函数--重载 编写三个重载的display函数

#include<iostream>
using namespace std;
double display(double num)
{
      cout<<"double:"<<num<<endl;
}
int display(int num)
{
      cout<<"int:"<<num<<endl;
}
char display(char num)
{
      cout<<"char:"<<num<<endl;
}
int main()
{
     double d=1.2;
     int i=2;
     char c ='p';
     display(d);
     display(i);
     display(c);
     return 0;
}