Struct boa_gc::GcRefMut

pub struct GcRefMut<'a, T: ?Sized + 'static, U: ?Sized = T> { /* private fields */ }

A wrapper type for a mutably borrowed value from a GcCell<T>.

Implementations

impl<'a, T: ?Sized, U: ?Sized> GcRefMut<'a, T, U>

pub fn try_map<V, F>(orig: Self, f: F) -> Option<GcRefMut<'a, T, V>>

where V: ?Sized, F: FnOnce(&mut U) -> Option<&mut V>,

Tries to make a new GcCellRefMut for a component of the borrowed data, returning None if the mapping function returns None.

The GcCellRefMut is already mutably borrowed, so this cannot fail.

This is an associated function that needs to be used as GcCellRefMut::map(...). A method would interfere with methods of the same name on the contents of a GcCell used through Deref.

pub fn map<V, F>(orig: Self, f: F) -> GcRefMut<'a, T, V>

where V: ?Sized, F: FnOnce(&mut U) -> &mut V,

Makes a new GcCellRefMut for a component of the borrowed data, e.g., an enum variant.

The GcCellRefMut is already mutably borrowed, so this cannot fail.

This is an associated function that needs to be used as GcCellRefMut::map(...). A method would interfere with methods of the same name on the contents of a GcCell used through Deref.

Trait Implementations

impl<T: Trace + ?Sized, U: Debug + ?Sized> Debug for GcRefMut<'_, T, U>

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

Formats the value using the given formatter.

impl<T: Trace + ?Sized, U: ?Sized> Deref for GcRefMut<'_, T, U>

type Target = U

The resulting type after dereferencing.

fn deref(&self) -> &U

Dereferences the value.

impl<T: Trace + ?Sized, U: ?Sized> DerefMut for GcRefMut<'_, T, U>

fn deref_mut(&mut self) -> &mut U

Mutably dereferences the value.

impl<T: Trace + ?Sized, U: Display + ?Sized> Display for GcRefMut<'_, T, U>

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

Formats the value using the given formatter.

impl<T: ?Sized, U: ?Sized> Drop for GcRefMut<'_, T, U>

fn drop(&mut self)

Executes the destructor for this type.