diff options
Diffstat (limited to 'library/alloc/src/sync.rs')
-rw-r--r-- | library/alloc/src/sync.rs | 31 |
1 files changed, 27 insertions, 4 deletions
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs index d3b755844..838987f67 100644 --- a/library/alloc/src/sync.rs +++ b/library/alloc/src/sync.rs @@ -1454,6 +1454,7 @@ impl<T: ?Sized, A: Allocator> Arc<T, A> { /// ``` #[must_use = "losing the pointer will leak memory"] #[stable(feature = "rc_raw", since = "1.17.0")] + #[cfg_attr(not(bootstrap), rustc_never_returns_null_ptr)] pub fn into_raw(this: Self) -> *const T { let ptr = Self::as_ptr(&this); mem::forget(this); @@ -1478,6 +1479,7 @@ impl<T: ?Sized, A: Allocator> Arc<T, A> { /// ``` #[must_use] #[stable(feature = "rc_as_ptr", since = "1.45.0")] + #[cfg_attr(not(bootstrap), rustc_never_returns_null_ptr)] pub fn as_ptr(this: &Self) -> *const T { let ptr: *mut ArcInner<T> = NonNull::as_ptr(this.ptr); @@ -1616,7 +1618,7 @@ impl<T: ?Sized, A: Allocator> Arc<T, A> { #[must_use] #[stable(feature = "arc_counts", since = "1.15.0")] pub fn weak_count(this: &Self) -> usize { - let cnt = this.inner().weak.load(Acquire); + let cnt = this.inner().weak.load(Relaxed); // If the weak count is currently locked, the value of the // count was 0 just before taking the lock. if cnt == usize::MAX { 0 } else { cnt - 1 } @@ -1646,7 +1648,7 @@ impl<T: ?Sized, A: Allocator> Arc<T, A> { #[must_use] #[stable(feature = "arc_counts", since = "1.15.0")] pub fn strong_count(this: &Self) -> usize { - this.inner().strong.load(Acquire) + this.inner().strong.load(Relaxed) } /// Increments the strong reference count on the `Arc<T>` associated with the @@ -2801,7 +2803,7 @@ impl<T: ?Sized, A: Allocator> Weak<T, A> { #[must_use] #[stable(feature = "weak_counts", since = "1.41.0")] pub fn strong_count(&self) -> usize { - if let Some(inner) = self.inner() { inner.strong.load(Acquire) } else { 0 } + if let Some(inner) = self.inner() { inner.strong.load(Relaxed) } else { 0 } } /// Gets an approximation of the number of `Weak` pointers pointing to this @@ -2820,7 +2822,7 @@ impl<T: ?Sized, A: Allocator> Weak<T, A> { pub fn weak_count(&self) -> usize { if let Some(inner) = self.inner() { let weak = inner.weak.load(Acquire); - let strong = inner.strong.load(Acquire); + let strong = inner.strong.load(Relaxed); if strong == 0 { 0 } else { @@ -3268,6 +3270,27 @@ impl<T> From<T> for Arc<T> { } #[cfg(not(no_global_oom_handling))] +#[stable(feature = "shared_from_array", since = "1.74.0")] +impl<T, const N: usize> From<[T; N]> for Arc<[T]> { + /// Converts a [`[T; N]`](prim@array) into an `Arc<[T]>`. + /// + /// The conversion moves the array into a newly allocated `Arc`. + /// + /// # Example + /// + /// ``` + /// # use std::sync::Arc; + /// let original: [i32; 3] = [1, 2, 3]; + /// let shared: Arc<[i32]> = Arc::from(original); + /// assert_eq!(&[1, 2, 3], &shared[..]); + /// ``` + #[inline] + fn from(v: [T; N]) -> Arc<[T]> { + Arc::<[T; N]>::from(v) + } +} + +#[cfg(not(no_global_oom_handling))] #[stable(feature = "shared_from_slice", since = "1.21.0")] impl<T: Clone> From<&[T]> for Arc<[T]> { /// Allocate a reference-counted slice and fill it by cloning `v`'s items. |