+/* Jim Meyering writes:
+
+ "... Some ctype macros are valid only for character codes that
+ isascii says are ASCII (SGI's IRIX-4.0.5 is one such system --when
+ using /bin/cc or gcc but without giving an ansi option). So, all
+ ctype uses should be through macros like ISPRINT... If
+ STDC_HEADERS is defined, then autoconf has verified that the ctype
+ macros don't need to be guarded with references to isascii. ...
+ Defining isascii to 1 should let any compiler worth its salt
+ eliminate the && through constant folding." */
+
+#if defined (STDC_HEADERS) || (!defined (isascii) && !defined (HAVE_ISASCII))
+#define ISASCII(c) 1
+#else
+#define ISASCII(c) isascii(c)
+#endif
+
+/* 1 if C is an ASCII character. */
+#define IS_REAL_ASCII(c) ((c) < 0200)
+
+/* This distinction is not meaningful, except in Emacs. */
+#define ISUNIBYTE(c) 1
+
+#define ISDIGIT(c) (ISASCII (c) && isdigit (c))
+#define ISCNTRL(c) (ISASCII (c) && iscntrl (c))
+#define ISXDIGIT(c) (ISASCII (c) && isxdigit (c))
+