enum idiom for non-c++11 environment

enum_idiom.cpp

#include<iostream>
#include<boost/variant.hpp>
namespace E1 {
	enum Type {
		a,b,c
	};
	struct stringize:std::string {
		stringize(Type e) {
			switch(e) {
				#define ENUM_STRINGIZE(elem) break;case elem:assign(#elem)
				ENUM_STRINGIZE(E1::a);
				ENUM_STRINGIZE(E1::b);
				ENUM_STRINGIZE(E1::c);
				#undef ENUM_STRINGIZE
				break;default:assign("Undef");
			}
		}
	};
}
namespace E2{
	enum Type {
		a,b,c
	};
	struct stringize: std::string{
		stringize(Type e){
			switch(e){
#define ENUM_STRINGIZE(elem) break;case elem:assign(#elem)
				ENUM_STRINGIZE(E2::a);
				ENUM_STRINGIZE(E2::b);
				ENUM_STRINGIZE(E2::c);
#undef ENUM_STRINGIZE
				break;default:assign("Undef");
			}
		}
	};
}
int main(){
	boost::variant<E1::Type, E2::Type, int> v = E2::b;
	std::cout <<
		v.which() <<
		E2::stringize(boost::get<E2::Type>(v))<<
		boost::get<int>(v)
	;
	
	return 0;
}