--- Libc/Libc-391.5.21/include/strings.h
+++ Libc/Libc-1669.0.4/include/strings.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000, 2007, 2010, 2023 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -55,27 +55,14 @@
  *	@(#)strings.h	8.1 (Berkeley) 6/2/93
  */
 
-#if !defined(_XOPEN_SOURCE) && !defined(_POSIX_C_SOURCE)
+#ifndef _STRINGS_H_
+#define _STRINGS_H_
 
+#include <_strings.h>
+
+#if __DARWIN_C_LEVEL >= __DARWIN_C_FULL
 #include <string.h>
-
-#else
-
-#include <_types.h>
-
-#ifndef	_SIZE_T
-#define	_SIZE_T
-typedef	__darwin_size_t	size_t;
 #endif
 
-int      bcmp(const void *, const void *, size_t);
-void     bcopy(const void *, void *, size_t);
-void     bzero(void *, size_t);
-int      ffs(int);
-char    *index(const char *, int);
-char    *rindex(const char *, int); 
-int      strcasecmp(const char *, const char *);
-int      strncasecmp(const char *, const char *, size_t);
+#endif  /* _STRINGS_H_ */
 
-#endif  /* _POSIX_C_SOURCE */
-