C / C ++ exchange two numbers, without the use of a third variable, function template to achieve

#include <iostream>

template<typename T>
void exchangeTwoNumber(T &t1, T &t2)；

void test();

int main()
{
    int a = 10, b = 20;
    double q = 10.1, w = 20.2;
    char z = 'z', x = 'x';

    std::cout << "交换前的 a = " << a << ", b = " << b << std::endl;
    std::cout << "交换前的 q = " << q << ", w = " << w << std::endl;
    std::cout << "交换前的 z = " << z << ", x = " << x << std::endl;

    exchangeTwoNumber(a, b);
    exchangeTwoNumber(q, w);
    exchangeTwoNumber(z, x);
    test();

    std::cout << std::endl;
    std::cout << std::endl;
    std::cout << "交换后的    a = " << a << ",    b = " << b <<:: endl STD; 
    STD :: COUT << " Q after exchange = " << << Q " , W = " << << W STD :: endl; 
    STD :: COUT << " Z after exchange = " << << Z " , Z = " << << X STD :: endl; 
} 


template <typename T>
 void exchangeTwoNumber (T1 & T, T & T2) // generic function templates 
{ 
    T1 = T1 + T2; 
    T2 = T1 - T2; 
    T1 = T1 - T2;
}



void test()  //XOR manner, deformed template function, the compiler does not pass through 
{
     int A = . 1 , B = 2 ; 
    A ^ = B; 
    B ^ = A; 
    A ^ = B; 

    STD :: COUT << " ... A = " << << A " , B = " << << B STD :: endl; 
}