运算符重载的问题 求解答……

#include<iostream.h>
class Complex
{
    double real;
    double image;

 public:
     Complex(double r=0,double i=0)
     {  
         real=r; image=i;
     }
     friend void inputcomplex(Complex &comp);
     friend Complex addcomplex(Complex c1,Complex c2);
     friend void outputcomplex(Complex comp);
};
void inputcomplex(Complex &comp)

 {  
    cin>>comp.real>>comp.image;
    }  

 Complex addcomplex(Complex c1,Complex c2)

 {
     Complex c;
     c.real=c1.real+c2.real;
     c.image=c1.image+c2.image;
     return c;

 }
void outputcomplex(Complex comp)

 {
    cout<<"("<<comp.real<<","<<comp.image<<")";

 }
void main()

 {
    Complex c1,c2,result;

    inputcomplex(c1);
    inputcomplex(c2);
    result=addcomplex(c1,c2);
    outputcomplex(c1);
    cout<<"+";
    outputcomplex(c2);
    cout<<"=";
    outputcomplex(result);
    cout<<endl;

 }