  #if !defined(BOOST_NO_CXX00_VARIADIC_TEMPLATES) && !defined(BOOST_NO_CXX00_RVALUE_REFERENCES)      template<typename Function, class ...ArgTypes>      inline void call_once(once_flag& flag, BOOST_THREAD_RV_REF(Function) f, BOOST_THREAD_RV_REF(ArgTypes)... args);  #else      