main.cpp

#include <iostream>
#include <string>
#include <boost/variant.hpp>
#include <boost/mpl/identity.hpp>
#include <boost/mpl/print.hpp>

typedef boost::mpl::print<int>::type hogehoge;


typedef boost::variant<std::string const&, char const*> any_string;

struct c_str_impl{
	typedef char const* result_type;
	result_type
	operator ()(any_string const& str) const{
		return boost::apply_visitor(*this, str);
	}
	result_type
	operator ()(std::string const& str) const{
		return str.c_str();
	}
	result_type
	operator ()(char const* str) const{
		return str;
	}
} c_str;

void
hoge(any_string v){
	std::cout << c_str(v) << std::endl;
}

int
main(){
	hoge("char*");
	hoge(std::string("string"));
	std::cout << "hello world" << std::endl;
	std::cout << "hel" << std::endl;
	return 0;
}