Struct OffsetArc 

pub struct OffsetArc<T: ?Sized> { /* private fields */ }

An Arc, except it holds a pointer to the T instead of to the entire ArcInner.

An OffsetArc<T> has the same layout and ABI as a non-null const T* in C, and may be used in FFI function signatures.

 Arc<T>    OffsetArc<T>
  |          |
  v          v
 ---------------------
| RefCount | T (data) | [ArcInner<T>]
 ---------------------

This means that this is a direct pointer to its contained data (and can be read from by both C++ and Rust), but we can also convert it to a “regular” Arc<T> by removing the offset.

This is very useful if you have an Arc-containing struct shared between Rust and C++, and wish for C++ to be able to read the data behind the Arc without incurring an FFI call overhead.

Implementations

impl<T> OffsetArc<T>

pub fn make_mut(&mut self) -> &mut T

where T: Clone,

If uniquely owned, provide a mutable reference Else create a copy, and mutate that

This is functionally the same thing as Arc::make_mut

impl<T: ?Sized> OffsetArc<T>

pub fn with_arc<F, U>(&self, f: F) -> U

where F: FnOnce(&Arc<T>) -> U,

Temporarily converts |self| into a bonafide Arc and exposes it to the provided callback. The refcount is not modified.

pub fn clone_arc(&self) -> Arc<T>

Clone it as an Arc

pub fn borrow_arc(&self) -> ArcBorrow<'_, T>

Produce a pointer to the data that can be converted back to an Arc

pub fn strong_count(this: &Self) -> usize

The reference count of this Arc.

The number does not include borrowed pointers, or temporary Arc pointers created with functions like ArcBorrow::with_arc.

The function is called strong_count to mirror std::sync::Arc::strong_count, however triomphe::Arc does not support weak references.

Trait Implementations

impl<T: ?Sized> Clone for OffsetArc<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: ?Sized + Debug> Debug for OffsetArc<T>

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

Formats the value using the given formatter.

impl<T: ?Sized> Deref for OffsetArc<T>

type Target = T

The resulting type after dereferencing.

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

Dereferences the value.

impl<T: ?Sized> Drop for OffsetArc<T>

fn drop(&mut self)

Executes the destructor for this type.

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.

impl<T: ?Sized + Eq> Eq for OffsetArc<T>

impl From<&str> for OffsetArc<str>

fn from(s: &str) -> Self

Converts to this type from the input type.

impl From<String> for OffsetArc<str>

fn from(s: String) -> Self

Converts to this type from the input type.

impl<T: ?Sized + Hash> Hash for OffsetArc<T>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: ?Sized + Ord> Ord for OffsetArc<T>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T: ?Sized + PartialEq> PartialEq for OffsetArc<T>

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

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

fn ne(&self, other: &OffsetArc<T>) -> bool

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

impl<T: ?Sized + PartialOrd> PartialOrd for OffsetArc<T>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: ?Sized + Sync + Send> Send for OffsetArc<T>

impl<T: ?Sized + Sync + Send> Sync for OffsetArc<T>

impl<T: ?Sized + RefUnwindSafe> UnwindSafe for OffsetArc<T>