Struct JsNullable 

pub struct JsNullable<T = JsValue> { /* private fields */ }

A nullable JS value of type T.

Unlike Option<T>, which is a Rust-side construct, JsNullable<T> represents a JS value that may be T or null, where the presence status is not yet known in Rust. The value remains in JS until inspected via methods like is_empty, as_option, or into_option.

This models WebIDL nullable types (T?). Following WebIDL’s ECMAScript conversion rules, where undefined coerces to null at nullable positions, both null and undefined are treated as absent. The canonical empty value produced from Rust is null.

For TypeScript-style T | undefined with strict undefined-only emptiness, use JsOption<T> instead.

T must implement JsGeneric, meaning it is any type that can be represented as a JsValue (e.g., JsString, Number, Object, etc.). JsNullable<T> itself implements JsGeneric, so it can be used in all generic positions that accept JS types.

Implementations

impl<T> JsNullable<T>

where T: JsGeneric,

pub fn new() -> JsNullable<T>

Creates an empty JsNullable<T> representing null.

pub fn wrap(val: T) -> JsNullable<T>

Wraps a value in a JsNullable<T>.

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

Creates a JsNullable<T> from an Option<T>.

Returns JsNullable::wrap(val) if Some(val), otherwise JsNullable::new().

pub fn is_empty(&self) -> bool

Tests whether this JsNullable<T> is empty (null or undefined).

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

Converts this JsNullable<T> to an Option<T> by cloning the inner value.

Returns None if the value is null or undefined, otherwise returns Some(T) with a clone of the contained value.

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

Converts this JsNullable<T> into an Option<T>, consuming self.

Returns None if the value is null or undefined, otherwise returns Some(T) with the contained value.

pub fn unwrap(self) -> T

Returns the contained value, consuming self.

Panics

Panics if the value is null or undefined.

pub fn expect(self, msg: &str) -> T

Returns the contained value, consuming self.

Panics

Panics if the value is null or undefined, with a panic message including the passed message.

pub fn unwrap_or_default(self) -> T

where T: Default,

Returns the contained value or a default.

Returns the contained value if not null or undefined, otherwise returns the default value of T.

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

where F: FnOnce() -> T,

Returns the contained value or computes it from a closure.

Returns the contained value if not null or undefined, otherwise calls f and returns the result.

Methods from Deref<Target = JsValue>

pub const NULL: JsValue

pub const UNDEFINED: JsValue

pub const TRUE: JsValue

pub const FALSE: JsValue

pub fn as_f64(&self) -> Option<f64>

Returns the f64 value of this JS value if it’s an instance of a number.

If this JS value is not an instance of a number then this returns None.

pub fn is_string(&self) -> bool

Tests whether this JS value is a JS string.

pub fn as_string(&self) -> Option<String>

If this JS value is a string value, this function copies the JS string value into Wasm linear memory, encoded as UTF-8, and returns it as a Rust String.

To avoid the copying and re-encoding, consider the JsString::try_from() function from js-sys instead.

If this JS value is not an instance of a string or if it’s not valid utf-8 then this returns None.

UTF-16 vs UTF-8

JavaScript strings in general are encoded as UTF-16, but Rust strings are encoded as UTF-8. This can cause the Rust string to look a bit different than the JS string sometimes. For more details see the documentation about the str type which contains a few caveats about the encodings.

pub fn as_bool(&self) -> Option<bool>

Returns the bool value of this JS value if it’s an instance of a boolean.

If this JS value is not an instance of a boolean then this returns None.

pub fn is_null(&self) -> bool

Tests whether this JS value is null

pub fn is_undefined(&self) -> bool

Tests whether this JS value is undefined

pub fn is_null_or_undefined(&self) -> bool

Tests whether this JS value is null or undefined

pub fn is_symbol(&self) -> bool

Tests whether the type of this JS value is symbol

pub fn is_object(&self) -> bool

Tests whether typeof self == "object" && self !== null.

pub fn is_array(&self) -> bool

Tests whether this JS value is an instance of Array.

pub fn is_function(&self) -> bool

Tests whether the type of this JS value is function.

pub fn is_bigint(&self) -> bool

Tests whether the type of this JS value is bigint.

pub fn js_typeof(&self) -> JsValue

Applies the unary typeof JS operator on a JsValue.

MDN documentation

pub fn js_in(&self, obj: &JsValue) -> bool

Applies the binary in JS operator on the two JsValues.

MDN documentation

pub fn is_truthy(&self) -> bool

Tests whether the value is “truthy”.

pub fn is_falsy(&self) -> bool

Tests whether the value is “falsy”.

pub fn loose_eq(&self, other: &JsValue) -> bool

Compare two JsValues for equality, using the == operator in JS.

MDN documentation

pub fn bit_not(&self) -> JsValue

Applies the unary ~ JS operator on a JsValue.

MDN documentation

pub fn unsigned_shr(&self, rhs: &JsValue) -> u32

Applies the binary >>> JS operator on the two JsValues.

MDN documentation

pub fn checked_div(&self, rhs: &JsValue) -> JsValue

Applies the binary / JS operator on two JsValues, catching and returning any RangeError thrown.

MDN documentation

pub fn pow(&self, rhs: &JsValue) -> JsValue

Applies the binary ** JS operator on the two JsValues.

MDN documentation

pub fn lt(&self, other: &JsValue) -> bool

Applies the binary < JS operator on the two JsValues.

MDN documentation

pub fn le(&self, other: &JsValue) -> bool

Applies the binary <= JS operator on the two JsValues.

MDN documentation

pub fn ge(&self, other: &JsValue) -> bool

Applies the binary >= JS operator on the two JsValues.

MDN documentation

pub fn gt(&self, other: &JsValue) -> bool

Applies the binary > JS operator on the two JsValues.

MDN documentation

pub fn unchecked_into_f64(&self) -> f64

Applies the unary + JS operator on a JsValue. Can throw.

MDN documentation

Trait Implementations

impl<T> AsRef<JsNullable<T>> for JsNullable<T>

fn as_ref(&self) -> &JsNullable<T>

Converts this type into a shared reference of the (usually inferred) input type.

impl<T> AsRef<JsValue> for JsNullable<T>

fn as_ref(&self) -> &JsValue

Converts this type into a shared reference of the (usually inferred) input type.

impl<T> Clone for JsNullable<T>

where T: Clone,

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

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> Debug for JsNullable<T>

where T: JsGeneric + Debug,

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

Formats the value using the given formatter.

impl<T> Default for JsNullable<T>

where T: JsGeneric,

fn default() -> JsNullable<T>

Returns the “default value” for a type.

impl<T> Deref for JsNullable<T>

type Target = JsValue

The resulting type after dereferencing.

fn deref(&self) -> &JsValue

Dereferences the value.

impl<T> Display for JsNullable<T>

where T: JsGeneric + Display,

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

Formats the value using the given formatter.

impl<T> ErasableGeneric for JsNullable<T>

type Repr = JsValue

The singular concrete type that all generic variants can be transmuted on

impl From<JsValue> for JsNullable

fn from(obj: JsValue) -> JsNullable

Converts to this type from the input type.

impl<T> FromWasmAbi for JsNullable<T>

type Abi = <JsValue as FromWasmAbi>::Abi

The Wasm ABI type that this converts from when coming back out from the ABI boundary.

unsafe fn from_abi(js: <JsNullable<T> as FromWasmAbi>::Abi) -> JsNullable<T>

Recover a Self from Self::Abi.

impl<T> IntoJsGeneric for JsNullable<T>

where JsNullable<T>: JsGeneric,

type JsCanon = JsNullable<T>

The canonical JsGeneric form of this type.

fn to_js(self) -> JsNullable<T>

Produce the canonical JsGeneric value for self.

impl<T> IntoWasmAbi for JsNullable<T>

type Abi = <JsValue as IntoWasmAbi>::Abi

The Wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self) -> <JsNullable<T> as IntoWasmAbi>::Abi

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl<'a, T> IntoWasmAbi for &'a JsNullable<T>

type Abi = <&'a JsValue as IntoWasmAbi>::Abi

The Wasm ABI type that this converts into when crossing the ABI boundary.

fn into_abi(self) -> <&'a JsNullable<T> as IntoWasmAbi>::Abi

Convert self into Self::Abi so that it can be sent across the wasm ABI boundary.

impl<T> JsCast for JsNullable<T>

fn instanceof(val: &JsValue) -> bool

Performs a dynamic instanceof check to see whether the JsValue provided is an instance of this type.

fn unchecked_from_js(val: JsValue) -> JsNullable<T>

Performs a zero-cost unchecked conversion from a JsValue into an instance of Self

fn unchecked_from_js_ref(val: &JsValue) -> &JsNullable<T>

Performs a zero-cost unchecked conversion from a &JsValue into an instance of &Self.

fn has_type<T>(&self) -> bool

where T: JsCast,

Test whether this JS value has a type T.

fn dyn_into<T>(self) -> Result<T, Self>

where T: JsCast,

Performs a dynamic cast (checked at runtime) of this value into the target type T.

fn dyn_ref<T>(&self) -> Option<&T>

where T: JsCast,

Performs a dynamic cast (checked at runtime) of this value into the target type T.

fn unchecked_into<T>(self) -> T

where T: JsCast,

Performs a zero-cost unchecked cast into the specified type.

fn unchecked_ref<T>(&self) -> &T

where T: JsCast,

Performs a zero-cost unchecked cast into a reference to the specified type.

fn is_instance_of<T>(&self) -> bool

where T: JsCast,

Test whether this JS value is an instance of the type T.

fn is_type_of(val: &JsValue) -> bool

Performs a dynamic check to see whether the JsValue provided is a value of this type.

impl<T> LongRefFromWasmAbi for JsNullable<T>

type Abi = <JsValue as LongRefFromWasmAbi>::Abi

Same as RefFromWasmAbi::Abi

type Anchor = JsNullable<T>

Same as RefFromWasmAbi::Anchor

unsafe fn long_ref_from_abi( js: <JsNullable<T> as LongRefFromWasmAbi>::Abi, ) -> <JsNullable<T> as LongRefFromWasmAbi>::Anchor

Same as RefFromWasmAbi::ref_from_abi

impl<T> OptionFromWasmAbi for JsNullable<T>

fn is_none(abi: &<JsNullable<T> as FromWasmAbi>::Abi) -> bool

Tests whether the argument is a “none” instance. If so it will be deserialized as None, and otherwise it will be passed to FromWasmAbi.

impl<T> OptionIntoWasmAbi for JsNullable<T>

fn none() -> <JsNullable<T> as IntoWasmAbi>::Abi

Returns an ABI instance indicating “none”, which JS will interpret as the None branch of this option.

impl<'a, T> OptionIntoWasmAbi for &'a JsNullable<T>

fn none() -> <&'a JsNullable<T> as IntoWasmAbi>::Abi

Returns an ABI instance indicating “none”, which JS will interpret as the None branch of this option.

impl<T> PartialEq for JsNullable<T>

where T: PartialEq,

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

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<T> Promising for JsNullable<T>

type Resolution = JsNullable<T>

The type that this value resolves to.

impl<T> RefFromWasmAbi for JsNullable<T>

type Abi = <JsValue as RefFromWasmAbi>::Abi

The Wasm ABI type references to Self are recovered from.

type Anchor = ManuallyDrop<JsNullable<T>>

The type that holds the reference to Self for the duration of the invocation of the function that has an &Self parameter. This is required to ensure that the lifetimes don’t persist beyond one function call, and so that they remain anonymous.

unsafe fn ref_from_abi( js: <JsNullable<T> as RefFromWasmAbi>::Abi, ) -> <JsNullable<T> as RefFromWasmAbi>::Anchor

Recover a Self::Anchor from Self::Abi.

impl<T> StructuralPartialEq for JsNullable<T>

where T: PartialEq,

impl<T> UpcastFrom<()> for JsNullable<T>

impl<T1, T2, Target1, Target2> UpcastFrom<(T1, T2)> for JsNullable<(Target1, Target2)>

where T1: JsGeneric, T2: JsGeneric, Target1: JsGeneric + UpcastFrom<T1>, Target2: JsGeneric + UpcastFrom<T2>,

impl<T1, T2, T3, Target1, Target2, Target3> UpcastFrom<(T1, T2, T3)> for JsNullable<(Target1, Target2, Target3)>

where T1: JsGeneric, T2: JsGeneric, T3: JsGeneric, Target1: JsGeneric + UpcastFrom<T1>, Target2: JsGeneric + UpcastFrom<T2>, Target3: JsGeneric + UpcastFrom<T3>,

impl<T1, T2, T3, T4, Target1, Target2, Target3, Target4> UpcastFrom<(T1, T2, T3, T4)> for JsNullable<(Target1, Target2, Target3, Target4)>

where T1: JsGeneric, T2: JsGeneric, T3: JsGeneric, T4: JsGeneric, Target1: JsGeneric + UpcastFrom<T1>, Target2: JsGeneric + UpcastFrom<T2>, Target3: JsGeneric + UpcastFrom<T3>, Target4: JsGeneric + UpcastFrom<T4>,

impl<T1, T2, T3, T4, T5, Target1, Target2, Target3, Target4, Target5> UpcastFrom<(T1, T2, T3, T4, T5)> for JsNullable<(Target1, Target2, Target3, Target4, Target5)>

where T1: JsGeneric, T2: JsGeneric, T3: JsGeneric, T4: JsGeneric, T5: JsGeneric, Target1: JsGeneric + UpcastFrom<T1>, Target2: JsGeneric + UpcastFrom<T2>, Target3: JsGeneric + UpcastFrom<T3>, Target4: JsGeneric + UpcastFrom<T4>, Target5: JsGeneric + UpcastFrom<T5>,

impl<T1, T2, T3, T4, T5, T6, Target1, Target2, Target3, Target4, Target5, Target6> UpcastFrom<(T1, T2, T3, T4, T5, T6)> for JsNullable<(Target1, Target2, Target3, Target4, Target5, Target6)>

where T1: JsGeneric, T2: JsGeneric, T3: JsGeneric, T4: JsGeneric, T5: JsGeneric, T6: JsGeneric, Target1: JsGeneric + UpcastFrom<T1>, Target2: JsGeneric + UpcastFrom<T2>, Target3: JsGeneric + UpcastFrom<T3>, Target4: JsGeneric + UpcastFrom<T4>, Target5: JsGeneric + UpcastFrom<T5>, Target6: JsGeneric + UpcastFrom<T6>,

impl<T1, T2, T3, T4, T5, T6, T7, Target1, Target2, Target3, Target4, Target5, Target6, Target7> UpcastFrom<(T1, T2, T3, T4, T5, T6, T7)> for JsNullable<(Target1, Target2, Target3, Target4, Target5, Target6, Target7)>

where T1: JsGeneric, T2: JsGeneric, T3: JsGeneric, T4: JsGeneric, T5: JsGeneric, T6: JsGeneric, T7: JsGeneric, Target1: JsGeneric + UpcastFrom<T1>, Target2: JsGeneric + UpcastFrom<T2>, Target3: JsGeneric + UpcastFrom<T3>, Target4: JsGeneric + UpcastFrom<T4>, Target5: JsGeneric + UpcastFrom<T5>, Target6: JsGeneric + UpcastFrom<T6>, Target7: JsGeneric + UpcastFrom<T7>,

impl<T1, T2, T3, T4, T5, T6, T7, T8, Target1, Target2, Target3, Target4, Target5, Target6, Target7, Target8> UpcastFrom<(T1, T2, T3, T4, T5, T6, T7, T8)> for JsNullable<(Target1, Target2, Target3, Target4, Target5, Target6, Target7, Target8)>

where T1: JsGeneric, T2: JsGeneric, T3: JsGeneric, T4: JsGeneric, T5: JsGeneric, T6: JsGeneric, T7: JsGeneric, T8: JsGeneric, Target1: JsGeneric + UpcastFrom<T1>, Target2: JsGeneric + UpcastFrom<T2>, Target3: JsGeneric + UpcastFrom<T3>, Target4: JsGeneric + UpcastFrom<T4>, Target5: JsGeneric + UpcastFrom<T5>, Target6: JsGeneric + UpcastFrom<T6>, Target7: JsGeneric + UpcastFrom<T7>, Target8: JsGeneric + UpcastFrom<T8>,

impl<T1, Target1> UpcastFrom<(T1,)> for JsNullable<(Target1,)>

where T1: JsGeneric, Target1: JsGeneric + UpcastFrom<T1>,

impl<T, Target> UpcastFrom<*const T> for JsNullable<*const Target>

where Target: UpcastFrom<T>,

impl UpcastFrom<AggregateError> for JsNullable<JsValue>

impl UpcastFrom<AggregateError> for JsNullable<AggregateError>

impl UpcastFrom<AggregateError> for JsNullable<Error>

impl UpcastFrom<AggregateError> for JsNullable<Object>

impl<T> UpcastFrom<Array<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<Array<T>> for JsNullable<Array<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<Array<T>> for JsNullable<Object>

impl UpcastFrom<ArrayBuffer> for JsNullable<JsValue>

impl UpcastFrom<ArrayBuffer> for JsNullable<ArrayBuffer>

impl UpcastFrom<ArrayBuffer> for JsNullable<Object>

impl UpcastFrom<ArrayBufferOptions> for JsNullable<JsValue>

impl UpcastFrom<ArrayBufferOptions> for JsNullable<ArrayBufferOptions>

impl UpcastFrom<ArrayBufferOptions> for JsNullable<Object>

impl<T1, T2, Target> UpcastFrom<ArrayTuple<(T1, T2)>> for JsNullable<Array<Target>>

where Target: UpcastFrom<T1> + UpcastFrom<T2>,

impl<T1, T2, T3, Target> UpcastFrom<ArrayTuple<(T1, T2, T3)>> for JsNullable<Array<Target>>

where Target: UpcastFrom<T1> + UpcastFrom<T2> + UpcastFrom<T3>,

impl<T1, T2, T3, T4, Target> UpcastFrom<ArrayTuple<(T1, T2, T3, T4)>> for JsNullable<Array<Target>>

where Target: UpcastFrom<T1> + UpcastFrom<T2> + UpcastFrom<T3> + UpcastFrom<T4>,

impl<T1, T2, T3, T4, T5, Target> UpcastFrom<ArrayTuple<(T1, T2, T3, T4, T5)>> for JsNullable<Array<Target>>

where Target: UpcastFrom<T1> + UpcastFrom<T2> + UpcastFrom<T3> + UpcastFrom<T4> + UpcastFrom<T5>,

impl<T1, T2, T3, T4, T5, T6, Target> UpcastFrom<ArrayTuple<(T1, T2, T3, T4, T5, T6)>> for JsNullable<Array<Target>>

where Target: UpcastFrom<T1> + UpcastFrom<T2> + UpcastFrom<T3> + UpcastFrom<T4> + UpcastFrom<T5> + UpcastFrom<T6>,

impl<T1, T2, T3, T4, T5, T6, T7, Target> UpcastFrom<ArrayTuple<(T1, T2, T3, T4, T5, T6, T7)>> for JsNullable<Array<Target>>

where Target: UpcastFrom<T1> + UpcastFrom<T2> + UpcastFrom<T3> + UpcastFrom<T4> + UpcastFrom<T5> + UpcastFrom<T6> + UpcastFrom<T7>,

impl<T1, T2, T3, T4, T5, T6, T7, T8, Target> UpcastFrom<ArrayTuple<(T1, T2, T3, T4, T5, T6, T7, T8)>> for JsNullable<Array<Target>>

where Target: UpcastFrom<T1> + UpcastFrom<T2> + UpcastFrom<T3> + UpcastFrom<T4> + UpcastFrom<T5> + UpcastFrom<T6> + UpcastFrom<T7> + UpcastFrom<T8>,

impl<T1, Target> UpcastFrom<ArrayTuple<(T1,)>> for JsNullable<Array<Target>>

where Target: UpcastFrom<T1>,

impl<T: JsTuple> UpcastFrom<ArrayTuple<T>> for JsNullable<JsValue>

impl<T> UpcastFrom<AsyncGenerator<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<AsyncGenerator<T>> for JsNullable<AsyncGenerator<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<AsyncGenerator<T>> for JsNullable<Object>

impl<T> UpcastFrom<AsyncIterator<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<AsyncIterator<T>> for JsNullable<AsyncIterator<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl UpcastFrom<BigInt64Array> for JsNullable<JsValue>

impl UpcastFrom<BigInt64Array> for JsNullable<BigInt64Array>

impl UpcastFrom<BigInt64Array> for JsNullable<Object>

impl UpcastFrom<BigInt> for JsNullable<JsValue>

impl UpcastFrom<BigInt> for JsNullable<BigInt>

impl UpcastFrom<BigInt> for JsNullable<Object>

impl UpcastFrom<BigUint64Array> for JsNullable<JsValue>

impl UpcastFrom<BigUint64Array> for JsNullable<BigUint64Array>

impl UpcastFrom<BigUint64Array> for JsNullable<Object>

impl UpcastFrom<Boolean> for JsNullable<JsValue>

impl UpcastFrom<Boolean> for JsNullable<Boolean>

impl UpcastFrom<Boolean> for JsNullable<Object>

impl UpcastFrom<Collator> for JsNullable<JsValue>

impl UpcastFrom<Collator> for JsNullable<Collator>

impl UpcastFrom<Collator> for JsNullable<Object>

impl UpcastFrom<CollatorOptions> for JsNullable<JsValue>

impl UpcastFrom<CollatorOptions> for JsNullable<CollatorOptions>

impl UpcastFrom<CollatorOptions> for JsNullable<Object>

impl UpcastFrom<CompileError> for JsNullable<JsValue>

impl UpcastFrom<CompileError> for JsNullable<CompileError>

impl UpcastFrom<CompileError> for JsNullable<Error>

impl UpcastFrom<DataView> for JsNullable<JsValue>

impl UpcastFrom<DataView> for JsNullable<DataView>

impl UpcastFrom<DataView> for JsNullable<Object>

impl UpcastFrom<Date> for JsNullable<JsValue>

impl UpcastFrom<Date> for JsNullable<Date>

impl UpcastFrom<Date> for JsNullable<Object>

impl UpcastFrom<DateTimeFormat> for JsNullable<JsValue>

impl UpcastFrom<DateTimeFormat> for JsNullable<DateTimeFormat>

impl UpcastFrom<DateTimeFormat> for JsNullable<Object>

impl UpcastFrom<DateTimeFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<DateTimeFormatOptions> for JsNullable<DateTimeFormatOptions>

impl UpcastFrom<DateTimeFormatOptions> for JsNullable<Object>

impl UpcastFrom<DateTimeFormatPart> for JsNullable<JsValue>

impl UpcastFrom<DateTimeFormatPart> for JsNullable<DateTimeFormatPart>

impl UpcastFrom<DateTimeFormatPart> for JsNullable<Object>

impl UpcastFrom<DateTimeRangeFormatPart> for JsNullable<JsValue>

impl UpcastFrom<DateTimeRangeFormatPart> for JsNullable<DateTimeRangeFormatPart>

impl UpcastFrom<DateTimeRangeFormatPart> for JsNullable<DateTimeFormatPart>

impl UpcastFrom<DisplayNames> for JsNullable<JsValue>

impl UpcastFrom<DisplayNames> for JsNullable<DisplayNames>

impl UpcastFrom<DisplayNames> for JsNullable<Object>

impl UpcastFrom<DisplayNamesOptions> for JsNullable<JsValue>

impl UpcastFrom<DisplayNamesOptions> for JsNullable<DisplayNamesOptions>

impl UpcastFrom<DisplayNamesOptions> for JsNullable<Object>

impl UpcastFrom<Duration> for JsNullable<JsValue>

impl UpcastFrom<Duration> for JsNullable<Duration>

impl UpcastFrom<Duration> for JsNullable<Object>

impl UpcastFrom<DurationFormat> for JsNullable<JsValue>

impl UpcastFrom<DurationFormat> for JsNullable<DurationFormat>

impl UpcastFrom<DurationFormat> for JsNullable<Object>

impl UpcastFrom<DurationFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<DurationFormatOptions> for JsNullable<DurationFormatOptions>

impl UpcastFrom<DurationFormatOptions> for JsNullable<Object>

impl UpcastFrom<DurationFormatPart> for JsNullable<JsValue>

impl UpcastFrom<DurationFormatPart> for JsNullable<DurationFormatPart>

impl UpcastFrom<DurationFormatPart> for JsNullable<Object>

impl UpcastFrom<Error> for JsNullable<JsValue>

impl UpcastFrom<Error> for JsNullable<Error>

impl UpcastFrom<Error> for JsNullable<Object>

impl UpcastFrom<ErrorOptions> for JsNullable<JsValue>

impl UpcastFrom<ErrorOptions> for JsNullable<ErrorOptions>

impl UpcastFrom<ErrorOptions> for JsNullable<Object>

impl UpcastFrom<EvalError> for JsNullable<JsValue>

impl UpcastFrom<EvalError> for JsNullable<EvalError>

impl UpcastFrom<EvalError> for JsNullable<Object>

impl UpcastFrom<EvalError> for JsNullable<Error>

impl UpcastFrom<Exception> for JsNullable<JsValue>

impl UpcastFrom<Exception> for JsNullable<Exception>

impl UpcastFrom<Exception> for JsNullable<Object>

impl UpcastFrom<FinalizationRegistry> for JsNullable<JsValue>

impl UpcastFrom<FinalizationRegistry> for JsNullable<FinalizationRegistry>

impl UpcastFrom<FinalizationRegistry> for JsNullable<Object>

impl UpcastFrom<Float16Array> for JsNullable<JsValue>

impl UpcastFrom<Float16Array> for JsNullable<Float16Array>

impl UpcastFrom<Float16Array> for JsNullable<Object>

impl UpcastFrom<Float32Array> for JsNullable<JsValue>

impl UpcastFrom<Float32Array> for JsNullable<Float32Array>

impl UpcastFrom<Float32Array> for JsNullable<Object>

impl UpcastFrom<Float64Array> for JsNullable<JsValue>

impl UpcastFrom<Float64Array> for JsNullable<Float64Array>

impl UpcastFrom<Float64Array> for JsNullable<Object>

impl<T: JsFunction> UpcastFrom<Function<T>> for JsNullable<JsValue>

impl<T: JsFunction> UpcastFrom<Function<T>> for JsNullable<Object>

impl<T> UpcastFrom<Generator<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<Generator<T>> for JsNullable<Generator<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<Generator<T>> for JsNullable<Object>

impl UpcastFrom<Global> for JsNullable<JsValue>

impl UpcastFrom<Global> for JsNullable<Global>

impl UpcastFrom<Global> for JsNullable<Object>

impl UpcastFrom<Instance> for JsNullable<JsValue>

impl UpcastFrom<Instance> for JsNullable<Instance>

impl UpcastFrom<Instance> for JsNullable<Object>

impl UpcastFrom<Int8Array> for JsNullable<JsValue>

impl UpcastFrom<Int8Array> for JsNullable<Int8Array>

impl UpcastFrom<Int8Array> for JsNullable<Object>

impl UpcastFrom<Int16Array> for JsNullable<JsValue>

impl UpcastFrom<Int16Array> for JsNullable<Int16Array>

impl UpcastFrom<Int16Array> for JsNullable<Object>

impl UpcastFrom<Int32Array> for JsNullable<JsValue>

impl UpcastFrom<Int32Array> for JsNullable<Int32Array>

impl UpcastFrom<Int32Array> for JsNullable<Object>

impl<T> UpcastFrom<Iterator<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<Iterator<T>> for JsNullable<Iterator<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<IteratorNext<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<IteratorNext<T>> for JsNullable<IteratorNext<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<IteratorNext<T>> for JsNullable<Object>

impl UpcastFrom<JsClosure> for JsNullable

impl UpcastFrom<JsClosure> for JsNullable<JsClosure>

impl UpcastFrom<JsError> for JsNullable

impl<T, U> UpcastFrom<JsNullable<U>> for JsNullable<T>

where T: UpcastFrom<U>,

impl<T, U> UpcastFrom<JsOption<U>> for JsNullable<T>

where T: UpcastFrom<U>,

impl UpcastFrom<JsString> for JsNullable<JsValue>

impl UpcastFrom<JsString> for JsNullable<JsString>

impl UpcastFrom<JsString> for JsNullable<Object>

impl UpcastFrom<JsValue> for JsNullable

impl UpcastFrom<LinkError> for JsNullable<JsValue>

impl UpcastFrom<LinkError> for JsNullable<LinkError>

impl UpcastFrom<LinkError> for JsNullable<Error>

impl UpcastFrom<ListFormat> for JsNullable<JsValue>

impl UpcastFrom<ListFormat> for JsNullable<ListFormat>

impl UpcastFrom<ListFormat> for JsNullable<Object>

impl UpcastFrom<ListFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<ListFormatOptions> for JsNullable<ListFormatOptions>

impl UpcastFrom<ListFormatOptions> for JsNullable<Object>

impl UpcastFrom<ListFormatPart> for JsNullable<JsValue>

impl UpcastFrom<ListFormatPart> for JsNullable<ListFormatPart>

impl UpcastFrom<ListFormatPart> for JsNullable<Object>

impl UpcastFrom<Locale> for JsNullable<JsValue>

impl UpcastFrom<Locale> for JsNullable<Locale>

impl UpcastFrom<Locale> for JsNullable<Object>

impl UpcastFrom<LocaleMatcherOptions> for JsNullable<JsValue>

impl UpcastFrom<LocaleMatcherOptions> for JsNullable<LocaleMatcherOptions>

impl UpcastFrom<LocaleMatcherOptions> for JsNullable<Object>

impl<K, V> UpcastFrom<Map<K, V>> for JsNullable<JsValue>

impl<K, V, __UpcastTarget0, __UpcastTarget1> UpcastFrom<Map<K, V>> for JsNullable<Map<__UpcastTarget0, __UpcastTarget1>>

where __UpcastTarget0: UpcastFrom<K>, __UpcastTarget1: UpcastFrom<V>,

impl<K, V> UpcastFrom<Map<K, V>> for JsNullable<Object>

impl UpcastFrom<Memory> for JsNullable<JsValue>

impl UpcastFrom<Memory> for JsNullable<Memory>

impl UpcastFrom<Memory> for JsNullable<Object>

impl UpcastFrom<Module> for JsNullable<JsValue>

impl UpcastFrom<Module> for JsNullable<Module>

impl UpcastFrom<Module> for JsNullable<Object>

impl<T> UpcastFrom<Null> for JsNullable<T>

impl UpcastFrom<Number> for JsNullable<JsValue>

impl UpcastFrom<Number> for JsNullable<Number>

impl UpcastFrom<Number> for JsNullable<Object>

impl UpcastFrom<NumberFormat> for JsNullable<JsValue>

impl UpcastFrom<NumberFormat> for JsNullable<NumberFormat>

impl UpcastFrom<NumberFormat> for JsNullable<Object>

impl UpcastFrom<NumberFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<NumberFormatOptions> for JsNullable<NumberFormatOptions>

impl UpcastFrom<NumberFormatOptions> for JsNullable<Object>

impl UpcastFrom<NumberFormatPart> for JsNullable<JsValue>

impl UpcastFrom<NumberFormatPart> for JsNullable<NumberFormatPart>

impl UpcastFrom<NumberFormatPart> for JsNullable<Object>

impl UpcastFrom<NumberRangeFormatPart> for JsNullable<JsValue>

impl UpcastFrom<NumberRangeFormatPart> for JsNullable<NumberRangeFormatPart>

impl UpcastFrom<NumberRangeFormatPart> for JsNullable<NumberFormatPart>

impl<T> UpcastFrom<Object<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<Object<T>> for JsNullable<Object<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T, Target> UpcastFrom<Option<T>> for JsNullable<Option<Target>>

where Target: UpcastFrom<T>,

impl UpcastFrom<PluralRules> for JsNullable<JsValue>

impl UpcastFrom<PluralRules> for JsNullable<PluralRules>

impl UpcastFrom<PluralRules> for JsNullable<Object>

impl UpcastFrom<PluralRulesOptions> for JsNullable<JsValue>

impl UpcastFrom<PluralRulesOptions> for JsNullable<PluralRulesOptions>

impl UpcastFrom<PluralRulesOptions> for JsNullable<Object>

impl<T> UpcastFrom<Promise<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<Promise<T>> for JsNullable<Promise<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<Promise<T>> for JsNullable<Object>

impl<T> UpcastFrom<PromiseState<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<PromiseState<T>> for JsNullable<PromiseState<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<PromiseState<T>> for JsNullable<Object>

impl<T> UpcastFrom<PropertyDescriptor<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<PropertyDescriptor<T>> for JsNullable<PropertyDescriptor<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<PropertyDescriptor<T>> for JsNullable<Object>

impl UpcastFrom<Proxy> for JsNullable<JsValue>

impl UpcastFrom<Proxy> for JsNullable<Proxy>

impl UpcastFrom<RangeError> for JsNullable<JsValue>

impl UpcastFrom<RangeError> for JsNullable<RangeError>

impl UpcastFrom<RangeError> for JsNullable<Error>

impl UpcastFrom<RangeError> for JsNullable<Object>

impl UpcastFrom<ReferenceError> for JsNullable<JsValue>

impl UpcastFrom<ReferenceError> for JsNullable<ReferenceError>

impl UpcastFrom<ReferenceError> for JsNullable<Error>

impl UpcastFrom<ReferenceError> for JsNullable<Object>

impl UpcastFrom<RegExp> for JsNullable<JsValue>

impl UpcastFrom<RegExp> for JsNullable<RegExp>

impl UpcastFrom<RegExp> for JsNullable<Object>

impl UpcastFrom<RegExpMatchArray> for JsNullable<JsValue>

impl UpcastFrom<RegExpMatchArray> for JsNullable<RegExpMatchArray>

impl UpcastFrom<RegExpMatchArray> for JsNullable<Object>

impl UpcastFrom<RegExpMatchArray> for JsNullable<Array>

impl UpcastFrom<RelativeTimeFormat> for JsNullable<JsValue>

impl UpcastFrom<RelativeTimeFormat> for JsNullable<RelativeTimeFormat>

impl UpcastFrom<RelativeTimeFormat> for JsNullable<Object>

impl UpcastFrom<RelativeTimeFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<RelativeTimeFormatOptions> for JsNullable<RelativeTimeFormatOptions>

impl UpcastFrom<RelativeTimeFormatOptions> for JsNullable<Object>

impl UpcastFrom<RelativeTimeFormatPart> for JsNullable<JsValue>

impl UpcastFrom<RelativeTimeFormatPart> for JsNullable<RelativeTimeFormatPart>

impl UpcastFrom<RelativeTimeFormatPart> for JsNullable<Object>

impl UpcastFrom<ResolvedCollatorOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedCollatorOptions> for JsNullable<ResolvedCollatorOptions>

impl UpcastFrom<ResolvedCollatorOptions> for JsNullable<CollatorOptions>

impl UpcastFrom<ResolvedDateTimeFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedDateTimeFormatOptions> for JsNullable<ResolvedDateTimeFormatOptions>

impl UpcastFrom<ResolvedDateTimeFormatOptions> for JsNullable<DateTimeFormatOptions>

impl UpcastFrom<ResolvedDisplayNamesOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedDisplayNamesOptions> for JsNullable<ResolvedDisplayNamesOptions>

impl UpcastFrom<ResolvedDisplayNamesOptions> for JsNullable<DisplayNamesOptions>

impl UpcastFrom<ResolvedDurationFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedDurationFormatOptions> for JsNullable<ResolvedDurationFormatOptions>

impl UpcastFrom<ResolvedDurationFormatOptions> for JsNullable<DurationFormatOptions>

impl UpcastFrom<ResolvedListFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedListFormatOptions> for JsNullable<ResolvedListFormatOptions>

impl UpcastFrom<ResolvedListFormatOptions> for JsNullable<ListFormatOptions>

impl UpcastFrom<ResolvedNumberFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedNumberFormatOptions> for JsNullable<ResolvedNumberFormatOptions>

impl UpcastFrom<ResolvedNumberFormatOptions> for JsNullable<NumberFormatOptions>

impl UpcastFrom<ResolvedPluralRulesOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedPluralRulesOptions> for JsNullable<ResolvedPluralRulesOptions>

impl UpcastFrom<ResolvedPluralRulesOptions> for JsNullable<PluralRulesOptions>

impl UpcastFrom<ResolvedRelativeTimeFormatOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedRelativeTimeFormatOptions> for JsNullable<ResolvedRelativeTimeFormatOptions>

impl UpcastFrom<ResolvedRelativeTimeFormatOptions> for JsNullable<RelativeTimeFormatOptions>

impl UpcastFrom<ResolvedSegmenterOptions> for JsNullable<JsValue>

impl UpcastFrom<ResolvedSegmenterOptions> for JsNullable<ResolvedSegmenterOptions>

impl UpcastFrom<ResolvedSegmenterOptions> for JsNullable<SegmenterOptions>

impl<T, E, TargetT, TargetE> UpcastFrom<Result<T, E>> for JsNullable<Result<TargetT, TargetE>>

where TargetT: UpcastFrom<T>, TargetE: UpcastFrom<E>,

impl UpcastFrom<RuntimeError> for JsNullable<JsValue>

impl UpcastFrom<RuntimeError> for JsNullable<RuntimeError>

impl UpcastFrom<RuntimeError> for JsNullable<Error>

impl UpcastFrom<SegmentData> for JsNullable<JsValue>

impl UpcastFrom<SegmentData> for JsNullable<SegmentData>

impl UpcastFrom<SegmentData> for JsNullable<Object>

impl UpcastFrom<Segmenter> for JsNullable<JsValue>

impl UpcastFrom<Segmenter> for JsNullable<Segmenter>

impl UpcastFrom<Segmenter> for JsNullable<Object>

impl UpcastFrom<SegmenterOptions> for JsNullable<JsValue>

impl UpcastFrom<SegmenterOptions> for JsNullable<SegmenterOptions>

impl UpcastFrom<SegmenterOptions> for JsNullable<Object>

impl UpcastFrom<Segments> for JsNullable<JsValue>

impl UpcastFrom<Segments> for JsNullable<Segments>

impl UpcastFrom<Segments> for JsNullable<Object>

impl<T> UpcastFrom<Set<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<Set<T>> for JsNullable<Set<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<Set<T>> for JsNullable<Object>

impl UpcastFrom<SharedArrayBuffer> for JsNullable<JsValue>

impl UpcastFrom<SharedArrayBuffer> for JsNullable<SharedArrayBuffer>

impl UpcastFrom<SharedArrayBuffer> for JsNullable<Object>

impl UpcastFrom<Symbol> for JsNullable<JsValue>

impl UpcastFrom<Symbol> for JsNullable<Symbol>

impl UpcastFrom<SyntaxError> for JsNullable<JsValue>

impl UpcastFrom<SyntaxError> for JsNullable<SyntaxError>

impl UpcastFrom<SyntaxError> for JsNullable<Error>

impl UpcastFrom<SyntaxError> for JsNullable<Object>

impl UpcastFrom<Table> for JsNullable<JsValue>

impl UpcastFrom<Table> for JsNullable<Table>

impl UpcastFrom<Table> for JsNullable<Object>

impl UpcastFrom<Tag> for JsNullable<JsValue>

impl UpcastFrom<Tag> for JsNullable<Tag>

impl UpcastFrom<Tag> for JsNullable<Object>

impl UpcastFrom<TextInfo> for JsNullable<JsValue>

impl UpcastFrom<TextInfo> for JsNullable<TextInfo>

impl UpcastFrom<TextInfo> for JsNullable<Object>

impl UpcastFrom<TypeError> for JsNullable<JsValue>

impl UpcastFrom<TypeError> for JsNullable<TypeError>

impl UpcastFrom<TypeError> for JsNullable<Error>

impl UpcastFrom<TypeError> for JsNullable<Object>

impl UpcastFrom<Uint8Array> for JsNullable<JsValue>

impl UpcastFrom<Uint8Array> for JsNullable<Uint8Array>

impl UpcastFrom<Uint8Array> for JsNullable<Object>

impl UpcastFrom<Uint8ClampedArray> for JsNullable<JsValue>

impl UpcastFrom<Uint8ClampedArray> for JsNullable<Uint8ClampedArray>

impl UpcastFrom<Uint8ClampedArray> for JsNullable<Object>

impl UpcastFrom<Uint16Array> for JsNullable<JsValue>

impl UpcastFrom<Uint16Array> for JsNullable<Uint16Array>

impl UpcastFrom<Uint16Array> for JsNullable<Object>

impl UpcastFrom<Uint32Array> for JsNullable<JsValue>

impl UpcastFrom<Uint32Array> for JsNullable<Uint32Array>

impl UpcastFrom<Uint32Array> for JsNullable<Object>

impl<T> UpcastFrom<Undefined> for JsNullable<T>

impl UpcastFrom<UriError> for JsNullable<JsValue>

impl UpcastFrom<UriError> for JsNullable<UriError>

impl UpcastFrom<UriError> for JsNullable<Error>

impl UpcastFrom<UriError> for JsNullable<Object>

impl<K, V> UpcastFrom<WeakMap<K, V>> for JsNullable<JsValue>

impl<K, V, __UpcastTarget0, __UpcastTarget1> UpcastFrom<WeakMap<K, V>> for JsNullable<WeakMap<__UpcastTarget0, __UpcastTarget1>>

where __UpcastTarget0: UpcastFrom<K>, __UpcastTarget1: UpcastFrom<V>,

impl<K, V> UpcastFrom<WeakMap<K, V>> for JsNullable<Object>

impl<T> UpcastFrom<WeakRef<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<WeakRef<T>> for JsNullable<WeakRef<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<WeakRef<T>> for JsNullable<Object>

impl<T> UpcastFrom<WeakSet<T>> for JsNullable<JsValue>

impl<T, __UpcastTarget0> UpcastFrom<WeakSet<T>> for JsNullable<WeakSet<__UpcastTarget0>>

where __UpcastTarget0: UpcastFrom<T>,

impl<T> UpcastFrom<WeakSet<T>> for JsNullable<Object>

impl UpcastFrom<WeekInfo> for JsNullable<JsValue>

impl UpcastFrom<WeekInfo> for JsNullable<WeekInfo>

impl UpcastFrom<WeekInfo> for JsNullable<Object>

impl UpcastFrom<bool> for JsNullable

impl UpcastFrom<char> for JsNullable

impl UpcastFrom<f32> for JsNullable

impl UpcastFrom<f32> for JsNullable<f64>

impl UpcastFrom<f64> for JsNullable

impl UpcastFrom<i8> for JsNullable

impl UpcastFrom<i8> for JsNullable<i16>

impl UpcastFrom<i8> for JsNullable<i32>

impl UpcastFrom<i8> for JsNullable<i64>

impl UpcastFrom<i8> for JsNullable<i128>

impl UpcastFrom<i16> for JsNullable

impl UpcastFrom<i16> for JsNullable<i32>

impl UpcastFrom<i16> for JsNullable<i64>

impl UpcastFrom<i16> for JsNullable<i128>

impl UpcastFrom<i32> for JsNullable

impl UpcastFrom<i32> for JsNullable<isize>

impl UpcastFrom<i32> for JsNullable<i64>

impl UpcastFrom<i32> for JsNullable<i128>

impl UpcastFrom<i64> for JsNullable

impl UpcastFrom<i64> for JsNullable<i128>

impl UpcastFrom<i128> for JsNullable

impl UpcastFrom<isize> for JsNullable

impl UpcastFrom<isize> for JsNullable<i64>

impl UpcastFrom<isize> for JsNullable<i128>

impl UpcastFrom<u8> for JsNullable

impl UpcastFrom<u8> for JsNullable<u16>

impl UpcastFrom<u8> for JsNullable<u32>

impl UpcastFrom<u8> for JsNullable<u64>

impl UpcastFrom<u8> for JsNullable<u128>

impl UpcastFrom<u16> for JsNullable

impl UpcastFrom<u16> for JsNullable<u32>

impl UpcastFrom<u16> for JsNullable<u64>

impl UpcastFrom<u16> for JsNullable<u128>

impl UpcastFrom<u32> for JsNullable

impl UpcastFrom<u32> for JsNullable<usize>

impl UpcastFrom<u32> for JsNullable<u64>

impl UpcastFrom<u32> for JsNullable<u128>

impl UpcastFrom<u64> for JsNullable

impl UpcastFrom<u64> for JsNullable<u128>

impl UpcastFrom<u128> for JsNullable

impl UpcastFrom<usize> for JsNullable

impl UpcastFrom<usize> for JsNullable<u64>

impl UpcastFrom<usize> for JsNullable<u128>