如何在C++中实现istream和重载？

#include <iostream>

class MyClass {
public:
    istream& input;
};

MyClass(istream& in) : input(in) {}

MyClass& operator>>(int& data) {
    input >> data;
    return *this;
}

#include <iostream>

class MyClass {
public:
    istream& input;

    MyClass(istream& in) : input(in) {}

    MyClass& operator>>(int& data) {
        input >> data;
        return *this;
    }
};

int main() {
    int num;
    MyClass myObj(std::cin);
    myObj >> num;
    std::cout << "You entered: " << num << std::endl;
    return 0;
}