问答题

#include ＜ iostream ＞
#include ＜ fstream ＞
using namespace std;
class complex
{ public:
int real;
int imag;
complex( int r = 0, int i = 0)
{ real = r;
imag = i;
}
};
complex operator + (______, complex& b)
{ int r = a.real + b.real;
int i = a.imag + b.imag;
return ______;
}
void main ()
{complex x(1,2), y(3,4), z;
z=x+y;
cout ＜＜ z.real ＜＜ " + " ＜＜ z.imag ＜＜ "i" ＜＜ endl;
}