// http://tinodidriksen.com/2010/01/31/snippet-custom-type-to-output-stream/
#include <ostream>
#include <iostream>
#include <string>

struct Custom {
    std::string m_str;
    friend std::ostream& operator<<(std::ostream& stm, const Custom& obj);
};

std::ostream& operator<<(std::ostream& stm, const Custom& obj) {
    stm << obj.m_str;
    return stm;
}

int main() {
    Custom cst;
    cst.m_str = "waffles";
    std::cout << cst << std::endl;
}