gdb cout

main.cpp

#include <iostream>

struct MyClass {
    int i;
    MyClass() { i = 0; }
};

std::ostream& operator<<(std::ostream &oss, const MyClass &my_class) {
    return oss << "MyClass: i = " << my_class.i;
}

int main() {
    MyClass i;
    std::cout << i << std::endl;
}