https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68265
--- Comment #2 from Zack Weinberg <zackw at panix dot com> --- This problem apparently goes back at least as far as 4.8. Stack Overflow people found a number of variations, please consult https://stackoverflow.com/questions/23033043/is-it-a-new-c11-style-of-comments https://stackoverflow.com/questions/23015482/strange-code-that-compiles-with-g
