text: #ifndef PYTHONIC_BUILTIN_SET_UNION_HPP
  #define PYTHONIC_BUILTIN_SET_UNION_HPP
  
  #include "pythonic/include/__builtin__/set/union_.hpp"
  
  #include "pythonic/types/set.hpp"
  #include "pythonic/utils/functor.hpp"
  
  namespace pythonic
  {
  
    namespace __builtin__
    {
  
      namespace set
      {
  
        template <typename T, typename... Types>
        typename __combined<types::set<T>, Types...>::type
        union_(types::set<T> const &set, Types const &... others)
        {
          return set.union_(others...);
        }
  
        template <typename... Types>
        typename __combined<types::empty_set, Types...>::type
        union_(types::empty_set const &init, Types const &... others)
        {
          return union_(others...);
        }
  
        template <typename T>
        types::set<T> union_(types::set<T> const &set)
        {
          return set;
        }
  
        template <typename T>
        typename __combined<types::empty_set, T>::type union_(T const &set)
        {
          return {set};
        }
  
        types::empty_set union_(types::empty_set const &init)
        {
          return types::empty_set();
        }
  
        DEFINE_FUNCTOR(pythonic::__builtin__::set, union_);
      }
    }
  }
  #endif
  