What's this about? Do all atomics need to be 8-aligned, even if it's an atomic<int>?

Does it have to be defined here, or would the following be just as good:

    private:
    #ifdef __arm__
        OIIO_ALIGN(8)
    #endif 
        volatile mutable T m_val;
    ...

Somehow I like that better than the '}' getting caught up in the #ifdef.