Struct script::dom::bindings::cell::DomRefCell

pub struct DomRefCell<T> {
    value: RefCell<T>,
}

A mutable field in the DOM.

This extends the API of std::cell::RefCell to allow unsafe access in certain situations, with dynamic checking in debug builds.

Fields

value: RefCell<T>

Implementations

impl<T> DomRefCell<T>

pub unsafe fn borrow_for_layout(&self) -> &T

Return a reference to the contents. For use in layout only.

Safety

Unlike RefCell::borrow, this method is unsafe because it does not return a Ref, thus leaving the borrow flag untouched. Mutably borrowing the RefCell while the reference returned by this method is alive is undefined behaviour.

Panics

Panics if this is called from anywhere other than the layout thread

Panics if the value is currently mutably borrowed.

pub unsafe fn borrow_for_script_deallocation(&self) -> &mut T

Borrow the contents for the purpose of script deallocation.

Safety

Unlike RefCell::borrow, this method is unsafe because it does not return a Ref, thus leaving the borrow flag untouched. Mutably borrowing the RefCell while the reference returned by this method is alive is undefined behaviour.

Panics

Panics if this is called from anywhere other than the script thread.

pub unsafe fn borrow_mut_for_layout(&self) -> &mut T

Mutably borrow a cell for layout. Ideally this would use RefCell::try_borrow_mut_unguarded but that doesn’t exist yet.

Safety

Unlike RefCell::borrow, this method is unsafe because it does not return a Ref, thus leaving the borrow flag untouched. Mutably borrowing the RefCell while the reference returned by this method is alive is undefined behaviour.

Panics

Panics if this is called from anywhere other than the layout thread.

impl<T> DomRefCell<T>

pub fn new(value: T) -> DomRefCell<T>

Create a new DomRefCell containing value.

pub fn borrow(&self) -> Ref<'_, T>

Immutably borrows the wrapped value.

The borrow lasts until the returned Ref exits scope. Multiple immutable borrows can be taken out at the same time.

Panics

Panics if the value is currently mutably borrowed.

pub fn borrow_mut(&self) -> RefMut<'_, T>

Mutably borrows the wrapped value.

The borrow lasts until the returned RefMut exits scope. The value cannot be borrowed while this borrow is active.

Panics

Panics if the value is currently borrowed.

pub fn try_borrow(&self) -> Result<Ref<'_, T>, BorrowError>

Attempts to immutably borrow the wrapped value.

The borrow lasts until the returned Ref exits scope. Multiple immutable borrows can be taken out at the same time.

Returns None if the value is currently mutably borrowed.

Panics

Panics if this is called off the script thread.

pub fn try_borrow_mut(&self) -> Result<RefMut<'_, T>, BorrowMutError>

Mutably borrows the wrapped value.

The borrow lasts until the returned RefMut exits scope. The value cannot be borrowed while this borrow is active.

Returns None if the value is currently borrowed.

Panics

Panics if this is called off the script thread.

Trait Implementations

impl<T: Clone> Clone for DomRefCell<T>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: CustomTraceable> CustomTraceable for DomRefCell<T>

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

Trace self.

impl<T: Debug> Debug for DomRefCell<T>

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

Formats the value using the given formatter.

impl<T: Default> Default for DomRefCell<T>

fn default() -> DomRefCell<T>

Returns the “default value” for a type.

impl<T> MallocSizeOf for DomRefCell<T>

where T: MallocSizeOf,

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.

impl<K, V> Maplike for DomRefCell<IndexMap<K, V>>

where K: ToJSValConvertible + Eq + PartialEq + Hash + Clone, V: ToJSValConvertible + Clone,

type Key = K

The type of the key of the map.

type Value = V

The type of the value of the map.

fn get_index(&self, index: u32) -> Option<(Self::Key, Self::Value)>

fn get(&self, key: Self::Key) -> Option<Self::Value>

fn size(&self) -> u32

fn set(&self, key: Self::Key, value: Self::Value)

fn has(&self, key: Self::Key) -> bool

fn clear(&self)

fn delete(&self, key: Self::Key) -> bool

impl<T: PartialEq> PartialEq for DomRefCell<T>

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<K> Setlike for DomRefCell<IndexSet<K>>

where K: ToJSValConvertible + Eq + PartialEq + Hash + Clone,

type Key = K

The type of the key of the set.

fn get_index(&self, index: u32) -> Option<Self::Key>

fn size(&self) -> u32

fn add(&self, key: Self::Key)

fn has(&self, key: Self::Key) -> bool

fn clear(&self)

fn delete(&self, key: Self::Key) -> bool

impl<T: JSTraceable> Traceable for DomRefCell<T>

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

Trace self.

impl<T> StructuralPartialEq for DomRefCell<T>