pub struct Arc<T> where T: ?Sized, { /* fields omitted */ }
A thread-safe reference-counting pointer. 'Arc' stands for 'Atomically Reference Counted'.
The type Arc<T> provides shared ownership of a value of type T, allocated in the heap. Invoking clone on Arc produces a new Arc instance, which points to the same allocation on the heap as the source Arc, while increasing a reference count. When the last Arc pointer to a given allocation is destroyed, the value stored in that allocation (often referred to as "inner value") is also dropped.
Shared references in Rust disallow mutation by default, and Arc is no exception: you cannot generally obtain a mutable reference to something inside an Arc. If you need to mutate through an Arc, use Mutex, RwLock, or one of the Atomic types.
Unlike Rc<T>, Arc<T> uses atomic operations for its reference counting. This means that it is thread-safe. The disadvantage is that atomic operations are more expensive than ordinary memory accesses. If you are not sharing reference-counted allocations between threads, consider using Rc<T> for lower overhead. Rc<T> is a safe default, because the compiler will catch any attempt to send an Rc<T> between threads. However, a library might choose Arc<T> in order to give library consumers more flexibility.
Arc<T> will implement Send and Sync as long as the T implements Send and Sync. Why can't you put a non-thread-safe type T in an Arc<T> to make it thread-safe? This may be a bit counter-intuitive at first: after all, isn't the point of Arc<T> thread safety? The key is this: Arc<T> makes it thread safe to have multiple ownership of the same data, but it doesn't add thread safety to its data. Consider Arc<RefCell<T>>. RefCell<T> isn't Sync, and if Arc<T> was always Send, Arc<RefCell<T>> would be as well. But then we'd have a problem: RefCell<T> is not thread safe; it keeps track of the borrowing count using non-atomic operations.
In the end, this means that you may need to pair Arc<T> with some sort of std::sync type, usually Mutex<T>.
Weak
The downgrade method can be used to create a non-owning Weak pointer. A Weak pointer can be upgraded to an Arc, but this will return None if the value stored in the allocation has already been dropped. In other words, Weak pointers do not keep the value inside the allocation alive; however, they do keep the allocation (the backing store for the value) alive.
A cycle between Arc pointers will never be deallocated. For this reason, Weak is used to break cycles. For example, a tree could have strong Arc pointers from parent nodes to children, and Weak pointers from children back to their parents.
Creating a new reference from an existing reference counted pointer is done using the Clone trait implemented for Arc<T> and Weak<T>.
use std::sync::Arc; let foo = Arc::new(vec![1.0, 2.0, 3.0]); // The two syntaxes below are equivalent. let a = foo.clone(); let b = Arc::clone(&foo); // a, b, and foo are all Arcs that point to the same memory location
Deref behaviorArc<T> automatically dereferences to T (via the Deref trait), so you can call T's methods on a value of type Arc<T>. To avoid name clashes with T's methods, the methods of Arc<T> itself are associated functions, called using function-like syntax:
use std::sync::Arc; let my_arc = Arc::new(()); Arc::downgrade(&my_arc);
Weak<T> does not auto-dereference to T, because the inner value may have already been dropped.
Sharing some immutable data between threads:
use std::sync::Arc;
use std::thread;
let five = Arc::new(5);
for _ in 0..10 {
let five = Arc::clone(&five);
thread::spawn(move || {
println!("{:?}", five);
});
}Sharing a mutable AtomicUsize:
use std::sync::Arc;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::thread;
let val = Arc::new(AtomicUsize::new(5));
for _ in 0..10 {
let val = Arc::clone(&val);
thread::spawn(move || {
let v = val.fetch_add(1, Ordering::SeqCst);
println!("{:?}", v);
});
}See the rc documentation for more examples of reference counting in general.
impl<T> Arc<T>[src]
pub fn new(data: T) -> Arc<T>[src]
Constructs a new Arc<T>.
use std::sync::Arc; let five = Arc::new(5);
pub fn new_cyclic(data_fn: impl FnOnce(&Weak<T>) -> T) -> Arc<T>[src]
Constructs a new Arc<T> using a weak reference to itself. Attempting to upgrade the weak reference before this function returns will result in a None value. However, the weak reference may be cloned freely and stored for use at a later time.
#![feature(arc_new_cyclic)]
#![allow(dead_code)]
use std::sync::{Arc, Weak};
struct Foo {
me: Weak<Foo>,
}
let foo = Arc::new_cyclic(|me| Foo {
me: me.clone(),
});pub fn new_uninit() -> Arc<MaybeUninit<T>>[src]
Constructs a new Arc with uninitialized contents.
#![feature(new_uninit)]
#![feature(get_mut_unchecked)]
use std::sync::Arc;
let mut five = Arc::<u32>::new_uninit();
let five = unsafe {
// Deferred initialization:
Arc::get_mut_unchecked(&mut five).as_mut_ptr().write(5);
five.assume_init()
};
assert_eq!(*five, 5)pub fn new_zeroed() -> Arc<MaybeUninit<T>>[src]
Constructs a new Arc with uninitialized contents, with the memory being filled with 0 bytes.
See MaybeUninit::zeroed for examples of correct and incorrect usage of this method.
#![feature(new_uninit)]
use std::sync::Arc;
let zero = Arc::<u32>::new_zeroed();
let zero = unsafe { zero.assume_init() };
assert_eq!(*zero, 0)pub fn pin(data: T) -> Pin<Arc<T>>ⓘNotable traits for Pin<P>
impl<P> Future for Pin<P> where
P: Unpin + DerefMut,
<P as Deref>::Target: Future,
type Output = <<P as Deref>::Target as Future>::Output;
[src]1.33.0
Constructs a new Pin<Arc<T>>. If T does not implement Unpin, then data will be pinned in memory and unable to be moved.
pub fn try_unwrap(this: Arc<T>) -> Result<T, Arc<T>>[src]1.4.0
Returns the inner value, if the Arc has exactly one strong reference.
Otherwise, an Err is returned with the same Arc that was passed in.
This will succeed even if there are outstanding weak references.
use std::sync::Arc; let x = Arc::new(3); assert_eq!(Arc::try_unwrap(x), Ok(3)); let x = Arc::new(4); let _y = Arc::clone(&x); assert_eq!(*Arc::try_unwrap(x).unwrap_err(), 4);
impl<T> Arc<[T]>[src]
pub fn new_uninit_slice(len: usize) -> Arc<[MaybeUninit<T>]>[src]
Constructs a new atomically reference-counted slice with uninitialized contents.
#![feature(new_uninit)]
#![feature(get_mut_unchecked)]
use std::sync::Arc;
let mut values = Arc::<[u32]>::new_uninit_slice(3);
let values = unsafe {
// Deferred initialization:
Arc::get_mut_unchecked(&mut values)[0].as_mut_ptr().write(1);
Arc::get_mut_unchecked(&mut values)[1].as_mut_ptr().write(2);
Arc::get_mut_unchecked(&mut values)[2].as_mut_ptr().write(3);
values.assume_init()
};
assert_eq!(*values, [1, 2, 3])pub fn new_zeroed_slice(len: usize) -> Arc<[MaybeUninit<T>]>[src]
Constructs a new atomically reference-counted slice with uninitialized contents, with the memory being filled with 0 bytes.
See MaybeUninit::zeroed for examples of correct and incorrect usage of this method.
#![feature(new_uninit)]
use std::sync::Arc;
let values = Arc::<[u32]>::new_zeroed_slice(3);
let values = unsafe { values.assume_init() };
assert_eq!(*values, [0, 0, 0])impl<T> Arc<MaybeUninit<T>>[src]
pub unsafe fn assume_init(self) -> Arc<T>[src]
Converts to Arc<T>.
As with MaybeUninit::assume_init, it is up to the caller to guarantee that the inner value really is in an initialized state. Calling this when the content is not yet fully initialized causes immediate undefined behavior.
#![feature(new_uninit)]
#![feature(get_mut_unchecked)]
use std::sync::Arc;
let mut five = Arc::<u32>::new_uninit();
let five = unsafe {
// Deferred initialization:
Arc::get_mut_unchecked(&mut five).as_mut_ptr().write(5);
five.assume_init()
};
assert_eq!(*five, 5)impl<T> Arc<[MaybeUninit<T>]>[src]
pub unsafe fn assume_init(self) -> Arc<[T]>[src]
Converts to Arc<[T]>.
As with MaybeUninit::assume_init, it is up to the caller to guarantee that the inner value really is in an initialized state. Calling this when the content is not yet fully initialized causes immediate undefined behavior.
#![feature(new_uninit)]
#![feature(get_mut_unchecked)]
use std::sync::Arc;
let mut values = Arc::<[u32]>::new_uninit_slice(3);
let values = unsafe {
// Deferred initialization:
Arc::get_mut_unchecked(&mut values)[0].as_mut_ptr().write(1);
Arc::get_mut_unchecked(&mut values)[1].as_mut_ptr().write(2);
Arc::get_mut_unchecked(&mut values)[2].as_mut_ptr().write(3);
values.assume_init()
};
assert_eq!(*values, [1, 2, 3])impl<T> Arc<T> where
T: ?Sized, [src]
pub fn into_raw(this: Arc<T>) -> *const T[src]1.17.0
Consumes the Arc, returning the wrapped pointer.
To avoid a memory leak the pointer must be converted back to an Arc using Arc::from_raw.
use std::sync::Arc;
let x = Arc::new("hello".to_owned());
let x_ptr = Arc::into_raw(x);
assert_eq!(unsafe { &*x_ptr }, "hello");pub fn as_ptr(this: &Arc<T>) -> *const T[src]1.45.0
Provides a raw pointer to the data.
The counts are not affected in any way and the Arc is not consumed. The pointer is valid for as long as there are strong counts in the Arc.
use std::sync::Arc;
let x = Arc::new("hello".to_owned());
let y = Arc::clone(&x);
let x_ptr = Arc::as_ptr(&x);
assert_eq!(x_ptr, Arc::as_ptr(&y));
assert_eq!(unsafe { &*x_ptr }, "hello");pub unsafe fn from_raw(ptr: *const T) -> Arc<T>[src]1.17.0
Constructs an Arc<T> from a raw pointer.
The raw pointer must have been previously returned by a call to Arc<U>::into_raw where U must have the same size and alignment as T. This is trivially true if U is T. Note that if U is not T but has the same size and alignment, this is basically like transmuting references of different types. See mem::transmute for more information on what restrictions apply in this case.
The user of from_raw has to make sure a specific value of T is only dropped once.
This function is unsafe because improper use may lead to memory unsafety, even if the returned Arc<T> is never accessed.
use std::sync::Arc;
let x = Arc::new("hello".to_owned());
let x_ptr = Arc::into_raw(x);
unsafe {
// Convert back to an `Arc` to prevent leak.
let x = Arc::from_raw(x_ptr);
assert_eq!(&*x, "hello");
// Further calls to `Arc::from_raw(x_ptr)` would be memory-unsafe.
}
// The memory was freed when `x` went out of scope above, so `x_ptr` is now dangling!pub fn downgrade(this: &Arc<T>) -> Weak<T>[src]1.4.0
Creates a new Weak pointer to this allocation.
use std::sync::Arc; let five = Arc::new(5); let weak_five = Arc::downgrade(&five);
pub fn weak_count(this: &Arc<T>) -> usize[src]1.15.0
Gets the number of Weak pointers to this allocation.
This method by itself is safe, but using it correctly requires extra care. Another thread can change the weak count at any time, including potentially between calling this method and acting on the result.
use std::sync::Arc; let five = Arc::new(5); let _weak_five = Arc::downgrade(&five); // This assertion is deterministic because we haven't shared // the `Arc` or `Weak` between threads. assert_eq!(1, Arc::weak_count(&five));
pub fn strong_count(this: &Arc<T>) -> usize[src]1.15.0
Gets the number of strong (Arc) pointers to this allocation.
This method by itself is safe, but using it correctly requires extra care. Another thread can change the strong count at any time, including potentially between calling this method and acting on the result.
use std::sync::Arc; let five = Arc::new(5); let _also_five = Arc::clone(&five); // This assertion is deterministic because we haven't shared // the `Arc` between threads. assert_eq!(2, Arc::strong_count(&five));
pub unsafe fn incr_strong_count(ptr: *const T)[src]
Increments the strong reference count on the Arc<T> associated with the provided pointer by one.
The pointer must have been obtained through Arc::into_raw, and the associated Arc instance must be valid (i.e. the strong count must be at least 1) for the duration of this method.
#![feature(arc_mutate_strong_count)]
use std::sync::Arc;
let five = Arc::new(5);
unsafe {
let ptr = Arc::into_raw(five);
Arc::incr_strong_count(ptr);
// This assertion is deterministic because we haven't shared
// the `Arc` between threads.
let five = Arc::from_raw(ptr);
assert_eq!(2, Arc::strong_count(&five));
}pub unsafe fn decr_strong_count(ptr: *const T)[src]
Decrements the strong reference count on the Arc<T> associated with the provided pointer by one.
The pointer must have been obtained through Arc::into_raw, and the associated Arc instance must be valid (i.e. the strong count must be at least 1) when invoking this method. This method can be used to release the final Arc and backing storage, but should not be called after the final Arc has been released.
#![feature(arc_mutate_strong_count)]
use std::sync::Arc;
let five = Arc::new(5);
unsafe {
let ptr = Arc::into_raw(five);
Arc::incr_strong_count(ptr);
// Those assertions are deterministic because we haven't shared
// the `Arc` between threads.
let five = Arc::from_raw(ptr);
assert_eq!(2, Arc::strong_count(&five));
Arc::decr_strong_count(ptr);
assert_eq!(1, Arc::strong_count(&five));
}pub fn ptr_eq(this: &Arc<T>, other: &Arc<T>) -> bool[src]1.17.0
Returns true if the two Arcs point to the same allocation (in a vein similar to ptr::eq).
use std::sync::Arc; let five = Arc::new(5); let same_five = Arc::clone(&five); let other_five = Arc::new(5); assert!(Arc::ptr_eq(&five, &same_five)); assert!(!Arc::ptr_eq(&five, &other_five));
impl<T> Arc<T> where
T: Clone, [src]
pub fn make_mut(this: &mut Arc<T>) -> &mut TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]1.4.0
Makes a mutable reference into the given Arc.
If there are other Arc or Weak pointers to the same allocation, then make_mut will create a new allocation and invoke clone on the inner value to ensure unique ownership. This is also referred to as clone-on-write.
Note that this differs from the behavior of Rc::make_mut which disassociates any remaining Weak pointers.
See also get_mut, which will fail rather than cloning.
use std::sync::Arc; let mut data = Arc::new(5); *Arc::make_mut(&mut data) += 1; // Won't clone anything let mut other_data = Arc::clone(&data); // Won't clone inner data *Arc::make_mut(&mut data) += 1; // Clones inner data *Arc::make_mut(&mut data) += 1; // Won't clone anything *Arc::make_mut(&mut other_data) *= 2; // Won't clone anything // Now `data` and `other_data` point to different allocations. assert_eq!(*data, 8); assert_eq!(*other_data, 12);
impl<T> Arc<T> where
T: ?Sized, [src]
pub fn get_mut(this: &mut Arc<T>) -> Option<&mut T>[src]1.4.0
Returns a mutable reference into the given Arc, if there are no other Arc or Weak pointers to the same allocation.
Returns None otherwise, because it is not safe to mutate a shared value.
See also make_mut, which will clone the inner value when there are other pointers.
use std::sync::Arc; let mut x = Arc::new(3); *Arc::get_mut(&mut x).unwrap() = 4; assert_eq!(*x, 4); let _y = Arc::clone(&x); assert!(Arc::get_mut(&mut x).is_none());
pub unsafe fn get_mut_unchecked(this: &mut Arc<T>) -> &mut TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]
Returns a mutable reference into the given Arc, without any check.
See also get_mut, which is safe and does appropriate checks.
Any other Arc or Weak pointers to the same allocation must not be dereferenced for the duration of the returned borrow. This is trivially the case if no such pointers exist, for example immediately after Arc::new.
#![feature(get_mut_unchecked)]
use std::sync::Arc;
let mut x = Arc::new(String::new());
unsafe {
Arc::get_mut_unchecked(&mut x).push_str("foo")
}
assert_eq!(*x, "foo");impl Arc<dyn Any + 'static + Sync + Send>[src]
pub fn downcast<T>(self) -> Result<Arc<T>, Arc<dyn Any + 'static + Sync + Send>> where
T: Any + Send + Sync + 'static, [src]1.29.0
Attempt to downcast the Arc<dyn Any + Send + Sync> to a concrete type.
use std::any::Any;
use std::sync::Arc;
fn print_if_string(value: Arc<dyn Any + Send + Sync>) {
if let Ok(string) = value.downcast::<String>() {
println!("String ({}): {}", string.len(), string);
}
}
let my_string = "Hello World".to_string();
print_if_string(Arc::new(my_string));
print_if_string(Arc::new(0i8));impl<T> AsRef<T> for Arc<T> where
T: ?Sized, [src]1.5.0
fn as_ref(&self) -> &TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]
impl<T> Borrow<T> for Arc<T> where
T: ?Sized, [src]
fn borrow(&self) -> &TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]
impl<T> Clone for Arc<T> where
T: ?Sized, [src]
fn clone(&self) -> Arc<T>[src]
Makes a clone of the Arc pointer.
This creates another pointer to the same allocation, increasing the strong reference count.
use std::sync::Arc; let five = Arc::new(5); let _ = Arc::clone(&five);
fn clone_from(&mut self, source: &Self)[src]
impl<T, U> CoerceUnsized<Arc<U>> for Arc<T> where
T: Unsize<U> + ?Sized,
U: ?Sized, [src]
impl<T> Debug for Arc<T> where
T: Debug + ?Sized, [src]
impl<T> Default for Arc<T> where
T: Default, [src]
fn default() -> Arc<T>[src]
Creates a new Arc<T>, with the Default value for T.
use std::sync::Arc; let x: Arc<i32> = Default::default(); assert_eq!(*x, 0);
impl<T> Deref for Arc<T> where
T: ?Sized, [src]
type Target = TThe resulting type after dereferencing.
fn deref(&self) -> &TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]
impl<T, U> DispatchFromDyn<Arc<U>> for Arc<T> where
T: Unsize<U> + ?Sized,
U: ?Sized, [src]
impl<T> Display for Arc<T> where
T: Display + ?Sized, [src]
impl<T> Drop for Arc<T> where
T: ?Sized, [src]
fn drop(&mut self)[src]
Drops the Arc.
This will decrement the strong reference count. If the strong reference count reaches zero then the only other references (if any) are Weak, so we drop the inner value.
use std::sync::Arc;
struct Foo;
impl Drop for Foo {
fn drop(&mut self) {
println!("dropped!");
}
}
let foo = Arc::new(Foo);
let foo2 = Arc::clone(&foo);
drop(foo); // Doesn't print anything
drop(foo2); // Prints "dropped!"impl<T> Eq for Arc<T> where
T: Eq + ?Sized, [src]
impl<'_, T> From<&'_ [T]> for Arc<[T]> where
T: Clone, [src]1.21.0
impl<'_> From<&'_ CStr> for Arc<CStr>[src]1.24.0
impl<'_> From<&'_ OsStr> for Arc<OsStr>[src]1.24.0
impl<'_> From<&'_ Path> for Arc<Path>[src]1.24.0
fn from(s: &Path) -> Arc<Path>[src]
Converts a Path into an Arc by copying the Path data into a new Arc buffer.
impl<'_> From<&'_ str> for Arc<str>[src]1.21.0
impl<W> From<Arc<W>> for RawWaker where
W: 'static + Wake + Send + Sync, [src]
impl<W> From<Arc<W>> for Waker where
W: 'static + Wake + Send + Sync, [src]
impl<T> From<Box<T>> for Arc<T> where
T: ?Sized, [src]1.21.0
impl From<CString> for Arc<CStr>[src]1.24.0
impl<'a, B> From<Cow<'a, B>> for Arc<B> where
B: ToOwned + ?Sized,
Arc<B>: From<&'a B>,
Arc<B>: From<<B as ToOwned>::Owned>, [src]1.45.0
impl From<OsString> for Arc<OsStr>[src]1.24.0
impl From<PathBuf> for Arc<Path>[src]1.24.0
fn from(s: PathBuf) -> Arc<Path>[src]
Converts a PathBuf into an Arc by moving the PathBuf data into a new Arc buffer.
impl From<String> for Arc<str>[src]1.21.0
impl<T> From<T> for Arc<T>[src]1.6.0
impl<T> From<Vec<T>> for Arc<[T]>[src]1.21.0
impl<T> FromIterator<T> for Arc<[T]>[src]1.37.0
fn from_iter<I>(iter: I) -> Arc<[T]> where
I: IntoIterator<Item = T>, [src]
Takes each element in the Iterator and collects it into an Arc<[T]>.
In the general case, collecting into Arc<[T]> is done by first collecting into a Vec<T>. That is, when writing the following:
let evens: Arc<[u8]> = (0..10).filter(|&x| x % 2 == 0).collect();
this behaves as if we wrote:
let evens: Arc<[u8]> = (0..10).filter(|&x| x % 2 == 0)
.collect::<Vec<_>>() // The first set of allocations happens here.
.into(); // A second allocation for `Arc<[T]>` happens here.This will allocate as many times as needed for constructing the Vec<T> and then it will allocate once for turning the Vec<T> into the Arc<[T]>.
When your Iterator implements TrustedLen and is of an exact size, a single allocation will be made for the Arc<[T]>. For example:
let evens: Arc<[u8]> = (0..10).collect(); // Just a single allocation happens here.
impl<T> Hash for Arc<T> where
T: Hash + ?Sized, [src]
fn hash<H>(&self, state: &mut H) where
H: Hasher, [src]
fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher, [src]1.3.0
impl<T> Ord for Arc<T> where
T: Ord + ?Sized, [src]
fn cmp(&self, other: &Arc<T>) -> Ordering[src]
Comparison for two Arcs.
The two are compared by calling cmp() on their inner values.
use std::sync::Arc; use std::cmp::Ordering; let five = Arc::new(5); assert_eq!(Ordering::Less, five.cmp(&Arc::new(6)));
fn max(self, other: Self) -> Self[src]1.21.0
fn min(self, other: Self) -> Self[src]1.21.0
fn clamp(self, min: Self, max: Self) -> Self[src]
impl<T> PartialEq<Arc<T>> for Arc<T> where
T: PartialEq<T> + ?Sized, [src]
fn eq(&self, other: &Arc<T>) -> bool[src]
Equality for two Arcs.
Two Arcs are equal if their inner values are equal, even if they are stored in different allocation.
If T also implements Eq (implying reflexivity of equality), two Arcs that point to the same allocation are always equal.
use std::sync::Arc; let five = Arc::new(5); assert!(five == Arc::new(5));
fn ne(&self, other: &Arc<T>) -> bool[src]
Inequality for two Arcs.
Two Arcs are unequal if their inner values are unequal.
If T also implements Eq (implying reflexivity of equality), two Arcs that point to the same value are never unequal.
use std::sync::Arc; let five = Arc::new(5); assert!(five != Arc::new(6));
impl<T> PartialOrd<Arc<T>> for Arc<T> where
T: PartialOrd<T> + ?Sized, [src]
fn partial_cmp(&self, other: &Arc<T>) -> Option<Ordering>[src]
Partial comparison for two Arcs.
The two are compared by calling partial_cmp() on their inner values.
use std::sync::Arc; use std::cmp::Ordering; let five = Arc::new(5); assert_eq!(Some(Ordering::Less), five.partial_cmp(&Arc::new(6)));
fn lt(&self, other: &Arc<T>) -> bool[src]
Less-than comparison for two Arcs.
The two are compared by calling < on their inner values.
use std::sync::Arc; let five = Arc::new(5); assert!(five < Arc::new(6));
fn le(&self, other: &Arc<T>) -> bool[src]
'Less than or equal to' comparison for two Arcs.
The two are compared by calling <= on their inner values.
use std::sync::Arc; let five = Arc::new(5); assert!(five <= Arc::new(5));
fn gt(&self, other: &Arc<T>) -> bool[src]
Greater-than comparison for two Arcs.
The two are compared by calling > on their inner values.
use std::sync::Arc; let five = Arc::new(5); assert!(five > Arc::new(4));
fn ge(&self, other: &Arc<T>) -> bool[src]
'Greater than or equal to' comparison for two Arcs.
The two are compared by calling >= on their inner values.
use std::sync::Arc; let five = Arc::new(5); assert!(five >= Arc::new(5));
impl<T> Pointer for Arc<T> where
T: ?Sized, [src]
impl<T> Send for Arc<T> where
T: Send + Sync + ?Sized, [src]
impl<T> Sync for Arc<T> where
T: Send + Sync + ?Sized, [src]
impl<T, const N: usize> TryFrom<Arc<[T]>> for Arc<[T; N]>[src]1.43.0
type Error = Arc<[T]>The type returned in the event of a conversion error.
fn try_from(
boxed_slice: Arc<[T]>
) -> Result<Arc<[T; N]>, <Arc<[T; N]> as TryFrom<Arc<[T]>>>::Error>[src]
impl<T> Unpin for Arc<T> where
T: ?Sized, [src]1.33.0
impl<T: RefUnwindSafe + ?Sized> UnwindSafe for Arc<T>[src]1.9.0
impl<T: ?Sized> RefUnwindSafe for Arc<T> where
T: RefUnwindSafe, impl<T> Any for T where
T: 'static + ?Sized, [src]
impl<T> Borrow<T> for T where
T: ?Sized, [src]
fn borrow(&self) -> &TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]
impl<T> BorrowMut<T> for T where
T: ?Sized, [src]
fn borrow_mut(&mut self) -> &mut TⓘNotable traits for &'_ mut F
impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized,
type Output = <F as Future>::Output;
impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized,
type Item = <I as Iterator>::Item;
impl<R: Read + ?Sized, '_> Read for &'_ mut R
impl<W: Write + ?Sized, '_> Write for &'_ mut W
[src]
impl<T> From<!> for T[src]
impl<T> From<T> for T[src]
impl<T, U> Into<U> for T where
U: From<T>, [src]
impl<T> ToOwned for T where
T: Clone, [src]
type Owned = TThe resulting type after obtaining ownership.
fn to_owned(&self) -> T[src]
fn clone_into(&self, target: &mut T)[src]
impl<T> ToString for T where
T: Display + ?Sized, [src]
impl<T, U> TryFrom<U> for T where
U: Into<T>, [src]
type Error = InfallibleThe type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>[src]
impl<T, U> TryInto<U> for T where
U: TryFrom<T>, [src]
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/sync/struct.Arc.html