I was hoping I'd be able to fix this once and be done with it, but alas it is not to be. I need to change my fix. The problem has been noted here already in the thread "std_min/std_max reference return value is problematic with boost::interval." Basically, the std_min/std_max helpers cannot be made to work on old compilers that cannot detect reference returns. I have to rip out std_min and std_max. If you want to make an unqualified call to min or max, the recommended way will be as follows: using std::min; min BOOST_PREVENT_MACRO_SUBSTITUTION ( a, b ); I have 2 questions: 1) Is this the best name for the macro? Perhaps people would prefer something shorter. I'm open to suggestions. 2) Is there anyone who wants me to hold off until they finish making some big check-in to avoid merge hell? If so, please contact me privately and we'll work out a schedule. Thanks. -- Eric Niebler Boost Consulting www.boost-consulting.com