From Laurens Voerman, "the current version of BufferObject causes a huge amount of warnings in Visual Studio 2012 like:

OpenSceneGraph/include\osg/BufferObject(701): warning C4138: '*/' found outside of comment (E:\osg\osgSvn\OpenSceneGraph\src\osg\Array.cpp)

adding a space before /* fixes the problem
        void removeClient(osg::Object * /*client*/) { --_numClients; }
"

include/osg/BufferObject

@@ -698,7 +698,7 @@ class OSG_EXPORT BufferData : public Object
 
         void addClient(osg::Object * /*client*/) { ++_numClients; }
 
-        void removeClient(osg::Object */*client*/) { --_numClients; }
+        void removeClient(osg::Object * /*client*/) { --_numClients; }
 
 protected: