#include <iostream>
using namespace std;
class Base {
public:
    int a = 10;
protected:
    int b = 20;
private:
    int c = 30;
};
class Derived : public Base {
public:
    void func() {
        // 此处测试派生类成员对基类成员的访问权限
    }
};
int main() {
    Derived d;
    // 此处测试派生类对象对基类成员的访问权限
    return 0;
}