diff options
Diffstat (limited to 'library/alloc/src/sync.rs')
| -rw-r--r-- | library/alloc/src/sync.rs | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs index 55d51e0a3c4..d91217f341a 100644 --- a/library/alloc/src/sync.rs +++ b/library/alloc/src/sync.rs @@ -3,6 +3,10 @@ //! Thread-safe reference-counting pointers. //! //! See the [`Arc<T>`][Arc] documentation for more details. +//! +//! **Note**: This module is only available on platforms that support atomic +//! loads and stores of pointers. This may be detected at compile time using +//! `#[cfg(target_has_atomic = "ptr")]`. use core::any::Any; use core::borrow; @@ -82,6 +86,11 @@ macro_rules! acquire { /// [`Mutex`][mutex], [`RwLock`][rwlock], or one of the [`Atomic`][atomic] /// types. /// +/// **Note**: This type is only available on platforms that support atomic +/// loads and stores of pointers, which includes all platforms that support +/// the `std` crate but not all those which only support [`alloc`](crate). +/// This may be detected at compile time using `#[cfg(target_has_atomic = "ptr")]`. +/// /// ## Thread Safety /// /// Unlike [`Rc<T>`], `Arc<T>` uses atomic operations for its reference |