c++ - How to swap variables without another variable, XOR usage

int a = 5;
int b = 10;

std::cout << "A = " << a << "\n";
std::cout << "B = " << b << "\n";
    
a ^= b;
b ^= a;
a ^= b;
    
std::cout << "A = " << a << "\n";
std::cout << "B = " << b << "\n";

Output:

A = 5
B = 10
A = 10
B = 5