Hello, my svn and compiler versions are: Path: . URL: http://svn.boost.org/svn/boost/trunk Repository Root: http://svn.boost.org/svn/boost Repository UUID: b8fc166d-592f-0410-95f2-cb63ce0dd405 Revision: 83985 Node Kind: directory Schedule: normal Last Changed Author: viboes Last Changed Rev: 83985 Last Changed Date: 2013-04-20 16:12:43 +0200 (Sat, 20 Apr 2013) $ LANG=en g++ --version g++ (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2) Copyright (C) 2011 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. and maybe the last changes $ svn log boost/thread/pthread/once_atomic.hpp ------------------------------------------------------------------------ r83466 | viboes | 2013-03-16 16:36:21 +0100 (Sa, 16. Mär 2013) | 1 Zeile Thread: add invoke when no variadic templates are available; adapt call_once. breaks my code now which is basically: ---8<--- namespace { struct id_string { static boost::once_flag flag; typedef std::map<int, std::string> map_type; ... static void do_init(token_id_string& self) { insert(self.m_map)(x, "y")(...) ; } std::string const& operator()(id::type id) const { boost::call_once(flag, &id_string::do_init, *this); map_iterator s = m_map.find(id); ... } }; id_string::map_type id_string::m_map; #ifdef BOOST_THREAD_PROVIDES_ONCE_CXX11 boost::once_flag id_string::flag; #else boost::once_flag id_string::flag = BOOST_ONCE_INIT; #endif } --->8--- The error is about /usr/local/include/boost/thread/detail/invoke.hpp: In function 'typename boost::enable_if_c<(! boost::is_member_function_pointer<Fp>::value), Ret>::type boost::detail::invoke(Fp&&, Args&& ...) [with Ret = void, Fp = void (*)({anonymous}::id_string&), Args = {{anonymous}::id_string}, typename boost::enable_if_c<(! boost::is_member_function_pointer<Fp>::value), Ret>::type = void]': /usr/local/include/boost/thread/pthread/once_atomic.hpp:127:9: instantiated from 'void boost::call_once(boost::once_flag&, Function&&, ArgTypes&& ...) [with Function = void (*)({anonymous}::id_string&), ArgTypes = {{anonymous}::id_string&}]' /home/olaf/work/token_ids.cpp:93:59: instantiated from here /usr/local/include/boost/thread/detail/invoke.hpp:406:65: error: invalid initialization of non-const reference of type '{anonymous}::id_string&' from an rvalue of type '{anonymous}::id_string' Is this intentionally or do I miss something? Thanks, Olaf