Portability problems not fixed by Gnulib:
@itemize
+@item
+Some platforms provide an @code{offsetof} macro that cannot be used in
+arbitrary expressions:
+Solaris 10
+This problem can be worked around by parenthesizing the
+@code{offsetof} expression in the unlikely case you use it with
+@code{sizeof} or @samp{[]}.
@end itemize