A breach of immutability due to memory implicit conversions to immutable without synchronisation, maybe??

[John Colvin]

On Monday, 12 November 2018 at 11:54:36 UTC, Kagamin wrote:
> On Monday, 12 November 2018 at 09:19:26 UTC, John Colvin wrote:
>> The MODIFY line changes the value where the pointer looks. I'm 
>> asking whether it's possible that either READ happens before 
>> MODIFY (which would be v. bad). Using two reads instead of one 
>> was just to turn the (potential) ordering bug in to a 
>> (potential) breach of immutability.
>
> For that you will need READ to happen before atomicLoad (in 
> which case it will just dereference null pointer?) or MODIFY to 
> happen after atomicStore?

The first one is definitely not allowed, I'm not worried about 
that. But is it actually forbidden for the MODIFY to happen after 
atomicStore?