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