单项选择题

有以下程序
#include ＜iostream＞
using namespace std;
class Complex

public:
Complex (double r=0, double i =0 :re(r) ,im (i)
double real() const return re;
double imag() const return im;
Complex operator + (Complex c const
return Complex(re+c.re, im+c.im);
privane:
double re,im;
;
int main

Complex a =Complex(1,1)+Complex(5);
cout＜＜a.real()＜＜’+’＜＜a.imag() ＜＜ ’i’ ＜＜endl
return 0;

程序执行后的输出结果是