pub struct MutNullableDom<T: DomObject> {
    ptr: UnsafeCell<Option<Dom<T>>>,
}
Expand description

A holder that provides interior mutability for GC-managed values such as Dom<T>, with nullability represented by an enclosing Option wrapper. Essentially a Cell<Option<Dom<T>>>, but safer.

This should only be used as a field in other DOM objects; see warning on Dom<T>.

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§ptr: UnsafeCell<Option<Dom<T>>>

Implementations§

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impl<T: DomObject> MutNullableDom<T>

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pub fn new(initial: Option<&T>) -> MutNullableDom<T>

Create a new MutNullableDom.

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pub fn or_init<F>(&self, cb: F) -> Root<Dom<T>>where
    F: FnOnce() -> Root<Dom<T>>,

Retrieve a copy of the current inner value. If it is None, it is initialized with the result of cb first.

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pub unsafe fn get_inner_as_layout(&self) -> Option<LayoutDom<'_, T>>

Retrieve a copy of the inner optional Dom<T> as LayoutDom<T>. For use by layout, which can’t use safe types like Temporary.

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

Get a rooted value out of this object

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pub fn set(&self, val: Option<&T>)

Set this MutNullableDom to the given value.

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pub fn take(&self) -> Option<Root<Dom<T>>>

Gets the current value out of this object and sets it to None.

Trait Implementations§

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impl<T: DomObject> Default for MutNullableDom<T>

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fn default() -> MutNullableDom<T>

Returns the “default value” for a type. Read more
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impl<T> JSTraceable for MutNullableDom<T>where
    T: JSTraceable + DomObject,

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unsafe fn trace(&self, tracer: *mut JSTracer)

Trace self.
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impl<T: DomObject> MallocSizeOf for MutNullableDom<T>

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fn size_of(&self, _ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself.
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impl<T: DomObject> PartialEq<MutNullableDom<T>> for MutNullableDom<T>

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fn eq(&self, other: &Self) -> 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<'a, T: DomObject> PartialEq<Option<&'a T>> for MutNullableDom<T>

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fn eq(&self, other: &Option<&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.

Auto Trait Implementations§

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impl<T> !RefUnwindSafe for MutNullableDom<T>

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impl<T> !Send for MutNullableDom<T>

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impl<T> !Sync for MutNullableDom<T>

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impl<T> Unpin for MutNullableDom<T>

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impl<T> UnwindSafe for MutNullableDom<T>where
    T: RefUnwindSafe,

Blanket Implementations§

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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,

const: unstable · source§

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

const: unstable · source§

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> MaybeBoxed<Box<T, Global>> for T

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fn maybe_boxed(self) -> Box<T, Global>

Convert
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impl<T> MaybeBoxed<T> for T

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fn maybe_boxed(self) -> T

Convert
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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<R, P> ReadPrimitive<R> for Pwhere
    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<T> for T

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type Output = T

Should always be Self
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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.
const: unstable · source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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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> Erased for T