There is usually another operator used for concatenation in math though: | or || or ⊕ The first two are already used for bitwise and logical or and the third i

There is usually another operator used for concatenation in math though: | or || or ⊕ The first two are already used for bitwise and logical or and the third isn't available in ASCII so I still think overloading + was a reasonable choice and doesn't cause any actual problems IME.