Method insert

code/data-structures/avl_tree.cpp:60–73

      else break; }
    return cur; }
  node* insert(const T &item) {
    node *prev = NULL, **cur = &root;
    while (*cur) {
      prev = *cur;
      if ((*cur)->item < item) cur = &((*cur)->r);
#if AVL_MULTISET
      else cur = &((*cur)->l);
#else
      else if (item < (*cur)->item) cur = &((*cur)->l);
      else return *cur;
#endif
    }
    node *n = new node(item, prev);
    *cur = n, fix(n); return n; }
  void erase(const T &item) { erase(find(item)); }
  void erase(node *n, bool free = true) {
    if (!n) return;