extern "C" {
#endif
-#undef NULL
-#ifdef __cplusplus
-#define NULL 0
-#else
-#define NULL ((void*)0)
-#endif
+#include <features.h>
+
+#define NULL 0L
#define LC_CTYPE 0
#define LC_NUMERIC 1
struct lconv *localeconv(void);
-#if 1
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)
#define __NEED_locale_t