#include 
     
       using namespace std; class Base {
   public: void fm(){cout<<"base::fm()\n";} void fm(int){cout<<"base::fm(int)\n";} }; class D:public Base {
   public: //using Base::fm;     void fm(){cout<<"D::fm()\n";} }; int main() {
       D d;     d.fm();     d.fm(1);//error D中fm隐藏了Base中的两个fm //  d.Base::fm(1);     return 0; }
     

方法一: 在D中使用 using Base::fm;

方法二: 使用 d.Base::fm(1);