As bearophile [pointed out](https://d.puremagic.com/issues/show_bug.cgi?id=4733#c7) this message is slightly misleading.
How about ", use array.length to test for an empty array instead.".
Also using [array.ptr](https://d.puremagic.com/issues/show_bug.cgi?id=4733#c18) is most definitely a bug.