Need help wrapping an existing C++ library as a ruby gem

I have an existing c++ library which I want to package as a rubygem. The c++ library is provided by a vendor and includes all header files and a swig interface as well. I don't have much experience with c++ or with building ruby extensions which is why I need someone to help me. My inital attempts to build with swig on osx have failed and I don't have enough knowledge to use the recommended packager for c++ to ruby which is Rice (http://rice.rubyforge.org/)