[−][src]Struct xarc::Xarc
Xarc
is a derefenceable atomically refcounted smart pointer.
Xarc
is roughly equivalent to Arc
but is compatible with AtomicXarc
.
Examples
Here is some typical usage of Xarc
.
use xarc::Xarc; let xarc = Xarc::new(42); let same = xarc.clone(); let different = Xarc::new(42); // Null checks assert!(!xarc.is_null()); assert_ne!(xarc, Xarc::null()); // Pointer comparisons assert_eq!(xarc, same); assert_ne!(xarc, different); // Value comparisons assert_eq!(xarc.maybe_deref().unwrap(), different.maybe_deref().unwrap()); assert_eq!(Xarc::<i64>::null().maybe_deref(), None);
When implementing a container you often need structures with an immutable part,
such as a pointer to another part of the structure, and a separate value that
you can take
to return a value as you remove it. UnsafeCell
comes to the rescue.
use core::{cell::UnsafeCell, mem}; use xarc::Xarc; struct Example { immutable: i64, takeable: UnsafeCell<i64>, } let mut xarc = Xarc::new(Example {immutable: 0, takeable: UnsafeCell::new(42)}); let value = unsafe { // You had better know what you're doing at this point. 🙂 core::mem::take(&mut *xarc.maybe_deref().unwrap().takeable.get()) }; assert_eq!(value, 42);
Implementations
impl<T: Send> Xarc<T>
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#[must_use]pub fn new(value: T) -> Self
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Initialize the smart pointer with value
.
#[must_use]pub fn null() -> Self
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Initialize the smart pointer with null.
pub fn reset(&mut self)
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Reset the smart pointer to null.
#[must_use]pub fn is_null(&self) -> bool
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Check if the smart pointer is null.
#[must_use]pub fn maybe_deref(&self) -> Option<&T>
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Dereference the pointer only if it is not null. None will be returned if it is null.
#[must_use]pub unsafe fn unguarded_maybe_deref_mut(&mut self) -> Option<&mut T>
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Dereference the pointer only if it is not null. None will be returned if it is null.
Safety
- This should be called only if you're absolutely, 100% certain that nobody else could possibly have access to this data or if you really know what you're doing.
Trait Implementations
impl<T: Send> Clone for Xarc<T>
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fn clone(&self) -> Self
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fn clone_from(&mut self, source: &Self)
1.0.0[src]
impl<T: Debug + Send> Debug for Xarc<T>
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impl<T: Send> Drop for Xarc<T>
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impl<T: Eq + Send> Eq for Xarc<T>
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impl<T: Send, '_> From<&'_ Xarc<T>> for AtomicXarc<T>
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impl<T: Send> Hash for Xarc<T>
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fn hash<H: Hasher>(&self, state: &mut H)
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fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,
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H: Hasher,
impl<T: Send> PartialEq<Xarc<T>> for Xarc<T>
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#[must_use]fn eq(&self, other: &Self) -> bool
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#[must_use]fn ne(&self, other: &Rhs) -> bool
1.0.0[src]
impl<T: Send> Send for Xarc<T>
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impl<T: Send> StructuralEq for Xarc<T>
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impl<T: Send> Sync for Xarc<T>
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Auto Trait Implementations
impl<T> RefUnwindSafe for Xarc<T> where
T: RefUnwindSafe,
T: RefUnwindSafe,
impl<T> Unpin for Xarc<T>
impl<T> UnwindSafe for Xarc<T> where
T: RefUnwindSafe,
T: RefUnwindSafe,
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
fn borrow_mut(&mut self) -> &mut T
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impl<T> From<T> for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T> ToOwned for T where
T: Clone,
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T: Clone,
type Owned = T
The resulting type after obtaining ownership.
fn to_owned(&self) -> T
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fn clone_into(&self, target: &mut T)
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impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
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impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,