Added osg::Identifer, osg::ValueMap and osg::ValueStack classes to provide a general purpose means for storing and retrieving values from map or stack containers.

Typical use will be for storing and passing values between nodes during traversals.

include/osg/ValueMap

@@ -0,0 +1,138 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2016 Robert Osfield
+ *
+ * This library is open source and may be redistributed and/or modified under
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * OpenSceneGraph Public License for more details.
+*/
+
+#ifndef OSG_VALUEMAP
+#define OSG_VALUEMAP 1
+
+#include <osg/ValueObject>
+#include <osg/Notify>
+#include <map>
+
+namespace osg {
+
+#define OSG_HAS_VALUEMAP
+
+class OSG_EXPORT ValueMap : public osg::Object
+{
+    public:
+
+        ValueMap();
+
+        ValueMap(const ValueMap& vm, const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
+
+        META_Object(osg, ValueMap)
+
+        typedef std::map< osg::ref_ptr<const osg::Referenced>, osg::ref_ptr<osg::Object>  > KeyValueMap;
+
+        void setKeyValueMap(KeyValueMap& properties) { _keyValueMap = properties; }
+
+        KeyValueMap& getKeyValueMap() { return _keyValueMap; }
+
+        const KeyValueMap& getKeyValueMap() const { return _keyValueMap; }
+
+        osg::Object* setValue(const osg::Referenced* key, osg::Object* object)
+        {
+            return (_keyValueMap[key] = object).get();
+        }
+
+        template<typename T>
+        osg::Object* setValue(const osg::Referenced* key, const T& value)
+        {
+            typedef TemplateValueObject<T> UserValueObject;
+            KeyValueMap::iterator itr = _keyValueMap.find(key);
+            if (itr!=_keyValueMap.end() && typeid(*(itr->second))==typeid(UserValueObject))
+            {
+                UserValueObject* uvo = static_cast<UserValueObject*>(itr->second.get());
+                uvo->setValue(value);
+                return uvo;
+            }
+            else
+            {
+                return (_keyValueMap[key] = new UserValueObject(value)).get();
+            }
+        }
+
+
+        inline osg::Object* getValue(const osg::Referenced* key)
+        {
+            KeyValueMap::iterator itr = _keyValueMap.find(key);
+            return (itr!=_keyValueMap.end()) ? itr->second.get() : 0;
+        }
+
+        inline const osg::Object* getValue(const osg::Referenced* key) const
+        {
+            KeyValueMap::const_iterator itr = _keyValueMap.find(key);
+            return (itr!=_keyValueMap.end()) ? itr->second.get() : 0;
+        }
+
+
+        template<typename T>
+        T* getValueOfType(const osg::Referenced* key)
+        {
+            Object* object = getValue(key);
+            return (object && typeid(*object)==typeid(T)) ? static_cast<T*>(object) : 0;
+        }
+
+
+        template<typename T>
+        const T* getValueOfType(const osg::Referenced* key) const
+        {
+            const Object* object = getValue(key);
+            return (object && typeid(*object)==typeid(T)) ? static_cast<const T*>(object) : 0;
+        }
+
+
+        template<typename T>
+        bool getValue(const osg::Referenced* key, T& value)
+        {
+            typedef TemplateValueObject<T> UserValueObject;
+            UserValueObject* uvo = getValueOfType<UserValueObject>(key);
+            if (uvo)
+            {
+                value = uvo->getValue();
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        template<typename T>
+        bool getValue(const osg::Referenced* key, T& value) const
+        {
+            typedef TemplateValueObject<T> UserValueObject;
+            const UserValueObject* uvo = getValueOfType<UserValueObject>(key);
+            if (uvo)
+            {
+                value = uvo->getValue();
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+
+    protected:
+
+        virtual ~ValueMap();
+
+        KeyValueMap _keyValueMap;
+
+};
+
+}
+
+#endif