re_exchangeable?

/*
 *  call-seq:
 *     Process::UID.re_exchangeable?   => true or false
 *
 *  Returns +true+ if the real and effective user IDs of a
 *  process may be exchanged on the current platform.
 *
 */

static VALUE
p_uid_exchangeable()
{
#if defined(HAVE_SETRESUID) &&  !defined(__CHECKER__)
    return Qtrue;
#elif defined(HAVE_SETREUID) && !defined(OBSOLETE_SETREUID)
    return Qtrue;
#else
    return Qfalse;
#endif
}