看看下面的代码

这是错误的

class A {
public:
	int x = 10;
};
class B :public A {
	using A::x;
	int x = 100;
};

看看函数

class A {
public:
	void fun()
	{
		cout << "uuuu" << endl;
	}
};
class B :public A {
public:
	using A::fun;
	void fun()
	{
		cout << "lalala" << endl;
	}
};


int main()
{
	B b;
	b.fun();   // 输出 lalala
	b.A::fun();  // 输出 uuuu
}