Struct ChildRoots

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pub(crate) struct ChildRoots(RefCell<Option<Box<ProtectPool>>>);

Expand description

Lazy retention of uncached ALTREP elements, shared by call scopes and owned views. Ordinary vectors already trace their elements and need no pool.

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§0: RefCell<Option<Box<ProtectPool>>>

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impl ChildRoots

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pub(crate) unsafe fn protect(&self, parent: SEXP, child: SEXP) -> SEXP

Keep child alive until this storage drops.

§Safety

R’s main thread; parent and child must be live on entry. An ordinary parent must remain rooted while its returned children are in use.

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impl Default for ChildRoots

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fn default() -> Self

Returns the “default value” for a type. Read more

Auto Trait Implementations§

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impl !RefUnwindSafe for ChildRoots

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impl UnsafeUnpin for ChildRoots

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impl UnwindSafe for ChildRoots

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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<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into 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> RDefault for T
where T: Default,

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fn r_default() -> T

Create a new instance with default values.

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impl<T> SizeHint for T
where T: ?Sized,

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default fn lower_bound(&self) -> usize

🔬This is a nightly-only experimental API. (core_io_internals)

Returns a lower bound on the number of elements this container-like item contains. For example, an array [u8; 12] could return any value between 0 and 12 inclusively as a correct implementation. Read more

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default fn upper_bound(&self) -> Option<usize>

🔬This is a nightly-only experimental API. (core_io_internals)

Returns an upper bound on the number of elements this container-like item contains if it can be determined, otherwise None. Read more

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final fn size_hint(&self) -> (usize, Option<usize>)

🔬This is a nightly-only experimental API. (core_io_internals)

Returns an estimate for the number of elements this container like type contains. Read more

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