继续添加功能，帮我写判断结构体相等的函数

当我们需要判断两个结构体是否相等时，可以重载“==”运算符来实现。以下是修改后的代码：

#include <iostream>
using namespace std;

struct MyStruct {
    int a, b;

    MyStruct(int a = 0, int b = 0) : a(a), b(b) {}

    // 加法运算符重载
    MyStruct operator+(const MyStruct& other) const {
        return MyStruct(a + other.a, b + other.b);
    }

    // 减法运算符重载
    MyStruct operator-(const MyStruct& other) const {
        return MyStruct(a - other.a, b - other.b);
    }

    // 乘法运算符重载
    MyStruct operator*(const MyStruct& other) const {
        return MyStruct(a * other.a, b * other.b);
    }

    // 除法运算符重载
    MyStruct operator/(const MyStruct& other) const {
        return MyStruct(a / other.a, b / other.b);
    }

    // 赋值函数
    MyStruct& operator=(const MyStruct& other) {
        a = other.a;
        b = other.b;
        return *this;
    }

    // 拷贝函数
    MyStruct(const MyStruct& other) {
        a = other.a;
        b = other.b;
    }

    // 友元函数
    friend ostream& operator<<(ostream& os, const MyStruct& obj) {
        os << "a: " << obj.a << ", b: " << obj.b;
        return os;
    }

    // 判断是否相等
    bool operator==(const MyStruct& other) const {
        return a == other.a && b == other.b;
    }
};

int main() {
    MyStruct a(1, 2), b(3, 4), c(1, 2);

    // 测试相等运算符重载
    cout << "a == b: " << (a == b) << endl;
    cout << "a == c: " << (a == c) << endl;

    return 0;
}

输出结果：

a == b: 0
a == c: 1

在代码中，重载“==”运算符的实现是比较结构体的成员变量是否相等，如果两个结构体的成员变量都相等，则认为它们相等。