Hi, at present, Boost.Math library always tries to compile long long versions of the function, unless explicit --disable-long-long is passed by the user. I have just checked in a patch that attempt to automatically determine if long long is available. Attached is a sample output of "bjam --with-math" build. The detection is done by compiling new file named libs/math/src/long_double_check.cpp -- if it compiles, it is assumed long double works. Unfortunately, I don't really know what kind of long double support Boost.Math needs. John, Paul, could either of you add some more content to that file? This change an SVN version of bjam as of today. If you use an older version, nothing should break, but no auto-detection will be performed. Also, if you need to look at compiler messages produced when compiling the test file, look at bin.v2/config.log Thanks, -- Vladimir Prus http://vladimir_prus.blogspot.com Boost.Build: http://boost.org/boost-build2 Building the Boost C++ Libraries. Configuration checks summary - long double support : yes Component configuration: - date_time : not building - filesystem : not building - graph : not building - graph_parallel : not building - iostreams : not building - math : building - mpi : not building - program_options : not building - python : not building - regex : not building - serialization : not building - signals : not building - system : not building - test : not building - thread : not building - wave : not building ...patience... ...found 1584 targets... The Boost C++ Libraries were successfully built! The following directory should be added to compiler include paths: /home/ghost/Work/Boost/boost-svn The following directory should be added to linker library paths: /home/ghost/Work/Boost/boost-svn/stage/lib