root/sys/sys/_null.h
/*      $OpenBSD: _null.h,v 1.2 2016/09/09 22:07:58 millert Exp $       */

/*
 * Written by Todd C. Miller, September 9, 2016
 * Public domain.
 */

#ifndef NULL
#if !defined(__cplusplus)
#define NULL    ((void *)0)
#elif __cplusplus >= 201103L
#define NULL    nullptr
#elif defined(__GNUG__)
#define NULL    __null
#else
#define NULL    0L
#endif
#endif