const
   _POSIX_JOB_CONTROL = 1;
   _POSIX_SAVED_IDS = 1;
   _POSIX_PRIORITY_SCHEDULING = 1;
   _POSIX_SYNCHRONIZED_IO = 1;
   _POSIX_FSYNC = 1;
   _POSIX_MAPPED_FILES = 1;
   _POSIX_MEMLOCK = 1;
   _POSIX_MEMLOCK_RANGE = 1;
   _POSIX_MEMORY_PROTECTION = 1;
   _POSIX_POLL = 1;
   _POSIX_SELECT = 1;
   _POSIX_CHOWN_RESTRICTED = 1;
   _POSIX_VDISABLE = #0;
   _POSIX_NO_TRUNC = 1;
   _XOPEN_REALTIME = 1;
   _XOPEN_REALTIME_THREADS = 1;
   _XOPEN_SHM = 1;
   _POSIX_THREADS = 1;
   _POSIX_REENTRANT_FUNCTIONS = 1;
   _POSIX_THREAD_SAFE_FUNCTIONS = 1;
   _POSIX_THREAD_PRIORITY_SCHEDULING = 1;
   _POSIX_THREAD_ATTR_STACKSIZE = 1;
   _POSIX_THREAD_ATTR_STACKADDR = 1;
   _POSIX_SEMAPHORES = 1;
   _POSIX_REALTIME_SIGNALS = 1;
   _POSIX_ASYNCHRONOUS_IO = 1;
   _POSIX_ASYNC_IO = 1;
   _LFS_ASYNCHRONOUS_IO = 1;
   _LFS64_ASYNCHRONOUS_IO = 1;
   _LFS_LARGEFILE = 1;
   _LFS64_LARGEFILE = 1;
   _LFS64_STDIO = 1;
   _POSIX_SHARED_MEMORY_OBJECTS = 1;
   _POSIX_CPUTIME = 200912;
   _POSIX_THREAD_CPUTIME = 200912;
   _POSIX_REGEXP = 1;
   _POSIX_READER_WRITER_LOCKS = 200912;
   _POSIX_SHELL = 1;
   _POSIX_TIMEOUTS = 200912;
   _POSIX_SPIN_LOCKS = 200912;
   _POSIX_SPAWN = 200912;
   _POSIX_TIMERS = 1;
   _POSIX_BARRIERS = 200912;