This is fun and has some hack value but I hope nobody ever uses such a kludge in real code. It totally fails with crappy C compilers that decide to feature C++

This is fun and has some hack value but I hope nobody ever uses such a kludge in real code. It totally fails with crappy C compilers that decide to feature C++ comments unannounced. IIRC gcc does this unless you give -ansi or -std=c89. And C99 officially supports the // -comments but hasn't got C++ features, of course.