53 typedef std::list<tree<T> > child_list;
56 typedef typename child_list::iterator iterator;
57 typedef typename child_list::const_iterator const_iterator;
61 explicit tree(
const T& that);
63 bool operator==(
const self_type& that)
const;
70 iterator find(
const T& v);
71 const_iterator find(
const T& v)
const;
76 const_iterator begin()
const;
77 const_iterator end()
const;