[boost] setting option specific for compiler in Jamfile

How can I apply an option in Jamfile which applies only for toolset-version onward? instead of writing: <toolset>gcc-4.7:<cxxflags>-fxyz <toolset>gcc-4.8:<cxxflags>-fxyz <toolset>gcc-4.9:<cxxflags>-fxyz I'd like to have a single line. <toolset>gcc-greater-eqal-4.7:<cxxflags>-fxyz best regards, Oliver