一元运算符操作符重载

#include <iostream>
using namespace std;
/*单目运算符重载*/
class Sigoptor{
friend Sigoptor & operator++(Sigoptor & op);
private:
int a;
int b;
public:
void operator--()
{
this->a--;
this->b--;
}
Sigoptor(int a, int b)
{
this->a = a;
this->b = b;
}
void print(void)
{
cout << a << "+" << b << "i" << endl;
}
};

Sigoptor & operator++(Sigoptor & op)
{
op.a++;
op.b++;
return op;
}
int main()
{
Sigoptor opp1(2, 3);
++opp1;
opp1.print();
--opp1;
opp1.print();
system("pause");
return 0;
}