1 files changed, 11 insertions, 4 deletions

diff --git a/gl/base64.h b/gl/base64.h
index 2be394bd..343150cb 100644
--- a/gl/base64.h
+++ b/gl/base64.h
@@ -1,5 +1,5 @@
 /* base64.h -- Encode binary data using printable characters.
-   Copyright (C) 2004, 2005, 2006, 2009, 2010 Free Software Foundation, Inc.
+   Copyright (C) 2004-2006, 2009-2013 Free Software Foundation, Inc.
    Written by Simon Josefsson.
 
    This program is free software; you can redistribute it and/or modify
@@ -13,8 +13,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
 
 #ifndef BASE64_H
 # define BASE64_H
@@ -25,6 +24,10 @@
 /* Get bool. */
 # include <stdbool.h>
 
+# ifdef __cplusplus
+extern "C" {
+# endif
+
 /* This uses that the expression (n+(k-1))/k means the smallest
    integer >= n/k, i.e., the ceiling of n/k.  */
 # define BASE64_LENGTH(inlen) ((((inlen) + 2) / 3) * 4)
@@ -35,7 +38,7 @@ struct base64_decode_context
   char buf[4];
 };
 
-extern bool isbase64 (char ch);
+extern bool isbase64 (char ch) _GL_ATTRIBUTE_CONST;
 
 extern void base64_encode (const char *restrict in, size_t inlen,
                            char *restrict out, size_t outlen);
@@ -58,4 +61,8 @@ extern bool base64_decode_alloc_ctx (struct base64_decode_context *ctx,
 #define base64_decode_alloc(in, inlen, out, outlen) \
         base64_decode_alloc_ctx (NULL, in, inlen, out, outlen)
 
+# ifdef __cplusplus
+}
+# endif
+
 #endif /* BASE64_H */