Boost 1.46.1, Property Tree: How to iterate through ptree receiving sub ptrees?

The property tree iterators point to pairs of the form (key, tree) of type ptree::value_type. The standard loop for iterating through the children of the node at path therefore looks like:

BOOST_FOREACH(const ptree::value_type &v, pt.get_child(path)) {
    // v.first is the name of the child.
    // v.second is the child tree.
}