#include <vector>
#include <string>
#include <iostream>
#include <iomanip>

using namespace std;


int main(int argc, const char * argv[])
{
 	{
        string s = "Hello, \0\0\0world"s;
        for(auto it = s.begin(); it != s.end(); ++it) cout << "code: " << hex << int(*it) <<endl;
 	}
 	cout << "---------------\n";
 	{
        string s = "Hello, \0\0\0world";
        for(auto it = s.begin(); it != s.end(); ++it) cout << "code: " << hex << int(*it) <<endl;
 	}
}