include/wx/stringimpl.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/stringimpl.h
   3 // Purpose:     wxStringImpl class, implementation of wxString
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     29/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 /*
  13     This header implements std::string-like string class, wxStringImpl, that is
  14     used by wxString to store the data. Alternatively, if wxUSE_STL=1,
  15     wxStringImpl is just a typedef to std:: string class.
  16 */
  17
  18 #ifndef _WX_WXSTRINGIMPL_H__
  19 #define _WX_WXSTRINGIMPL_H__
  20
  21 // ----------------------------------------------------------------------------
  22 // headers
  23 // ----------------------------------------------------------------------------
  24
  25 #include "wx/defs.h"        // everybody should include this
  26 #include "wx/chartype.h"    // for wxChar
  27 #include "wx/wxcrtbase.h"   // for wxStrlen() etc.
  28
  29 #include <stdlib.h>
  30
  31 // ---------------------------------------------------------------------------
  32 // macros
  33 // ---------------------------------------------------------------------------
  34
  35 // implementation only
  36 #define   wxASSERT_VALID_INDEX(i) \
  37     wxASSERT_MSG( (size_t)(i) <= length(), _T("invalid index in wxString") )
  38
  39
  40 // ----------------------------------------------------------------------------
  41 // global data
  42 // ----------------------------------------------------------------------------
  43
  44 // global pointer to empty string
  45 extern WXDLLIMPEXP_DATA_BASE(const wxChar*) wxEmptyString;
  46 #if wxUSE_UNICODE_UTF8
  47 // FIXME-UTF8: we should have only one wxEmptyString
  48 extern WXDLLIMPEXP_DATA_BASE(const wxStringCharType*) wxEmptyStringImpl;
  49 #endif
  50
  51
  52 // ----------------------------------------------------------------------------
  53 // deal with STL/non-STL/non-STL-but-wxUSE_STD_STRING
  54 // ----------------------------------------------------------------------------
  55
  56 // using STL implies using std::string
  57 #if wxUSE_STL
  58     #undef wxUSE_STD_STRING
  59     #define wxUSE_STD_STRING 1
  60 #endif
  61
  62 // we use STL-based string internally if we use std::string at all now, there
  63 // should be no reason to prefer our internal implement but if you really need
  64 // it you can predefine wxUSE_STL_BASED_WXSTRING as 0 when building the library
  65 #ifndef wxUSE_STL_BASED_WXSTRING
  66     #define wxUSE_STL_BASED_WXSTRING  wxUSE_STD_STRING
  67 #endif
  68
  69 // in both cases we need to define wxStdString
  70 #if wxUSE_STL_BASED_WXSTRING || wxUSE_STD_STRING
  71
  72 #include "wx/beforestd.h"
  73 #include <string>
  74 #include "wx/afterstd.h"
  75
  76 #ifdef HAVE_STD_WSTRING
  77     typedef std::wstring wxStdWideString;
  78 #else
  79     typedef std::basic_string<wchar_t> wxStdWideString;
  80 #endif
  81
  82 #if wxUSE_UNICODE_WCHAR
  83     typedef wxStdWideString wxStdString;
  84 #else
  85     typedef std::string wxStdString;
  86 #endif
  87
  88 #endif // wxUSE_STL_BASED_WXSTRING || wxUSE_STD_STRING
  89
  90
  91 #if wxUSE_STL_BASED_WXSTRING
  92
  93     // we always want ctor from std::string when using std::string internally
  94     #undef wxUSE_STD_STRING
  95     #define wxUSE_STD_STRING 1
  96
  97     // the versions of std::string included with gcc 2.95 and VC6 (for which
  98     // _MSC_VER == 1200) and eVC4 (_MSC_VER == 1201) lack clear() method
  99     #if (defined(__GNUG__) && (__GNUG__ < 3)) || \
 100         !wxCHECK_VISUALC_VERSION(7) || defined(__EVC4__)
 101         #define wxSTRING_BASE_HASNT_CLEAR
 102     #endif
 103
 104     typedef wxStdString wxStringImpl;
 105 #else // if !wxUSE_STL_BASED_WXSTRING
 106
 107 // in non-STL mode, compare() is implemented in wxString and not wxStringImpl
 108 #undef HAVE_STD_STRING_COMPARE
 109
 110 // ---------------------------------------------------------------------------
 111 // string data prepended with some housekeeping info (used by wxString class),
 112 // is never used directly (but had to be put here to allow inlining)
 113 // ---------------------------------------------------------------------------
 114
 115 struct WXDLLIMPEXP_BASE wxStringData
 116 {
 117   int     nRefs;        // reference count
 118   size_t  nDataLength,  // actual string length
 119           nAllocLength; // allocated memory size
 120
 121   // mimics declaration 'wxStringCharType data[nAllocLength]'
 122   wxStringCharType* data() const { return (wxStringCharType*)(this + 1); }
 123
 124   // empty string has a special ref count so it's never deleted
 125   bool  IsEmpty()   const { return (nRefs == -1); }
 126   bool  IsShared()  const { return (nRefs > 1);   }
 127
 128   // lock/unlock
 129   void  Lock()   { if ( !IsEmpty() ) nRefs++;                    }
 130
 131   // VC++ will refuse to inline Unlock but profiling shows that it is wrong
 132 #if defined(__VISUALC__) && (__VISUALC__ >= 1200)
 133   __forceinline
 134 #endif
 135   // VC++ free must take place in same DLL as allocation when using non dll
 136   // run-time library (e.g. Multithreaded instead of Multithreaded DLL)
 137 #if defined(__VISUALC__) && defined(_MT) && !defined(_DLL)
 138   void  Unlock() { if ( !IsEmpty() && --nRefs == 0) Free();  }
 139   // we must not inline deallocation since allocation is not inlined
 140   void  Free();
 141 #else
 142   void  Unlock() { if ( !IsEmpty() && --nRefs == 0) free(this);  }
 143 #endif
 144
 145   // if we had taken control over string memory (GetWriteBuf), it's
 146   // intentionally put in invalid state
 147   void  Validate(bool b)  { nRefs = (b ? 1 : 0); }
 148   bool  IsValid() const   { return (nRefs != 0); }
 149 };
 150
 151 class WXDLLIMPEXP_BASE wxStringImpl
 152 {
 153 public:
 154   // an 'invalid' value for string index, moved to this place due to a CW bug
 155   static const size_t npos;
 156
 157 protected:
 158   // points to data preceded by wxStringData structure with ref count info
 159   wxStringCharType *m_pchData;
 160
 161   // accessor to string data
 162   wxStringData* GetStringData() const { return (wxStringData*)m_pchData - 1; }
 163
 164   // string (re)initialization functions
 165     // initializes the string to the empty value (must be called only from
 166     // ctors, use Reinit() otherwise)
 167 #if wxUSE_UNICODE_UTF8
 168   void Init() { m_pchData = (wxStringCharType *)wxEmptyStringImpl; } // FIXME-UTF8
 169 #else
 170   void Init() { m_pchData = (wxStringCharType *)wxEmptyString; }
 171 #endif
 172     // initializes the string with (a part of) C-string
 173   void InitWith(const wxStringCharType *psz, size_t nPos = 0, size_t nLen = npos);
 174     // as Init, but also frees old data
 175   void Reinit() { GetStringData()->Unlock(); Init(); }
 176
 177   // memory allocation
 178     // allocates memory for string of length nLen
 179   bool AllocBuffer(size_t nLen);
 180     // effectively copies data to string
 181   bool AssignCopy(size_t, const wxStringCharType *);
 182
 183   // append a (sub)string
 184   bool ConcatSelf(size_t nLen, const wxStringCharType *src, size_t nMaxLen);
 185   bool ConcatSelf(size_t nLen, const wxStringCharType *src)
 186     { return ConcatSelf(nLen, src, nLen); }
 187
 188   // functions called before writing to the string: they copy it if there
 189   // are other references to our data (should be the only owner when writing)
 190   bool CopyBeforeWrite();
 191   bool AllocBeforeWrite(size_t);
 192
 193     // compatibility with wxString
 194   bool Alloc(size_t nLen);
 195
 196 public:
 197   // standard types
 198   typedef wxStringCharType value_type;
 199   typedef wxStringCharType char_type;
 200   typedef size_t size_type;
 201   typedef value_type& reference;
 202   typedef const value_type& const_reference;
 203   typedef value_type* pointer;
 204   typedef const value_type* const_pointer;
 205
 206   // macro to define the bulk of iterator and const_iterator classes
 207   #define WX_DEFINE_STRINGIMPL_ITERATOR(iterator_name, ref_type, ptr_type)    \
 208     public:                                                                   \
 209         typedef wxStringCharType value_type;                                  \
 210         typedef ref_type reference;                                           \
 211         typedef ptr_type pointer;                                             \
 212         typedef int difference_type;                                          \
 213                                                                               \
 214         iterator_name() : m_ptr(NULL) { }                                     \
 215         iterator_name(pointer ptr) : m_ptr(ptr) { }                           \
 216                                                                               \
 217         reference operator*() const { return *m_ptr; }                        \
 218                                                                               \
 219         iterator_name& operator++() { m_ptr++; return *this; }                \
 220         iterator_name operator++(int)                                         \
 221         {                                                                     \
 222             const iterator_name tmp(*this);                                   \
 223             m_ptr++;                                                          \
 224             return tmp;                                                       \
 225         }                                                                     \
 226                                                                               \
 227         iterator_name& operator--() { m_ptr--; return *this; }                \
 228         iterator_name operator--(int)                                         \
 229         {                                                                     \
 230             const iterator_name tmp(*this);                                   \
 231             m_ptr--;                                                          \
 232             return tmp;                                                       \
 233         }                                                                     \
 234                                                                               \
 235         iterator_name operator+(ptrdiff_t n) const                            \
 236             { return iterator_name(m_ptr + n); }                              \
 237         iterator_name operator-(ptrdiff_t n) const                            \
 238             { return iterator_name(m_ptr - n); }                              \
 239         iterator_name& operator+=(ptrdiff_t n)                                \
 240             { m_ptr += n; return *this; }                                     \
 241         iterator_name& operator-=(ptrdiff_t n)                                \
 242             { m_ptr -= n; return *this; }                                     \
 243                                                                               \
 244         difference_type operator-(const iterator_name& i) const               \
 245             { return m_ptr - i.m_ptr; }                                       \
 246                                                                               \
 247         bool operator==(const iterator_name& i) const                         \
 248           { return m_ptr == i.m_ptr; }                                        \
 249         bool operator!=(const iterator_name& i) const                         \
 250           { return m_ptr != i.m_ptr; }                                        \
 251                                                                               \
 252         bool operator<(const iterator_name& i) const                          \
 253           { return m_ptr < i.m_ptr; }                                         \
 254         bool operator>(const iterator_name& i) const                          \
 255           { return m_ptr > i.m_ptr; }                                         \
 256         bool operator<=(const iterator_name& i) const                         \
 257           { return m_ptr <= i.m_ptr; }                                        \
 258         bool operator>=(const iterator_name& i) const                         \
 259           { return m_ptr >= i.m_ptr; }                                        \
 260                                                                               \
 261     private:                                                                  \
 262         /* for wxStringImpl use only */                                       \
 263         pointer GetPtr() const { return m_ptr; }                              \
 264                                                                               \
 265         friend class wxStringImpl;                                            \
 266                                                                               \
 267         pointer m_ptr
 268
 269   // we need to declare const_iterator in wxStringImpl scope, the friend
 270   // declaration inside iterator class itself is not enough, or at least not
 271   // for g++ 3.4 (g++ 4 is ok)
 272   class WXDLLIMPEXP_FWD_BASE const_iterator;
 273
 274   class WXDLLIMPEXP_BASE iterator
 275   {
 276     WX_DEFINE_STRINGIMPL_ITERATOR(iterator,
 277                                   wxStringCharType&,
 278                                   wxStringCharType*);
 279
 280     friend class const_iterator;
 281   };
 282
 283   class WXDLLIMPEXP_BASE const_iterator
 284   {
 285   public:
 286       const_iterator(iterator i) : m_ptr(i.m_ptr) { }
 287
 288       WX_DEFINE_STRINGIMPL_ITERATOR(const_iterator,
 289                                     const wxStringCharType&,
 290                                     const wxStringCharType*);
 291   };
 292
 293   #undef WX_DEFINE_STRINGIMPL_ITERATOR
 294
 295
 296   // constructors and destructor
 297     // ctor for an empty string
 298   wxStringImpl() { Init(); }
 299     // copy ctor
 300   wxStringImpl(const wxStringImpl& stringSrc)
 301   {
 302     wxASSERT_MSG( stringSrc.GetStringData()->IsValid(),
 303                   _T("did you forget to call UngetWriteBuf()?") );
 304
 305     if ( stringSrc.empty() ) {
 306       // nothing to do for an empty string
 307       Init();
 308     }
 309     else {
 310       m_pchData = stringSrc.m_pchData;            // share same data
 311       GetStringData()->Lock();                    // => one more copy
 312     }
 313   }
 314     // string containing nRepeat copies of ch
 315   wxStringImpl(size_type nRepeat, wxStringCharType ch);
 316     // ctor takes first nLength characters from C string
 317     // (default value of npos means take all the string)
 318   wxStringImpl(const wxStringCharType *psz)
 319       { InitWith(psz, 0, npos); }
 320   wxStringImpl(const wxStringCharType *psz, size_t nLength)
 321       { InitWith(psz, 0, nLength); }
 322     // take nLen chars starting at nPos
 323   wxStringImpl(const wxStringImpl& str, size_t nPos, size_t nLen)
 324   {
 325     wxASSERT_MSG( str.GetStringData()->IsValid(),
 326                   _T("did you forget to call UngetWriteBuf()?") );
 327     Init();
 328     size_t strLen = str.length() - nPos; nLen = strLen < nLen ? strLen : nLen;
 329     InitWith(str.c_str(), nPos, nLen);
 330   }
 331     // take everything between start and end
 332   wxStringImpl(const_iterator start, const_iterator end);
 333
 334
 335     // ctor from and conversion to std::string
 336 #if wxUSE_STD_STRING
 337   wxStringImpl(const wxStdString& impl)
 338       { InitWith(impl.c_str(), 0, impl.length()); }
 339
 340   operator wxStdString() const
 341       { return wxStdString(c_str(), length()); }
 342 #endif
 343
 344 #if defined(__VISUALC__) && (__VISUALC__ >= 1200)
 345     // disable warning about Unlock() below not being inlined (first, it
 346     // seems to be inlined nevertheless and second, even if it isn't, there
 347     // is nothing we can do about this
 348     #pragma warning(push)
 349     #pragma warning (disable:4714)
 350 #endif
 351
 352     // dtor is not virtual, this class must not be inherited from!
 353   ~wxStringImpl()
 354   {
 355       GetStringData()->Unlock();
 356   }
 357
 358 #if defined(__VISUALC__) && (__VISUALC__ >= 1200)
 359     #pragma warning(pop)
 360 #endif
 361
 362   // overloaded assignment
 363     // from another wxString
 364   wxStringImpl& operator=(const wxStringImpl& stringSrc);
 365     // from a character
 366   wxStringImpl& operator=(wxStringCharType ch);
 367     // from a C string
 368   wxStringImpl& operator=(const wxStringCharType *psz);
 369
 370     // return the length of the string
 371   size_type length() const { return GetStringData()->nDataLength; }
 372     // return the length of the string
 373   size_type size() const { return length(); }
 374     // return the maximum size of the string
 375   size_type max_size() const { return npos; }
 376     // resize the string, filling the space with c if c != 0
 377   void resize(size_t nSize, wxStringCharType ch = '\0');
 378     // delete the contents of the string
 379   void clear() { erase(0, npos); }
 380     // returns true if the string is empty
 381   bool empty() const { return length() == 0; }
 382     // inform string about planned change in size
 383   void reserve(size_t sz) { Alloc(sz); }
 384   size_type capacity() const { return GetStringData()->nAllocLength; }
 385
 386   // lib.string.access
 387     // return the character at position n
 388   value_type operator[](size_type n) const { return m_pchData[n]; }
 389   value_type at(size_type n) const
 390     { wxASSERT_VALID_INDEX( n ); return m_pchData[n]; }
 391     // returns the writable character at position n
 392   reference operator[](size_type n) { CopyBeforeWrite(); return m_pchData[n]; }
 393   reference at(size_type n)
 394   {
 395     wxASSERT_VALID_INDEX( n );
 396     CopyBeforeWrite();
 397     return m_pchData[n];
 398   } // FIXME-UTF8: not useful for us...?
 399
 400   // lib.string.modifiers
 401     // append elements str[pos], ..., str[pos+n]
 402   wxStringImpl& append(const wxStringImpl& str, size_t pos, size_t n)
 403   {
 404     wxASSERT(pos <= str.length());
 405     ConcatSelf(n, str.c_str() + pos, str.length() - pos);
 406     return *this;
 407   }
 408     // append a string
 409   wxStringImpl& append(const wxStringImpl& str)
 410     { ConcatSelf(str.length(), str.c_str()); return *this; }
 411     // append first n (or all if n == npos) characters of sz
 412   wxStringImpl& append(const wxStringCharType *sz)
 413     { ConcatSelf(wxStrlen(sz), sz); return *this; }
 414   wxStringImpl& append(const wxStringCharType *sz, size_t n)
 415     { ConcatSelf(n, sz); return *this; }
 416     // append n copies of ch
 417   wxStringImpl& append(size_t n, wxStringCharType ch);
 418     // append from first to last
 419   wxStringImpl& append(const_iterator first, const_iterator last)
 420     { ConcatSelf(last - first, first.GetPtr()); return *this; }
 421
 422     // same as `this_string = str'
 423   wxStringImpl& assign(const wxStringImpl& str)
 424     { return *this = str; }
 425     // same as ` = str[pos..pos + n]
 426   wxStringImpl& assign(const wxStringImpl& str, size_t pos, size_t n)
 427     { return replace(0, npos, str, pos, n); }
 428     // same as `= first n (or all if n == npos) characters of sz'
 429   wxStringImpl& assign(const wxStringCharType *sz)
 430     { return replace(0, npos, sz, wxStrlen(sz)); }
 431   wxStringImpl& assign(const wxStringCharType *sz, size_t n)
 432     { return replace(0, npos, sz, n); }
 433     // same as `= n copies of ch'
 434   wxStringImpl& assign(size_t n, wxStringCharType ch)
 435     { return replace(0, npos, n, ch); }
 436     // assign from first to last
 437   wxStringImpl& assign(const_iterator first, const_iterator last)
 438     { return replace(begin(), end(), first, last); }
 439
 440     // first valid index position
 441   const_iterator begin() const { return m_pchData; }
 442   iterator begin();
 443     // position one after the last valid one
 444   const_iterator end() const { return m_pchData + length(); }
 445   iterator end();
 446
 447     // insert another string
 448   wxStringImpl& insert(size_t nPos, const wxStringImpl& str)
 449   {
 450     wxASSERT( str.GetStringData()->IsValid() );
 451     return insert(nPos, str.c_str(), str.length());
 452   }
 453     // insert n chars of str starting at nStart (in str)
 454   wxStringImpl& insert(size_t nPos, const wxStringImpl& str, size_t nStart, size_t n)
 455   {
 456     wxASSERT( str.GetStringData()->IsValid() );
 457     wxASSERT( nStart < str.length() );
 458     size_t strLen = str.length() - nStart;
 459     n = strLen < n ? strLen : n;
 460     return insert(nPos, str.c_str() + nStart, n);
 461   }
 462     // insert first n (or all if n == npos) characters of sz
 463   wxStringImpl& insert(size_t nPos, const wxStringCharType *sz, size_t n = npos);
 464     // insert n copies of ch
 465   wxStringImpl& insert(size_t nPos, size_t n, wxStringCharType ch)
 466     { return insert(nPos, wxStringImpl(n, ch)); }
 467   iterator insert(iterator it, wxStringCharType ch)
 468     { size_t idx = it - begin(); insert(idx, 1, ch); return begin() + idx; }
 469   void insert(iterator it, const_iterator first, const_iterator last)
 470     { insert(it - begin(), first.GetPtr(), last - first); }
 471   void insert(iterator it, size_type n, wxStringCharType ch)
 472     { insert(it - begin(), n, ch); }
 473
 474     // delete characters from nStart to nStart + nLen
 475   wxStringImpl& erase(size_type pos = 0, size_type n = npos);
 476   iterator erase(iterator first, iterator last)
 477   {
 478     size_t idx = first - begin();
 479     erase(idx, last - first);
 480     return begin() + idx;
 481   }
 482   iterator erase(iterator first);
 483
 484   // explicit conversion to C string (use this with printf()!)
 485   const wxStringCharType* c_str() const { return m_pchData; }
 486   const wxStringCharType* data() const { return m_pchData; }
 487
 488     // replaces the substring of length nLen starting at nStart
 489   wxStringImpl& replace(size_t nStart, size_t nLen, const wxStringCharType* sz)
 490     { return replace(nStart, nLen, sz, npos); }
 491     // replaces the substring of length nLen starting at nStart
 492   wxStringImpl& replace(size_t nStart, size_t nLen, const wxStringImpl& str)
 493     { return replace(nStart, nLen, str.c_str(), str.length()); }
 494     // replaces the substring with nCount copies of ch
 495   wxStringImpl& replace(size_t nStart, size_t nLen,
 496                         size_t nCount, wxStringCharType ch)
 497     { return replace(nStart, nLen, wxStringImpl(nCount, ch)); }
 498     // replaces a substring with another substring
 499   wxStringImpl& replace(size_t nStart, size_t nLen,
 500                         const wxStringImpl& str, size_t nStart2, size_t nLen2)
 501     { return replace(nStart, nLen, str.substr(nStart2, nLen2)); }
 502     // replaces the substring with first nCount chars of sz
 503   wxStringImpl& replace(size_t nStart, size_t nLen,
 504                         const wxStringCharType* sz, size_t nCount);
 505
 506   wxStringImpl& replace(iterator first, iterator last, const_pointer s)
 507     { return replace(first - begin(), last - first, s); }
 508   wxStringImpl& replace(iterator first, iterator last, const_pointer s,
 509                         size_type n)
 510     { return replace(first - begin(), last - first, s, n); }
 511   wxStringImpl& replace(iterator first, iterator last, const wxStringImpl& s)
 512     { return replace(first - begin(), last - first, s); }
 513   wxStringImpl& replace(iterator first, iterator last, size_type n, wxStringCharType c)
 514     { return replace(first - begin(), last - first, n, c); }
 515   wxStringImpl& replace(iterator first, iterator last,
 516                         const_iterator first1, const_iterator last1)
 517     { return replace(first - begin(), last - first, first1.GetPtr(), last1 - first1); }
 518
 519     // swap two strings
 520   void swap(wxStringImpl& str);
 521
 522     // All find() functions take the nStart argument which specifies the
 523     // position to start the search on, the default value is 0. All functions
 524     // return npos if there were no match.
 525
 526     // find a substring
 527   size_t find(const wxStringImpl& str, size_t nStart = 0) const;
 528
 529     // find first n characters of sz
 530   size_t find(const wxStringCharType* sz, size_t nStart = 0, size_t n = npos) const;
 531
 532     // find the first occurrence of character ch after nStart
 533   size_t find(wxStringCharType ch, size_t nStart = 0) const;
 534
 535     // rfind() family is exactly like find() but works right to left
 536
 537     // as find, but from the end
 538   size_t rfind(const wxStringImpl& str, size_t nStart = npos) const;
 539
 540     // as find, but from the end
 541   size_t rfind(const wxStringCharType* sz, size_t nStart = npos,
 542                size_t n = npos) const;
 543     // as find, but from the end
 544   size_t rfind(wxStringCharType ch, size_t nStart = npos) const;
 545
 546   size_type copy(wxStringCharType* s, size_type n, size_type pos = 0);
 547
 548   // substring extraction
 549   wxStringImpl substr(size_t nStart = 0, size_t nLen = npos) const;
 550
 551       // string += string
 552   wxStringImpl& operator+=(const wxStringImpl& s) { return append(s); }
 553       // string += C string
 554   wxStringImpl& operator+=(const wxStringCharType *psz) { return append(psz); }
 555       // string += char
 556   wxStringImpl& operator+=(wxStringCharType ch) { return append(1, ch); }
 557
 558   // helpers for wxStringBuffer and wxStringBufferLength
 559   wxStringCharType *DoGetWriteBuf(size_t nLen);
 560   void DoUngetWriteBuf();
 561   void DoUngetWriteBuf(size_t nLen);
 562
 563   friend class WXDLLIMPEXP_FWD_BASE wxString;
 564 };
 565
 566 #endif // !wxUSE_STL_BASED_WXSTRING
 567
 568 // don't pollute the library user's name space
 569 #undef wxASSERT_VALID_INDEX
 570
 571 #endif  // _WX_WXSTRINGIMPL_H__