Its become clear to me that this is an important and way non-trivial subject that I'm not going to get into the details of. Sooo - here's what I'm going to do. I'm going to make / use a very simple lightweight singleton which has an interface similar or identical to your proposal. I can modify all the places in the serialization library which now implement this functionality in an ad-hoc way so that they depend on this single header. There are a number of such cases - at last 7 !!. So this will make my code more clear and shorter. It won't make the serialization thread-safe however. But when or if this ever gets sorted out, It will be trivial to just change a few #includes and I'll done. If anyone can't wait for a Boost threadsafe singleton, they can substitute my trivial one for one of their own choosing. That is, I'm offloading this issue to anyone else Robert Ramey