summaryrefslogtreecommitdiff
path: root/sql/sql_list.h
blob: 1b672e120bdbb1295691cb6af110b92b6a141238 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
#ifndef INCLUDES_MYSQL_SQL_LIST_H
#define INCLUDES_MYSQL_SQL_LIST_H
/* Copyright (c) 2000, 2012, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#ifdef USE_PRAGMA_INTERFACE
#pragma interface			/* gcc class implementation */
#endif

#include "my_sys.h"                    /* alloc_root, TRASH, MY_WME,
                                          MY_FAE, MY_ALLOW_ZERO_PTR */
#include "m_string.h"                           /* bfill */
#include "thr_malloc.h"                         /* sql_alloc */

/* mysql standard class memory allocator */

class Sql_alloc
{
public:
  static void *operator new(size_t size) throw ()
  {
    return sql_alloc(size);
  }
  static void *operator new[](size_t size) throw ()
  {
    return sql_alloc(size);
  }
  static void *operator new[](size_t size, MEM_ROOT *mem_root) throw ()
  { return alloc_root(mem_root, size); }
  static void *operator new(size_t size, MEM_ROOT *mem_root) throw ()
  { return alloc_root(mem_root, size); }
  static void operator delete(void *ptr, size_t size) { TRASH(ptr, size); }
  static void operator delete(void *ptr, MEM_ROOT *mem_root)
  { /* never called */ }
  static void operator delete[](void *ptr, MEM_ROOT *mem_root)
  { /* never called */ }
  static void operator delete[](void *ptr, size_t size) { TRASH(ptr, size); }
#ifdef HAVE_valgrind
  bool dummy;
  inline Sql_alloc() :dummy(0) {}
  inline ~Sql_alloc() {}
#else
  inline Sql_alloc() {}
  inline ~Sql_alloc() {}
#endif

};


/**
  Simple intrusive linked list.

  @remark Similar in nature to base_list, but intrusive. It keeps a
          a pointer to the first element in the list and a indirect
          reference to the last element.
*/
template <typename T>
class SQL_I_List :public Sql_alloc
{
public:
  uint elements;
  /** The first element in the list. */
  T *first;
  /** A reference to the next element in the list. */
  T **next;

  SQL_I_List() { empty(); }

  SQL_I_List(const SQL_I_List &tmp) : Sql_alloc()
  {
    elements= tmp.elements;
    first= tmp.first;
    next= elements ? tmp.next : &first;
  }

  inline void empty()
  {
    elements= 0;
    first= NULL;
    next= &first;
  }

  inline void link_in_list(T *element, T **next_ptr)
  {
    elements++;
    (*next)= element;
    next= next_ptr;
    *next= NULL;
  }

  inline void save_and_clear(SQL_I_List<T> *save)
  {
    *save= *this;
    empty();
  }

  inline void push_front(SQL_I_List<T> *save)
  {
    /* link current list last */
    *save->next= first;
    first= save->first;
    elements+= save->elements;
  }

  inline void push_back(SQL_I_List<T> *save)
  {
    if (save->first)
    {
      *next= save->first;
      next= save->next;
      elements+= save->elements;
    }
  }
};


/*
  Basic single linked list
  Used for item and item_buffs.
  All list ends with a pointer to the 'end_of_list' element, which
  data pointer is a null pointer and the next pointer points to itself.
  This makes it very fast to traverse lists as we don't have to
  test for a specialend condition for list that can't contain a null
  pointer.
*/


/**
  list_node - a node of a single-linked list.
  @note We never call a destructor for instances of this class.
*/

struct list_node :public Sql_alloc
{
  list_node *next;
  void *info;
  list_node(void *info_par,list_node *next_par)
    :next(next_par),info(info_par)
  {}
  list_node()					/* For end_of_list */
  {
    info= 0;
    next= this;
  }
};

typedef bool List_eq(void *a, void *b);

extern MYSQL_PLUGIN_IMPORT list_node end_of_list;

class base_list :public Sql_alloc
{
protected:
  list_node *first,**last;

public:
  uint elements;

  bool operator==(const base_list &rhs) const
  {
    return
      elements == rhs.elements &&
      first == rhs.first &&
      last == rhs.last;
  }

  inline void empty() { elements=0; first= &end_of_list; last=&first;}
  inline base_list() { empty(); }
  /**
    This is a shallow copy constructor that implicitly passes the ownership
    from the source list to the new instance. The old instance is not
    updated, so both objects end up sharing the same nodes. If one of
    the instances then adds or removes a node, the other becomes out of
    sync ('last' pointer), while still operational. Some old code uses and
    relies on this behaviour. This logic is quite tricky: please do not use
    it in any new code.
  */
  inline base_list(const base_list &tmp) :Sql_alloc()
  {
    elements= tmp.elements;
    first= tmp.first;
    last= elements ? tmp.last : &first;
  }
  /**
    Construct a deep copy of the argument in memory root mem_root.
    The elements themselves are copied by pointer. If you also
    need to copy elements by value, you should employ
    list_copy_and_replace_each_value after creating a copy.
  */
  base_list(const base_list &rhs, MEM_ROOT *mem_root);
  inline base_list(bool error) { }
  inline bool push_back(void *info)
  {
    if (((*last)=new list_node(info, &end_of_list)))
    {
      last= &(*last)->next;
      elements++;
      return 0;
    }
    return 1;
  }
  inline bool push_back(void *info, MEM_ROOT *mem_root)
  {
    if (((*last)=new (mem_root) list_node(info, &end_of_list)))
    {
      last= &(*last)->next;
      elements++;
      return 0;
    }
    return 1;
  }
  inline bool push_front(void *info)
  {
    list_node *node=new list_node(info,first);
    if (node)
    {
      if (last == &first)
	last= &node->next;
      first=node;
      elements++;
      return 0;
    }
    return 1;
  }
  void remove(list_node **prev)
  {
    list_node *node=(*prev)->next;
    if (!--elements)
      last= &first;
    else if (last == &(*prev)->next)
      last= prev;
    delete *prev;
    *prev=node;
  }
  inline void append(base_list *list)
  {
    if (!list->is_empty())
    {
      if (is_empty())
      {
        *this= *list;
        return;
      }
      *last= list->first;
      last= list->last;
      elements+= list->elements;
    }
  }
  inline void *pop(void)
  {
    if (first == &end_of_list) return 0;
    list_node *tmp=first;
    first=first->next;
    if (!--elements)
      last= &first;
    return tmp->info;
  }

  /*
    Remove from this list elements that are contained in the passed list. 
    We assume that the passed list is a tail of this list (that is, the whole 
    list_node* elements are shared).
  */
  inline void disjoin(const base_list *list)
  {
    list_node **prev= &first;
    list_node *node= first;
    list_node *list_first= list->first;
    elements=0;
    while (node != &end_of_list && node != list_first)
    {
      prev= &node->next;
      node= node->next;
      elements++;
      if (node == &end_of_list)
        return;
    }
    *prev= &end_of_list;
    last= prev;
  }
  inline void prepend(base_list *list)
  {
    if (!list->is_empty())
    {
      if (is_empty())
        last= list->last;
      *list->last= first;
      first= list->first;
      elements+= list->elements;
    }
  }
  /**
    Swap two lists.
  */
  inline void swap(base_list &rhs)
  {
    swap_variables(list_node *, first, rhs.first);
    swap_variables(list_node **, last, rhs.last);
    swap_variables(uint, elements, rhs.elements);
  }
  inline list_node* last_node() { return *last; }
  inline list_node* first_node() { return first;}
  inline void *head() { return first->info; }
  inline void **head_ref() { return first != &end_of_list ? &first->info : 0; }
  inline bool is_empty() { return first == &end_of_list ; }
  inline list_node *last_ref() { return &end_of_list; }
  inline bool add_unique(void *info, List_eq *eq)
  {
    list_node *node= first;
    for (;
         node != &end_of_list && (!(*eq)(node->info, info));
         node= node->next) ;
    if (node == &end_of_list)
      return push_back(info);
    return 1;
  }
  friend class base_list_iterator;
  friend class error_list;
  friend class error_list_iterator;

#ifndef DBUG_OFF
  /*
    Debugging help: return N-th element in the list, or NULL if the list has
    less than N elements.
  */
  void *elem(int n)
  {
    list_node *node= first;
    void *data= NULL;
    for (int i=0; i <= n; i++)
    {
      if (node == &end_of_list)
      {
        data= NULL;
        break;
      }
      data= node->info;
      node= node->next;
    }
    return data;
  }
#endif

#ifdef LIST_EXTRA_DEBUG
  /*
    Check list invariants and print results into trace. Invariants are:
      - (*last) points to end_of_list
      - There are no NULLs in the list.
      - base_list::elements is the number of elements in the list.

    SYNOPSIS
      check_list()
        name  Name to print to trace file

    RETURN 
      1  The list is Ok.
      0  List invariants are not met.
  */

  bool check_list(const char *name)
  {
    base_list *list= this;
    list_node *node= first;
    uint cnt= 0;

    while (node->next != &end_of_list)
    {
      if (!node->info)
      {
        DBUG_PRINT("list_invariants",("%s: error: NULL element in the list", 
                                      name));
        return FALSE;
      }
      node= node->next;
      cnt++;
    }
    if (last != &(node->next))
    {
      DBUG_PRINT("list_invariants", ("%s: error: wrong last pointer", name));
      return FALSE;
    }
    if (cnt+1 != elements)
    {
      DBUG_PRINT("list_invariants", ("%s: error: wrong element count", name));
      return FALSE;
    }
    DBUG_PRINT("list_invariants", ("%s: list is ok", name));
    return TRUE;
  }
#endif // LIST_EXTRA_DEBUG

protected:
  void after(void *info,list_node *node)
  {
    list_node *new_node=new list_node(info,node->next);
    node->next=new_node;
    elements++;
    if (last == &(node->next))
      last= &new_node->next;
  }
};


class base_list_iterator
{
protected:
  base_list *list;
  list_node **el,**prev,*current;
  void sublist(base_list &ls, uint elm)
  {
    ls.first= *el;
    ls.last= list->last;
    ls.elements= elm;
  }
public:
  base_list_iterator() 
    :list(0), el(0), prev(0), current(0)
  {}

  base_list_iterator(base_list &list_par) 
  { init(list_par); }

  inline void init(base_list &list_par)
  {
    list= &list_par;
    el= &list_par.first;
    prev= 0;
    current= 0;
  }

  inline void *next(void)
  {
    prev=el;
    current= *el;
    el= &current->next;
    return current->info;
  }
  inline void *next_fast(void)
  {
    list_node *tmp;
    tmp= *el;
    el= &tmp->next;
    return tmp->info;
  }
  inline void rewind(void)
  {
    el= &list->first;
  }
  inline void *replace(void *element)
  {						// Return old element
    void *tmp=current->info;
    DBUG_ASSERT(current->info != 0);
    current->info=element;
    return tmp;
  }
  void *replace(base_list &new_list)
  {
    void *ret_value=current->info;
    if (!new_list.is_empty())
    {
      *new_list.last=current->next;
      current->info=new_list.first->info;
      current->next=new_list.first->next;
      if ((list->last == &current->next) && (new_list.elements > 1))
	list->last= new_list.last;
      list->elements+=new_list.elements-1;
    }
    return ret_value;				// return old element
  }
  inline void remove(void)			// Remove current
  {
    list->remove(prev);
    el=prev;
    current=0;					// Safeguard
  }
  void after(void *element)			// Insert element after current
  {
    list->after(element,current);
    current=current->next;
    el= &current->next;
  }
  inline void **ref(void)			// Get reference pointer
  {
    return &current->info;
  }
  inline bool is_last(void)
  {
    return el == &list->last_ref()->next;
  }
  friend class error_list_iterator;
};

template <class T> class List :public base_list
{
public:
  inline List() :base_list() {}
  inline List(const List<T> &tmp) :base_list(tmp) {}
  inline List(const List<T> &tmp, MEM_ROOT *mem_root) :
    base_list(tmp, mem_root) {}
  inline bool push_back(T *a) { return base_list::push_back(a); }
  inline bool push_back(T *a, MEM_ROOT *mem_root)
  { return base_list::push_back(a, mem_root); }
  inline bool push_front(T *a) { return base_list::push_front(a); }
  inline T* head() {return (T*) base_list::head(); }
  inline T** head_ref() {return (T**) base_list::head_ref(); }
  inline T* pop()  {return (T*) base_list::pop(); }
  inline void append(List<T> *list) { base_list::append(list); }
  inline void prepend(List<T> *list) { base_list::prepend(list); }
  inline void disjoin(List<T> *list) { base_list::disjoin(list); }
  inline bool add_unique(T *a, bool (*eq)(T *a, T *b))
  { return base_list::add_unique(a, (List_eq *)eq); }
  void delete_elements(void)
  {
    list_node *element,*next;
    for (element=first; element != &end_of_list; element=next)
    {
      next=element->next;
      delete (T*) element->info;
    }
    empty();
  }
#ifndef DBUG_OFF
  T *elem(int n) { return (T*)base_list::elem(n); }
#endif
};


template <class T> class List_iterator :public base_list_iterator
{
public:
  List_iterator(List<T> &a) : base_list_iterator(a) {}
  List_iterator() : base_list_iterator() {}
  inline void init(List<T> &a) { base_list_iterator::init(a); }
  inline T* operator++(int) { return (T*) base_list_iterator::next(); }
  inline T *replace(T *a)   { return (T*) base_list_iterator::replace(a); }
  inline T *replace(List<T> &a) { return (T*) base_list_iterator::replace(a); }
  inline void rewind(void)  { base_list_iterator::rewind(); }
  inline void remove()      { base_list_iterator::remove(); }
  inline void after(T *a)   { base_list_iterator::after(a); }
  inline T** ref(void)	    { return (T**) base_list_iterator::ref(); }
};


template <class T> class List_iterator_fast :public base_list_iterator
{
protected:
  inline T *replace(T *a)   { return (T*) 0; }
  inline T *replace(List<T> &a) { return (T*) 0; }
  inline void remove(void)  { }
  inline void after(T *a)   { }
  inline T** ref(void)	    { return (T**) 0; }

public:
  inline List_iterator_fast(List<T> &a) : base_list_iterator(a) {}
  inline List_iterator_fast() : base_list_iterator() {}
  inline void init(List<T> &a) { base_list_iterator::init(a); }
  inline T* operator++(int) { return (T*) base_list_iterator::next_fast(); }
  inline void rewind(void)  { base_list_iterator::rewind(); }
  void sublist(List<T> &list_arg, uint el_arg)
  {
    base_list_iterator::sublist(list_arg, el_arg);
  }
};


/*
  Bubble sort algorithm for List<T>.
  This sort function is supposed to be used only for very short list.
  Currently it is used for the lists of Item_equal objects and
  for some lists in the table elimination algorithms. In both
  cases the sorted lists are very short.
*/

template <class T> 
inline void bubble_sort(List<T> *list_to_sort,
                        int (*sort_func)(T *a, T *b, void *arg), void *arg)
{
  bool swap;
  T **ref1= 0;
  T **ref2= 0;
  List_iterator<T> it(*list_to_sort);
  do
  {
    T **last_ref= ref1;
    T *item1= it++;
    ref1= it.ref();
    T *item2;

    swap= FALSE;
    while ((item2= it++) && (ref2= it.ref()) != last_ref)
    {
      if (sort_func(item1, item2, arg) < 0)
      {
        *ref1= item2;
        *ref2= item1;
        swap= TRUE;
      }
      else
        item1= item2;
      ref1= ref2;
    }
    it.rewind();
  } while (swap);
}


/*
  A simple intrusive list which automaticly removes element from list
  on delete (for THD element)
*/

struct ilink
{
  struct ilink **prev,*next;
  static void *operator new(size_t size) throw ()
  {
    return (void*)my_malloc((uint)size, MYF(MY_WME | MY_FAE | ME_FATALERROR));
  }
  static void operator delete(void* ptr_arg, size_t size)
  {
     my_free(ptr_arg);
  }

  inline ilink()
  {
    prev=0; next=0;
  }
  inline void unlink()
  {
    /* Extra tests because element doesn't have to be linked */
    if (prev) *prev= next;
    if (next) next->prev=prev;
    prev=0 ; next=0;
  }
  virtual ~ilink() { unlink(); }		/*lint -e1740 */
};


/* Needed to be able to have an I_List of char* strings in mysqld.cc. */

class i_string: public ilink
{
public:
  const char* ptr;
  i_string():ptr(0) { }
  i_string(const char* s) : ptr(s) {}
};

/* needed for linked list of two strings for replicate-rewrite-db */
class i_string_pair: public ilink
{
public:
  const char* key;
  const char* val;
  i_string_pair():key(0),val(0) { }
  i_string_pair(const char* key_arg, const char* val_arg) : 
    key(key_arg),val(val_arg) {}
};


template <class T> class I_List_iterator;


class base_ilist
{
  struct ilink *first;
  struct ilink last;
public:
  inline void empty() { first= &last; last.prev= &first; }
  base_ilist() { empty(); }
  inline bool is_empty() {  return first == &last; }
  // Returns true if p is the last "real" object in the list,
  // i.e. p->next points to the sentinel.
  inline bool is_last(ilink *p) { return p->next == NULL || p->next == &last; }
  inline void append(ilink *a)
  {
    first->prev= &a->next;
    a->next=first; a->prev= &first; first=a;
  }
  inline void push_back(ilink *a)
  {
    *last.prev= a;
    a->next= &last;
    a->prev= last.prev;
    last.prev= &a->next;
  }
  inline struct ilink *get()
  {
    struct ilink *first_link=first;
    if (first_link == &last)
      return 0;
    first_link->unlink();			// Unlink from list
    return first_link;
  }
  inline struct ilink *head()
  {
    return (first != &last) ? first : 0;
  }

  /**
    Moves list elements to new owner, and empties current owner (i.e. this).

    @param[in,out]  new_owner  The new owner of the list elements.
                               Should be empty in input.
  */

  void move_elements_to(base_ilist *new_owner)
  {
    DBUG_ASSERT(new_owner->is_empty());
    new_owner->first= first;
    new_owner->last= last;
    empty();
  }

  friend class base_ilist_iterator;
 private:
  /*
    We don't want to allow copying of this class, as that would give us
    two list heads containing the same elements.
    So we declare, but don't define copy CTOR and assignment operator.
  */
  base_ilist(const base_ilist&);
  void operator=(const base_ilist&);
};


class base_ilist_iterator
{
  base_ilist *list;
  struct ilink **el,*current;
public:
  base_ilist_iterator(base_ilist &list_par) :list(&list_par),
    el(&list_par.first),current(0) {}
  void *next(void)
  {
    /* This is coded to allow push_back() while iterating */
    current= *el;
    if (current == &list->last) return 0;
    el= &current->next;
    return current;
  }
};


template <class T>
class I_List :private base_ilist
{
public:
  I_List() :base_ilist()	{}
  inline bool is_last(T *p)     { return base_ilist::is_last(p); }
  inline void empty()		{ base_ilist::empty(); }
  inline bool is_empty()        { return base_ilist::is_empty(); } 
  inline void append(T* a)	{ base_ilist::append(a); }
  inline void push_back(T* a)	{ base_ilist::push_back(a); }
  inline T* get()		{ return (T*) base_ilist::get(); }
  inline T* head()		{ return (T*) base_ilist::head(); }
  inline void move_elements_to(I_List<T>* new_owner) {
    base_ilist::move_elements_to(new_owner);
  }
#ifndef _lint
  friend class I_List_iterator<T>;
#endif
};


template <class T> class I_List_iterator :public base_ilist_iterator
{
public:
  I_List_iterator(I_List<T> &a) : base_ilist_iterator(a) {}
  inline T* operator++(int) { return (T*) base_ilist_iterator::next(); }
};

/**
  Make a deep copy of each list element.

  @note A template function and not a template method of class List
  is employed because of explicit template instantiation:
  in server code there are explicit instantiations of List<T> and
  an explicit instantiation of a template requires that any method
  of the instantiated class used in the template can be resolved.
  Evidently not all template arguments have clone() method with
  the right signature.

  @return You must query the error state in THD for out-of-memory
  situation after calling this function.
*/

template <typename T>
inline
void
list_copy_and_replace_each_value(List<T> &list, MEM_ROOT *mem_root)
{
  /* Make a deep copy of each element */
  List_iterator<T> it(list);
  T *el;
  while ((el= it++))
    it.replace(el->clone(mem_root));
}

void free_list(I_List <i_string_pair> *list);
void free_list(I_List <i_string> *list);

#endif // INCLUDES_MYSQL_SQL_LIST_H