[gotoeleven]

I think the parent comment is asking what process or algorithm is there that would result in an array that was sometimes but not always a heap, and you'd want to do something based on whether the array was in fact a heap or not? Like in your example, what process do you have in mind that might result in a heap and might not?

[simonask]

Any time you deal with semi-trusted input, like an internal protocol or deserialization. :-)