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