There's a lot more to these singletons than meets the eye.
- It would seem that such usage of raw MemoryOrder in AtomicSingleton would be wrong (e.g. return to acq/rel is in order, which should not pose any performance issues on X86, as Sean mentioned).
- The instance references should be qualified shared.This needs more serious review, even if only for academic purposes. I'll see what I can come up with :) In the meantime, if anyone has anything to add to the list, please chime in!
