C++使用基类指针访问派生类方法

我正在尝试访问get_workhour()函数。我该怎么做？多态性是否仅适用于覆盖函数？

manager类有一个特殊的函数get_workhour()该函数在基类employee中不存在。当两个类的对象都存储在employee类型的向量中时，我们如何使用多态性调用该函数？

#include <iostream>
#include <vector>
using namespace std;
class employee{
    protected:
        string name;
        double pay;
    public:
        employee(){
            name="xyz";
            pay =0.0;
        }
        employee(string name,double pay) {
            this->name = name;
            this->pay = pay;
        }
        string get_name(){
            return name;
        }
        virtual double get_pay(){
            return pay;
        }
    };
    class manager:public employee{
         protected:
             int workhour;
         public:
             manager(){
                 workhour = 0;
             }
             manager(string name,double pay,int workhour):
                 employee(name,pay){
                 this->workhour = workhour;
             }
             virtual int get_workhour(){
                 return workhour;
             }
             virtual double get_pay() {
                 return pay + 100;
             }
    };
    int main()
    {
        employee emp1("vivek",1500);
        manager m1("william",1300,10);
        vector<employee*> emps;
        emps.push_back(&m1);
        emps.push_back(&emp1);
        cout<<"Name of manager is : "<<emps[0]->get_name()<<endl;
        cout<<"Pay for the manager is :"<<emps[0]->get_pay()<<endl;
        cout<<"Workhour of manager is : "<<ptr->get_workhour()<<endl;
        cout<<"Name of employee is : "<<emps[1]->get_name()<<endl;
        cout<<"Pay for the employee is : "<<emps[1]->get_pay()<<endl;
        return 0;
    }