c++ - 创建具有多态性和 op 的模板。 C++中的重载

Question

我是学C++的，想请教:

如何在模板中转换类“时间”？像这样的东西:

template <class genericType>
class time {

我不擅长 C++，我想做的是在 main 中使用其他类型的数据，而不仅仅是下面代码中的“int”。

我想做这样的事情:

time <char>t('a','a','a');
t.show();

er <char>t2('b','b','b');
t2.show();

time <char>t3=t+t2;
t3.show();

谢谢大家。这是我想在模板中转换的代码:

#include <iostream>
using namespace std;

class time{
protected:

   int hour, minuts , seconds;

public:

    time(int x=0, int y=0, int z=0){
        hour=x;
        minuts=y;
        seconds=z;
    }
   virtual void show(){
        cout<<"it's "<<hour<<":"<<minuts<<":"<<seconds<<endl;
    }


   time operator+(time &te){

         cout<<"sum everything: ";
         time bho;
         bho.hour=hour+te.hour;
         bho.minuts+=minuts+te.minuts;
         bho.seconds+=seconds+te.seconds;
         return bho;
   }

};

class er: public time {

public:

   er(int x=0,int y=0,int z=0):time(x,y,z){};

   void show() {
     cout<< "Inside er: it's  "<<hour<<":"<<minuts<<":"<<seconds<<endl;
   };
};

int main()
{

    time t(10,10,10);
    t.show();

    er t2(20,20,20);
    t2.show();

    time *pt= new er(60,60,60);
    pt->show();

    time t3=t+t2;
    t3.show();

    return 0;
}

Answer 1

这是真的，@serge Ballesta 的解决方案是错误的。也许你可以试试这个:

#include <iostream>
using namespace std;

template <class genericType>
class time{
 protected:

    genericType hour, minutes , seconds;

public:

    time(genericType x=0, genericType y=0, genericType z=0){
        hour=x;
        minutes=y;
        seconds=z;
    }
   virtual void  show(){
        cout<<"it's: "<<hour<<":"<<minutes<<":"<<seconds<<endl;
    }

   time operator+(time &te){

         cout<<"sum everything: "<<endl;
         time bho;
         bho.hour=hour+te.hour;
         bho.minutes+=minutes+te.minutes;
         bho.seconds+=seconds+te.seconds;
         return bho;
   }

};

template <class genericType>
class er: public time <genericType>{

   public:

   er(genericType x=0,genericType y=0, genericType z=0){
      time<genericType>::hour=x;
      time<genericType>::minutes=y;
      time<genericType>::seconds=z;
   }

  void show() {
    cout<< "Inside er: it's "<<time<genericType>::hour<<":"<<time<genericType>::minutes<<":"<<time<genericType>::seconds<<endl;
   };
};

int main()
{
    time <char>t('a','a','a');
    t.show();

    er <char>t2('b','b','b');
    t2.show();

    time <char>t3=t+t2;
    t3.show();

    return 0;
}