https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62086
--- Comment #5 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- See <http://www.open-std.org/jtc1/sc22/wg14/12596> regarding the #if 0 question. You could always raise a DR with WG14 or WG21 to try to get this question resolved properly. (4.9 implements the C11/C++11 sets of UCNs allowed in identifiers, but of course you need to select the right -std option. Previous versions didn't have that support, just the C99/C++98 sets.)
