_SC_IPV6          153 ext/etc/constdefs.h #if !defined(_SC_IPV6)
_SC_IPV6          155 ext/etc/constdefs.h #  define _SC_IPV6 _SC_IPV6
_SC_IPV6         1031 ext/etc/constdefs.h #if defined(_SC_IPV6)
_SC_IPV6         1032 ext/etc/constdefs.h     rb_define_const(mod, "SC_IPV6", INTEGER2NUM(_SC_IPV6));