# tree.hh

    00001 /*
    00002
    00003    $Id: tree.hh,v 1.6 2006/07/20 04:41:16 benoitg Exp $
    00004
    00005    STL-like templated tree class.
    00006    Copyright (C) 2001-2005  Kasper Peeters <kasper.peeters@aei.mpg.de>.
    00007
    00008 */
    00009
    00026 /*
    00027    This program is free software; you can redistribute it and/or modify
    00028    it under the terms of the GNU General Public License as published by
    00029    the Free Software Foundation; version 2.
    00030
    00031    This program is distributed in the hope that it will be useful,
    00032    but WITHOUT ANY WARRANTY; without even the implied warranty of
    00033    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00034    GNU General Public License for more details.
    00035
    00036    You should have received a copy of the GNU General Public License
    00037    along with this program; if not, write to the Free Software
    00038    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    00039 */
    00040
    00058 #ifndef tree_hh_
    00059 #define tree_hh_
    00060
    00061 #include <cassert>
    00062 #include <memory>
    00063 #include <stdexcept>
    00064 #include <iterator>
    00065 #include <set>
    00066
    00067 // HP-style construct/destroy have gone from the standard,
    00068 // so here is a copy.
    00069
    00070 namespace kp {
    00071
    00072 template <class T1, class T2>
    00073 void constructor(T1* p, T2& val)
    00074    {
    00075    new ((void *) p) T1(val);
    00076    }
    00077
    00078 template <class T1>
    00079 void constructor(T1* p)
    00080    {
    00081    new ((void *) p) T1;
    00082    }
    00083
    00084 template <class T1>
    00085 void destructor(T1* p)
    00086    {
    00087    p->~T1();
    00088    }
    00089
    00090 };
    00091
    00093 template<class T>
    00094 class tree_node_ { // size: 5*4=20 bytes (on 32 bit arch), can be reduced by 8.
    00095    public:
    00096       tree_node_<T> *parent;
    00097       tree_node_<T> *first_child, *last_child;
    00098       tree_node_<T> *prev_sibling, *next_sibling;
    00099       T data;
    00100 }; // __attribute__((packed));
    00101
    00102 template <class T, class tree_node_allocator = std::allocator<tree_node_<T> > >
    00103 class tree {
    00104    protected:
    00105       typedef tree_node_<T> tree_node;
    00106    public:
    00108       typedef T value_type;
    00109
    00110       class iterator_base;
    00111       class pre_order_iterator;
    00112       class post_order_iterator;
    00113       class sibling_iterator;
    00114
    00115       tree();
    00116       tree(const T&);
    00117       tree(const iterator_base&);
    00118       tree(const tree<T, tree_node_allocator>&);
    00119       ~tree();
    00120       void operator=(const tree<T, tree_node_allocator>&);
    00121
    00123 #ifdef __SGI_STL_PORT
    00124       class iterator_base : public stlport::bidirectional_iterator<T, ptrdiff_t> {
    00125 #else
    00126       class iterator_base {
    00127 #endif
    00128          public:
    00129             typedef T                               value_type;
    00130             typedef T*                              pointer;
    00131             typedef T&                              reference;
    00132             typedef size_t                          size_type;
    00133             typedef ptrdiff_t                       difference_type;
    00134             typedef std::bidirectional_iterator_tag iterator_category;
    00135
    00136             iterator_base();
    00137             iterator_base(tree_node *);
    00138
    00139             T&             operator*() const;
    00140             T*             operator->() const;
    00141
    00143             void         skip_children();
    00145             unsigned int number_of_children() const;
    00146
    00147             sibling_iterator begin() const;
    00148             sibling_iterator end() const;
    00149
    00150             tree_node *node;
    00151          protected:
    00152             bool skip_current_children_;
    00153       };
    00154
    00156       class pre_order_iterator : public iterator_base {
    00157          public:
    00158             pre_order_iterator();
    00159             pre_order_iterator(tree_node *);
    00160             pre_order_iterator(const iterator_base&);
    00161             pre_order_iterator(const sibling_iterator&);
    00162
    00163             bool    operator==(const pre_order_iterator&) const;
    00164             bool    operator!=(const pre_order_iterator&) const;
    00165             pre_order_iterator&  operator++();
    00166             pre_order_iterator&  operator--();
    00167             pre_order_iterator   operator++(int);
    00168             pre_order_iterator   operator--(int);
    00169             pre_order_iterator&  operator+=(unsigned int);
    00170             pre_order_iterator&  operator-=(unsigned int);
    00171       };
    00172
    00174       class post_order_iterator : public iterator_base {
    00175          public:
    00176             post_order_iterator();
    00177             post_order_iterator(tree_node *);
    00178             post_order_iterator(const iterator_base&);
    00179             post_order_iterator(const sibling_iterator&);
    00180
    00181             bool    operator==(const post_order_iterator&) const;
    00182             bool    operator!=(const post_order_iterator&) const;
    00183             post_order_iterator&  operator++();
    00184             post_order_iterator&  operator--();
    00185             post_order_iterator   operator++(int);
    00186             post_order_iterator   operator--(int);
    00187             post_order_iterator&  operator+=(unsigned int);
    00188             post_order_iterator&  operator-=(unsigned int);
    00189
    00191             void descend_all();
    00192       };
    00193
    00195       typedef pre_order_iterator iterator;
    00196
    00198       class fixed_depth_iterator : public iterator_base {
    00199          public:
    00200             fixed_depth_iterator();
    00201             fixed_depth_iterator(tree_node *);
    00202             fixed_depth_iterator(const iterator_base&);
    00203             fixed_depth_iterator(const sibling_iterator&);
    00204             fixed_depth_iterator(const fixed_depth_iterator&);
    00205
    00206             bool    operator==(const fixed_depth_iterator&) const;
    00207             bool    operator!=(const fixed_depth_iterator&) const;
    00208             fixed_depth_iterator&  operator++();
    00209             fixed_depth_iterator&  operator--();
    00210             fixed_depth_iterator   operator++(int);
    00211             fixed_depth_iterator   operator--(int);
    00212             fixed_depth_iterator&  operator+=(unsigned int);
    00213             fixed_depth_iterator&  operator-=(unsigned int);
    00214
    00215             tree_node *first_parent_;
    00216          private:
    00217             void set_first_parent_();
    00218             void find_leftmost_parent_();
    00219       };
    00220
    00222       class sibling_iterator : public iterator_base {
    00223          public:
    00224             sibling_iterator();
    00225             sibling_iterator(tree_node *);
    00226             sibling_iterator(const sibling_iterator&);
    00227             sibling_iterator(const iterator_base&);
    00228
    00229             bool    operator==(const sibling_iterator&) const;
    00230             bool    operator!=(const sibling_iterator&) const;
    00231             sibling_iterator&  operator++();
    00232             sibling_iterator&  operator--();
    00233             sibling_iterator   operator++(int);
    00234             sibling_iterator   operator--(int);
    00235             sibling_iterator&  operator+=(unsigned int);
    00236             sibling_iterator&  operator-=(unsigned int);
    00237
    00238             tree_node *range_first() const;
    00239             tree_node *range_last() const;
    00240             tree_node *parent_;
    00241          private:
    00242             void set_parent_();
    00243       };
    00244
    00246       inline pre_order_iterator   begin() const;
    00248       inline pre_order_iterator   end() const;
    00250       post_order_iterator  begin_post() const;
    00252       post_order_iterator  end_post() const;
    00254       fixed_depth_iterator begin_fixed(const iterator_base&, unsigned int) const;
    00256       fixed_depth_iterator end_fixed(const iterator_base&, unsigned int) const;
    00258       sibling_iterator     begin(const iterator_base&) const;
    00260       sibling_iterator     end(const iterator_base&) const;
    00261
    00263       template<typename iter> iter parent(iter) const;
    00265       template<typename iter> iter previous_sibling(iter) const;
    00267       template<typename iter> iter next_sibling(iter) const;
    00269       template<typename iter> iter next_at_same_depth(iter) const;
    00270
    00272       void     clear();
    00274       template<typename iter> iter erase(iter);
    00276       void     erase_children(const iterator_base&);
    00277
    00279       template<typename iter> iter append_child(iter position);
    00281       template<typename iter> iter append_child(iter position, const T& x);
    00283       template<typename iter> iter append_child(iter position, iter other_position);
    00285       template<typename iter> iter append_children(iter position, sibling_iterator from, sibling_iterator to);
    00286
    00288       pre_order_iterator set_head(const T& x);
    00290       template<typename iter> iter insert(iter position, const T& x);
    00292       sibling_iterator insert(sibling_iterator position, const T& x);
    00294       template<typename iter> iter insert_subtree(iter position, const iterator_base& subtree);
    00296       template<typename iter> iter insert_after(iter position, const T& x);
    00297
    00299       template<typename iter> iter replace(iter position, const T& x);
    00301       template<typename iter> iter replace(iter position, const iterator_base& from);
    00303       sibling_iterator replace(sibling_iterator orig_begin, sibling_iterator orig_end,
    00304                                sibling_iterator new_begin,  sibling_iterator new_end);
    00305
    00307       template<typename iter> iter flatten(iter position);
    00309       template<typename iter> iter reparent(iter position, sibling_iterator begin, sibling_iterator end);
    00311       template<typename iter> iter reparent(iter position, iter from);
    00312
    00314       template<typename iter> iter move_after(iter target, iter source);
    00316       template<typename iter> iter move_before(iter target, iter source);
    00318       template<typename iter> iter move_ontop(iter target, iter source);
    00319
    00321       void     merge(sibling_iterator, sibling_iterator, sibling_iterator, sibling_iterator,
    00322                      bool duplicate_leaves=false);
    00324       void     sort(sibling_iterator from, sibling_iterator to, bool deep=false);
    00325       template<class StrictWeakOrdering>
    00326       void     sort(sibling_iterator from, sibling_iterator to, StrictWeakOrdering comp, bool deep=false);
    00328       template<typename iter>
    00329       bool     equal(const iter& one, const iter& two, const iter& three) const;
    00330       template<typename iter, class BinaryPredicate>
    00331       bool     equal(const iter& one, const iter& two, const iter& three, BinaryPredicate) const;
    00332       template<typename iter>
    00333       bool     equal_subtree(const iter& one, const iter& two) const;
    00334       template<typename iter, class BinaryPredicate>
    00335       bool     equal_subtree(const iter& one, const iter& two, BinaryPredicate) const;
    00337       tree     subtree(sibling_iterator from, sibling_iterator to) const;
    00338       void     subtree(tree&, sibling_iterator from, sibling_iterator to) const;
    00340       void     swap(sibling_iterator it);
    00341
    00343       int      size() const;
    00345       bool     empty() const;
    00347       int      depth(const iterator_base&) const;
    00349       unsigned int number_of_children(const iterator_base&) const;
    00351       unsigned int number_of_siblings(const iterator_base&) const;
    00353       bool     is_in_subtree(const iterator_base& position, const iterator_base& begin,
    00354                              const iterator_base& end) const;
    00356       bool     is_valid(const iterator_base&) const;
    00357
    00359       unsigned int index(sibling_iterator it) const;
    00361       sibling_iterator  child(const iterator_base& position, unsigned int) const;
    00362
    00364       class iterator_base_less {
    00365          public:
    00366             bool operator()(const typename tree<T, tree_node_allocator>::iterator_base& one,
    00367                             const typename tree<T, tree_node_allocator>::iterator_base& two) const
    00368                {
    00369                return one.node < two.node;
    00370                }
    00371       };
    00372       tree_node *head, *feet;    // head/feet are always dummy; if an iterator points to them it is invalid
    00373    private:
    00374       tree_node_allocator alloc_;
    00375       void head_initialise_();
    00376       void copy_(const tree<T, tree_node_allocator>& other);
    00377
    00379       template<class StrictWeakOrdering>
    00380       class compare_nodes {
    00381          public:
    00382             compare_nodes(StrictWeakOrdering comp) : comp_(comp) {};
    00383
    00384             bool operator()(const tree_node *a, const tree_node *b)
    00385                {
    00386                static StrictWeakOrdering comp;
    00387                return comp(a->data, b->data);
    00388                }
    00389          private:
    00390             StrictWeakOrdering comp_;
    00391       };
    00392 };
    00393
    00394 //template <class T, class tree_node_allocator>
    00395 //class iterator_base_less {
    00396 // public:
    00397 //    bool operator()(const typename tree<T, tree_node_allocator>::iterator_base& one,
    00398 //                  const typename tree<T, tree_node_allocator>::iterator_base& two) const
    00399 //       {
    00400 //       txtout << "operatorclass<" << one.node < two.node << std::endl;
    00401 //       return one.node < two.node;
    00402 //       }
    00403 //};
    00404
    00405 //template <class T, class tree_node_allocator>
    00406 //bool operator<(const typename tree<T, tree_node_allocator>::iterator& one,
    00407 //             const typename tree<T, tree_node_allocator>::iterator& two)
    00408 // {
    00409 // txtout << "operator< " << one.node < two.node << std::endl;
    00410 // if(one.node < two.node) return true;
    00411 // return false;
    00412 // }
    00413
    00414 template <class T, class tree_node_allocator>
    00415 bool operator>(const typename tree<T, tree_node_allocator>::iterator_base& one,
    00416                const typename tree<T, tree_node_allocator>::iterator_base& two)
    00417    {
    00418    if(one.node > two.node) return true;
    00419    return false;
    00420    }
    00421
    00422
    00423
    00424 // Tree
    00425
    00426 template <class T, class tree_node_allocator>
    00427 tree<T, tree_node_allocator>::tree()
    00428    {
    00429    head_initialise_();
    00430    }
    00431
    00432 template <class T, class tree_node_allocator>
    00433 tree<T, tree_node_allocator>::tree(const T& x)
    00434    {
    00435    head_initialise_();
    00436    set_head(x);
    00437    }
    00438
    00439 template <class T, class tree_node_allocator>
    00440 tree<T, tree_node_allocator>::tree(const iterator_base& other)
    00441    {
    00442    head_initialise_();
    00443    set_head((*other));
    00444    replace(begin(), other);
    00445    }
    00446
    00447 template <class T, class tree_node_allocator>
    00448 tree<T, tree_node_allocator>::~tree()
    00449    {
    00450    clear();
    00451    alloc_.deallocate(head,1);
    00452    alloc_.deallocate(feet,1);
    00453    }
    00454
    00455 template <class T, class tree_node_allocator>
    00456 void tree<T, tree_node_allocator>::head_initialise_()
    00457    {
    00458    head = alloc_.allocate(1,0); // MSVC does not have default second argument
    00459    feet = alloc_.allocate(1,0);
    00460
    00461    head->parent=0;
    00462    head->first_child=0;
    00463    head->last_child=0;
    00464    head->prev_sibling=0; //head;
    00465    head->next_sibling=feet; //head;
    00466
    00467    feet->parent=0;
    00468    feet->first_child=0;
    00469    feet->last_child=0;
    00470    feet->prev_sibling=head;
    00471    feet->next_sibling=0;
    00472    }
    00473
    00474 template <class T, class tree_node_allocator>
    00475 void tree<T, tree_node_allocator>::operator=(const tree<T, tree_node_allocator>& other)
    00476    {
    00477    copy_(other);
    00478    }
    00479
    00480 template <class T, class tree_node_allocator>
    00481 tree<T, tree_node_allocator>::tree(const tree<T, tree_node_allocator>& other)
    00482    {
    00483    head_initialise_();
    00484    copy_(other);
    00485    }
    00486
    00487 template <class T, class tree_node_allocator>
    00488 void tree<T, tree_node_allocator>::copy_(const tree<T, tree_node_allocator>& other)
    00489    {
    00490    clear();
    00491    pre_order_iterator it=other.begin(), to=begin();
    00492    while(it!=other.end()) {
    00493       to=insert(to, (*it));
    00494       it.skip_children();
    00495       ++it;
    00496       }
    00497    to=begin();
    00498    it=other.begin();
    00499    while(it!=other.end()) {
    00500       to=replace(to, it);
    00501       to.skip_children();
    00502       it.skip_children();
    00503       ++to;
    00504       ++it;
    00505       }
    00506    }
    00507
    00508 template <class T, class tree_node_allocator>
    00509 void tree<T, tree_node_allocator>::clear()
    00510    {
    00511    if(head)
    00512       while(head->next_sibling!=feet)
    00513          erase(pre_order_iterator(head->next_sibling));
    00514    }
    00515
    00516 template<class T, class tree_node_allocator>
    00517 void tree<T, tree_node_allocator>::erase_children(const iterator_base& it)
    00518    {
    00519    tree_node *cur=it.node->first_child;
    00520    tree_node *prev=0;
    00521
    00522    while(cur!=0) {
    00523       prev=cur;
    00524       cur=cur->next_sibling;
    00525       erase_children(pre_order_iterator(prev));
    00526       kp::destructor(&prev->data);
    00527       alloc_.deallocate(prev,1);
    00528       }
    00529    it.node->first_child=0;
    00530    it.node->last_child=0;
    00531    }
    00532
    00533 template<class T, class tree_node_allocator>
    00534 template<class iter>
    00535 iter tree<T, tree_node_allocator>::erase(iter it)
    00536    {
    00537    tree_node *cur=it.node;
    00538    assert(cur!=head);
    00539    iter ret=it;
    00540    ret.skip_children();
    00541    ++ret;
    00542    erase_children(it);
    00543    if(cur->prev_sibling==0) {
    00544       cur->parent->first_child=cur->next_sibling;
    00545       }
    00546    else {
    00547       cur->prev_sibling->next_sibling=cur->next_sibling;
    00548       }
    00549    if(cur->next_sibling==0) {
    00550       cur->parent->last_child=cur->prev_sibling;
    00551       }
    00552    else {
    00553       cur->next_sibling->prev_sibling=cur->prev_sibling;
    00554       }
    00555
    00556    kp::destructor(&cur->data);
    00557    alloc_.deallocate(cur,1);
    00558    return ret;
    00559    }
    00560
    00561 template <class T, class tree_node_allocator>
    00562 typename tree<T, tree_node_allocator>::pre_order_iterator tree<T, tree_node_allocator>::begin() const
    00563    {
    00564    return pre_order_iterator(head->next_sibling);
    00565    }
    00566
    00567 template <class T, class tree_node_allocator>
    00568 typename tree<T, tree_node_allocator>::pre_order_iterator tree<T, tree_node_allocator>::end() const
    00569    {
    00570    return pre_order_iterator(feet);
    00571    }
    00572
    00573 template <class T, class tree_node_allocator>
    00574 typename tree<T, tree_node_allocator>::post_order_iterator tree<T, tree_node_allocator>::begin_post() const
    00575    {
    00576    tree_node *tmp=head->next_sibling;
    00577    if(tmp!=feet) {
    00578       while(tmp->first_child)
    00579          tmp=tmp->first_child;
    00580       }
    00581    return post_order_iterator(tmp);
    00582    }
    00583
    00584 template <class T, class tree_node_allocator>
    00585 typename tree<T, tree_node_allocator>::post_order_iterator tree<T, tree_node_allocator>::end_post() const
    00586    {
    00587    return post_order_iterator(feet);
    00588    }
    00589
    00590 template <class T, class tree_node_allocator>
    00591 typename tree<T, tree_node_allocator>::fixed_depth_iterator tree<T, tree_node_allocator>::begin_fixed(const iterator_base& pos, unsigned int dp) const
    00592    {
    00593    tree_node *tmp=pos.node;
    00594    unsigned int curdepth=0;
    00595    while(curdepth<dp) { // go down one level
    00596       while(tmp->first_child==0) {
    00597          tmp=tmp->next_sibling;
    00598          if(tmp==0)
    00599             throw std::range_error("tree: begin_fixed out of range");
    00600          }
    00601       tmp=tmp->first_child;
    00602       ++curdepth;
    00603       }
    00604    return tmp;
    00605    }
    00606
    00607 template <class T, class tree_node_allocator>
    00608 typename tree<T, tree_node_allocator>::fixed_depth_iterator tree<T, tree_node_allocator>::end_fixed(const iterator_base& pos, unsigned int dp) const
    00609    {
    00610    assert(1==0); // FIXME: not correct yet
    00611    tree_node *tmp=pos.node;
    00612    unsigned int curdepth=1;
    00613    while(curdepth<dp) { // go down one level
    00614       while(tmp->first_child==0) {
    00615          tmp=tmp->next_sibling;
    00616          if(tmp==0)
    00617             throw std::range_error("tree: end_fixed out of range");
    00618          }
    00619       tmp=tmp->first_child;
    00620       ++curdepth;
    00621       }
    00622    return tmp;
    00623    }
    00624
    00625 template <class T, class tree_node_allocator>
    00626 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::begin(const iterator_base& pos) const
    00627    {
    00628    if(pos.node->first_child==0) {
    00629       return end(pos);
    00630       }
    00631    return pos.node->first_child;
    00632    }
    00633
    00634 template <class T, class tree_node_allocator>
    00635 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::end(const iterator_base& pos) const
    00636    {
    00637    sibling_iterator ret(0);
    00638    ret.parent_=pos.node;
    00639    return ret;
    00640    }
    00641
    00642 template <class T, class tree_node_allocator>
    00643 template <typename iter>
    00644 iter tree<T, tree_node_allocator>::parent(iter position) const
    00645    {
    00646    assert(position.node!=0);
    00647    return iter(position.node->parent);
    00648    }
    00649
    00650 template <class T, class tree_node_allocator>
    00651 template <typename iter>
    00652 iter tree<T, tree_node_allocator>::previous_sibling(iter position) const
    00653    {
    00654    assert(position.node!=0);
    00655    iter ret(position);
    00656    ret.node=position.node->prev_sibling;
    00657    return ret;
    00658    }
    00659
    00660 template <class T, class tree_node_allocator>
    00661 template <typename iter>
    00662 iter tree<T, tree_node_allocator>::next_sibling(iter position) const
    00663    {
    00664    assert(position.node!=0);
    00665    iter ret(position);
    00666    ret.node=position.node->next_sibling;
    00667    return ret;
    00668    }
    00669
    00670 template <class T, class tree_node_allocator>
    00671 template <typename iter>
    00672 iter tree<T, tree_node_allocator>::next_at_same_depth(iter position) const
    00673    {
    00674    assert(position.node!=0);
    00675    iter ret(position);
    00676
    00677    if(position.node->next_sibling) {
    00678       ret.node=position.node->next_sibling;
    00679       }
    00680    else {
    00681       int relative_depth=0;
    00682       upper:
    00683       do {
    00684          ret.node=ret.node->parent;
    00685          if(ret.node==0) return ret;
    00686          --relative_depth;
    00687          } while(ret.node->next_sibling==0);
    00688       lower:
    00689       ret.node=ret.node->next_sibling;
    00690       while(ret.node->first_child==0) {
    00691          if(ret.node->next_sibling==0)
    00692             goto upper;
    00693          ret.node=ret.node->next_sibling;
    00694          if(ret.node==0) return ret;
    00695          }
    00696       while(relative_depth<0 && ret.node->first_child!=0) {
    00697          ret.node=ret.node->first_child;
    00698          ++relative_depth;
    00699          }
    00700       if(relative_depth<0) {
    00701          if(ret.node->next_sibling==0) goto upper;
    00702          else                          goto lower;
    00703          }
    00704       }
    00705    return ret;
    00706    }
    00707
    00708 template <class T, class tree_node_allocator>
    00709 template <typename iter>
    00710 iter tree<T, tree_node_allocator>::append_child(iter position)
    00711    {
    00712    assert(position.node!=head);
    00713
    00714    tree_node* tmp = alloc_.allocate(1,0);
    00715    kp::constructor(&tmp->data);
    00716    tmp->first_child=0;
    00717    tmp->last_child=0;
    00718
    00719    tmp->parent=position.node;
    00720    if(position.node->last_child!=0) {
    00721       position.node->last_child->next_sibling=tmp;
    00722       }
    00723    else {
    00724       position.node->first_child=tmp;
    00725       }
    00726    tmp->prev_sibling=position.node->last_child;
    00727    position.node->last_child=tmp;
    00728    tmp->next_sibling=0;
    00729    return tmp;
    00730    }
    00731
    00732 template <class T, class tree_node_allocator>
    00733 template <class iter>
    00734 iter tree<T, tree_node_allocator>::append_child(iter position, const T& x)
    00735    {
    00736    // If your program fails here you probably used 'append_child' to add the top
    00737    // node to an empty tree. From version 1.45 the top element should be added
    00738    // using 'insert'. See the documentation for further information, and sorry about
    00739    // the API change.
    00740    assert(position.node!=head);
    00741
    00742    tree_node* tmp = alloc_.allocate(1,0);
    00743    kp::constructor(&tmp->data, x);
    00744    tmp->first_child=0;
    00745    tmp->last_child=0;
    00746
    00747    tmp->parent=position.node;
    00748    if(position.node->last_child!=0) {
    00749       position.node->last_child->next_sibling=tmp;
    00750       }
    00751    else {
    00752       position.node->first_child=tmp;
    00753       }
    00754    tmp->prev_sibling=position.node->last_child;
    00755    position.node->last_child=tmp;
    00756    tmp->next_sibling=0;
    00757    return tmp;
    00758    }
    00759
    00760 template <class T, class tree_node_allocator>
    00761 template <class iter>
    00762 iter tree<T, tree_node_allocator>::append_child(iter position, iter other)
    00763    {
    00764    assert(position.node!=head);
    00765
    00766    sibling_iterator aargh=append_child(position, value_type());
    00767    return replace(aargh, other);
    00768    }
    00769
    00770 template <class T, class tree_node_allocator>
    00771 template <class iter>
    00772 iter tree<T, tree_node_allocator>::append_children(iter position, sibling_iterator from, sibling_iterator to)
    00773    {
    00774    iter ret=from;
    00775
    00776    while(from!=to) {
    00777       insert_subtree(position.end(), from);
    00778       ++from;
    00779       }
    00780    return ret;
    00781    }
    00782
    00783 template <class T, class tree_node_allocator>
    00784 typename tree<T, tree_node_allocator>::pre_order_iterator tree<T, tree_node_allocator>::set_head(const T& x)
    00785    {
    00786    assert(head->next_sibling==feet);
    00787    return insert(iterator(feet), x);
    00788    }
    00789
    00790 template <class T, class tree_node_allocator>
    00791 template <class iter>
    00792 iter tree<T, tree_node_allocator>::insert(iter position, const T& x)
    00793    {
    00794    if(position.node==0) {
    00795       position.node=feet; // Backward compatibility: when calling insert on a null node,
    00796                           // insert before the feet.
    00797       }
    00798    tree_node* tmp = alloc_.allocate(1,0);
    00799    kp::constructor(&tmp->data, x);
    00800    tmp->first_child=0;
    00801    tmp->last_child=0;
    00802
    00803    tmp->parent=position.node->parent;
    00804    tmp->next_sibling=position.node;
    00805    tmp->prev_sibling=position.node->prev_sibling;
    00806    position.node->prev_sibling=tmp;
    00807
    00808    if(tmp->prev_sibling==0) {
    00809       if(tmp->parent) // when inserting nodes at the head, there is no parent
    00810          tmp->parent->first_child=tmp;
    00811       }
    00812    else
    00813       tmp->prev_sibling->next_sibling=tmp;
    00814    return tmp;
    00815    }
    00816
    00817 template <class T, class tree_node_allocator>
    00818 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::insert(sibling_iterator position, const T& x)
    00819    {
    00820    tree_node* tmp = alloc_.allocate(1,0);
    00821    kp::constructor(&tmp->data, x);
    00822    tmp->first_child=0;
    00823    tmp->last_child=0;
    00824
    00825    tmp->next_sibling=position.node;
    00826    if(position.node==0) { // iterator points to end of a subtree
    00827       tmp->parent=position.parent_;
    00828       tmp->prev_sibling=position.range_last();
    00829       tmp->parent->last_child=tmp;
    00830       }
    00831    else {
    00832       tmp->parent=position.node->parent;
    00833       tmp->prev_sibling=position.node->prev_sibling;
    00834       position.node->prev_sibling=tmp;
    00835       }
    00836
    00837    if(tmp->prev_sibling==0) {
    00838       if(tmp->parent) // when inserting nodes at the head, there is no parent
    00839          tmp->parent->first_child=tmp;
    00840       }
    00841    else
    00842       tmp->prev_sibling->next_sibling=tmp;
    00843    return tmp;
    00844    }
    00845
    00846 template <class T, class tree_node_allocator>
    00847 template <class iter>
    00848 iter tree<T, tree_node_allocator>::insert_after(iter position, const T& x)
    00849    {
    00850    tree_node* tmp = alloc_.allocate(1,0);
    00851    kp::constructor(&tmp->data, x);
    00852    tmp->first_child=0;
    00853    tmp->last_child=0;
    00854
    00855    tmp->parent=position.node->parent;
    00856    tmp->prev_sibling=position.node;
    00857    tmp->next_sibling=position.node->next_sibling;
    00858    position.node->next_sibling=tmp;
    00859
    00860    if(tmp->next_sibling==0) {
    00861       if(tmp->parent) // when inserting nodes at the head, there is no parent
    00862          tmp->parent->last_child=tmp;
    00863       }
    00864    else {
    00865       tmp->next_sibling->prev_sibling=tmp;
    00866       }
    00867    return tmp;
    00868    }
    00869
    00870 template <class T, class tree_node_allocator>
    00871 template <class iter>
    00872 iter tree<T, tree_node_allocator>::insert_subtree(iter position, const iterator_base& subtree)
    00873    {
    00874    // insert dummy
    00875    iter it=insert(position, value_type());
    00876    // replace dummy with subtree
    00877    return replace(it, subtree);
    00878    }
    00879
    00880 // template <class T, class tree_node_allocator>
    00881 // template <class iter>
    00882 // iter tree<T, tree_node_allocator>::insert_subtree(sibling_iterator position, iter subtree)
    00883 //    {
    00884 //    // insert dummy
    00885 //    iter it(insert(position, value_type()));
    00886 //    // replace dummy with subtree
    00887 //    return replace(it, subtree);
    00888 //    }
    00889
    00890 template <class T, class tree_node_allocator>
    00891 template <class iter>
    00892 iter tree<T, tree_node_allocator>::replace(iter position, const T& x)
    00893    {
    00894    kp::destructor(&position.node->data);
    00895    kp::constructor(&position.node->data, x);
    00896    return position;
    00897    }
    00898
    00899 template <class T, class tree_node_allocator>
    00900 template <class iter>
    00901 iter tree<T, tree_node_allocator>::replace(iter position, const iterator_base& from)
    00902    {
    00903    assert(position.node!=head);
    00904    tree_node *current_from=from.node;
    00905    tree_node *start_from=from.node;
    00906    tree_node *current_to  =position.node;
    00907
    00908    // replace the node at position with head of the replacement tree at from
    00909    erase_children(position);
    00910    tree_node* tmp = alloc_.allocate(1,0);
    00911    kp::constructor(&tmp->data, (*from));
    00912    tmp->first_child=0;
    00913    tmp->last_child=0;
    00914    if(current_to->prev_sibling==0) {
    00915       current_to->parent->first_child=tmp;
    00916       }
    00917    else {
    00918       current_to->prev_sibling->next_sibling=tmp;
    00919       }
    00920    tmp->prev_sibling=current_to->prev_sibling;
    00921    if(current_to->next_sibling==0) {
    00922       current_to->parent->last_child=tmp;
    00923       }
    00924    else {
    00925       current_to->next_sibling->prev_sibling=tmp;
    00926       }
    00927    tmp->next_sibling=current_to->next_sibling;
    00928    tmp->parent=current_to->parent;
    00929    kp::destructor(&current_to->data);
    00930    alloc_.deallocate(current_to,1);
    00931    current_to=tmp;
    00932
    00933    // only at this stage can we fix 'last'
    00934    tree_node *last=from.node->next_sibling;
    00935
    00936    pre_order_iterator toit=tmp;
    00937    // copy all children
    00938    do {
    00939       assert(current_from!=0);
    00940       if(current_from->first_child != 0) {
    00941          current_from=current_from->first_child;
    00942          toit=append_child(toit, current_from->data);
    00943          }
    00944       else {
    00945          while(current_from->next_sibling==0 && current_from!=start_from) {
    00946             current_from=current_from->parent;
    00947             toit=parent(toit);
    00948             assert(current_from!=0);
    00949             }
    00950          current_from=current_from->next_sibling;
    00951          if(current_from!=last) {
    00952             toit=append_child(parent(toit), current_from->data);
    00953             }
    00954          }
    00955       } while(current_from!=last);
    00956
    00957    return current_to;
    00958    }
    00959
    00960 template <class T, class tree_node_allocator>
    00961 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::replace(
    00962    sibling_iterator orig_begin,
    00963    sibling_iterator orig_end,
    00964    sibling_iterator new_begin,
    00965    sibling_iterator new_end)
    00966    {
    00967    tree_node *orig_first=orig_begin.node;
    00968    tree_node *new_first=new_begin.node;
    00969    tree_node *orig_last=orig_first;
    00970    while((++orig_begin)!=orig_end)
    00971       orig_last=orig_last->next_sibling;
    00972    tree_node *new_last=new_first;
    00973    while((++new_begin)!=new_end)
    00974       new_last=new_last->next_sibling;
    00975
    00976    // insert all siblings in new_first..new_last before orig_first
    00977    bool first=true;
    00978    pre_order_iterator ret;
    00979    while(1==1) {
    00980       pre_order_iterator tt=insert_subtree(pre_order_iterator(orig_first), pre_order_iterator(new_first));
    00981       if(first) {
    00982          ret=tt;
    00983          first=false;
    00984          }
    00985       if(new_first==new_last)
    00986          break;
    00987       new_first=new_first->next_sibling;
    00988       }
    00989
    00990    // erase old range of siblings
    00991    bool last=false;
    00992    tree_node *next=orig_first;
    00993    while(1==1) {
    00994       if(next==orig_last)
    00995          last=true;
    00996       next=next->next_sibling;
    00997       erase((pre_order_iterator)orig_first);
    00998       if(last)
    00999          break;
    01000       orig_first=next;
    01001       }
    01002    return ret;
    01003    }
    01004
    01005 template <class T, class tree_node_allocator>
    01006 template <typename iter>
    01007 iter tree<T, tree_node_allocator>::flatten(iter position)
    01008    {
    01009    if(position.node->first_child==0)
    01010       return position;
    01011
    01012    tree_node *tmp=position.node->first_child;
    01013    while(tmp) {
    01014       tmp->parent=position.node->parent;
    01015       tmp=tmp->next_sibling;
    01016       }
    01017    if(position.node->next_sibling) {
    01018       position.node->last_child->next_sibling=position.node->next_sibling;
    01019       position.node->next_sibling->prev_sibling=position.node->last_child;
    01020       }
    01021    else {
    01022       position.node->parent->last_child=position.node->last_child;
    01023       }
    01024    position.node->next_sibling=position.node->first_child;
    01025    position.node->next_sibling->prev_sibling=position.node;
    01026    position.node->first_child=0;
    01027    position.node->last_child=0;
    01028
    01029    return position;
    01030    }
    01031
    01032
    01033 template <class T, class tree_node_allocator>
    01034 template <typename iter>
    01035 iter tree<T, tree_node_allocator>::reparent(iter position, sibling_iterator begin, sibling_iterator end)
    01036    {
    01037    tree_node *first=begin.node;
    01038    tree_node *last=first;
    01039    if(begin==end) return begin;
    01040    // determine last node
    01041    while((++begin)!=end) {
    01042       last=last->next_sibling;
    01043       }
    01044    // move subtree
    01045    if(first->prev_sibling==0) {
    01046       first->parent->first_child=last->next_sibling;
    01047       }
    01048    else {
    01049       first->prev_sibling->next_sibling=last->next_sibling;
    01050       }
    01051    if(last->next_sibling==0) {
    01052       last->parent->last_child=first->prev_sibling;
    01053       }
    01054    else {
    01055       last->next_sibling->prev_sibling=first->prev_sibling;
    01056       }
    01057    if(position.node->first_child==0) {
    01058       position.node->first_child=first;
    01059       position.node->last_child=last;
    01060       first->prev_sibling=0;
    01061       }
    01062    else {
    01063       position.node->last_child->next_sibling=first;
    01064       first->prev_sibling=position.node->last_child;
    01065       position.node->last_child=last;
    01066       }
    01067    last->next_sibling=0;
    01068
    01069    tree_node *pos=first;
    01070    while(1==1) {
    01071       pos->parent=position.node;
    01072       if(pos==last) break;
    01073       pos=pos->next_sibling;
    01074       }
    01075
    01076    return first;
    01077    }
    01078
    01079 template <class T, class tree_node_allocator>
    01080 template <typename iter> iter tree<T, tree_node_allocator>::reparent(iter position, iter from)
    01081    {
    01082    if(from.node->first_child==0) return position;
    01083    return reparent(position, from.node->first_child, end(from));
    01084    }
    01085
    01086 template <class T, class tree_node_allocator>
    01087 template <typename iter> iter tree<T, tree_node_allocator>::move_after(iter target, iter source)
    01088    {
    01089    tree_node *dst=target.node;
    01090    tree_node *src=source.node;
    01091    assert(dst);
    01092    assert(src);
    01093
    01094    if(dst==src) return source;
    01095
    01096    // take src out of the tree
    01097    if(src->prev_sibling!=0) src->prev_sibling->next_sibling=src->next_sibling;
    01098    else                     src->parent->first_child=src->next_sibling;
    01099    if(src->next_sibling!=0) src->next_sibling->prev_sibling=src->prev_sibling;
    01100    else                     src->parent->last_child=src->prev_sibling;
    01101
    01102    // connect it to the new point
    01103    if(dst->next_sibling!=0) dst->next_sibling->prev_sibling=src;
    01104    else                     dst->parent->last_child=src;
    01105    src->next_sibling=dst->next_sibling;
    01106    dst->next_sibling=src;
    01107    src->prev_sibling=dst;
    01108    src->parent=dst->parent;
    01109    return src;
    01110    }
    01111
    01112
    01113 template <class T, class tree_node_allocator>
    01114 template <typename iter> iter tree<T, tree_node_allocator>::move_before(iter target, iter source)
    01115    {
    01116    tree_node *dst=target.node;
    01117    tree_node *src=source.node;
    01118    assert(dst);
    01119    assert(src);
    01120
    01121    if(dst==src) return source;
    01122
    01123    // take src out of the tree
    01124    if(src->prev_sibling!=0) src->prev_sibling->next_sibling=src->next_sibling;
    01125    else                     src->parent->first_child=src->next_sibling;
    01126    if(src->next_sibling!=0) src->next_sibling->prev_sibling=src->prev_sibling;
    01127    else                     src->parent->last_child=src->prev_sibling;
    01128
    01129    // connect it to the new point
    01130    if(dst->prev_sibling!=0) dst->prev_sibling->next_sibling=src;
    01131    else                     dst->parent->first_child=src;
    01132    src->prev_sibling=dst->prev_sibling;
    01133    dst->prev_sibling=src;
    01134    src->next_sibling=dst;
    01135    src->parent=dst->parent;
    01136    return src;
    01137    }
    01138
    01139 template <class T, class tree_node_allocator>
    01140 template <typename iter> iter tree<T, tree_node_allocator>::move_ontop(iter target, iter source)
    01141    {
    01142    tree_node *dst=target.node;
    01143    tree_node *src=source.node;
    01144    assert(dst);
    01145    assert(src);
    01146
    01147    if(dst==src) return source;
    01148
    01149    // remember connection points
    01150    tree_node *b_prev_sibling=dst->prev_sibling;
    01151    tree_node *b_next_sibling=dst->next_sibling;
    01152    tree_node *b_parent=dst->parent;
    01153
    01154    // remove target
    01155    erase(target);
    01156
    01157    // take src out of the tree
    01158    if(src->prev_sibling!=0) src->prev_sibling->next_sibling=src->next_sibling;
    01159    else                     src->parent->first_child=src->next_sibling;
    01160    if(src->next_sibling!=0) src->next_sibling->prev_sibling=src->prev_sibling;
    01161    else                     src->parent->last_child=src->prev_sibling;
    01162
    01163    // connect it to the new point
    01164    if(b_prev_sibling!=0) b_prev_sibling->next_sibling=src;
    01165    else                  b_parent->first_child=src;
    01166    if(b_next_sibling!=0) b_next_sibling->prev_sibling=src;
    01167    else                  b_parent->last_child=src;
    01168    src->prev_sibling=b_prev_sibling;
    01169    src->next_sibling=b_next_sibling;
    01170    src->parent=b_parent;
    01171    return src;
    01172    }
    01173
    01174 template <class T, class tree_node_allocator>
    01175 void tree<T, tree_node_allocator>::merge(sibling_iterator to1,   sibling_iterator to2,
    01176                                           sibling_iterator from1, sibling_iterator from2,
    01177                                           bool duplicate_leaves)
    01178    {
    01179    sibling_iterator fnd;
    01180    while(from1!=from2) {
    01181       if((fnd=std::find(to1, to2, (*from1))) != to2) { // element found
    01182          if(from1.begin()==from1.end()) { // full depth reached
    01183             if(duplicate_leaves)
    01184                append_child(parent(to1), (*from1));
    01185             }
    01186          else { // descend further
    01187             merge(fnd.begin(), fnd.end(), from1.begin(), from1.end(), duplicate_leaves);
    01188             }
    01189          }
    01190       else { // element missing
    01191          insert_subtree(to2, from1);
    01192          }
    01193       ++from1;
    01194       }
    01195    }
    01196
    01197
    01198 template <class T, class tree_node_allocator>
    01199 void tree<T, tree_node_allocator>::sort(sibling_iterator from, sibling_iterator to, bool deep)
    01200    {
    01201    std::less<T> comp;
    01202    sort(from, to, comp, deep);
    01203    }
    01204
    01205 template <class T, class tree_node_allocator>
    01206 template <class StrictWeakOrdering>
    01207 void tree<T, tree_node_allocator>::sort(sibling_iterator from, sibling_iterator to,
    01208                                         StrictWeakOrdering comp, bool deep)
    01209    {
    01210    if(from==to) return;
    01211    // make list of sorted nodes
    01212    // CHECK: if multiset stores equivalent nodes in the order in which they
    01213    // are inserted, then this routine should be called 'stable_sort'.
    01214    std::multiset<tree_node *, compare_nodes<StrictWeakOrdering> > nodes(comp);
    01215    sibling_iterator it=from, it2=to;
    01216    while(it != to) {
    01217       nodes.insert(it.node);
    01218       ++it;
    01219       }
    01220    // reassemble
    01221    --it2;
    01222
    01223    // prev and next are the nodes before and after the sorted range
    01224    tree_node *prev=from.node->prev_sibling;
    01225    tree_node *next=it2.node->next_sibling;
    01226    typename std::multiset<tree_node *, compare_nodes<StrictWeakOrdering> >::iterator nit=nodes.begin(), eit=nodes.end();
    01227    if(prev==0) {
    01228       if((*nit)->parent!=0) // to catch "sorting the head" situations, when there is no parent
    01229          (*nit)->parent->first_child=(*nit);
    01230       }
    01231    else prev->next_sibling=(*nit);
    01232
    01233    --eit;
    01234    while(nit!=eit) {
    01235       (*nit)->prev_sibling=prev;
    01236       if(prev)
    01237          prev->next_sibling=(*nit);
    01238       prev=(*nit);
    01239       ++nit;
    01240       }
    01241    // prev now points to the last-but-one node in the sorted range
    01242    if(prev)
    01243       prev->next_sibling=(*eit);
    01244
    01245    // eit points to the last node in the sorted range.
    01246    (*eit)->next_sibling=next;
    01247    (*eit)->prev_sibling=prev; // missed in the loop above
    01248    if(next==0) {
    01249       if((*eit)->parent!=0) // to catch "sorting the head" situations, when there is no parent
    01250          (*eit)->parent->last_child=(*eit);
    01251       }
    01252    else next->prev_sibling=(*eit);
    01253
    01254    if(deep) {  // sort the children of each node too
    01255       sibling_iterator bcs(*nodes.begin());
    01256       sibling_iterator ecs(*eit);
    01257       ++ecs;
    01258       while(bcs!=ecs) {
    01259          sort(begin(bcs), end(bcs), comp, deep);
    01260          ++bcs;
    01261          }
    01262       }
    01263    }
    01264
    01265 template <class T, class tree_node_allocator>
    01266 template <typename iter>
    01267 bool tree<T, tree_node_allocator>::equal(const iter& one_, const iter& two, const iter& three_) const
    01268    {
    01269    std::equal_to<T> comp;
    01270    return equal(one_, two, three_, comp);
    01271    }
    01272
    01273 template <class T, class tree_node_allocator>
    01274 template <typename iter>
    01275 bool tree<T, tree_node_allocator>::equal_subtree(const iter& one_, const iter& two_) const
    01276    {
    01277    std::equal_to<T> comp;
    01278    return equal_subtree(one_, two_, comp);
    01279    }
    01280
    01281 template <class T, class tree_node_allocator>
    01282 template <typename iter, class BinaryPredicate>
    01283 bool tree<T, tree_node_allocator>::equal(const iter& one_, const iter& two, const iter& three_, BinaryPredicate fun) const
    01284    {
    01285    pre_order_iterator one(one_), three(three_);
    01286
    01287 // if(one==two && is_valid(three) && three.number_of_children()!=0)
    01288 //    return false;
    01289    while(one!=two && is_valid(three)) {
    01290       if(!fun(*one,*three))
    01291          return false;
    01292       if(one.number_of_children()!=three.number_of_children())
    01293          return false;
    01294       ++one;
    01295       ++three;
    01296       }
    01297    return true;
    01298    }
    01299
    01300 template <class T, class tree_node_allocator>
    01301 template <typename iter, class BinaryPredicate>
    01302 bool tree<T, tree_node_allocator>::equal_subtree(const iter& one_, const iter& two_, BinaryPredicate fun) const
    01303    {
    01304    pre_order_iterator one(one_), two(two_);
    01305
    01306    if(!fun(*one,*two)) return false;
    01307    if(number_of_children(one)!=number_of_children(two)) return false;
    01308    return equal(begin(one),end(one),begin(two),fun);
    01309    }
    01310
    01311 template <class T, class tree_node_allocator>
    01312 tree<T, tree_node_allocator> tree<T, tree_node_allocator>::subtree(sibling_iterator from, sibling_iterator to) const
    01313    {
    01314    tree tmp;
    01315    tmp.set_head(value_type());
    01316    tmp.replace(tmp.begin(), tmp.end(), from, to);
    01317    return tmp;
    01318    }
    01319
    01320 template <class T, class tree_node_allocator>
    01321 void tree<T, tree_node_allocator>::subtree(tree& tmp, sibling_iterator from, sibling_iterator to) const
    01322    {
    01323    tmp.set_head(value_type());
    01324    tmp.replace(tmp.begin(), tmp.end(), from, to);
    01325    }
    01326
    01327 template <class T, class tree_node_allocator>
    01328 int tree<T, tree_node_allocator>::size() const
    01329    {
    01330    int i=0;
    01331    pre_order_iterator it=begin(), eit=end();
    01332    while(it!=eit) {
    01333       ++i;
    01334       ++it;
    01335       }
    01336    return i;
    01337    }
    01338
    01339 template <class T, class tree_node_allocator>
    01340 bool tree<T, tree_node_allocator>::empty() const
    01341    {
    01342    pre_order_iterator it=begin(), eit=end();
    01343    return (it==eit);
    01344    }
    01345
    01346 template <class T, class tree_node_allocator>
    01347 int tree<T, tree_node_allocator>::depth(const iterator_base& it) const
    01348    {
    01349    tree_node* pos=it.node;
    01350    assert(pos!=0);
    01351    int ret=0;
    01352    while(pos->parent!=0) {
    01353       pos=pos->parent;
    01354       ++ret;
    01355       }
    01356    return ret;
    01357    }
    01358
    01359 template <class T, class tree_node_allocator>
    01360 unsigned int tree<T, tree_node_allocator>::number_of_children(const iterator_base& it) const
    01361    {
    01362    tree_node *pos=it.node->first_child;
    01363    if(pos==0) return 0;
    01364
    01365    unsigned int ret=1;
    01366 //   while(pos!=it.node->last_child) {
    01367 //      ++ret;
    01368 //      pos=pos->next_sibling;
    01369 //      }
    01370    while((pos=pos->next_sibling))
    01371       ++ret;
    01372    return ret;
    01373    }
    01374
    01375 template <class T, class tree_node_allocator>
    01376 unsigned int tree<T, tree_node_allocator>::number_of_siblings(const iterator_base& it) const
    01377    {
    01378    tree_node *pos=it.node;
    01379    unsigned int ret=0;
    01380    while(pos->next_sibling &&
    01381          pos->next_sibling!=head &&
    01382          pos->next_sibling!=feet) {
    01383       ++ret;
    01384       pos=pos->next_sibling;
    01385       }
    01386    return ret;
    01387    }
    01388
    01389 template <class T, class tree_node_allocator>
    01390 void tree<T, tree_node_allocator>::swap(sibling_iterator it)
    01391    {
    01392    tree_node *nxt=it.node->next_sibling;
    01393    if(nxt) {
    01394       if(it.node->prev_sibling)
    01395          it.node->prev_sibling->next_sibling=nxt;
    01396       else
    01397          it.node->parent->first_child=nxt;
    01398       nxt->prev_sibling=it.node->prev_sibling;
    01399       tree_node *nxtnxt=nxt->next_sibling;
    01400       if(nxtnxt)
    01401          nxtnxt->prev_sibling=it.node;
    01402       else
    01403          it.node->parent->last_child=it.node;
    01404       nxt->next_sibling=it.node;
    01405       it.node->prev_sibling=nxt;
    01406       it.node->next_sibling=nxtnxt;
    01407       }
    01408    }
    01409
    01410 // template <class BinaryPredicate>
    01411 // tree<T, tree_node_allocator>::iterator tree<T, tree_node_allocator>::find_subtree(
    01412 //    sibling_iterator subfrom, sibling_iterator subto, iterator from, iterator to,
    01413 //    BinaryPredicate fun) const
    01414 //    {
    01415 //    assert(1==0); // this routine is not finished yet.
    01416 //    while(from!=to) {
    01417 //       if(fun(*subfrom, *from)) {
    01418 //
    01419 //          }
    01420 //       }
    01421 //    return to;
    01422 //    }
    01423
    01424 template <class T, class tree_node_allocator>
    01425 bool tree<T, tree_node_allocator>::is_in_subtree(const iterator_base& it, const iterator_base& begin,
    01426                                                  const iterator_base& end) const
    01427    {
    01428    // FIXME: this should be optimised.
    01429    pre_order_iterator tmp=begin;
    01430    while(tmp!=end) {
    01431       if(tmp==it) return true;
    01432       ++tmp;
    01433       }
    01434    return false;
    01435    }
    01436
    01437 template <class T, class tree_node_allocator>
    01438 bool tree<T, tree_node_allocator>::is_valid(const iterator_base& it) const
    01439    {
    01440    if(it.node==0 || it.node==feet) return false;
    01441    else return true;
    01442    }
    01443
    01444 template <class T, class tree_node_allocator>
    01445 unsigned int tree<T, tree_node_allocator>::index(sibling_iterator it) const
    01446    {
    01447    unsigned int ind=0;
    01448    if(it.node->parent==0) {
    01449       while(it.node->prev_sibling!=head) {
    01450          it.node=it.node->prev_sibling;
    01451          ++ind;
    01452          }
    01453       }
    01454    else {
    01455       while(it.node->prev_sibling!=0) {
    01456          it.node=it.node->prev_sibling;
    01457          ++ind;
    01458          }
    01459       }
    01460    return ind;
    01461    }
    01462
    01463
    01464 template <class T, class tree_node_allocator>
    01465 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::child(const iterator_base& it, unsigned int num) const
    01466    {
    01467    tree_node *tmp=it.node->first_child;
    01468    while(num--) {
    01469       assert(tmp!=0);
    01470       tmp=tmp->next_sibling;
    01471       }
    01472    return tmp;
    01473    }
    01474
    01475
    01476
    01477
    01478 // Iterator base
    01479
    01480 template <class T, class tree_node_allocator>
    01481 tree<T, tree_node_allocator>::iterator_base::iterator_base()
    01482    : node(0), skip_current_children_(false)
    01483    {
    01484    }
    01485
    01486 template <class T, class tree_node_allocator>
    01487 tree<T, tree_node_allocator>::iterator_base::iterator_base(tree_node *tn)
    01488    : node(tn), skip_current_children_(false)
    01489    {
    01490    }
    01491
    01492 template <class T, class tree_node_allocator>
    01493 T& tree<T, tree_node_allocator>::iterator_base::operator*() const
    01494    {
    01495    return node->data;
    01496    }
    01497
    01498 template <class T, class tree_node_allocator>
    01499 T* tree<T, tree_node_allocator>::iterator_base::operator->() const
    01500    {
    01501    return &(node->data);
    01502    }
    01503
    01504 template <class T, class tree_node_allocator>
    01505 bool tree<T, tree_node_allocator>::post_order_iterator::operator!=(const post_order_iterator& other) const
    01506    {
    01507    if(other.node!=this->node) return true;
    01508    else return false;
    01509    }
    01510
    01511 template <class T, class tree_node_allocator>
    01512 bool tree<T, tree_node_allocator>::post_order_iterator::operator==(const post_order_iterator& other) const
    01513    {
    01514    if(other.node==this->node) return true;
    01515    else return false;
    01516    }
    01517
    01518 template <class T, class tree_node_allocator>
    01519 bool tree<T, tree_node_allocator>::pre_order_iterator::operator!=(const pre_order_iterator& other) const
    01520    {
    01521    if(other.node!=this->node) return true;
    01522    else return false;
    01523    }
    01524
    01525 template <class T, class tree_node_allocator>
    01526 bool tree<T, tree_node_allocator>::pre_order_iterator::operator==(const pre_order_iterator& other) const
    01527    {
    01528    if(other.node==this->node) return true;
    01529    else return false;
    01530    }
    01531
    01532 template <class T, class tree_node_allocator>
    01533 bool tree<T, tree_node_allocator>::sibling_iterator::operator!=(const sibling_iterator& other) const
    01534    {
    01535    if(other.node!=this->node) return true;
    01536    else return false;
    01537    }
    01538
    01539 template <class T, class tree_node_allocator>
    01540 bool tree<T, tree_node_allocator>::sibling_iterator::operator==(const sibling_iterator& other) const
    01541    {
    01542    if(other.node==this->node) return true;
    01543    else return false;
    01544    }
    01545
    01546 template <class T, class tree_node_allocator>
    01547 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::iterator_base::begin() const
    01548    {
    01549    sibling_iterator ret(node->first_child);
    01550    ret.parent_=this->node;
    01551    return ret;
    01552    }
    01553
    01554 template <class T, class tree_node_allocator>
    01555 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::iterator_base::end() const
    01556    {
    01557    sibling_iterator ret(0);
    01558    ret.parent_=node;
    01559    return ret;
    01560    }
    01561
    01562 template <class T, class tree_node_allocator>
    01563 void tree<T, tree_node_allocator>::iterator_base::skip_children()
    01564    {
    01565    skip_current_children_=true;
    01566    }
    01567
    01568 template <class T, class tree_node_allocator>
    01569 unsigned int tree<T, tree_node_allocator>::iterator_base::number_of_children() const
    01570    {
    01571    tree_node *pos=node->first_child;
    01572    if(pos==0) return 0;
    01573
    01574    unsigned int ret=1;
    01575    while(pos!=node->last_child) {
    01576       ++ret;
    01577       pos=pos->next_sibling;
    01578       }
    01579    return ret;
    01580    }
    01581
    01582
    01583
    01584 // Pre-order iterator
    01585
    01586 template <class T, class tree_node_allocator>
    01587 tree<T, tree_node_allocator>::pre_order_iterator::pre_order_iterator()
    01588    : iterator_base(0)
    01589    {
    01590    }
    01591
    01592 template <class T, class tree_node_allocator>
    01593 tree<T, tree_node_allocator>::pre_order_iterator::pre_order_iterator(tree_node *tn)
    01594    : iterator_base(tn)
    01595    {
    01596    }
    01597
    01598 template <class T, class tree_node_allocator>
    01599 tree<T, tree_node_allocator>::pre_order_iterator::pre_order_iterator(const iterator_base &other)
    01600    : iterator_base(other.node)
    01601    {
    01602    }
    01603
    01604 template <class T, class tree_node_allocator>
    01605 tree<T, tree_node_allocator>::pre_order_iterator::pre_order_iterator(const sibling_iterator& other)
    01606    : iterator_base(other.node)
    01607    {
    01608    if(this->node==0) {
    01609       if(other.range_last()!=0)
    01610          this->node=other.range_last();
    01611       else
    01612          this->node=other.parent_;
    01613       this->skip_children();
    01614       ++(*this);
    01615       }
    01616    }
    01617
    01618 template <class T, class tree_node_allocator>
    01619 typename tree<T, tree_node_allocator>::pre_order_iterator& tree<T, tree_node_allocator>::pre_order_iterator::operator++()
    01620    {
    01621    assert(this->node!=0);
    01622    if(!this->skip_current_children_ && this->node->first_child != 0) {
    01623       this->node=this->node->first_child;
    01624       }
    01625    else {
    01626       this->skip_current_children_=false;
    01627       while(this->node->next_sibling==0) {
    01628          this->node=this->node->parent;
    01629          if(this->node==0)
    01630             return *this;
    01631          }
    01632       this->node=this->node->next_sibling;
    01633       }
    01634    return *this;
    01635    }
    01636
    01637 template <class T, class tree_node_allocator>
    01638 typename tree<T, tree_node_allocator>::pre_order_iterator& tree<T, tree_node_allocator>::pre_order_iterator::operator--()
    01639    {
    01640    assert(this->node!=0);
    01641    if(this->node->prev_sibling) {
    01642       this->node=this->node->prev_sibling;
    01643       while(this->node->last_child)
    01644          this->node=this->node->last_child;
    01645       }
    01646    else {
    01647       this->node=this->node->parent;
    01648       if(this->node==0)
    01649          return *this;
    01650       }
    01651    return *this;
    01652 }
    01653
    01654 template <class T, class tree_node_allocator>
    01655 typename tree<T, tree_node_allocator>::pre_order_iterator tree<T, tree_node_allocator>::pre_order_iterator::operator++(int n)
    01656    {
    01657    pre_order_iterator copy = *this;
    01658    ++(*this);
    01659    return copy;
    01660    }
    01661
    01662 template <class T, class tree_node_allocator>
    01663 typename tree<T, tree_node_allocator>::pre_order_iterator tree<T, tree_node_allocator>::pre_order_iterator::operator--(int n)
    01664 {
    01665   pre_order_iterator copy = *this;
    01666   --(*this);
    01667   return copy;
    01668 }
    01669
    01670 template <class T, class tree_node_allocator>
    01671 typename tree<T, tree_node_allocator>::pre_order_iterator& tree<T, tree_node_allocator>::pre_order_iterator::operator+=(unsigned int num)
    01672    {
    01673    while(num>0) {
    01674       ++(*this);
    01675       --num;
    01676       }
    01677    return (*this);
    01678    }
    01679
    01680 template <class T, class tree_node_allocator>
    01681 typename tree<T, tree_node_allocator>::pre_order_iterator& tree<T, tree_node_allocator>::pre_order_iterator::operator-=(unsigned int num)
    01682    {
    01683    while(num>0) {
    01684       --(*this);
    01685       --num;
    01686       }
    01687    return (*this);
    01688    }
    01689
    01690
    01691
    01692 // Post-order iterator
    01693
    01694 template <class T, class tree_node_allocator>
    01695 tree<T, tree_node_allocator>::post_order_iterator::post_order_iterator()
    01696    : iterator_base(0)
    01697    {
    01698    }
    01699
    01700 template <class T, class tree_node_allocator>
    01701 tree<T, tree_node_allocator>::post_order_iterator::post_order_iterator(tree_node *tn)
    01702    : iterator_base(tn)
    01703    {
    01704    }
    01705
    01706 template <class T, class tree_node_allocator>
    01707 tree<T, tree_node_allocator>::post_order_iterator::post_order_iterator(const iterator_base &other)
    01708    : iterator_base(other.node)
    01709    {
    01710    }
    01711
    01712 template <class T, class tree_node_allocator>
    01713 tree<T, tree_node_allocator>::post_order_iterator::post_order_iterator(const sibling_iterator& other)
    01714    : iterator_base(other.node)
    01715    {
    01716    if(this->node==0) {
    01717       if(other.range_last()!=0)
    01718          this->node=other.range_last();
    01719       else
    01720          this->node=other.parent_;
    01721       this->skip_children();
    01722       ++(*this);
    01723       }
    01724    }
    01725
    01726 template <class T, class tree_node_allocator>
    01727 typename tree<T, tree_node_allocator>::post_order_iterator& tree<T, tree_node_allocator>::post_order_iterator::operator++()
    01728    {
    01729    assert(this->node!=0);
    01730    if(this->node->next_sibling==0) {
    01731       this->node=this->node->parent;
    01732       this->skip_current_children_=false;
    01733       }
    01734    else {
    01735       this->node=this->node->next_sibling;
    01736       if(this->skip_current_children_) {
    01737          this->skip_current_children_=false;
    01738          }
    01739       else {
    01740          while(this->node->first_child)
    01741             this->node=this->node->first_child;
    01742          }
    01743       }
    01744    return *this;
    01745    }
    01746
    01747 template <class T, class tree_node_allocator>
    01748 typename tree<T, tree_node_allocator>::post_order_iterator& tree<T, tree_node_allocator>::post_order_iterator::operator--()
    01749    {
    01750    assert(this->node!=0);
    01751    if(this->skip_current_children_ || this->node->last_child==0) {
    01752       this->skip_current_children_=false;
    01753       while(this->node->prev_sibling==0)
    01754          this->node=this->node->parent;
    01755       this->node=this->node->prev_sibling;
    01756       }
    01757    else {
    01758       this->node=this->node->last_child;
    01759       }
    01760    return *this;
    01761 }
    01762
    01763 template <class T, class tree_node_allocator>
    01764 typename tree<T, tree_node_allocator>::post_order_iterator tree<T, tree_node_allocator>::post_order_iterator::operator++(int)
    01765    {
    01766    post_order_iterator copy = *this;
    01767    ++(*this);
    01768    return copy;
    01769    }
    01770
    01771 template <class T, class tree_node_allocator>
    01772 typename tree<T, tree_node_allocator>::post_order_iterator tree<T, tree_node_allocator>::post_order_iterator::operator--(int)
    01773    {
    01774    post_order_iterator copy = *this;
    01775    --(*this);
    01776    return copy;
    01777    }
    01778
    01779
    01780 template <class T, class tree_node_allocator>
    01781 typename tree<T, tree_node_allocator>::post_order_iterator& tree<T, tree_node_allocator>::post_order_iterator::operator+=(unsigned int num)
    01782    {
    01783    while(num>0) {
    01784       ++(*this);
    01785       --num;
    01786       }
    01787    return (*this);
    01788    }
    01789
    01790 template <class T, class tree_node_allocator>
    01791 typename tree<T, tree_node_allocator>::post_order_iterator& tree<T, tree_node_allocator>::post_order_iterator::operator-=(unsigned int num)
    01792    {
    01793    while(num>0) {
    01794       --(*this);
    01795       --num;
    01796       }
    01797    return (*this);
    01798    }
    01799
    01800 template <class T, class tree_node_allocator>
    01801 void tree<T, tree_node_allocator>::post_order_iterator::descend_all()
    01802    {
    01803    assert(this->node!=0);
    01804    while(this->node->first_child)
    01805       this->node=this->node->first_child;
    01806    }
    01807
    01808
    01809 // Fixed depth iterator
    01810
    01811 template <class T, class tree_node_allocator>
    01812 tree<T, tree_node_allocator>::fixed_depth_iterator::fixed_depth_iterator()
    01813    : iterator_base()
    01814    {
    01815    set_first_parent_();
    01816    }
    01817
    01818 template <class T, class tree_node_allocator>
    01819 tree<T, tree_node_allocator>::fixed_depth_iterator::fixed_depth_iterator(tree_node *tn)
    01820    : iterator_base(tn)
    01821    {
    01822    set_first_parent_();
    01823    }
    01824
    01825 template <class T, class tree_node_allocator>
    01826 tree<T, tree_node_allocator>::fixed_depth_iterator::fixed_depth_iterator(const iterator_base& other)
    01827    : iterator_base(other.node)
    01828    {
    01829    set_first_parent_();
    01830    }
    01831
    01832 template <class T, class tree_node_allocator>
    01833 tree<T, tree_node_allocator>::fixed_depth_iterator::fixed_depth_iterator(const sibling_iterator& other)
    01834    : iterator_base(other.node), first_parent_(other.parent_)
    01835    {
    01836    find_leftmost_parent_();
    01837    }
    01838
    01839 template <class T, class tree_node_allocator>
    01840 tree<T, tree_node_allocator>::fixed_depth_iterator::fixed_depth_iterator(const fixed_depth_iterator& other)
    01841    : iterator_base(other.node), first_parent_(other.first_parent_)
    01842    {
    01843    }
    01844
    01845 template <class T, class tree_node_allocator>
    01846 void tree<T, tree_node_allocator>::fixed_depth_iterator::set_first_parent_()
    01847    {
    01848    return; // FIXME: we do not use first_parent_ yet, and it actually needs some serious reworking if
    01849            // it is ever to work at the 'head' level.
    01850    first_parent_=0;
    01851    if(this->node==0) return;
    01852    if(this->node->parent!=0)
    01853       first_parent_=this->node->parent;
    01854    if(first_parent_)
    01855       find_leftmost_parent_();
    01856    }
    01857
    01858 template <class T, class tree_node_allocator>
    01859 void tree<T, tree_node_allocator>::fixed_depth_iterator::find_leftmost_parent_()
    01860    {
    01861    return; // FIXME: see 'set_first_parent()'
    01862    tree_node *tmppar=first_parent_;
    01863    while(tmppar->prev_sibling) {
    01864       tmppar=tmppar->prev_sibling;
    01865       if(tmppar->first_child)
    01866          first_parent_=tmppar;
    01867       }
    01868    }
    01869
    01870 template <class T, class tree_node_allocator>
    01871 typename tree<T, tree_node_allocator>::fixed_depth_iterator& tree<T, tree_node_allocator>::fixed_depth_iterator::operator++()
    01872    {
    01873    assert(this->node!=0);
    01874
    01875    if(this->node->next_sibling) {
    01876       this->node=this->node->next_sibling;
    01877       }
    01878    else {
    01879       int relative_depth=0;
    01880       upper:
    01881       do {
    01882          this->node=this->node->parent;
    01883          if(this->node==0) return *this;
    01884          --relative_depth;
    01885          } while(this->node->next_sibling==0);
    01886       lower:
    01887       this->node=this->node->next_sibling;
    01888       while(this->node->first_child==0) {
    01889          if(this->node->next_sibling==0)
    01890             goto upper;
    01891          this->node=this->node->next_sibling;
    01892          if(this->node==0) return *this;
    01893          }
    01894       while(relative_depth<0 && this->node->first_child!=0) {
    01895          this->node=this->node->first_child;
    01896          ++relative_depth;
    01897          }
    01898       if(relative_depth<0) {
    01899          if(this->node->next_sibling==0) goto upper;
    01900          else                          goto lower;
    01901          }
    01902       }
    01903    return *this;
    01904
    01905 // if(this->node->next_sibling!=0) {
    01906 //    this->node=this->node->next_sibling;
    01907 //    assert(this->node!=0);
    01908 //    if(this->node->parent==0 && this->node->next_sibling==0) // feet element
    01909 //       this->node=0;
    01910 //    }
    01911 // else {
    01912 //    tree_node *par=this->node->parent;
    01913 //    do {
    01914 //       par=par->next_sibling;
    01915 //       if(par==0) { // FIXME: need to keep track of this!
    01916 //          this->node=0;
    01917 //          return *this;
    01918 //          }
    01919 //       } while(par->first_child==0);
    01920 //    this->node=par->first_child;
    01921 //    }
    01922    return *this;
    01923    }
    01924
    01925 template <class T, class tree_node_allocator>
    01926 typename tree<T, tree_node_allocator>::fixed_depth_iterator& tree<T, tree_node_allocator>::fixed_depth_iterator::operator--()
    01927    {
    01928    assert(this->node!=0);
    01929    if(this->node->prev_sibling!=0) {
    01930       this->node=this->node->prev_sibling;
    01931       assert(this->node!=0);
    01932       if(this->node->parent==0 && this->node->prev_sibling==0) // head element
    01933          this->node=0;
    01934       }
    01935    else {
    01936       tree_node *par=this->node->parent;
    01937       do {
    01938          par=par->prev_sibling;
    01939          if(par==0) { // FIXME: need to keep track of this!
    01940             this->node=0;
    01941             return *this;
    01942             }
    01943          } while(par->last_child==0);
    01944       this->node=par->last_child;
    01945       }
    01946    return *this;
    01947 }
    01948
    01949 template <class T, class tree_node_allocator>
    01950 typename tree<T, tree_node_allocator>::fixed_depth_iterator tree<T, tree_node_allocator>::fixed_depth_iterator::operator++(int)
    01951    {
    01952    fixed_depth_iterator copy = *this;
    01953    ++(*this);
    01954    return copy;
    01955    }
    01956
    01957 template <class T, class tree_node_allocator>
    01958 typename tree<T, tree_node_allocator>::fixed_depth_iterator tree<T, tree_node_allocator>::fixed_depth_iterator::operator--(int)
    01959 {
    01960   fixed_depth_iterator copy = *this;
    01961   --(*this);
    01962   return copy;
    01963 }
    01964
    01965 template <class T, class tree_node_allocator>
    01966 typename tree<T, tree_node_allocator>::fixed_depth_iterator& tree<T, tree_node_allocator>::fixed_depth_iterator::operator-=(unsigned int num)
    01967    {
    01968    while(num>0) {
    01969       --(*this);
    01970       --(num);
    01971       }
    01972    return (*this);
    01973    }
    01974
    01975 template <class T, class tree_node_allocator>
    01976 typename tree<T, tree_node_allocator>::fixed_depth_iterator& tree<T, tree_node_allocator>::fixed_depth_iterator::operator+=(unsigned int num)
    01977    {
    01978    while(num>0) {
    01979       ++(*this);
    01980       --(num);
    01981       }
    01982    return *this;
    01983    }
    01984
    01985 // FIXME: add the other members of fixed_depth_iterator.
    01986
    01987
    01988 // Sibling iterator
    01989
    01990 template <class T, class tree_node_allocator>
    01991 tree<T, tree_node_allocator>::sibling_iterator::sibling_iterator()
    01992    : iterator_base()
    01993    {
    01994    set_parent_();
    01995    }
    01996
    01997 template <class T, class tree_node_allocator>
    01998 tree<T, tree_node_allocator>::sibling_iterator::sibling_iterator(tree_node *tn)
    01999    : iterator_base(tn)
    02000    {
    02001    set_parent_();
    02002    }
    02003
    02004 template <class T, class tree_node_allocator>
    02005 tree<T, tree_node_allocator>::sibling_iterator::sibling_iterator(const iterator_base& other)
    02006    : iterator_base(other.node)
    02007    {
    02008    set_parent_();
    02009    }
    02010
    02011 template <class T, class tree_node_allocator>
    02012 tree<T, tree_node_allocator>::sibling_iterator::sibling_iterator(const sibling_iterator& other)
    02013    : iterator_base(other), parent_(other.parent_)
    02014    {
    02015    }
    02016
    02017 template <class T, class tree_node_allocator>
    02018 void tree<T, tree_node_allocator>::sibling_iterator::set_parent_()
    02019    {
    02020    parent_=0;
    02021    if(this->node==0) return;
    02022    if(this->node->parent!=0)
    02023       parent_=this->node->parent;
    02024    }
    02025
    02026 template <class T, class tree_node_allocator>
    02027 typename tree<T, tree_node_allocator>::sibling_iterator& tree<T, tree_node_allocator>::sibling_iterator::operator++()
    02028    {
    02029    if(this->node)
    02030       this->node=this->node->next_sibling;
    02031    return *this;
    02032    }
    02033
    02034 template <class T, class tree_node_allocator>
    02035 typename tree<T, tree_node_allocator>::sibling_iterator& tree<T, tree_node_allocator>::sibling_iterator::operator--()
    02036    {
    02037    if(this->node) this->node=this->node->prev_sibling;
    02038    else {
    02039       assert(parent_);
    02040       this->node=parent_->last_child;
    02041       }
    02042    return *this;
    02043 }
    02044
    02045 template <class T, class tree_node_allocator>
    02046 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::sibling_iterator::operator++(int)
    02047    {
    02048    sibling_iterator copy = *this;
    02049    ++(*this);
    02050    return copy;
    02051    }
    02052
    02053 template <class T, class tree_node_allocator>
    02054 typename tree<T, tree_node_allocator>::sibling_iterator tree<T, tree_node_allocator>::sibling_iterator::operator--(int)
    02055    {
    02056    sibling_iterator copy = *this;
    02057    --(*this);
    02058    return copy;
    02059    }
    02060
    02061 template <class T, class tree_node_allocator>
    02062 typename tree<T, tree_node_allocator>::sibling_iterator& tree<T, tree_node_allocator>::sibling_iterator::operator+=(unsigned int num)
    02063    {
    02064    while(num>0) {
    02065       ++(*this);
    02066       --num;
    02067       }
    02068    return (*this);
    02069    }
    02070
    02071 template <class T, class tree_node_allocator>
    02072 typename tree<T, tree_node_allocator>::sibling_iterator& tree<T, tree_node_allocator>::sibling_iterator::operator-=(unsigned int num)
    02073    {
    02074    while(num>0) {
    02075       --(*this);
    02076       --num;
    02077       }
    02078    return (*this);
    02079    }
    02080
    02081 template <class T, class tree_node_allocator>
    02082 typename tree<T, tree_node_allocator>::tree_node *tree<T, tree_node_allocator>::sibling_iterator::range_first() const
    02083    {
    02084    tree_node *tmp=parent_->first_child;
    02085    return tmp;
    02086    }
    02087
    02088 template <class T, class tree_node_allocator>
    02089 typename tree<T, tree_node_allocator>::tree_node *tree<T, tree_node_allocator>::sibling_iterator::range_last() const
    02090    {
    02091    return parent_->last_child;
    02092    }
    02093
    02094
    02095 #endif
    02096
    02097 // Local variables:
    02098 // default-tab-width: 3
    02099 // End: