How to add two numbers without using ++ or + or another arithmetic operator

Question

How do I add two numbers without using ++ or + or any other arithmetic operator?

It was a question asked a long time ago in some campus interview. Anyway, today some

Answer 1

All arithmetic operations decompose to bitwise operations to be implemented in electronics, using NAND, AND, OR, etc. gates.

Adder composition can be seen here.