流运算符重载

class MyClass {
public:
    friend std::ostream& operator<<(std::ostream& os, const MyClass& obj) {
        os<< obj.myData;
        return os;
    }
private:
    int myData;
};

#include<iostream>

class MyClass {
public:
    friend std::ostream& operator<<(std::ostream& os, const MyClass& obj) {
        os<< obj.myData;
        return os;
    }

    friend std::istream& operator>>(std::istream& is, MyClass& obj) {
        is >> obj.myData;
        return is;
    }
private:
    int myData;
};

int main() {
    MyClass obj;
    std::cin >> obj;
    std::cout<< obj;
    return 0;
}