other. Read more
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fn max(self, other: Self) -> Self
where Self: Sized,

Compares and returns the maximum of two values. Read more
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fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
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fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
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impl<T> PartialEq for JsOption<T>
where T: PartialEq,

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fn eq(&self, other: &JsOption<T>) -> bool

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl<T> PartialOrd for JsOption<T>
where T: PartialOrd,

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fn partial_cmp(&self, other: &JsOption<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists. Read more
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fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator. Read more
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fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
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fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator. Read more
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fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
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impl<T> Serialize for JsOption<T>
where T: Serialize,

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fn serialize<S>( &self, serializer: S ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>
where S: Serializer,

Serialize a JsOption.

Serialization will fail for JsOption::Undefined. You need to use #[skip_serializing_if = "JsOption::is_undefined"] to stop the field from being serialized altogether.

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impl<T> Copy for JsOption<T>
where T: Copy,

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impl<T> Eq for JsOption<T>
where T: Eq,

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impl<T> StructuralPartialEq for JsOption<T>

Auto Trait Implementations§

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impl<T> RefUnwindSafe for JsOption<T>
where T: RefUnwindSafe,

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

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impl<T> Sync for JsOption<T>
where T: Sync,

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

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impl<T> UnwindSafe for JsOption<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<Q, K> Comparable<K> for Q
where Q: Ord + ?Sized, K: Borrow<Q> + ?Sized,

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fn compare(&self, key: &K) -> Ordering

Compare self to key and return their ordering.
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impl<T> CompatExt for T

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fn compat(self) -> Compat<T>

Applies the [Compat] adapter by value. Read more
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fn compat_ref(&self) -> Compat<&T>

Applies the [Compat] adapter by shared reference. Read more
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fn compat_mut(&mut self) -> Compat<&mut T>

Applies the [Compat] adapter by mutable reference. Read more
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impl<T> DynClone for T
where T: Clone,

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fn __clone_box(&self, _: Private) -> *mut ()

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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

Checks if this value is equivalent to the given key. 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<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> FromRef<T> for T
where T: Clone,

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fn from_ref(input: &T) -> T

Converts to this type from a reference to the input type.
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impl<T> FutureExt for T

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fn with_context(self, otel_cx: Context) -> WithContext<Self>

Attaches the provided Context to this type, returning a WithContext wrapper. Read more
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fn with_current_context(self) -> WithContext<Self>

Attaches the current Context to this type, returning a WithContext wrapper. Read more
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impl<T, UT> HandleAlloc<UT> for T
where T: Send + Sync,

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fn new_handle(value: Arc<T>) -> Handle

Create a new handle for an Arc value Read more
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fn clone_handle(handle: Handle) -> Handle

Clone a handle Read more
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fn consume_handle(handle: Handle) -> Arc<T>

Consume a handle, getting back the initial Arc<>
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fn get_arc(handle: Handle) -> Arc<Self>

Get a clone of the Arc<> using a “borrowed” handle. Read more
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impl<T, W> HasTypeWitness<W> for T
where W: MakeTypeWitness<Arg = T>, T: ?Sized,

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const WITNESS: W = W::MAKE

A constant of the type witness
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impl<T> Identity for T
where T: ?Sized,

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type Type = T

The same type as Self, used to emulate type equality bounds (T == U) with associated type equality constraints (T: Identity<Type = U>).
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const TYPE_EQ: TypeEq<T, <T as Identity>::Type> = TypeEq::NEW

Proof that Self is the same type as Self::Type, provides methods for casting between Self and Self::Type.
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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<R, P> ReadPrimitive<R> for P
where R: Read + ReadEndian<P>, P: Default,

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fn read_from_little_endian(read: &mut R) -> Result<Self, Error>

Read this value from the supplied reader. Same as ReadEndian::read_from_little_endian().
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fn read_from_big_endian(read: &mut R) -> Result<Self, Error>

Read this value from the supplied reader. Same as ReadEndian::read_from_big_endian().
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fn read_from_native_endian(read: &mut R) -> Result<Self, Error>

Read this value from the supplied reader. Same as ReadEndian::read_from_native_endian().
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impl<T> Same for T

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type Output = T

Should always be Self
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impl<T> ToOwned for T
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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impl<V, T> VZip<V> for T
where 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> Any for T
where T: Any,

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impl<T> AsyncTraitDeps for T

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impl<T> CloneAny for T
where T: Any + Clone,

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impl<T> CloneAnySend for T
where T: Any + Send + Clone,

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impl<T> CloneAnySendSync for T
where T: Any + Send + Sync + Clone,

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impl<T> CloneAnySync for T
where T: Any + Sync + Clone,

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impl<T> DeserializeOwned for T
where T: for<'de> Deserialize<'de>,

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

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impl<T> SyncOutsideWasm for T
where T: Sync,