C++如何为自定义类型重载运算符_C++流操作符重载与自定义输入输出

#include <iostream>
#include <string>
using namespace std;

class Person {
public:
    string name;
    int age;

    Person(string n, int a) : name(n), age(a) {}

    // 声明为友元以便访问私有成员（如果成员是私有的）
    friend bool operator>(const Person& p1, const Person& p2);
};

// 重载 > 运算符：按年龄比较
bool operator>(const Person& p1, const Person& p2) {
    return p1.age > p2.age;
}

// 重载 << 用于输出
ostream&amp; operator<<(ostream&amp; out, const Person& p) {
    out << "Name: " << p.name << ", Age: " << p.age;
    return out;  // 返回流对象以支持链式输出
}

// 重载 >> 用于输入
istream&amp; operator>>(istream&amp; in, Person& p) {
    cout << "Enter name: ";
    in >> p.name;
    cout << "Enter age: ";
    in >> p.age;
    return in;  // 返回流对象以支持链式输入
}

int main() {
    Person p1("Alice", 25);
    Person p2("Bob", 30);

    if (p1 > p2) {
        cout << p1 << " is older than " << p2 << endl;
    } else {
        cout << p1 << " is not older than " << p2 << endl;
    }

    Person p3("", 0);
    cin >> p3;
    cout << "You entered: " << p3 << endl;

    return 0;
}