1 files changed, 64 insertions, 26 deletions

diff --git a/indra/llcommon/llinstancetracker.h b/indra/llcommon/llinstancetracker.h
index ea50acbbc5..039d68faef 100644
--- a/indra/llcommon/llinstancetracker.h
+++ b/indra/llcommon/llinstancetracker.h
@@ -38,22 +38,53 @@
 
 #include "string_table.h"
 #include <boost/utility.hpp>
-
-// This mix-in class adds support for tracking all instances of the specified class parameter T
-// The (optional) key associates a value of type KEY with a given instance of T, for quick lookup
-// If KEY is not provided, then instances are stored in a simple set
-// *NOTE: see explicit specialization below for default KEY==T* case
+#include <boost/function.hpp>
+#include <boost/bind.hpp>
+#include <boost/iterator/transform_iterator.hpp>
+#include <boost/iterator/indirect_iterator.hpp>
+
+/// This mix-in class adds support for tracking all instances of the specified class parameter T
+/// The (optional) key associates a value of type KEY with a given instance of T, for quick lookup
+/// If KEY is not provided, then instances are stored in a simple set
+/// @NOTE: see explicit specialization below for default KEY==T* case
 template<typename T, typename KEY = T*>
 class LLInstanceTracker : boost::noncopyable
 {
+	typedef typename std::map<KEY, T*> InstanceMap;
+	typedef boost::function<const KEY&(typename InstanceMap::value_type&)> KeyGetter;
+	typedef boost::function<T*(typename InstanceMap::value_type&)> InstancePtrGetter;
 public:
-	typedef typename std::map<KEY, T*>::iterator instance_iter;
-	typedef typename std::map<KEY, T*>::const_iterator instance_const_iter;
-
-	static T* getInstance(const KEY& k) { instance_iter found = getMap().find(k); return (found == getMap().end()) ? NULL : found->second; }
+	/// Dereferencing key_iter gives you a const KEY&
+	typedef boost::transform_iterator<KeyGetter, typename InstanceMap::iterator> key_iter;
+	/// Dereferencing instance_iter gives you a T&
+	typedef boost::indirect_iterator< boost::transform_iterator<InstancePtrGetter, typename InstanceMap::iterator> > instance_iter;
+
+	static T* getInstance(const KEY& k)
+	{
+		typename InstanceMap::const_iterator found = getMap().find(k);
+		return (found == getMap().end()) ? NULL : found->second;
+	}
 
-	static instance_iter beginInstances() { return getMap().begin(); }
-	static instance_iter endInstances() { return getMap().end(); }
+	static key_iter beginKeys()
+	{
+		return boost::make_transform_iterator(getMap().begin(),
+											  boost::bind(&InstanceMap::value_type::first, _1));
+	}
+	static key_iter endKeys()
+	{
+		return boost::make_transform_iterator(getMap().end(),
+											  boost::bind(&InstanceMap::value_type::first, _1));
+	}
+	static instance_iter beginInstances()
+	{
+		return instance_iter(boost::make_transform_iterator(getMap().begin(),
+															boost::bind(&InstanceMap::value_type::second, _1)));
+	}
+	static instance_iter endInstances()
+	{
+		return instance_iter(boost::make_transform_iterator(getMap().end(),
+															boost::bind(&InstanceMap::value_type::second, _1)));
+	}
 	static S32 instanceCount() { return getMap().size(); }
 protected:
 	LLInstanceTracker(KEY key) { add(key); }
@@ -69,11 +100,11 @@ private:
 	}
 	void remove() { getMap().erase(mKey); }
 
-    static std::map<KEY, T*>& getMap()
+    static InstanceMap& getMap()
     {
         if (! sInstances)
         {
-            sInstances = new std::map<KEY, T*>;
+            sInstances = new InstanceMap;
         }
         return *sInstances;
     }
@@ -81,20 +112,27 @@ private:
 private:
 
 	KEY mKey;
-	static std::map<KEY, T*>* sInstances;
+	static InstanceMap* sInstances;
 };
 
-// explicit specialization for default case where KEY is T*
-// use a simple std::set<T*>
+/// explicit specialization for default case where KEY is T*
+/// use a simple std::set<T*>
 template<typename T>
 class LLInstanceTracker<T, T*>
 {
+	typedef typename std::set<T*> InstanceSet;
 public:
-	typedef typename std::set<T*>::iterator instance_iter;
-	typedef typename std::set<T*>::const_iterator instance_const_iter;
-
-	static instance_iter beginInstances() { return getSet().begin(); }
-	static instance_iter endInstances() { return getSet().end(); }
+	/// Dereferencing key_iter gives you a T* (since T* is the key)
+	typedef typename InstanceSet::iterator key_iter;
+	/// Dereferencing instance_iter gives you a T&
+	typedef boost::indirect_iterator<key_iter> instance_iter;
+
+	/// for completeness of analogy with the generic implementation
+	static T* getInstance(T* k) { return k; }
+	static key_iter beginKeys() { return getSet().begin(); }
+	static key_iter endKeys()   { return getSet().end(); }
+	static instance_iter beginInstances() { return instance_iter(getSet().begin()); }
+	static instance_iter endInstances()   { return instance_iter(getSet().end()); }
 	static S32 instanceCount() { return getSet().size(); }
 
 protected:
@@ -103,19 +141,19 @@ protected:
 
 	LLInstanceTracker(const LLInstanceTracker& other) { getSet().insert(static_cast<T*>(this)); }
 
-    static std::set<T*>& getSet()   // called after getReady() but before go()
+    static InstanceSet& getSet()   // called after getReady() but before go()
     {
         if (! sInstances)
         {
-            sInstances = new std::set<T*>;
+            sInstances = new InstanceSet;
         }
         return *sInstances;
     }
 
-	static std::set<T*>* sInstances;
+	static InstanceSet* sInstances;
 };
 
-template <typename T, typename KEY> std::map<KEY, T*>* LLInstanceTracker<T, KEY>::sInstances = NULL;
-template <typename T> std::set<T*>* LLInstanceTracker<T, T*>::sInstances = NULL;
+template <typename T, typename KEY> typename LLInstanceTracker<T, KEY>::InstanceMap* LLInstanceTracker<T, KEY>::sInstances = NULL;
+template <typename T> typename LLInstanceTracker<T, T*>::InstanceSet* LLInstanceTracker<T, T*>::sInstances = NULL;
 
 #endif