Struct ArcAtomicCount 

pub struct ArcAtomicCount { /* private fields */ }

Shared-owner wrapper around AtomicCount.

This type is a convenience newtype for Arc<AtomicCount>. Cloning an ArcAtomicCount clones the shared owner handle, so all clones operate on the same underlying non-negative counter.

Example

use qubit_atomic::ArcAtomicCount;

let counter = ArcAtomicCount::zero();
let shared = counter.clone();

shared.inc();
assert_eq!(counter.get(), 1);
assert_eq!(counter.strong_count(), 2);

Implementations

impl ArcAtomicCount

pub fn new(value: usize) -> Self

Creates a new shared non-negative atomic counter.

Parameters

• value - The initial counter value.

Returns

A shared counter wrapper initialized to value.

pub fn zero() -> Self

Creates a new shared counter initialized to zero.

Returns

A shared counter wrapper whose current value is zero.

pub fn from_count(counter: AtomicCount) -> Self

Wraps an existing AtomicCount in an Arc.

Parameters

• counter - The counter container to share.

Returns

A shared counter wrapper owning counter.

pub fn from_arc(inner: Arc<AtomicCount>) -> Self

Wraps an existing shared atomic counter.

Parameters

• inner - The shared atomic counter to wrap.

Returns

A wrapper around inner.

pub fn as_arc(&self) -> &Arc<AtomicCount>

Returns the underlying Arc without cloning it.

Returns

A shared reference to the underlying Arc<AtomicCount>.

pub fn into_arc(self) -> Arc<AtomicCount>

Consumes this wrapper and returns the underlying Arc.

Returns

The underlying Arc<AtomicCount>.

pub fn strong_count(&self) -> usize

Returns the number of strong Arc owners.

Returns

The current strong reference count of the shared counter.

Methods from Deref<Target = AtomicCount>

pub fn get(&self) -> usize

Gets the current counter value.

Returns

The current counter value.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::new(7);
assert_eq!(counter.get(), 7);

pub fn is_zero(&self) -> bool

Returns whether the current counter value is zero.

Returns

true if the current value is zero, otherwise false.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::zero();
assert!(counter.is_zero());

pub fn is_positive(&self) -> bool

Returns whether the current counter value is greater than zero.

Returns

true if the current value is greater than zero, otherwise false.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::new(1);
assert!(counter.is_positive());

pub fn inc(&self) -> usize

Increments the counter by one and returns the new value.

Returns

The counter value after the increment.

Panics

Panics if the increment would overflow usize::MAX.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::zero();
assert_eq!(counter.inc(), 1);

pub fn add(&self, delta: usize) -> usize

Adds delta to the counter and returns the new value.

Parameters

• delta - The amount to add.

Returns

The counter value after the addition.

Panics

Panics if the addition would overflow usize::MAX.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::new(2);
assert_eq!(counter.add(3), 5);

pub fn try_add(&self, delta: usize) -> Option<usize>

Tries to add delta to the counter.

Parameters

• delta - The amount to add.

Returns

Some(new_value) if the addition succeeds, or None if it would overflow usize::MAX. On None, the counter is left unchanged.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::new(2);
assert_eq!(counter.try_add(3), Some(5));

pub fn dec(&self) -> usize

Decrements the counter by one and returns the new value.

This method is useful for detecting the transition to zero:

use qubit_atomic::AtomicCount;

let counter = AtomicCount::new(1);
if counter.dec() == 0 {
    // This call consumed the final counted item.
}

Returns

The counter value after the decrement.

Panics

Panics if the current value is zero.

pub fn try_dec(&self) -> Option<usize>

Tries to decrement the counter by one.

Returns

Some(new_value) if the decrement succeeds, or None if the current value is zero. On None, the counter is left unchanged.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::new(1);
assert_eq!(counter.try_dec(), Some(0));
assert_eq!(counter.try_dec(), None);

pub fn sub(&self, delta: usize) -> usize

Subtracts delta from the counter and returns the new value.

Parameters

• delta - The amount to subtract.

Returns

The counter value after the subtraction.

Panics

Panics if the subtraction would make the counter negative.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::new(5);
assert_eq!(counter.sub(2), 3);

pub fn try_sub(&self, delta: usize) -> Option<usize>

Tries to subtract delta from the counter.

Parameters

• delta - The amount to subtract.

Returns

Some(new_value) if the subtraction succeeds, or None if it would make the counter negative. On None, the counter is left unchanged.

Example

use qubit_atomic::AtomicCount;

let counter = AtomicCount::new(3);
assert_eq!(counter.try_sub(2), Some(1));
assert_eq!(counter.try_sub(2), None);

Trait Implementations

impl Clone for ArcAtomicCount

fn clone(&self) -> Self

Clones the shared owner handle.

Returns

A new wrapper pointing to the same underlying atomic counter.

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

Performs copy-assignment from source.

impl Debug for ArcAtomicCount

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

Formats the current counter value and sharing state for debugging.

Parameters

• f - The formatter receiving the debug representation.

Returns

A formatting result from the formatter.

impl Default for ArcAtomicCount

fn default() -> Self

Creates a zero-valued shared atomic counter.

Returns

A shared counter wrapper whose current value is zero.

impl Deref for ArcAtomicCount

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

Dereferences to the underlying AtomicCount.

Returns

A shared reference to the atomic counter.

type Target = AtomicCount

The resulting type after dereferencing.

impl Display for ArcAtomicCount

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

Formats the current counter value with decimal display formatting.

Parameters

• f - The formatter receiving the displayed value.

Returns

A formatting result from the formatter.

impl From<Arc<AtomicCount>> for ArcAtomicCount

fn from(inner: Arc<AtomicCount>) -> Self

Converts an existing shared atomic counter into its wrapper.

Parameters

• inner - The shared atomic counter to wrap.

Returns

A wrapper around inner.

impl From<AtomicCount> for ArcAtomicCount

fn from(counter: AtomicCount) -> Self

Converts an atomic counter into a shared atomic counter wrapper.

Parameters

• counter - The counter container to share.

Returns

A shared counter wrapper owning counter.

impl From<usize> for ArcAtomicCount

fn from(value: usize) -> Self

Converts an initial counter value into a shared atomic counter.

Parameters

• value - The initial counter value.

Returns

A shared counter wrapper initialized to value.