Keep order of nodes when wxHashMap is resized; this ensures
[wxWidgets.git] / include / wx / hashmap.h
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: hashmap.h
3 // Purpose: wxHashMap class
4 // Author: Mattia Barbon
5 // Modified by:
6 // Created: 29/01/2002
7 // RCS-ID: $Id$
8 // Copyright: (c) Mattia Barbon
9 // Licence: wxWindows licence
10 /////////////////////////////////////////////////////////////////////////////
11
12 #ifndef _WX_HASHMAP_H_
13 #define _WX_HASHMAP_H_
14
15 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
16 #pragma interface "hashmap.h"
17 #endif
18
19 #include "wx/string.h"
20
21 #include <stddef.h> // for ptrdiff_t
22
23 #ifdef __WXWINCE__
24 typedef int ptrdiff_t;
25 #endif
26
27 // private
28 struct WXDLLIMPEXP_BASE _wxHashTable_NodeBase
29 {
30 _wxHashTable_NodeBase() : m_nxt(0) {}
31
32 _wxHashTable_NodeBase* m_nxt;
33
34 // Cannot do this:
35 // DECLARE_NO_COPY_CLASS(_wxHashTable_NodeBase)
36 // without rewriting the macros, which require a public copy constructor.
37 };
38
39 // private
40 class WXDLLIMPEXP_BASE _wxHashTableBase2
41 {
42 public:
43 typedef void (*NodeDtor)(_wxHashTable_NodeBase*);
44 typedef unsigned long (*BucketFromNode)(_wxHashTableBase2*,_wxHashTable_NodeBase*);
45 typedef _wxHashTable_NodeBase* (*ProcessNode)(_wxHashTable_NodeBase*);
46 protected:
47 static _wxHashTable_NodeBase* DummyProcessNode(_wxHashTable_NodeBase* node);
48 static void DeleteNodes( size_t buckets, _wxHashTable_NodeBase** table,
49 NodeDtor dtor );
50 static _wxHashTable_NodeBase* GetFirstNode( size_t buckets,
51 _wxHashTable_NodeBase** table )
52 {
53 for( size_t i = 0; i < buckets; ++i )
54 if( table[i] )
55 return table[i];
56 return 0;
57 }
58
59 // as static const unsigned prime_count = 31 but works with all compilers
60 enum { prime_count = 31 };
61 static const unsigned long ms_primes[prime_count];
62
63 // returns the first prime in ms_primes greater than n
64 static unsigned long GetNextPrime( unsigned long n );
65
66 // returns the first prime in ms_primes smaller than n
67 // ( or ms_primes[0] if n is very small )
68 static unsigned long GetPreviousPrime( unsigned long n );
69
70 static void CopyHashTable( _wxHashTable_NodeBase** srcTable,
71 size_t srcBuckets, _wxHashTableBase2* dst,
72 _wxHashTable_NodeBase** dstTable,
73 size_t dstBuckets,
74 BucketFromNode func, ProcessNode proc );
75
76 static void** AllocTable( size_t sz )
77 {
78 return (void **)calloc(sz, sizeof(void*));
79 }
80 };
81
82 #define _WX_DECLARE_HASHTABLE( VALUE_T, KEY_T, HASH_T, KEY_EX_T, KEY_EQ_T, CLASSNAME, CLASSEXP, SHOULD_GROW, SHOULD_SHRINK ) \
83 CLASSEXP CLASSNAME : protected _wxHashTableBase2 \
84 { \
85 public: \
86 typedef KEY_T key_type; \
87 typedef VALUE_T value_type; \
88 typedef HASH_T hasher; \
89 typedef KEY_EQ_T key_equal; \
90 \
91 typedef size_t size_type; \
92 typedef ptrdiff_t difference_type; \
93 typedef value_type* pointer; \
94 typedef const value_type* const_pointer; \
95 typedef value_type& reference; \
96 typedef const value_type& const_reference; \
97 /* should these be protected? */ \
98 typedef const KEY_T const_key_type; \
99 typedef const VALUE_T const_mapped_type; \
100 public: \
101 struct Node; \
102 typedef KEY_EX_T key_extractor; \
103 typedef CLASSNAME Self; \
104 protected: \
105 Node** m_table; \
106 size_t m_tableBuckets; \
107 size_t m_items; \
108 hasher m_hasher; \
109 key_equal m_equals; \
110 key_extractor m_getKey; \
111 public: \
112 struct Node:public _wxHashTable_NodeBase \
113 { \
114 public: \
115 Node( const value_type& value ) \
116 : m_value( value ) {} \
117 Node* m_next() { return (Node*)this->m_nxt; } \
118 \
119 value_type m_value; \
120 }; \
121 \
122 struct Iterator; \
123 friend struct Iterator; \
124 protected: \
125 static void DeleteNode( _wxHashTable_NodeBase* node ) \
126 { \
127 delete (Node*)node; \
128 } \
129 public: \
130 /* */ \
131 /* forward iterator */ \
132 /* */ \
133 struct Iterator \
134 { \
135 Node* m_node; \
136 Self* m_ht; \
137 \
138 Iterator() : m_node(0), m_ht(0) {} \
139 Iterator( Node* node, const Self* ht ) \
140 : m_node(node), m_ht((Self*)ht) {} \
141 bool operator ==( const Iterator& it ) const \
142 { return m_node == it.m_node; } \
143 bool operator !=( const Iterator& it ) const \
144 { return m_node != it.m_node; } \
145 protected: \
146 Node* GetNextNode() \
147 { \
148 size_type bucket = GetBucketForNode(m_ht,m_node); \
149 for( size_type i = bucket + 1; i < m_ht->m_tableBuckets; ++i ) \
150 { \
151 if( m_ht->m_table[i] ) \
152 return m_ht->m_table[i]; \
153 } \
154 return 0; \
155 } \
156 \
157 void PlusPlus() \
158 { \
159 Node* next = m_node->m_next(); \
160 m_node = next ? next : GetNextNode(); \
161 } \
162 }; \
163 \
164 public: \
165 struct iterator:public Iterator \
166 { \
167 iterator() : Iterator() {} \
168 iterator( Node* node, Self* ht ) : Iterator( node, ht ) {} \
169 iterator& operator++() { PlusPlus(); return *this; } \
170 iterator operator++(int) { iterator it=*this;PlusPlus();return it; } \
171 reference operator *() const { return m_node->m_value; } \
172 pointer operator ->() const { return &(m_node->m_value); } \
173 }; \
174 \
175 struct const_iterator:public Iterator \
176 { \
177 const_iterator() : Iterator() {} \
178 const_iterator( Node* node, const Self* ht ) \
179 : Iterator( node, (Self*)ht ) {} \
180 const_iterator& operator++() { PlusPlus();return *this; } \
181 const_iterator operator++(int) { const_iterator it=*this;PlusPlus();return it; } \
182 const_reference operator *() const { return m_node->m_value; } \
183 const_pointer operator ->() const { return &(m_node->m_value); } \
184 }; \
185 \
186 CLASSNAME( size_type sz = 10, const hasher& hfun = hasher(), \
187 const key_equal& k_eq = key_equal(), \
188 const key_extractor& k_ex = key_extractor() ) \
189 : m_tableBuckets( GetNextPrime( (unsigned long) sz ) ), \
190 m_items( 0 ), \
191 m_hasher( hfun ), \
192 m_equals( k_eq ), \
193 m_getKey( k_ex ) \
194 { \
195 m_table = (Node**)AllocTable( m_tableBuckets ); \
196 } \
197 \
198 CLASSNAME( const Self& ht ) \
199 : m_table( 0 ), \
200 m_tableBuckets( 0 ), \
201 m_items( ht.m_items ), \
202 m_hasher( ht.m_hasher ), \
203 m_equals( ht.m_equals ), \
204 m_getKey( ht.m_getKey ) \
205 { \
206 HashCopy( ht ); \
207 } \
208 \
209 const Self& operator=( const Self& ht ) \
210 { \
211 clear(); \
212 m_hasher = ht.m_hasher; \
213 m_equals = ht.m_equals; \
214 m_getKey = ht.m_getKey; \
215 m_items = ht.m_items; \
216 HashCopy( ht ); \
217 return *this; \
218 } \
219 \
220 ~CLASSNAME() \
221 { \
222 clear(); \
223 \
224 free(m_table); \
225 } \
226 \
227 hasher hash_funct() { return m_hasher; } \
228 key_equal key_eq() { return m_equals; } \
229 \
230 /* removes all elements from the hash table, but does not */ \
231 /* shrink it ( perhaps it should ) */ \
232 void clear() \
233 { \
234 DeleteNodes( m_tableBuckets, (_wxHashTable_NodeBase**)m_table, \
235 DeleteNode ); \
236 m_items = 0; \
237 } \
238 \
239 size_type size() const { return m_items; } \
240 size_type max_size() const { return size_type(-1); } \
241 bool empty() const { return size() == 0; } \
242 \
243 const_iterator end() const { return const_iterator( 0, this ); } \
244 iterator end() { return iterator( 0, this ); } \
245 const_iterator begin() const \
246 { return const_iterator( (Node*)GetFirstNode( m_tableBuckets, (_wxHashTable_NodeBase**)m_table ), this ); }; \
247 iterator begin() \
248 { return iterator( (Node*)GetFirstNode( m_tableBuckets, (_wxHashTable_NodeBase**)m_table ), this ); }; \
249 \
250 size_type erase( const const_key_type& key ) \
251 { \
252 Node** node = GetNodePtr( key ); \
253 \
254 if( !node ) \
255 return 0; \
256 \
257 --m_items; \
258 Node* temp = (*node)->m_next(); \
259 delete *node; \
260 (*node) = temp; \
261 if( SHOULD_SHRINK( m_tableBuckets, m_items ) ) \
262 ResizeTable( GetPreviousPrime( (unsigned long) m_tableBuckets ) - 1 ); \
263 return 1; \
264 } \
265 \
266 protected: \
267 static size_type GetBucketForNode( Self* ht, Node* node ) \
268 { \
269 return ht->m_hasher( ht->m_getKey( node->m_value ) ) \
270 % ht->m_tableBuckets; \
271 } \
272 static Node* CopyNode( Node* node ) { return new Node( *node ); } \
273 \
274 Node* GetOrCreateNode( const value_type& value ) \
275 { \
276 const const_key_type& key = m_getKey( value ); \
277 size_t bucket = m_hasher( key ) % m_tableBuckets; \
278 Node* node = m_table[bucket]; \
279 \
280 while( node ) \
281 { \
282 if( m_equals( m_getKey( node->m_value ), key ) ) \
283 return node; \
284 node = node->m_next(); \
285 } \
286 return CreateNode( value , bucket); \
287 }\
288 Node * CreateNode( const value_type& value, size_t bucket ) \
289 {\
290 Node* node = new Node( value ); \
291 node->m_nxt = m_table[bucket]; \
292 m_table[bucket] = node; \
293 \
294 /* must be after the node is inserted */ \
295 ++m_items; \
296 if( SHOULD_GROW( m_tableBuckets, m_items ) ) \
297 ResizeTable( m_tableBuckets ); \
298 \
299 return node; \
300 } \
301 void CreateNodeLast( const value_type& value ) \
302 { \
303 size_t bucket = m_hasher( m_getKey(value) ) % m_tableBuckets; \
304 Node* curr = m_table[bucket], \
305 * next = m_table[bucket]; \
306 while( next ) { curr = next; next = next->m_next(); } \
307 Node** ptr = curr ? (Node**)&curr->m_nxt : &m_table[bucket]; \
308 *ptr = new Node( value ); \
309 /* must be after the node is inserted */ \
310 ++m_items; \
311 if( SHOULD_GROW( m_tableBuckets, m_items ) ) \
312 ResizeTable( m_tableBuckets ); \
313 } \
314 void CreateNode( const value_type& value ) \
315 {\
316 CreateNode(value, m_hasher( m_getKey(value) ) % m_tableBuckets ); \
317 }\
318 \
319 /* returns NULL if not found */ \
320 Node** GetNodePtr( const const_key_type& key ) const \
321 { \
322 unsigned long hash = m_hasher( key ); \
323 Node** node = &m_table[hash % m_tableBuckets]; \
324 \
325 while( *node ) \
326 { \
327 if( m_equals( m_getKey( (*node)->m_value ), key ) ) \
328 return node; \
329 node = (Node**)&(*node)->m_nxt; \
330 } \
331 \
332 return 0; \
333 } \
334 \
335 /* returns NULL if not found */ \
336 /* expressing it in terms of GetNodePtr is 5-8% slower :-( */ \
337 Node* GetNode( const const_key_type& key ) const \
338 { \
339 unsigned long hash = m_hasher( key ); \
340 Node* node = m_table[hash % m_tableBuckets]; \
341 \
342 while( node ) \
343 { \
344 if( m_equals( m_getKey( node->m_value ), key ) ) \
345 return node; \
346 node = node->m_next(); \
347 } \
348 \
349 return 0; \
350 } \
351 \
352 void ResizeTable( size_t newSize ) \
353 { \
354 newSize = GetNextPrime( (unsigned long)newSize ); \
355 Node** srcTable = m_table; \
356 size_t srcBuckets = m_tableBuckets; \
357 m_table = (Node**)AllocTable( newSize ); \
358 m_tableBuckets = newSize; \
359 \
360 CopyHashTable( (_wxHashTable_NodeBase**)srcTable, srcBuckets, \
361 this, (_wxHashTable_NodeBase**)m_table, newSize, \
362 (BucketFromNode)GetBucketForNode,\
363 (ProcessNode)&DummyProcessNode ); \
364 free(srcTable); \
365 } \
366 \
367 /* this must be called _after_ m_table has been cleaned */ \
368 void HashCopy( const Self& ht ) \
369 { \
370 ResizeTable( ht.size() ); \
371 CopyHashTable( (_wxHashTable_NodeBase**)ht.m_table, ht.m_tableBuckets,\
372 (_wxHashTableBase2*)this, \
373 (_wxHashTable_NodeBase**)m_table, m_tableBuckets, \
374 (BucketFromNode)GetBucketForNode, \
375 (ProcessNode)CopyNode ); \
376 } \
377 };
378
379 // defines an STL-like pair class CLASSNAME storing two fields: first of type
380 // KEY_T and second of type VALUE_T
381 #define _WX_DECLARE_PAIR( KEY_T, VALUE_T, CLASSNAME, CLASSEXP ) \
382 CLASSEXP CLASSNAME \
383 { \
384 public: \
385 typedef KEY_T t1; \
386 typedef VALUE_T t2; \
387 typedef const KEY_T const_t1; \
388 typedef const VALUE_T const_t2; \
389 \
390 CLASSNAME( const const_t1& f, const const_t2& s ):first(t1(f)),second(t2(s)) {} \
391 \
392 t1 first; \
393 t2 second; \
394 };
395
396 // defines the class CLASSNAME returning the key part (of type KEY_T) from a
397 // pair of type PAIR_T
398 #define _WX_DECLARE_HASH_MAP_KEY_EX( KEY_T, PAIR_T, CLASSNAME, CLASSEXP ) \
399 CLASSEXP CLASSNAME \
400 { \
401 typedef KEY_T key_type; \
402 typedef PAIR_T pair_type; \
403 typedef const key_type const_key_type; \
404 typedef const pair_type const_pair_type; \
405 typedef const_key_type& const_key_reference; \
406 typedef const_pair_type& const_pair_reference; \
407 public: \
408 CLASSNAME() { } \
409 const_key_reference operator()( const_pair_reference pair ) const { return pair.first; }\
410 \
411 /* the dummy assignment operator is needed to suppress compiler */ \
412 /* warnings from hash table class' operator=(): gcc complains about */ \
413 /* "statement with no effect" without it */ \
414 CLASSNAME& operator=(const CLASSNAME&) { return *this; } \
415 };
416
417 // grow/shrink predicates
418 inline bool never_grow( size_t, size_t ) { return FALSE; }
419 inline bool never_shrink( size_t, size_t ) { return FALSE; }
420 inline bool grow_lf70( size_t buckets, size_t items )
421 {
422 return float(items)/float(buckets) >= 0.85;
423 }
424
425 // ----------------------------------------------------------------------------
426 // hashing and comparison functors
427 // ----------------------------------------------------------------------------
428
429 // NB: implementation detail: all of these classes must have dummy assignment
430 // operators to suppress warnings about "statement with no effect" from gcc
431 // in the hash table class assignment operator (where they're assigned)
432
433 // integer types
434 class WXDLLIMPEXP_BASE wxIntegerHash
435 {
436 public:
437 wxIntegerHash() { }
438 unsigned long operator()( long x ) const { return (unsigned long)x; }
439 unsigned long operator()( unsigned long x ) const { return x; }
440 unsigned long operator()( int x ) const { return (unsigned long)x; }
441 unsigned long operator()( unsigned int x ) const { return x; }
442 unsigned long operator()( short x ) const { return (unsigned long)x; }
443 unsigned long operator()( unsigned short x ) const { return x; }
444
445 wxIntegerHash& operator=(const wxIntegerHash&) { return *this; }
446 };
447
448 class WXDLLIMPEXP_BASE wxIntegerEqual
449 {
450 public:
451 wxIntegerEqual() { }
452 bool operator()( long a, long b ) const { return a == b; }
453 bool operator()( unsigned long a, unsigned long b ) const { return a == b; }
454 bool operator()( int a, int b ) const { return a == b; }
455 bool operator()( unsigned int a, unsigned int b ) const { return a == b; }
456 bool operator()( short a, short b ) const { return a == b; }
457 bool operator()( unsigned short a, unsigned short b ) const { return a == b; }
458
459 wxIntegerEqual& operator=(const wxIntegerEqual&) { return *this; }
460 };
461
462 // pointers
463 class WXDLLIMPEXP_BASE wxPointerHash
464 {
465 public:
466 wxPointerHash() { }
467
468 // TODO: this might not work well on architectures with 64 bit pointers but
469 // 32 bit longs, we should use % ULONG_MAX there
470 unsigned long operator()( const void* k ) const { return (unsigned long)wxPtrToULong(k); }
471
472 wxPointerHash& operator=(const wxPointerHash&) { return *this; }
473 };
474
475 class WXDLLIMPEXP_BASE wxPointerEqual
476 {
477 public:
478 wxPointerEqual() { }
479 bool operator()( const void* a, const void* b ) const { return a == b; }
480
481 wxPointerEqual& operator=(const wxPointerEqual&) { return *this; }
482 };
483
484 // wxString, char*, wxChar*
485 class WXDLLIMPEXP_BASE wxStringHash
486 {
487 public:
488 wxStringHash() {}
489 unsigned long operator()( const wxString& x ) const
490 { return wxCharStringHash( x.c_str() ); }
491 unsigned long operator()( const wxChar* x ) const
492 { return wxCharStringHash( x ); }
493 static unsigned long wxCharStringHash( const wxChar* );
494 #if wxUSE_UNICODE
495 unsigned long operator()( const char* x ) const
496 { return charStringHash( x ); }
497 static unsigned long charStringHash( const char* );
498 #endif // wxUSE_UNICODE
499
500 wxStringHash& operator=(const wxStringHash&) { return *this; }
501 };
502
503 class WXDLLIMPEXP_BASE wxStringEqual
504 {
505 public:
506 wxStringEqual() {}
507 bool operator()( const wxString& a, const wxString& b ) const
508 { return a == b; }
509 bool operator()( const wxChar* a, const wxChar* b ) const
510 { return wxStrcmp( a, b ) == 0; }
511 #if wxUSE_UNICODE
512 bool operator()( const char* a, const char* b ) const
513 { return strcmp( a, b ) == 0; }
514 #endif // wxUSE_UNICODE
515
516 wxStringEqual& operator=(const wxStringEqual&) { return *this; }
517 };
518
519 #define _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, CLASSEXP ) \
520 _WX_DECLARE_PAIR( KEY_T, VALUE_T, CLASSNAME##_wxImplementation_Pair, CLASSEXP ) \
521 _WX_DECLARE_HASH_MAP_KEY_EX( KEY_T, CLASSNAME##_wxImplementation_Pair, CLASSNAME##_wxImplementation_KeyEx, CLASSEXP ) \
522 _WX_DECLARE_HASHTABLE( CLASSNAME##_wxImplementation_Pair, KEY_T, HASH_T, CLASSNAME##_wxImplementation_KeyEx, KEY_EQ_T, CLASSNAME##_wxImplementation_HashTable, CLASSEXP, grow_lf70, never_shrink ) \
523 CLASSEXP CLASSNAME:public CLASSNAME##_wxImplementation_HashTable \
524 { \
525 public: \
526 typedef VALUE_T mapped_type; \
527 \
528 CLASSNAME( size_type hint = 100, hasher hf = hasher(), key_equal eq = key_equal() ) \
529 : CLASSNAME##_wxImplementation_HashTable( hint, hf, eq, CLASSNAME##_wxImplementation_KeyEx() ) {} \
530 \
531 mapped_type& operator[]( const const_key_type& key ) \
532 { \
533 return GetOrCreateNode( CLASSNAME##_wxImplementation_Pair( key, mapped_type() ) )->m_value.second; \
534 } \
535 \
536 const_iterator find( const const_key_type& key ) const \
537 { \
538 return const_iterator( GetNode( key ), this ); \
539 } \
540 \
541 iterator find( const const_key_type& key ) \
542 { \
543 return iterator( GetNode( key ), this ); \
544 } \
545 \
546 void insert( const value_type& v ) { (*this)[v.first] = v.second; } \
547 \
548 size_type erase( const key_type& k ) \
549 { return CLASSNAME##_wxImplementation_HashTable::erase( k ); } \
550 void erase( const iterator& it ) { erase( it->first ); } \
551 void erase( const const_iterator& it ) { erase( it->first ); } \
552 \
553 /* count() == 0 | 1 */ \
554 size_type count( const const_key_type& key ) \
555 { return GetNode( key ) ? 1 : 0; } \
556 }
557
558 // these macros are to be used in the user code
559 #define WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME) \
560 _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, class )
561
562 #define WX_DECLARE_STRING_HASH_MAP( VALUE_T, CLASSNAME ) \
563 _WX_DECLARE_HASH_MAP( wxString, VALUE_T, wxStringHash, wxStringEqual, \
564 CLASSNAME, class )
565
566 #define WX_DECLARE_VOIDPTR_HASH_MAP( VALUE_T, CLASSNAME ) \
567 _WX_DECLARE_HASH_MAP( void*, VALUE_T, wxPointerHash, wxPointerEqual, \
568 CLASSNAME, class )
569
570 // and these do exactly the same thing but should be used inside the
571 // library
572 #define WX_DECLARE_HASH_MAP_WITH_DECL( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, DECL) \
573 _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, DECL )
574
575 #define WX_DECLARE_EXPORTED_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME) \
576 WX_DECLARE_HASH_MAP_WITH_DECL( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, \
577 CLASSNAME, class WXDLLEXPORT )
578
579 #define WX_DECLARE_STRING_HASH_MAP_WITH_DECL( VALUE_T, CLASSNAME, DECL ) \
580 _WX_DECLARE_HASH_MAP( wxString, VALUE_T, wxStringHash, wxStringEqual, \
581 CLASSNAME, DECL )
582
583 #define WX_DECLARE_EXPORTED_STRING_HASH_MAP( VALUE_T, CLASSNAME ) \
584 WX_DECLARE_STRING_HASH_MAP_WITH_DECL( VALUE_T, CLASSNAME, \
585 class WXDLLEXPORT )
586
587 #define WX_DECLARE_VOIDPTR_HASH_MAP_WITH_DECL( VALUE_T, CLASSNAME, DECL ) \
588 _WX_DECLARE_HASH_MAP( void*, VALUE_T, wxPointerHash, wxPointerEqual, \
589 CLASSNAME, DECL )
590
591 #define WX_DECLARE_EXPORTED_VOIDPTR_HASH_MAP( VALUE_T, CLASSNAME ) \
592 WX_DECLARE_VOIDPTR_HASH_MAP_WITH_DECL( VALUE_T, CLASSNAME, \
593 class WXDLLEXPORT )
594
595 // delete all hash elements
596 //
597 // NB: the class declaration of the hash elements must be visible from the
598 // place where you use this macro, otherwise the proper destructor may not
599 // be called (a decent compiler should give a warning about it, but don't
600 // count on it)!
601 #define WX_CLEAR_HASH_MAP(type, hashmap) \
602 { \
603 type::iterator it, en; \
604 for( it = (hashmap).begin(), en = (hashmap).end(); it != en; ++it ) \
605 delete it->second; \
606 (hashmap).clear(); \
607 }
608
609 #endif // _WX_HASHMAP_H_
610