include/wx/hashset.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/hashset.h
   3 // Purpose:     wxHashSet class
   4 // Author:      Mattia Barbon
   5 // Modified by:
   6 // Created:     11/08/2003
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Mattia Barbon
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_HASHSET_H_
  13 #define _WX_HASHSET_H_
  14
  15 #include "wx/hashmap.h"
  16
  17 // see comment in wx/hashmap.h which also applies to different standard hash
  18 // set classes
  19
  20 #if wxUSE_STD_CONTAINERS && \
  21     (defined(HAVE_STD_UNORDERED_SET) || defined(HAVE_TR1_UNORDERED_SET))
  22
  23 #if defined(HAVE_STD_UNORDERED_SET)
  24     #include <unordered_set>
  25     #define WX_HASH_SET_BASE_TEMPLATE std::unordered_set
  26 #elif defined(HAVE_TR1_UNORDERED_SET)
  27     #include <tr1/unordered_set>
  28     #define WX_HASH_SET_BASE_TEMPLATE std::tr1::unordered_set
  29 #else
  30     #error Update this code: unordered_set is available, but I do not know where.
  31 #endif
  32
  33 #elif wxUSE_STD_CONTAINERS && defined(HAVE_STL_HASH_MAP)
  34
  35 #if defined(HAVE_EXT_HASH_MAP)
  36     #include <ext/hash_set>
  37 #elif defined(HAVE_HASH_MAP)
  38     #include <hash_set>
  39 #endif
  40
  41 #define WX_HASH_SET_BASE_TEMPLATE WX_HASH_MAP_NAMESPACE::hash_set
  42
  43 #endif // different hash_set/unordered_set possibilities
  44
  45 #ifdef WX_HASH_SET_BASE_TEMPLATE
  46
  47 // we need to define the class declared by _WX_DECLARE_HASH_SET as a class and
  48 // not a typedef to allow forward declaring it
  49 #define _WX_DECLARE_HASH_SET_IMPL( KEY_T, HASH_T, KEY_EQ_T, PTROP, CLASSNAME, CLASSEXP )  \
  50 CLASSEXP CLASSNAME                                                            \
  51     : public WX_HASH_SET_BASE_TEMPLATE< KEY_T, HASH_T, KEY_EQ_T >             \
  52 {                                                                             \
  53 public:                                                                       \
  54     explicit CLASSNAME(size_type n = 3,                                       \
  55                        const hasher& h = hasher(),                            \
  56                        const key_equal& ke = key_equal(),                     \
  57                        const allocator_type& a = allocator_type())            \
  58         : WX_HASH_SET_BASE_TEMPLATE< KEY_T, HASH_T, KEY_EQ_T >(n, h, ke, a)   \
  59     {}                                                                        \
  60     template <class InputIterator>                                            \
  61     CLASSNAME(InputIterator f, InputIterator l,                               \
  62               const hasher& h = hasher(),                                     \
  63               const key_equal& ke = key_equal(),                              \
  64               const allocator_type& a = allocator_type())                     \
  65         : WX_HASH_SET_BASE_TEMPLATE< KEY_T, HASH_T, KEY_EQ_T >(f, l, h, ke, a)\
  66     {}                                                                        \
  67     CLASSNAME(const WX_HASH_SET_BASE_TEMPLATE< KEY_T, HASH_T, KEY_EQ_T >& s)  \
  68         : WX_HASH_SET_BASE_TEMPLATE< KEY_T, HASH_T, KEY_EQ_T >(s)             \
  69     {}                                                                        \
  70 }
  71
  72 // In some standard library implementations (in particular, the libstdc++ that
  73 // ships with g++ 4.7), std::unordered_set inherits privately from its hasher
  74 // and comparator template arguments for purposes of empty base optimization.
  75 // As a result, in the declaration of a class deriving from std::unordered_set
  76 // the names of the hasher and comparator classes are interpreted as naming
  77 // the base class which is inaccessible.
  78 // The workaround is to prefix the class names with 'struct'; however, don't
  79 // do this on MSVC because it causes a warning there if the class was
  80 // declared as a 'class' rather than a 'struct' (and MSVC's std::unordered_set
  81 // implementation does not suffer from the access problem).
  82 #ifdef _MSC_VER
  83 #define WX_MAYBE_PREFIX_WITH_STRUCT(STRUCTNAME) STRUCTNAME
  84 #else
  85 #define WX_MAYBE_PREFIX_WITH_STRUCT(STRUCTNAME) struct STRUCTNAME
  86 #endif
  87
  88 #define _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, PTROP, CLASSNAME, CLASSEXP )   \
  89     _WX_DECLARE_HASH_SET_IMPL(                                                \
  90         KEY_T,                                                                \
  91         WX_MAYBE_PREFIX_WITH_STRUCT(HASH_T),                                  \
  92         WX_MAYBE_PREFIX_WITH_STRUCT(KEY_EQ_T),                                \
  93         PTROP,                                                                \
  94         CLASSNAME,                                                            \
  95         CLASSEXP)
  96
  97 #else // no appropriate STL class, use our own implementation
  98
  99 // this is a complex way of defining an easily inlineable identity function...
 100 #define _WX_DECLARE_HASH_SET_KEY_EX( KEY_T, CLASSNAME, CLASSEXP )            \
 101 CLASSEXP CLASSNAME                                                           \
 102 {                                                                            \
 103     typedef KEY_T key_type;                                                  \
 104     typedef const key_type const_key_type;                                   \
 105     typedef const_key_type& const_key_reference;                             \
 106 public:                                                                      \
 107     CLASSNAME() { }                                                          \
 108     const_key_reference operator()( const_key_reference key ) const          \
 109         { return key; }                                                      \
 110                                                                              \
 111     /* the dummy assignment operator is needed to suppress compiler */       \
 112     /* warnings from hash table class' operator=(): gcc complains about */   \
 113     /* "statement with no effect" without it */                              \
 114     CLASSNAME& operator=(const CLASSNAME&) { return *this; }                 \
 115 };
 116
 117 #define _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, PTROP, CLASSNAME, CLASSEXP )\
 118 _WX_DECLARE_HASH_SET_KEY_EX( KEY_T, CLASSNAME##_wxImplementation_KeyEx, CLASSEXP ) \
 119 _WX_DECLARE_HASHTABLE( KEY_T, KEY_T, HASH_T,                                 \
 120     CLASSNAME##_wxImplementation_KeyEx, KEY_EQ_T, PTROP,                     \
 121     CLASSNAME##_wxImplementation_HashTable, CLASSEXP, grow_lf70, never_shrink ) \
 122 CLASSEXP CLASSNAME:public CLASSNAME##_wxImplementation_HashTable             \
 123 {                                                                            \
 124 public:                                                                      \
 125     _WX_DECLARE_PAIR( iterator, bool, Insert_Result, CLASSEXP )              \
 126                                                                              \
 127     wxEXPLICIT CLASSNAME( size_type hint = 100, hasher hf = hasher(),        \
 128                           key_equal eq = key_equal() )                       \
 129         : CLASSNAME##_wxImplementation_HashTable( hint, hf, eq,              \
 130                       CLASSNAME##_wxImplementation_KeyEx() ) {}              \
 131                                                                              \
 132     Insert_Result insert( const key_type& key )                              \
 133     {                                                                        \
 134         bool created;                                                        \
 135         Node *node = GetOrCreateNode( key, created );                        \
 136         return Insert_Result( iterator( node, this ), created );             \
 137     }                                                                        \
 138                                                                              \
 139     const_iterator find( const const_key_type& key ) const                   \
 140     {                                                                        \
 141         return const_iterator( GetNode( key ), this );                       \
 142     }                                                                        \
 143                                                                              \
 144     iterator find( const const_key_type& key )                               \
 145     {                                                                        \
 146         return iterator( GetNode( key ), this );                             \
 147     }                                                                        \
 148                                                                              \
 149     size_type erase( const key_type& k )                                     \
 150         { return CLASSNAME##_wxImplementation_HashTable::erase( k ); }       \
 151     void erase( const iterator& it ) { erase( *it ); }                       \
 152     void erase( const const_iterator& it ) { erase( *it ); }                 \
 153                                                                              \
 154     /* count() == 0 | 1 */                                                   \
 155     size_type count( const const_key_type& key ) const                       \
 156         { return GetNode( key ) ? 1 : 0; }                                   \
 157 }
 158
 159 #endif // STL/wx implementations
 160
 161
 162 // these macros are to be used in the user code
 163 #define WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME) \
 164     _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NORMAL, CLASSNAME, class )
 165
 166 // and these do exactly the same thing but should be used inside the
 167 // library
 168 #define WX_DECLARE_HASH_SET_WITH_DECL( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME, DECL) \
 169     _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NORMAL, CLASSNAME, DECL )
 170
 171 #define WX_DECLARE_EXPORTED_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME) \
 172     WX_DECLARE_HASH_SET_WITH_DECL( KEY_T, HASH_T, KEY_EQ_T, \
 173                                    CLASSNAME, class WXDLLIMPEXP_CORE )
 174
 175 // Finally these versions allow to define hash sets of non-objects (including
 176 // pointers, hence the confusing but wxArray-compatible name) without
 177 // operator->() which can't be used for them. This is mostly used inside the
 178 // library itself to avoid warnings when using such hash sets with some less
 179 // common compilers (notably Sun CC).
 180 #define WX_DECLARE_HASH_SET_PTR( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME) \
 181     _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NOP, CLASSNAME, class )
 182 #define WX_DECLARE_HASH_SET_WITH_DECL_PTR( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME, DECL) \
 183     _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NOP, CLASSNAME, DECL )
 184
 185 // delete all hash elements
 186 //
 187 // NB: the class declaration of the hash elements must be visible from the
 188 //     place where you use this macro, otherwise the proper destructor may not
 189 //     be called (a decent compiler should give a warning about it, but don't
 190 //     count on it)!
 191 #define WX_CLEAR_HASH_SET(type, hashset)                                     \
 192     {                                                                        \
 193         type::iterator it, en;                                               \
 194         for( it = (hashset).begin(), en = (hashset).end(); it != en; ++it )  \
 195             delete *it;                                                      \
 196         (hashset).clear();                                                   \
 197     }
 198
 199 #endif // _WX_HASHSET_H_