The problem is that it's portable to every other compiler we've
tested. I am curious what icc and xlc do, but those are the only
two not tested.
Sorry, I have a different meaning of portable, for me the term is
related to the standard, meaning that standard conforming compilers
are required to process the code correctly.
"Happens to work on (some/most/all) compilers" is not the same
thing at all for me. COmpetent programmers write portable code
by knowing what the standard requires, not by trial and error :-)