#include <iostream>
using namespace std;
class Base {
public:
    int a = 1;
protected:
    int b = 2;
private:
    int c = 3;
};
class Derive : protected Base {
public:
    void func() {
        // 访问基类继承来的成员
    }
};
int main() {
    Derive d;
    // 通过d对象访问成员
    return 0;
}