Add node_ref::operator <

Moved from VirtualDirectoryManager. Defining the operator static doesn't
work with gcc 4 and it's useful to have globally available anyway.

headers/os/storage/Node.h

@@ -22,6 +22,7 @@ struct node_ref {
 
 	bool operator==(const node_ref& ref) const;
 	bool operator!=(const node_ref& ref) const;
+	bool operator<(const node_ref& ref) const;
 	node_ref& operator=(const node_ref& ref);
 
 	dev_t device;

src/kits/storage/Node.cpp

@@ -68,6 +68,16 @@ node_ref::operator!=(const node_ref &ref) const
 	return !(*this == ref);
 }
 
+
+bool
+node_ref::operator<(const node_ref& other) const
+{
+	if (this->device != other.device)
+		return this->device < other.device;
+	return this->node < other.node;
+}
+
+
 // =
 node_ref&
 node_ref::operator=(const node_ref &ref)

src/kits/tracker/VirtualDirectoryManager.cpp

@@ -35,15 +35,6 @@ static const char* const kTemporaryDefinitionFileBaseDirectoryPath
 	= "/tmp/tracker/virtual-directories";
 
 
-static bool
-operator<(const node_ref& a, const node_ref& b)
-{
-	if (a.device != b.device)
-		return a.device < b.device;
-	return a.node < b.node;
-}
-
-
 // #pragma mark - Info