SDUT OJ类型转换函数的应用

#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

class Complex
{
    private:
      double real;
      double imag;
    public:
      Complex()
      {
          real=0;
          imag=0;
      }
      Complex(double r, double i)
      {
          real=r; imag=i;
      }
      operator double()
      {
          return real;
      }
      void sett()
      {
          cin>>real>>imag;
      }
};

int main()
{
    double dd;
    Complex c1;
    c1.sett();
    cin>>dd;
    dd=dd+c1;
    cout<<dd<<endl;

    return 0;
}