Boost C++ Libraries

namespace boost {
  namespace icl {
    namespace interval_combine {
       BOOST_STATIC_CONSTANT(int, unknown = 0);
       BOOST_STATIC_CONSTANT(int, joining = 1);
       BOOST_STATIC_CONSTANT(int, separating = 2);
       BOOST_STATIC_CONSTANT(int, splitting = 3);
       BOOST_STATIC_CONSTANT(int, elemental = 4);
    }
  }
}