I had to remove the assert in the windows TimeStampValue::TimeStampValue() so
it could be constexpr. another option would be to make the constructors being
constexpr conditional on DEBUG, but that requires a couple ifdefs, and it just
seems simpler to make that constructor private and assume TimeStamp code itself
won't be so dumb as to pass that constructor a meaningful value expecting
something to be done with it.
