U>Вильямс походу не в курсе о получении актуального значения через release/acquire : http://stackoverflow.com/questions/8819095/concurrency-atomic-and-volatile-in-c11-memory-model

The only way to guarantee you have the "latest" value is to use a read-modify-write operation such as exchange(), compare_exchange_strong() or fetch_add(). Read-modify-write operations have an additional constraint that they always operate on the "latest" value, so a sequence of ai.fetch_add(1) operations by a series of threads will return a sequence of values with no duplicates or gaps. In the absence of additional constraints, there's still no guarantee which threads will see which values though.