I've seen that example before, but I don't like it. It's an example of fixed-point overflow, but it wouldn't occur in practice.

It would manifest itself with 32-bit integer indexes and with arrays of greater than 2^30 elements. So phooey. You can't even fit that many array elements into a 32-bit address space. And if you're in a 64-bit address space, you should be using 64-bit indexes.

Whine: way back in the 1960s, the IBM S/360 threw a fixed-point overflow exception (okay, to be pedantic, they called it a "program interruption", but it's the same idea) when you did that. Sadly, the Fortran compiler of the day masked it. And this same philosophy has carried over to today. About 99 times out of 100, fixed point overflow is bad, why is it being masked off?