include/wx/vector.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/vector.h
   3 // Purpose:     STL vector clone
   4 // Author:      Lindsay Mathieson
   5 // Modified by: Vaclav Slavik - make it a template
   6 // Created:     30.07.2001
   7 // Copyright:   (c) 2001 Lindsay Mathieson <lindsay@mathieson.org>,
   8 //                  2007 Vaclav Slavik <vslavik@fastmail.fm>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_VECTOR_H_
  13 #define _WX_VECTOR_H_
  14
  15 #include "wx/defs.h"
  16
  17 #if wxUSE_STL
  18
  19 #include <vector>
  20 #define wxVector std::vector
  21
  22 #else // !wxUSE_STL
  23
  24 #include "wx/utils.h"
  25 #include "wx/meta/movable.h"
  26 #include "wx/meta/if.h"
  27
  28 #include "wx/beforestd.h"
  29 #include <new> // for placement new
  30 #include "wx/afterstd.h"
  31
  32 namespace wxPrivate
  33 {
  34
  35 // These templates encapsulate memory operations for use by wxVector; there are
  36 // two implementations, both in generic way for any C++ types and as an
  37 // optimized version for "movable" types that uses realloc() and memmove().
  38
  39 // version for movable types:
  40 template<typename T>
  41 struct wxVectorMemOpsMovable
  42 {
  43     static void Free(T* array)
  44         { free(array); }
  45
  46     static T* Realloc(T* old, size_t newCapacity, size_t WXUNUSED(occupiedSize))
  47         { return (T*)realloc(old, newCapacity * sizeof(T)); }
  48
  49     static void MemmoveBackward(T* dest, T* source, size_t count)
  50         { memmove(dest, source, count * sizeof(T)); }
  51
  52     static void MemmoveForward(T* dest, T* source, size_t count)
  53         { memmove(dest, source, count * sizeof(T)); }
  54 };
  55
  56 // generic version for non-movable types:
  57 template<typename T>
  58 struct wxVectorMemOpsGeneric
  59 {
  60     static void Free(T* array)
  61         { ::operator delete(array); }
  62
  63     static T* Realloc(T* old, size_t newCapacity, size_t occupiedSize)
  64     {
  65         T *mem = (T*)::operator new(newCapacity * sizeof(T));
  66         for ( size_t i = 0; i < occupiedSize; i++ )
  67         {
  68             new(mem + i) T(old[i]);
  69             old[i].~T();
  70         }
  71         ::operator delete(old);
  72         return mem;
  73     }
  74
  75     static void MemmoveBackward(T* dest, T* source, size_t count)
  76     {
  77         wxASSERT( dest < source );
  78         T* destptr = dest;
  79         T* sourceptr = source;
  80         for ( size_t i = count; i > 0; --i, ++destptr, ++sourceptr )
  81         {
  82             new(destptr) T(*sourceptr);
  83             sourceptr->~T();
  84         }
  85     }
  86
  87     static void MemmoveForward(T* dest, T* source, size_t count)
  88     {
  89         wxASSERT( dest > source );
  90         T* destptr = dest + count - 1;
  91         T* sourceptr = source + count - 1;
  92         for ( size_t i = count; i > 0; --i, --destptr, --sourceptr )
  93         {
  94             new(destptr) T(*sourceptr);
  95             sourceptr->~T();
  96         }
  97     }
  98 };
  99
 100
 101 } // namespace wxPrivate
 102
 103 template<typename T>
 104 class wxVector
 105     // this cryptic expression means "derive from wxVectorMemOpsMovable if
 106     // type T is movable type, otherwise derive from wxVectorMemOpsGeneric
 107     : private wxIf< wxIsMovable<T>::value,
 108                     wxPrivate::wxVectorMemOpsMovable<T>,
 109                     wxPrivate::wxVectorMemOpsGeneric<T> >::value
 110 {
 111 public:
 112     typedef size_t size_type;
 113     typedef T value_type;
 114     typedef value_type* iterator;
 115     typedef const value_type* const_iterator;
 116     typedef value_type& reference;
 117
 118     wxVector() : m_size(0), m_capacity(0), m_values(NULL) {}
 119
 120     wxVector(const wxVector& c)
 121     {
 122         Copy(c);
 123     }
 124
 125     ~wxVector()
 126     {
 127         clear();
 128     }
 129
 130     void clear()
 131     {
 132         // call destructors of stored objects:
 133         for ( size_type i = 0; i < m_size; i++ )
 134         {
 135             m_values[i].~T();
 136         }
 137
 138         Free(m_values);
 139         m_values = NULL;
 140         m_size = m_capacity = 0;
 141     }
 142
 143     void reserve(size_type n)
 144     {
 145         if ( n <= m_capacity )
 146             return;
 147
 148         // increase the size twice, unless we're already too big or unless
 149         // more is requested
 150         //
 151         // NB: casts to size_type are needed to suppress mingw32 warnings about
 152         //     mixing enums and ints in the same expression
 153         const size_type increment = m_size > 0
 154                                      ? wxMin(m_size, (size_type)ALLOC_MAX_SIZE)
 155                                      : (size_type)ALLOC_INITIAL_SIZE;
 156         if ( m_capacity + increment > n )
 157             n = m_capacity + increment;
 158
 159         m_values = Realloc(m_values, n * sizeof(value_type), m_size);
 160         m_capacity = n;
 161     }
 162
 163     size_type size() const
 164     {
 165         return m_size;
 166     }
 167
 168     size_type capacity() const
 169     {
 170         return m_capacity;
 171     }
 172
 173     bool empty() const
 174     {
 175         return size() == 0;
 176     }
 177
 178     wxVector& operator=(const wxVector& vb)
 179     {
 180         Copy(vb);
 181         return *this;
 182     }
 183
 184     void push_back(const value_type& v)
 185     {
 186         reserve(size() + 1);
 187
 188         // use placement new to initialize new object in preallocated place in
 189         // m_values and store 'v' in it:
 190         void* const place = m_values + m_size;
 191         new(place) value_type(v);
 192
 193         // only increase m_size if the ctor didn't throw an exception; notice
 194         // that if it _did_ throw, everything is OK, because we only increased
 195         // vector's capacity so far and possibly written some data to
 196         // uninitialized memory at the end of m_values
 197         m_size++;
 198     }
 199
 200     void pop_back()
 201     {
 202         erase(end() - 1);
 203     }
 204
 205     const value_type& at(size_type idx) const
 206     {
 207         wxASSERT(idx < m_size);
 208         return m_values[idx];
 209     }
 210
 211     value_type& at(size_type idx)
 212     {
 213         wxASSERT(idx < m_size);
 214         return m_values[idx];
 215     }
 216
 217     const value_type& operator[](size_type idx) const  { return at(idx); }
 218     value_type& operator[](size_type idx) { return at(idx); }
 219     const value_type& front() const { return at(0); }
 220     value_type& front() { return at(0); }
 221     const value_type& back() const { return at(size() - 1); }
 222     value_type& back() { return at(size() - 1); }
 223
 224     const_iterator begin() const { return m_values; }
 225     iterator begin() { return m_values; }
 226     const_iterator end() const { return m_values + size(); }
 227     iterator end() { return m_values + size(); }
 228
 229     iterator insert(iterator it, const value_type& v = value_type())
 230     {
 231         // NB: this must be done before reserve(), because reserve()
 232         //     invalidates iterators!
 233         const size_t idx = it - begin();
 234         const size_t after = end() - it;
 235
 236         reserve(size() + 1);
 237
 238         // unless we're inserting at the end, move following elements out of
 239         // the way:
 240         if ( after > 0 )
 241         {
 242             MemmoveForward(m_values + idx + 1, m_values + idx, after);
 243         }
 244
 245 #if wxUSE_EXCEPTIONS
 246         try
 247         {
 248 #endif
 249             // use placement new to initialize new object in preallocated place
 250             // in m_values and store 'v' in it:
 251             void* const place = m_values + idx;
 252             new(place) value_type(v);
 253 #if wxUSE_EXCEPTIONS
 254         }
 255         catch ( ... )
 256         {
 257             // if the ctor threw an exception, we need to move all the elements
 258             // back to their original positions in m_values
 259             if ( after > 0 )
 260             {
 261                 MemmoveBackward(m_values + idx, m_values + idx + 1, after);
 262             }
 263
 264             throw; // rethrow the exception
 265         }
 266 #endif // wxUSE_EXCEPTIONS
 267
 268         // increment m_size only if ctor didn't throw -- if it did, we'll be
 269         // left with m_values larger than necessary, but number of elements will
 270         // be the same
 271         m_size++;
 272
 273         return begin() + idx;
 274     }
 275
 276     iterator erase(iterator it)
 277     {
 278         return erase(it, it + 1);
 279     }
 280
 281     iterator erase(iterator first, iterator last)
 282     {
 283         if ( first == last )
 284             return first;
 285         wxASSERT( first < end() && last <= end() );
 286
 287         const size_type idx = first - begin();
 288         const size_type count = last - first;
 289         const size_type after = end() - last;
 290
 291         // erase elements by calling their destructors:
 292         for ( iterator i = first; i < last; ++i )
 293             i->~T();
 294
 295         // once that's done, move following elements over to the freed space:
 296         if ( after > 0 )
 297         {
 298             MemmoveBackward(m_values + idx, m_values + idx + count, after);
 299         }
 300
 301         m_size -= count;
 302
 303         return begin() + idx;
 304     }
 305
 306 #if WXWIN_COMPATIBILITY_2_8
 307     wxDEPRECATED( size_type erase(size_type n) );
 308 #endif // WXWIN_COMPATIBILITY_2_8
 309
 310 private:
 311     // VC6 can't compile static const int members
 312     enum { ALLOC_INITIAL_SIZE = 16 };
 313     enum { ALLOC_MAX_SIZE = 4096 };
 314
 315     void Copy(const wxVector& vb)
 316     {
 317         clear();
 318         reserve(vb.size());
 319
 320         for ( const_iterator i = vb.begin(); i != vb.end(); ++i )
 321             push_back(*i);
 322     }
 323
 324 private:
 325     size_type m_size,
 326               m_capacity;
 327     value_type *m_values;
 328 };
 329
 330 #if WXWIN_COMPATIBILITY_2_8
 331 template<typename T>
 332 inline typename wxVector<T>::size_type wxVector<T>::erase(size_type n)
 333 {
 334     erase(begin() + n);
 335     return n;
 336 }
 337 #endif // WXWIN_COMPATIBILITY_2_8
 338
 339 #endif // wxUSE_STL/!wxUSE_STL
 340
 341 #if WXWIN_COMPATIBILITY_2_8
 342     #define WX_DECLARE_VECTORBASE(obj, cls) typedef wxVector<obj> cls
 343     #define _WX_DECLARE_VECTOR(obj, cls, exp) WX_DECLARE_VECTORBASE(obj, cls)
 344     #define WX_DECLARE_VECTOR(obj, cls) WX_DECLARE_VECTORBASE(obj, cls)
 345 #endif // WXWIN_COMPATIBILITY_2_8
 346
 347 #endif // _WX_VECTOR_H_