LLInstanceTracker and LLSingleton updated yet again.

indra/llcommon/llinstancetracker.cpp

@@ -35,13 +35,15 @@
 //static 
 void * & LLInstanceTrackerBase::getInstances(std::type_info const & info)
 {
-	static std::map<std::string, void *> instances;
+	typedef std::map<std::string, void *> InstancesMap;
+	static InstancesMap instances;
 
-	std::string k = info.name();
-	if(instances.find(k) == instances.end())
-	{
-		instances[k] = NULL;
-	}
-
-	return instances[k];
+	// std::map::insert() is just what we want here. You attempt to insert a
+	// (key, value) pair. If the specified key doesn't yet exist, it inserts
+	// the pair and returns a std::pair of (iterator, true). If the specified
+	// key DOES exist, insert() simply returns (iterator, false). One lookup
+	// handles both cases.
+	return instances.insert(InstancesMap::value_type(info.name(),
+													 InstancesMap::mapped_type()))
+		.first->second;
 }