X-Git-Url: http://sjero.net/git/?p=wget;a=blobdiff_plain;f=lib%2Fc-ctype.h;h=4d72e90b7bff9a0122d37812a16af954e9f60c22;hp=76d5b0bbe8bc5bad77469568b64d4d6025194905;hb=2456d9bc547aacc8ad387f441e81455cd9301fe7;hpb=a75ed01852de52cf0f93c7db964c66977966f096

diff --git a/lib/c-ctype.h b/lib/c-ctype.h
index 76d5b0bb..4d72e90b 100644
--- a/lib/c-ctype.h
+++ b/lib/c-ctype.h
@@ -5,7 +5,8 @@
    <ctype.h> functions' behaviour depends on the current locale set via
    setlocale.
 
-   Copyright (C) 2000-2003, 2006 Free Software Foundation, Inc.
+   Copyright (C) 2000, 2001, 2002, 2003, 2006, 2008, 2009 Free Software
+   Foundation, Inc.
 
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
@@ -103,6 +104,21 @@ extern "C" {
 
 /* Function declarations. */
 
+/* Unlike the functions in <ctype.h>, which require an argument in the range
+   of the 'unsigned char' type, the functions here operate on values that are
+   in the 'unsigned char' range or in the 'char' range.  In other words,
+   when you have a 'char' value, you need to cast it before using it as
+   argument to a <ctype.h> function:
+
+         const char *s = ...;
+         if (isalpha ((unsigned char) *s)) ...
+
+   but you don't need to cast it for the functions defined in this file:
+
+         const char *s = ...;
+         if (c_isalpha (*s)) ...
+ */
+
 extern bool c_isascii (int c); /* not locale dependent */
 
 extern bool c_isalnum (int c);