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 #include <algorithm>
  21
  22 #define wxVector std::vector
  23 template<typename T>
  24 inline void wxVectorSort(wxVector<T>& v)
  25 {
  26     std::sort(v.begin(), v.end());
  27 }
  28
  29 #else // !wxUSE_STL
  30
  31 #include "wx/utils.h"
  32 #include "wx/scopeguard.h"
  33 #include "wx/meta/movable.h"
  34 #include "wx/meta/if.h"
  35
  36 #include "wx/beforestd.h"
  37 #include <new> // for placement new
  38 #include "wx/afterstd.h"
  39
  40 namespace wxPrivate
  41 {
  42
  43 // These templates encapsulate memory operations for use by wxVector; there are
  44 // two implementations, both in generic way for any C++ types and as an
  45 // optimized version for "movable" types that uses realloc() and memmove().
  46
  47 // version for movable types:
  48 template<typename T>
  49 struct wxVectorMemOpsMovable
  50 {
  51     static void Free(T* array)
  52         { free(array); }
  53
  54     static T* Realloc(T* old, size_t newCapacity, size_t WXUNUSED(occupiedSize))
  55         { return (T*)realloc(old, newCapacity * sizeof(T)); }
  56
  57     static void MemmoveBackward(T* dest, T* source, size_t count)
  58         { memmove(dest, source, count * sizeof(T)); }
  59
  60     static void MemmoveForward(T* dest, T* source, size_t count)
  61         { memmove(dest, source, count * sizeof(T)); }
  62 };
  63
  64 // generic version for non-movable types:
  65 template<typename T>
  66 struct wxVectorMemOpsGeneric
  67 {
  68     static void Free(T* array)
  69         { ::operator delete(array); }
  70
  71     static T* Realloc(T* old, size_t newCapacity, size_t occupiedSize)
  72     {
  73         T *mem = (T*)::operator new(newCapacity * sizeof(T));
  74         for ( size_t i = 0; i < occupiedSize; i++ )
  75         {
  76             ::new(mem + i) T(old[i]);
  77             old[i].~T();
  78         }
  79         ::operator delete(old);
  80         return mem;
  81     }
  82
  83     static void MemmoveBackward(T* dest, T* source, size_t count)
  84     {
  85         wxASSERT( dest < source );
  86         T* destptr = dest;
  87         T* sourceptr = source;
  88         for ( size_t i = count; i > 0; --i, ++destptr, ++sourceptr )
  89         {
  90             ::new(destptr) T(*sourceptr);
  91             sourceptr->~T();
  92         }
  93     }
  94
  95     static void MemmoveForward(T* dest, T* source, size_t count)
  96     {
  97         wxASSERT( dest > source );
  98         T* destptr = dest + count - 1;
  99         T* sourceptr = source + count - 1;
 100         for ( size_t i = count; i > 0; --i, --destptr, --sourceptr )
 101         {
 102             ::new(destptr) T(*sourceptr);
 103             sourceptr->~T();
 104         }
 105     }
 106 };
 107
 108
 109 } // namespace wxPrivate
 110
 111 template<typename T>
 112 class wxVector
 113 {
 114 private:
 115     // This cryptic expression means "typedef Ops to wxVectorMemOpsMovable if
 116     // type T is movable type, otherwise to wxVectorMemOpsGeneric".
 117     //
 118     // Note that we use typedef instead of privately deriving from this (which
 119     // would allowed us to omit "Ops::" prefixes below) to keep VC6 happy,
 120     // it can't compile code that derives from wxIf<...>::value.
 121     typedef typename wxIf< wxIsMovable<T>::value,
 122                            wxPrivate::wxVectorMemOpsMovable<T>,
 123                            wxPrivate::wxVectorMemOpsGeneric<T> >::value
 124             Ops;
 125
 126 public:
 127     typedef size_t size_type;
 128     typedef size_t difference_type;
 129     typedef T value_type;
 130     typedef value_type* pointer;
 131     typedef value_type* iterator;
 132     typedef const value_type* const_iterator;
 133     typedef value_type& reference;
 134
 135     class reverse_iterator
 136     {
 137     public:
 138         reverse_iterator() : m_ptr(NULL) { }
 139         wxEXPLICIT reverse_iterator(iterator it) : m_ptr(it) { }
 140         reverse_iterator(const reverse_iterator& it) : m_ptr(it.m_ptr) { }
 141
 142         reference operator*() const { return *m_ptr; }
 143         pointer operator->() const { return m_ptr; }
 144
 145         iterator base() const { return m_ptr; }
 146
 147         reverse_iterator& operator++()
 148             { --m_ptr; return *this; }
 149         reverse_iterator operator++(int)
 150             { reverse_iterator tmp = *this; --m_ptr; return tmp; }
 151         reverse_iterator& operator--()
 152             { ++m_ptr; return *this; }
 153         reverse_iterator operator--(int)
 154             { reverse_iterator tmp = *this; ++m_ptr; return tmp; }
 155
 156         reverse_iterator operator+(difference_type n) const
 157             { return reverse_iterator(m_ptr - n); }
 158         reverse_iterator& operator+=(difference_type n)
 159             { m_ptr -= n; return *this; }
 160         reverse_iterator operator-(difference_type n) const
 161             { return reverse_iterator(m_ptr + n); }
 162         reverse_iterator& operator-=(difference_type n)
 163             { m_ptr += n; return *this; }
 164
 165         reference operator[](difference_type n) const
 166             { return *(*this + n); }
 167
 168         bool operator ==(const reverse_iterator& it) const
 169             { return m_ptr == it.m_ptr; }
 170         bool operator !=(const reverse_iterator& it) const
 171             { return m_ptr != it.m_ptr; }
 172
 173     private:
 174         value_type *m_ptr;
 175     };
 176
 177     wxVector() : m_size(0), m_capacity(0), m_values(NULL) {}
 178
 179     wxVector(size_type p_size)
 180         : m_size(0), m_capacity(0), m_values(NULL)
 181     {
 182         reserve(p_size);
 183         for ( size_t n = 0; n < p_size; n++ )
 184             push_back(value_type());
 185     }
 186
 187     wxVector(size_type p_size, const value_type& v)
 188         : m_size(0), m_capacity(0), m_values(NULL)
 189     {
 190         reserve(p_size);
 191         for ( size_t n = 0; n < p_size; n++ )
 192             push_back(v);
 193     }
 194
 195     wxVector(const wxVector& c) : m_size(0), m_capacity(0), m_values(NULL)
 196     {
 197         Copy(c);
 198     }
 199
 200     ~wxVector()
 201     {
 202         clear();
 203     }
 204
 205     void swap(wxVector& v)
 206     {
 207         wxSwap(m_size, v.m_size);
 208         wxSwap(m_capacity, v.m_capacity);
 209         wxSwap(m_values, v.m_values);
 210     }
 211
 212     void clear()
 213     {
 214         // call destructors of stored objects:
 215         for ( size_type i = 0; i < m_size; i++ )
 216         {
 217             m_values[i].~T();
 218         }
 219
 220         Ops::Free(m_values);
 221         m_values = NULL;
 222         m_size =
 223         m_capacity = 0;
 224     }
 225
 226     void reserve(size_type n)
 227     {
 228         if ( n <= m_capacity )
 229             return;
 230
 231         // increase the size twice, unless we're already too big or unless
 232         // more is requested
 233         //
 234         // NB: casts to size_type are needed to suppress mingw32 warnings about
 235         //     mixing enums and ints in the same expression
 236         const size_type increment = m_size > 0
 237                                      ? wxMin(m_size, (size_type)ALLOC_MAX_SIZE)
 238                                      : (size_type)ALLOC_INITIAL_SIZE;
 239         if ( m_capacity + increment > n )
 240             n = m_capacity + increment;
 241
 242         m_values = Ops::Realloc(m_values, n * sizeof(value_type), m_size);
 243         m_capacity = n;
 244     }
 245
 246     void resize(size_type n)
 247     {
 248         if ( n < m_size )
 249             Shrink(n);
 250         else if ( n > m_size )
 251             Extend(n, value_type());
 252     }
 253
 254     void resize(size_type n, const value_type& v)
 255     {
 256         if ( n < m_size )
 257             Shrink(n);
 258         else if ( n > m_size )
 259             Extend(n, v);
 260     }
 261
 262     size_type size() const
 263     {
 264         return m_size;
 265     }
 266
 267     size_type capacity() const
 268     {
 269         return m_capacity;
 270     }
 271
 272     bool empty() const
 273     {
 274         return size() == 0;
 275     }
 276
 277     wxVector& operator=(const wxVector& vb)
 278     {
 279         if (this != &vb)
 280         {
 281             clear();
 282             Copy(vb);
 283         }
 284         return *this;
 285     }
 286
 287     void push_back(const value_type& v)
 288     {
 289         reserve(size() + 1);
 290
 291         // use placement new to initialize new object in preallocated place in
 292         // m_values and store 'v' in it:
 293         void* const place = m_values + m_size;
 294         ::new(place) value_type(v);
 295
 296         // only increase m_size if the ctor didn't throw an exception; notice
 297         // that if it _did_ throw, everything is OK, because we only increased
 298         // vector's capacity so far and possibly written some data to
 299         // uninitialized memory at the end of m_values
 300         m_size++;
 301     }
 302
 303     void pop_back()
 304     {
 305         erase(end() - 1);
 306     }
 307
 308     const value_type& at(size_type idx) const
 309     {
 310         wxASSERT(idx < m_size);
 311         return m_values[idx];
 312     }
 313
 314     value_type& at(size_type idx)
 315     {
 316         wxASSERT(idx < m_size);
 317         return m_values[idx];
 318     }
 319
 320     const value_type& operator[](size_type idx) const  { return at(idx); }
 321     value_type& operator[](size_type idx) { return at(idx); }
 322     const value_type& front() const { return at(0); }
 323     value_type& front() { return at(0); }
 324     const value_type& back() const { return at(size() - 1); }
 325     value_type& back() { return at(size() - 1); }
 326
 327     const_iterator begin() const { return m_values; }
 328     iterator begin() { return m_values; }
 329     const_iterator end() const { return m_values + size(); }
 330     iterator end() { return m_values + size(); }
 331
 332     reverse_iterator rbegin() { return reverse_iterator(end() - 1); }
 333     reverse_iterator rend() { return reverse_iterator(begin() - 1); }
 334
 335     iterator insert(iterator it, const value_type& v = value_type())
 336     {
 337         // NB: this must be done before reserve(), because reserve()
 338         //     invalidates iterators!
 339         const size_t idx = it - begin();
 340         const size_t after = end() - it;
 341
 342         reserve(size() + 1);
 343
 344         // the place where the new element is going to be inserted
 345         value_type * const place = m_values + idx;
 346
 347         // unless we're inserting at the end, move following elements out of
 348         // the way:
 349         if ( after > 0 )
 350             Ops::MemmoveForward(place + 1, place, after);
 351
 352         // if the ctor called below throws an exception, we need to move all
 353         // the elements back to their original positions in m_values
 354         wxScopeGuard moveBack = wxMakeGuard(
 355                 Ops::MemmoveBackward, place, place + 1, after);
 356         if ( !after )
 357             moveBack.Dismiss();
 358
 359         // use placement new to initialize new object in preallocated place in
 360         // m_values and store 'v' in it:
 361         ::new(place) value_type(v);
 362
 363         // now that we did successfully add the new element, increment the size
 364         // and disable moving the items back
 365         moveBack.Dismiss();
 366         m_size++;
 367
 368         return begin() + idx;
 369     }
 370
 371     iterator erase(iterator it)
 372     {
 373         return erase(it, it + 1);
 374     }
 375
 376     iterator erase(iterator first, iterator last)
 377     {
 378         if ( first == last )
 379             return first;
 380         wxASSERT( first < end() && last <= end() );
 381
 382         const size_type idx = first - begin();
 383         const size_type count = last - first;
 384         const size_type after = end() - last;
 385
 386         // erase elements by calling their destructors:
 387         for ( iterator i = first; i < last; ++i )
 388             i->~T();
 389
 390         // once that's done, move following elements over to the freed space:
 391         if ( after > 0 )
 392         {
 393             Ops::MemmoveBackward(m_values + idx, m_values + idx + count, after);
 394         }
 395
 396         m_size -= count;
 397
 398         return begin() + idx;
 399     }
 400
 401 #if WXWIN_COMPATIBILITY_2_8
 402     wxDEPRECATED( size_type erase(size_type n) );
 403 #endif // WXWIN_COMPATIBILITY_2_8
 404
 405 private:
 406     // VC6 can't compile static const int members
 407     enum { ALLOC_INITIAL_SIZE = 16 };
 408     enum { ALLOC_MAX_SIZE = 4096 };
 409
 410     void Copy(const wxVector& vb)
 411     {
 412         reserve(vb.size());
 413
 414         for ( const_iterator i = vb.begin(); i != vb.end(); ++i )
 415             push_back(*i);
 416     }
 417
 418 private:
 419     void Shrink(size_type n)
 420     {
 421         for ( size_type i = n; i < m_size; i++ )
 422             m_values[i].~T();
 423         m_size = n;
 424     }
 425
 426     void Extend(size_type n, const value_type& v)
 427     {
 428         reserve(n);
 429         for ( size_type i = m_size; i < n; i++ )
 430             push_back(v);
 431     }
 432
 433     size_type m_size,
 434               m_capacity;
 435     value_type *m_values;
 436 };
 437
 438 #if WXWIN_COMPATIBILITY_2_8
 439 template<typename T>
 440 inline typename wxVector<T>::size_type wxVector<T>::erase(size_type n)
 441 {
 442     erase(begin() + n);
 443     return n;
 444 }
 445 #endif // WXWIN_COMPATIBILITY_2_8
 446
 447
 448
 449 namespace wxPrivate
 450 {
 451
 452 // This is a helper for the wxVectorSort function, and should not be used
 453 // directly in user's code.
 454 template<typename T>
 455 struct wxVectorSort
 456 {
 457     static int wxCMPFUNC_CONV
 458     Compare(const void* pitem1, const void* pitem2, const void* )
 459     {
 460         const T& item1 = *reinterpret_cast<const T*>(pitem1);
 461         const T& item2 = *reinterpret_cast<const T*>(pitem2);
 462
 463         if (item1 < item2)
 464             return -1;
 465         else if (item2 < item1)
 466             return 1;
 467         else
 468             return 0;
 469     }
 470 };
 471
 472 }  // namespace wxPrivate
 473
 474
 475
 476 template<typename T>
 477 void wxVectorSort(wxVector<T>& v)
 478 {
 479     wxQsort(v.begin(), v.size(), sizeof(T),
 480             wxPrivate::wxVectorSort<T>::Compare, NULL);
 481 }
 482
 483
 484
 485 #endif // wxUSE_STL/!wxUSE_STL
 486
 487 #if WXWIN_COMPATIBILITY_2_8
 488     #define WX_DECLARE_VECTORBASE(obj, cls) typedef wxVector<obj> cls
 489     #define _WX_DECLARE_VECTOR(obj, cls, exp) WX_DECLARE_VECTORBASE(obj, cls)
 490     #define WX_DECLARE_VECTOR(obj, cls) WX_DECLARE_VECTORBASE(obj, cls)
 491 #endif // WXWIN_COMPATIBILITY_2_8
 492
 493 #endif // _WX_VECTOR_H_