Struct OwnedProtect

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pub struct OwnedProtect {
    sexp: SEXP,
    armed: bool,
    _nosend: PhantomData<Rc<()>>,
}

Expand description

A single-object RAII guard: PROTECT on create, UNPROTECT(1) on drop.

Use this for simple cases where you’re protecting a single value and don’t need the batching benefits of ProtectScope.

§Example

unsafe fn allocate_and_fill() -> SEXP {
    let guard = OwnedProtect::new(Rf_allocVector(REALSXP, 10));
    fill_vector(guard.get());
    // Return the SEXP - guard drops and unprotects on this line.
    // This is safe because no GC can occur between unprotect and return.
    guard.get()
}

§Warning: Stack Ordering

OwnedProtect uses UNPROTECT(1), which removes the top of the protection stack. If you have nested protections from other sources, the drop order matters!

For complex scenarios, prefer ProtectScope which unprotects all its values at once when dropped.

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§sexp: SEXP§armed: bool§_nosend: PhantomData<Rc<()>>

Implementations§

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impl OwnedProtect

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pub unsafe fn new(x: SEXP) -> Self

Create a new protection guard for x.

Calls Rf_protect(x) immediately.

§Safety

Must be called from the R main thread
x must be a valid SEXP

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pub fn get(&self) -> SEXP

Get the protected SEXP.

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pub unsafe fn forget(self)

Escape hatch: do not UNPROTECT(1) on drop.

§Safety

Leaks one protection entry unless unprotected elsewhere.

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impl Deref for OwnedProtect

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type Target = SEXP

The resulting type after dereferencing.

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fn deref(&self) -> &Self::Target

Dereferences the value.

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impl Drop for OwnedProtect

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fn drop(&mut self)

Executes the destructor for this type. Read more

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fn pin_drop(self: Pin<&mut Self>)

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

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned. Read more

Auto Trait Implementations§

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impl RefUnwindSafe for OwnedProtect

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impl UnsafeUnpin for OwnedProtect

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impl UnwindSafe for OwnedProtect

Blanket Implementations§

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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<P, T> Receiver for P
where P: Deref<Target = T> + ?Sized, T: ?Sized,

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type Target = T

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

The target type on which the method may be called.

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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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