Hello, when compiling a file that uses float_distance from #include I get a linking error: undefined reference to `boost::math::tools::promote_args::type boost::math::float_distance(double const&, double const&)' I try to add all boost_math libs I could find, but none helped: -lboost_system -lboost_filesystem -lboost_math_tr1 -lboost_math_c99 -lboost_math_c99 Since float_distance is not a C99 / TR1 function, should'nt boost.math work as header only? What is the problem here? Thanks, Florian