Iterable objects and array type hinting?

I have a lot of functions that either have type hinting for arrays or use is_array() to check the array-ness of a variable.

Now I'm starting to use objects that are iterable. They implement Iterator or IteratorAggregate. Will these be accepted as arrays if they pass through type hinting, or undergo is_array()?

If I have to modify my code, is there a generic sort of is_iterable(), or must I do something like:

if ( is_array($var) OR $var instance_of Iterable OR $var instanceof IteratorAggregate ) { ... }

What other iterable interfaces are out there?