Feature: Add xml_tree_walker::out(const xml_node&) which is called after each node traversed

src/pugixml.cpp

@@ -6811,17 +6811,28 @@ namespace pugi
 					cur = cur->first_child;
 				}
 				else if (cur->next_sibling)
+				{
 					cur = cur->next_sibling;
+					walker.out(arg_for_each);
+				}
 				else
 				{
 					while (!cur->next_sibling && cur != _root && cur->parent)
 					{
+						xml_node arg_out(cur);
+
 						--walker._depth;
 						cur = cur->parent;
+
+						walker.out(arg_out);
 					}
 
 					if (cur != _root)
+					{
+						xml_node arg_out(cur);
 						cur = cur->next_sibling;
+						walker.out(arg_out);
+					}
 				}
 			}
 			while (cur && cur != _root);

src/pugixml.hpp

@@ -1048,6 +1048,8 @@ namespace pugi
 
 		// Callback that is called for each node traversed
 		virtual bool for_each(xml_node& node) = 0;
+		// Callback that is called after each node traversed
+		virtual void out(const xml_node& ){}
 
 		// Callback that is called when traversal ends
 		virtual bool end(xml_node& node);