Of course a basic iteration between begin()/end() will never contain out of range elements, but neither will valid increment between two integers. No need for iterators in that case either.

Say I want to do something fancy, like getting element number 11 from an array.

With an integer index I can pass 11, with random access iterators I can use begin() + 11.

Now my array only has five elements. So I check.

11 < 5? Comparison valid, successfully avoided a crash.

begin() + 11 < end() ? How where the rules for pointer comparison again, something about within an allocation and one past the end?