Hmm. You need at least "#define EFOO EFOO" to make "#ifdef EFOO" work. But one of the reasons for the current style of definition is in particular so that "#if EAGAIN != EWOULDBLOCK" works right. That can only win if it's a cpp-interpretable expression, which cannot use enum constants or syntax like casts. (The cpp rules mean that the enum constants are unknown identifiers and treated as zero, so any EFOO == EBAR comparison says they are equal.) I am hesitant to risk breaking any such #if expressions now compiled in C++ on Hurd. (The error_t usage being broken in C++ is at least not a silent change or breakage of something that already works.)
It may also be a problem in some other C++ way I'm not aware of off hand, for the type of EFOO not to be int. I'm open to suggestions. But I think we might just have to live with C++ using (error_t) EFOO, or else supply a C++ <errno> or whatever where there is explicitly no expectation of int-valued or cpp-usable values, if people would actually use that. Thanks, Roland
