[atomics.types.operations] (original) (raw)

Effects: Retrieves the value in expected.

It then atomically compares the value representation of the value pointed to by thisfor equality with that previously retrieved from expected, and if true, replaces the value pointed to by this with that in desired.

If and only if the comparison is true, memory is affected according to the value of success, and if the comparison is false, memory is affected according to the value of failure.

When only one memory_order argument is supplied, the value of success is order, and the value offailure is order except that a value of memory_order​::​acq_relshall be replaced by the value memory_order​::​acquire and a value ofmemory_order​::​release shall be replaced by the valuememory_order​::​relaxed.

If and only if the comparison is false then, after the atomic operation, the value in expected is replaced by the value pointed to by this during the atomic comparison.

If the operation returns true, these operations are atomic read-modify-write operations ([intro.multithread]) on the memory pointed to by this.

Otherwise, these operations are atomic load operations on that memory.