d` takes an [`Ordering`] argument which describes the memory ordering
of this operation. All ordering modes are possible. Note that using
[`Acquire`] makes the store part of this operation [`Relaxed`], and
using [`Release`] makes the load part [`Relaxed`].

# Examples

```
use portable_atomic::{AtomicU32, Ordering};

let foo = AtomicU32::new(0);
assert_eq!(foo.fetch_add(10, Ordering::SeqCst), 0);
assert_eq!(foo.load(Ordering::SeqCst), 10);
```