As Travis says in his reply to my post here:
Given 220.127.116.11 p1 and p2, it is pretty clear to me that the two iterators are both non-end-of-stream type, and they are both created on different streams. The streams are different, so the iterators should not compare equal. I guess one could claim that 18.104.22.168 p6 conflicts with 24.5 p3 because 'end-of-stream' isn't clearly defined, but in this particular case that doesn't matter.
This program aborts with stdcxx but not with gcc: