Make C++ compatible.

include/cdio/rock.h

@@ -1,5 +1,5 @@
 /*
-    $Id: rock.h,v 1.8 2005/02/22 10:42:50 rocky Exp $
+    $Id: rock.h,v 1.9 2005/08/27 14:25:58 rocky Exp $
 
     Copyright (C) 2005 Rocky Bernstein <rocky@panix.com>
 
@@ -33,6 +33,10 @@
 
 #include <cdio/types.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
 /*! An enumeration for some of the ISO_ROCK_* #defines below. This isn't
   really an enumeration one would really use in a program it is to
   be helpful in debuggers where wants just to refer to the ISO_ROCK_*
@@ -358,6 +362,10 @@ extern iso_rock_nm_flag_t iso_rock_nm_flag;
 extern iso_rock_sl_flag_t iso_rock_sl_flag;
 extern iso_rock_tf_flag_t iso_rock_tf_flag;
 
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
 #endif /* __ISO_ROCK_H__ */
 
 /*