#define _hex_array_size 256
#define _hex_bad 99
-extern char _hex_value[_hex_array_size];
+extern const char _hex_value[_hex_array_size];
extern void hex_init PARAMS ((void));
#define hex_p(c) (hex_value (c) != _hex_bad)
/* If you change this, note well: Some code relies on side effects in