不用+,-,*,/求两个数的和

#include<iostream>
using namespace std;

int sum(int a, int b)
{
	int ret = 0;
	while (b)
	{
		ret = a & b;
		a = a ^ b;
		b = ret << 1;
	}
	return a;
}

int main()
{
	cout << sum(11, 9) << endl;
}