How to access correct class member?

I've been running across this snippet of code and after execution I found out that everything compiles and executes fine (the int code member of the derived class is set to 65). However I was wondering how would one be able to access the char code member of the derived class?

#include <iostream>
using namespace std;

class base {
public:
    base() : code('B') { }
    char code;
};

class derived : public base
{
public:
    int code;
};

int main(void)
{
    derived d;
    d.code = 65;
    std::cout << d.code;
};