It actually declares a STL 'map' iterator (
http://www.sgi.com/tech/stl/Map.html) which is used to iterator throug a std::map' which uses integers (the 1st template argument) as the key and maps these to a pointer to a 'ComReactor' object with the comparator used being 'less()' (
http://www.sgi.com/tech/stl/less.html).