How to swap two numbers without using temp variables or arithmetic operations?

Question

This equation swaps two numbers without a temporary variable, but uses arithmetic operations:

a = (a+b) - (b=a);

How can I do it without arithmetic operations? I was thinking about XOR.

user_440168 · Answer

C++11 allows to:

std::swap_ranges(a.begin(), a.end(), b.begin());

Create LValue tuple with tie:

std::tie(b, a) = std::make_tuple(a, b);

std::tie(c, b, a) = std::make_tuple(a, b, c);

user_2695282 · Answer

a =((a = a + b) - (b = a - b));