Enum Ordering

#[non_exhaustive]
pub enum Ordering {
    Relaxed,
    Release,
    Acquire,
    AcqRel,
    SeqCst,
}

Atomic memory orderings

Memory orderings specify the way atomic operations synchronize memory. In its weakest Ordering::Relaxed, only the memory directly touched by the operation is synchronized. On the other hand, a store-load pair of Ordering::SeqCst operations synchronize other memory while additionally preserving a total order of such operations across all threads.

Rust’s memory orderings are the same as those of C++20.

For more information see the nomicon.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.