That's all true, but unfortunately it doesn't help. You can still have two indices greater than half the maximum value of a size_t, and cause an overflow. The

That's all true, but unfortunately it doesn't help. You can still have two indices greater than half the maximum value of a size_t, and cause an overflow. The problem here isn't the maximum value of whatever data type we are using, it is that no matter what that maximum is, you can always exceed it by adding two sufficiently large values of that same type together.