Fixed typo.

[wxWidgets.git] / include / wx / string.h

diff --git a/include/wx/string.h b/include/wx/string.h
index b72a312f45576726cbbeac7e8c1c24b99a3a3a27..f51d3f066023a02d3a89c4672f47d5d03e520559 100644 (file)
--- a/include/wx/string.h
+++ b/include/wx/string.h
@@ -57,6 +57,38 @@
 #include "wx/stringops.h"
 #include "wx/unichar.h"
 
 #include "wx/stringops.h"
 #include "wx/unichar.h"
 

+// by default we cache the mapping of the positions in UTF-8 string to the byte
+// offset as this results in noticeable performance improvements for loops over
+// strings using indices; comment out this line to disable this
+//
+// notice that this optimization is well worth using even in debug builds as it
+// changes asymptotic complexity of algorithms using indices to iterate over
+// wxString back to expected linear from quadratic
+//
+// also notice that wxTLS_TYPE() (__declspec(thread) in this case) is unsafe to
+// use in DLL build under pre-Vista Windows so we disable this code for now, if
+// anybody really needs to use UTF-8 build under Windows with this optimization
+// it would have to be re-tested and probably corrected
+// CS: under OSX release builds the string destructor/cache cleanup sometimes
+// crashes, disable until we find the true reason or a better workaround
+#if wxUSE_UNICODE_UTF8 && !defined(__WXMSW__) && !defined(__WXOSX__)
+    #define wxUSE_STRING_POS_CACHE 1
+#else
+    #define wxUSE_STRING_POS_CACHE 0
+#endif
+
+#if wxUSE_STRING_POS_CACHE
+    #include "wx/tls.h"
+
+    // change this 0 to 1 to enable additional (very expensive) asserts
+    // verifying that string caching logic works as expected
+    #if 0
+        #define wxSTRING_CACHE_ASSERT(cond) wxASSERT(cond)
+    #else
+        #define wxSTRING_CACHE_ASSERT(cond)
+    #endif
+#endif // wxUSE_STRING_POS_CACHE
+

 class WXDLLIMPEXP_FWD_BASE wxString;
 
 // unless this symbol is predefined to disable the compatibility functions, do
 class WXDLLIMPEXP_FWD_BASE wxString;
 
 // unless this symbol is predefined to disable the compatibility functions, do


@@ -177,7 +209,7 @@ inline int Stricmp(const char *psz1, const char *psz2)
 
 // Lightweight object returned by wxString::c_str() and implicitly convertible
 // to either const char* or const wchar_t*.
 
 // Lightweight object returned by wxString::c_str() and implicitly convertible
 // to either const char* or const wchar_t*.

-class WXDLLIMPEXP_BASE wxCStrData
+class wxCStrData

 {
 private:
     // Ctors; for internal use by wxString and wxCStrData only
 {
 private:
     // Ctors; for internal use by wxString and wxCStrData only


@@ -193,19 +225,19 @@ public:
 
     inline ~wxCStrData();
 
 
     inline ~wxCStrData();
 

-    // methods defined inline below must be declared inline or mingw32 3.4.5
-    // warns about "<symbol> defined locally after being referenced with
-    // dllimport linkage"
-#if wxUSE_UNICODE_WCHAR
-    inline
-#endif
-    const wchar_t* AsWChar() const;
+    // AsWChar() and AsChar() can't be defined here as they use wxString and so
+    // must come after it and because of this won't be inlined when called from
+    // wxString methods (without a lot of work to extract these wxString methods
+    // from inside the class itself). But we still define them being inline
+    // below to let compiler inline them from elsewhere. And because of this we
+    // must declare them as inline here because otherwise some compilers give
+    // warnings about them, e.g. mingw32 3.4.5 warns about "<symbol> defined
+    // locally after being referenced with dllimport linkage" while IRIX
+    // mipsPro 7.4 warns about "function declared inline after being called".
+    inline const wchar_t* AsWChar() const;

     operator const wchar_t*() const { return AsWChar(); }
 
     operator const wchar_t*() const { return AsWChar(); }
 

-#if !wxUSE_UNICODE || wxUSE_UTF8_LOCALE_ONLY
-    inline
-#endif
-    const char* AsChar() const;
+    inline const char* AsChar() const;

     const unsigned char* AsUnsignedChar() const
         { return (const unsigned char *) AsChar(); }
     operator const char*() const { return AsChar(); }
     const unsigned char* AsUnsignedChar() const
         { return (const unsigned char *) AsChar(); }
     operator const char*() const { return AsChar(); }


@@ -213,8 +245,16 @@ public:
 
     operator const void*() const { return AsChar(); }
 
 
     operator const void*() const { return AsChar(); }
 

-    inline const wxCharBuffer AsCharBuf() const;
-    inline const wxWCharBuffer AsWCharBuf() const;
+    // returns buffers that are valid as long as the associated wxString exists
+    const wxScopedCharBuffer AsCharBuf() const
+    {
+        return wxScopedCharBuffer::CreateNonOwned(AsChar());
+    }
+
+    const wxScopedWCharBuffer AsWCharBuf() const
+    {
+        return wxScopedWCharBuffer::CreateNonOwned(AsWChar());
+    }

 
     inline wxString AsString() const;
 
 
     inline wxString AsString() const;
 


@@ -230,9 +270,11 @@ public:
     wxUniChar operator[](unsigned int n) const { return operator[](size_t(n)); }
 #endif // size_t != unsigned int
 
     wxUniChar operator[](unsigned int n) const { return operator[](size_t(n)); }
 #endif // size_t != unsigned int
 

-    // these operators are needed to emulate the pointer semantics of c_str():
+    // These operators are needed to emulate the pointer semantics of c_str():

     // expressions like "wxChar *p = str.c_str() + 1;" should continue to work
     // expressions like "wxChar *p = str.c_str() + 1;" should continue to work

-    // (we need both versions to resolve ambiguities):
+    // (we need both versions to resolve ambiguities). Note that this means
+    // the 'n' value is interpreted as addition to char*/wchar_t* pointer, it
+    // is *not* number of Unicode characters in wxString.

     wxCStrData operator+(int n) const
         { return wxCStrData(m_str, m_offset + n, m_owned); }
     wxCStrData operator+(long n) const
     wxCStrData operator+(int n) const
         { return wxCStrData(m_str, m_offset + n, m_owned); }
     wxCStrData operator+(long n) const


@@ -246,7 +288,7 @@ public:
     wxCStrData operator-(ptrdiff_t n) const
     {
         wxASSERT_MSG( n <= (ptrdiff_t)m_offset,
     wxCStrData operator-(ptrdiff_t n) const
     {
         wxASSERT_MSG( n <= (ptrdiff_t)m_offset,

-                      _T("attempt to construct address before the beginning of the string") );
+                      wxT("attempt to construct address before the beginning of the string") );

         return wxCStrData(m_str, m_offset - n, m_owned);
     }
 
         return wxCStrData(m_str, m_offset - n, m_owned);
     }
 


@@ -255,8 +297,16 @@ public:
     inline wxUniChar operator*() const;
 
 private:
     inline wxUniChar operator*() const;
 
 private:

+    // the wxString this object was returned for

     const wxString *m_str;
     const wxString *m_str;

+    // Offset into c_str() return value. Note that this is *not* offset in
+    // m_str in Unicode characters. Instead, it is index into the
+    // char*/wchar_t* buffer returned by c_str(). It's interpretation depends
+    // on how is the wxCStrData instance used: if it is eventually cast to
+    // const char*, m_offset will be in bytes form string's start; if it is
+    // cast to const wchar_t*, it will be in wchar_t values.

     size_t m_offset;
     size_t m_offset;

+    // should m_str be deleted, i.e. is it owned by us?

     bool m_owned;
 
     friend class WXDLLIMPEXP_FWD_BASE wxString;
     bool m_owned;
 
     friend class WXDLLIMPEXP_FWD_BASE wxString;


@@ -318,7 +368,7 @@ public:
     // these are duplicated wxString methods, they're also declared below
     // if !wxNEEDS_WXSTRING_PRINTF_MIXIN:
 
     // these are duplicated wxString methods, they're also declared below
     // if !wxNEEDS_WXSTRING_PRINTF_MIXIN:
 

-    // static wxString Format(const wString& format, ...) ATTRIBUTE_PRINTF_1;
+    // static wxString Format(const wString& format, ...) WX_ATTRIBUTE_PRINTF_1;

     WX_DEFINE_VARARG_FUNC_SANS_N0(static typename StringReturnType<T1>::type,
                                   Format, 1, (const wxFormatString&),
                                   DoFormatWchar, DoFormatUtf8)
     WX_DEFINE_VARARG_FUNC_SANS_N0(static typename StringReturnType<T1>::type,
                                   Format, 1, (const wxFormatString&),
                                   DoFormatWchar, DoFormatUtf8)


@@ -340,7 +390,7 @@ public:
     // int Printf(const wxString& format, ...);
     WX_DEFINE_VARARG_FUNC(int, Printf, 1, (const wxFormatString&),
                           DoPrintfWchar, DoPrintfUtf8)
     // int Printf(const wxString& format, ...);
     WX_DEFINE_VARARG_FUNC(int, Printf, 1, (const wxFormatString&),
                           DoPrintfWchar, DoPrintfUtf8)

-    // int sprintf(const wxString& format, ...) ATTRIBUTE_PRINTF_2;
+    // int sprintf(const wxString& format, ...) WX_ATTRIBUTE_PRINTF_2;

     WX_DEFINE_VARARG_FUNC(int, sprintf, 1, (const wxFormatString&),
                           DoPrintfWchar, DoPrintfUtf8)
 
     WX_DEFINE_VARARG_FUNC(int, sprintf, 1, (const wxFormatString&),
                           DoPrintfWchar, DoPrintfUtf8)
 


@@ -358,6 +408,7 @@ protected:
 #ifdef wxNEEDS_WXSTRING_PRINTF_MIXIN
     // "non dll-interface class 'wxStringPrintfMixin' used as base interface
     // for dll-interface class 'wxString'" -- this is OK in our case
 #ifdef wxNEEDS_WXSTRING_PRINTF_MIXIN
     // "non dll-interface class 'wxStringPrintfMixin' used as base interface
     // for dll-interface class 'wxString'" -- this is OK in our case

+    #pragma warning (push)

     #pragma warning (disable:4275)
 #endif
 
     #pragma warning (disable:4275)
 #endif
 


@@ -394,7 +445,7 @@ private:
 
     // the node belongs to a particular iterator instance, it's not copied
     // when a copy of the iterator is made
 
     // the node belongs to a particular iterator instance, it's not copied
     // when a copy of the iterator is made

-    DECLARE_NO_COPY_CLASS(wxStringIteratorNode)
+    wxDECLARE_NO_COPY_CLASS(wxStringIteratorNode);

 };
 #endif // wxUSE_UNICODE_UTF8
 
 };
 #endif // wxUSE_UNICODE_UTF8
 


@@ -444,14 +495,14 @@ private:
 
 #if wxUSE_UNICODE_UTF8
   // even char* -> char* needs conversion, from locale charset to UTF-8
 
 #if wxUSE_UNICODE_UTF8
   // even char* -> char* needs conversion, from locale charset to UTF-8

-  typedef SubstrBufFromType<wxCharBuffer>    SubstrBufFromWC;
-  typedef SubstrBufFromType<wxCharBuffer>    SubstrBufFromMB;
+  typedef SubstrBufFromType<wxScopedCharBuffer>    SubstrBufFromWC;
+  typedef SubstrBufFromType<wxScopedCharBuffer>    SubstrBufFromMB;

 #elif wxUSE_UNICODE_WCHAR
 #elif wxUSE_UNICODE_WCHAR

-  typedef SubstrBufFromType<const wchar_t*>  SubstrBufFromWC;
-  typedef SubstrBufFromType<wxWCharBuffer>   SubstrBufFromMB;
+  typedef SubstrBufFromType<const wchar_t*>        SubstrBufFromWC;
+  typedef SubstrBufFromType<wxScopedWCharBuffer>   SubstrBufFromMB;

 #else
 #else

-  typedef SubstrBufFromType<const char*>     SubstrBufFromMB;
-  typedef SubstrBufFromType<wxCharBuffer>    SubstrBufFromWC;
+  typedef SubstrBufFromType<const char*>           SubstrBufFromMB;
+  typedef SubstrBufFromType<wxScopedCharBuffer>    SubstrBufFromWC;

 #endif
 
 
 #endif
 
 


@@ -480,8 +531,8 @@ private:
     { return str ? str : wxT(""); }
   static const SubstrBufFromWC ImplStr(const wchar_t* str, size_t n)
     { return SubstrBufFromWC(str, (str && n == npos) ? wxWcslen(str) : n); }
     { return str ? str : wxT(""); }
   static const SubstrBufFromWC ImplStr(const wchar_t* str, size_t n)
     { return SubstrBufFromWC(str, (str && n == npos) ? wxWcslen(str) : n); }

-  static wxWCharBuffer ImplStr(const char* str,
-                               const wxMBConv& conv = wxConvLibc)
+  static wxScopedWCharBuffer ImplStr(const char* str,
+                                     const wxMBConv& conv = wxConvLibc)

     { return ConvertStr(str, npos, conv).data; }
   static SubstrBufFromMB ImplStr(const char* str, size_t n,
                                  const wxMBConv& conv = wxConvLibc)
     { return ConvertStr(str, npos, conv).data; }
   static SubstrBufFromMB ImplStr(const char* str, size_t n,
                                  const wxMBConv& conv = wxConvLibc)


@@ -493,7 +544,7 @@ private:
   static const SubstrBufFromMB ImplStr(const char* str, size_t n,
                                        const wxMBConv& WXUNUSED(conv) = wxConvLibc)
     { return SubstrBufFromMB(str, (str && n == npos) ? wxStrlen(str) : n); }
   static const SubstrBufFromMB ImplStr(const char* str, size_t n,
                                        const wxMBConv& WXUNUSED(conv) = wxConvLibc)
     { return SubstrBufFromMB(str, (str && n == npos) ? wxStrlen(str) : n); }

-  static wxCharBuffer ImplStr(const wchar_t* str)
+  static wxScopedCharBuffer ImplStr(const wchar_t* str)

     { return ConvertStr(str, npos, wxConvLibc).data; }
   static SubstrBufFromWC ImplStr(const wchar_t* str, size_t n)
     { return ConvertStr(str, n, wxConvLibc); }
     { return ConvertStr(str, npos, wxConvLibc).data; }
   static SubstrBufFromWC ImplStr(const wchar_t* str, size_t n)
     { return ConvertStr(str, n, wxConvLibc); }


@@ -508,81 +559,296 @@ private:
   static size_t LenToImpl(size_t len) { return len; }
   static size_t PosFromImpl(size_t pos) { return pos; }
 
   static size_t LenToImpl(size_t len) { return len; }
   static size_t PosFromImpl(size_t pos) { return pos; }
 

-  // we don't want to define this as an empty inline function as it could
+  // we don't want to define these as empty inline functions as it could

   // result in noticeable (and quite unnecessary in non-UTF-8 build) slowdown
   // in debug build where the inline functions are not effectively inlined
   // result in noticeable (and quite unnecessary in non-UTF-8 build) slowdown
   // in debug build where the inline functions are not effectively inlined

-  #define wxSTRING_INVALIDATE_INDEX_CACHE()
+  #define wxSTRING_INVALIDATE_CACHE()
+  #define wxSTRING_INVALIDATE_CACHED_LENGTH()
+  #define wxSTRING_UPDATE_CACHED_LENGTH(n)
+  #define wxSTRING_SET_CACHED_LENGTH(n)

 
 #else // wxUSE_UNICODE_UTF8
 
 
 #else // wxUSE_UNICODE_UTF8
 

-  static wxCharBuffer ImplStr(const char* str,
-                              const wxMBConv& conv = wxConvLibc)
+  static wxScopedCharBuffer ImplStr(const char* str,
+                                    const wxMBConv& conv = wxConvLibc)

     { return ConvertStr(str, npos, conv).data; }
   static SubstrBufFromMB ImplStr(const char* str, size_t n,
                                  const wxMBConv& conv = wxConvLibc)
     { return ConvertStr(str, n, conv); }
 
     { return ConvertStr(str, npos, conv).data; }
   static SubstrBufFromMB ImplStr(const char* str, size_t n,
                                  const wxMBConv& conv = wxConvLibc)
     { return ConvertStr(str, n, conv); }
 

-  static wxCharBuffer ImplStr(const wchar_t* str)
+  static wxScopedCharBuffer ImplStr(const wchar_t* str)

     { return ConvertStr(str, npos, wxMBConvUTF8()).data; }
   static SubstrBufFromWC ImplStr(const wchar_t* str, size_t n)
     { return ConvertStr(str, n, wxMBConvUTF8()); }
 
     { return ConvertStr(str, npos, wxMBConvUTF8()).data; }
   static SubstrBufFromWC ImplStr(const wchar_t* str, size_t n)
     { return ConvertStr(str, n, wxMBConvUTF8()); }
 

-  // this is an extremely simple cache used by PosToImpl()
-  struct PosToImplCache
+#if wxUSE_STRING_POS_CACHE
+  // this is an extremely simple cache used by PosToImpl(): each cache element
+  // contains the string it applies to and the index corresponding to the last
+  // used position in this wxString in its m_impl string
+  //
+  // NB: notice that this struct (and nested Element one) must be a POD or we
+  //     wouldn't be able to use a thread-local variable of this type, in
+  //     particular it should have no ctor -- we rely on statics being
+  //     initialized to 0 instead
+  struct Cache

   {
   {

-      const wxString *str;
-      size_t pos,
-             impl;
+      enum { SIZE = 8 };
+
+      struct Element
+      {
+          const wxString *str;  // the string to which this element applies
+          size_t pos,           // the cached index in this string
+                 impl,          // the corresponding position in its m_impl
+                 len;           // cached length or npos if unknown
+
+          // reset cached index to 0
+          void ResetPos() { pos = impl = 0; }
+
+          // reset position and length
+          void Reset() { ResetPos(); len = npos; }
+      };
+
+      // cache the indices mapping for the last few string used
+      Element cached[SIZE];
+
+      // the last used index
+      unsigned lastUsed;

   };
 
   };
 

-  static PosToImplCache ms_cache;
+#ifndef wxHAS_COMPILER_TLS
+  // we must use an accessor function and not a static variable when the TLS
+  // variables support is implemented in the library (and not by the compiler)
+  // because the global s_cache variable could be not yet initialized when a
+  // ctor of another global object is executed and if that ctor uses any
+  // wxString methods, bad things happen
+  //
+  // however notice that this approach does not work when compiler TLS is used,
+  // at least not with g++ 4.1.2 under amd64 as it apparently compiles code
+  // using this accessor incorrectly when optimizations are enabled (-O2 is
+  // enough) -- luckily we don't need it then neither as static __thread
+  // variables are initialized by 0 anyhow then and so we can use the variable
+  // directly
+  WXEXPORT static Cache& GetCache()
+  {
+      static wxTLS_TYPE(Cache) s_cache;

 
 

-  size_t PosToImpl(size_t pos) const
+      return wxTLS_VALUE(s_cache);
+  }
+
+  // this helper struct is used to ensure that GetCache() is called during
+  // static initialization time, i.e. before any threads creation, as otherwise
+  // the static s_cache construction inside GetCache() wouldn't be MT-safe
+  friend struct wxStrCacheInitializer;
+#else // wxHAS_COMPILER_TLS
+  static wxTLS_TYPE(Cache) ms_cache;
+  static Cache& GetCache() { return wxTLS_VALUE(ms_cache); }
+#endif // !wxHAS_COMPILER_TLS/wxHAS_COMPILER_TLS
+
+  static Cache::Element *GetCacheBegin() { return GetCache().cached; }
+  static Cache::Element *GetCacheEnd() { return GetCacheBegin() + Cache::SIZE; }
+  static unsigned& LastUsedCacheElement() { return GetCache().lastUsed; }
+
+  // this is used in debug builds only to provide a convenient function,
+  // callable from a debugger, to show the cache contents
+  friend struct wxStrCacheDumper;
+
+  // uncomment this to have access to some profiling statistics on program
+  // termination
+  //#define wxPROFILE_STRING_CACHE
+
+#ifdef wxPROFILE_STRING_CACHE
+  static struct PosToImplCacheStats

   {
   {

-      if ( pos == 0 || pos == npos )
-          return pos;
+      unsigned postot,  // total non-trivial calls to PosToImpl
+               poshits, // cache hits from PosToImpl()
+               mishits, // cached position beyond the needed one
+               sumpos,  // sum of all positions, used to compute the
+                        // average position after dividing by postot
+               sumofs,  // sum of all offsets after using the cache, used to
+                        // compute the average after dividing by hits
+               lentot,  // number of total calls to length()
+               lenhits; // number of cache hits in length()
+  } ms_cacheStats;
+
+  friend struct wxStrCacheStatsDumper;
+
+  #define wxCACHE_PROFILE_FIELD_INC(field) ms_cacheStats.field++
+  #define wxCACHE_PROFILE_FIELD_ADD(field, val) ms_cacheStats.field += (val)
+#else // !wxPROFILE_STRING_CACHE
+  #define wxCACHE_PROFILE_FIELD_INC(field)
+  #define wxCACHE_PROFILE_FIELD_ADD(field, val)
+#endif // wxPROFILE_STRING_CACHE/!wxPROFILE_STRING_CACHE
+
+  // note: it could seem that the functions below shouldn't be inline because
+  // they are big, contain loops and so the compiler shouldn't be able to
+  // inline them anyhow, however moving them into string.cpp does decrease the
+  // code performance by ~5%, at least when using g++ 4.1 so do keep them here
+  // unless tests show that it's not advantageous any more
+
+  // return the pointer to the cache element for this string or NULL if not
+  // cached
+  Cache::Element *FindCacheElement() const
+  {
+      // profiling seems to show a small but consistent gain if we use this
+      // simple loop instead of starting from the last used element (there are
+      // a lot of misses in this function...)
+      Cache::Element * const cacheBegin = GetCacheBegin();
+#ifndef wxHAS_COMPILER_TLS
+      // during destruction tls calls may return NULL, in this case return NULL
+      // immediately without accessing anything else
+      if ( cacheBegin == NULL )
+        return NULL;
+#endif
+      Cache::Element * const cacheEnd = GetCacheEnd();
+      for ( Cache::Element *c = cacheBegin; c != cacheEnd; c++ )
+      {
+          if ( c->str == this )
+              return c;
+      }

 
 

-      PosToImplCache& cache = ms_cache;
-      if ( this == cache.str )
+      return NULL;
+  }
+
+  // unlike FindCacheElement(), this one always returns a valid pointer to the
+  // cache element for this string, it may have valid last cached position and
+  // its corresponding index in the byte string or not
+  Cache::Element *GetCacheElement() const
+  {
+      Cache::Element * const cacheBegin = GetCacheBegin();
+      Cache::Element * const cacheEnd = GetCacheEnd();
+      Cache::Element * const cacheStart = cacheBegin + LastUsedCacheElement();
+
+      // check the last used first, this does no (measurable) harm for a miss
+      // but does help for simple loops addressing the same string all the time
+      if ( cacheStart->str == this )
+          return cacheStart;
+
+      // notice that we're going to check cacheStart again inside this call but
+      // profiling shows that it's still faster to use a simple loop like
+      // inside FindCacheElement() than manually looping with wrapping starting
+      // from the cache entry after the start one
+      Cache::Element *c = FindCacheElement();
+      if ( !c )

       {
       {

-          if ( pos == cache.pos )
-              return cache.impl;
+          // claim the next cache entry for this string
+          c = cacheStart;
+          if ( ++c == cacheEnd )
+              c = cacheBegin;

 
 

-          // TODO: is it worth complicating this function even further by going
-          //       backwards from the last position? it might be if we're just
-          //       before it...
-          if ( cache.pos > pos )
-          {
-              cache.pos =
-              cache.impl = 0;
-          }
+          c->str = this;
+          c->Reset();
+
+          // and remember the last used element
+          LastUsedCacheElement() = c - cacheBegin;

       }
       }

-      else // data for this string not cached
+
+      return c;
+  }
+
+  size_t DoPosToImpl(size_t pos) const
+  {
+      wxCACHE_PROFILE_FIELD_INC(postot);
+
+      // NB: although the case of pos == 1 (and offset from cached position
+      //     equal to 1) are common, nothing is gained by writing special code
+      //     for handling them, the compiler (at least g++ 4.1 used) seems to
+      //     optimize the code well enough on its own
+
+      wxCACHE_PROFILE_FIELD_ADD(sumpos, pos);
+
+      Cache::Element * const cache = GetCacheElement();
+
+      // cached position can't be 0 so if it is, it means that this entry was
+      // used for length caching only so far, i.e. it doesn't count as a hit
+      // from our point of view
+      if ( cache->pos )
+      {
+          wxCACHE_PROFILE_FIELD_INC(poshits);
+      }
+
+      if ( pos == cache->pos )
+          return cache->impl;
+
+      // this seems to happen only rarely so just reset the cache in this case
+      // instead of complicating code even further by seeking backwards in this
+      // case
+      if ( cache->pos > pos )

       {
       {

-          cache.str = this;
-          cache.pos =
-          cache.impl = 0;
+          wxCACHE_PROFILE_FIELD_INC(mishits);
+
+          cache->ResetPos();

       }
 
       }
 

-      wxStringImpl::const_iterator i(m_impl.begin() + cache.impl);
-      for ( size_t n = cache.pos; n < pos; n++ )
+      wxCACHE_PROFILE_FIELD_ADD(sumofs, pos - cache->pos);
+
+
+      wxStringImpl::const_iterator i(m_impl.begin() + cache->impl);
+      for ( size_t n = cache->pos; n < pos; n++ )

           wxStringOperations::IncIter(i);
 
           wxStringOperations::IncIter(i);
 

-      cache.pos = pos;
-      return cache.impl = i - m_impl.begin();
+      cache->pos = pos;
+      cache->impl = i - m_impl.begin();
+
+      wxSTRING_CACHE_ASSERT(
+          (int)cache->impl == (begin() + pos).impl() - m_impl.begin() );
+
+      return cache->impl;
+  }
+
+  void InvalidateCache()
+  {
+      Cache::Element * const cache = FindCacheElement();
+      if ( cache )
+          cache->Reset();
+  }
+
+  void InvalidateCachedLength()
+  {
+      Cache::Element * const cache = FindCacheElement();
+      if ( cache )
+          cache->len = npos;

   }
 
   }
 

-  void InvalidatePosToImplCache()
+  void SetCachedLength(size_t len)

   {
   {

-      PosToImplCache& cache = ms_cache;
-      if ( cache.str == this )
+      // we optimistically cache the length here even if the string wasn't
+      // present in the cache before, this seems to do no harm and the
+      // potential for avoiding length recomputation for long strings looks
+      // interesting
+      GetCacheElement()->len = len;
+  }
+
+  void UpdateCachedLength(ptrdiff_t delta)
+  {
+      Cache::Element * const cache = FindCacheElement();
+      if ( cache && cache->len != npos )

       {
       {

-          cache.pos =
-              cache.impl = 0;
+          wxSTRING_CACHE_ASSERT( (ptrdiff_t)cache->len + delta >= 0 );
+
+          cache->len += delta;

       }
   }
 
       }
   }
 

-  #define wxSTRING_INVALIDATE_INDEX_CACHE() InvalidatePosToImplCache()
+  #define wxSTRING_INVALIDATE_CACHE() InvalidateCache()
+  #define wxSTRING_INVALIDATE_CACHED_LENGTH() InvalidateCachedLength()
+  #define wxSTRING_UPDATE_CACHED_LENGTH(n) UpdateCachedLength(n)
+  #define wxSTRING_SET_CACHED_LENGTH(n) SetCachedLength(n)
+#else // !wxUSE_STRING_POS_CACHE
+  size_t DoPosToImpl(size_t pos) const
+  {
+      return (begin() + pos).impl() - m_impl.begin();
+  }
+
+  #define wxSTRING_INVALIDATE_CACHE()
+  #define wxSTRING_INVALIDATE_CACHED_LENGTH()
+  #define wxSTRING_UPDATE_CACHED_LENGTH(n)
+  #define wxSTRING_SET_CACHED_LENGTH(n)
+#endif // wxUSE_STRING_POS_CACHE/!wxUSE_STRING_POS_CACHE
+
+  size_t PosToImpl(size_t pos) const
+  {
+      return pos == 0 || pos == npos ? pos : DoPosToImpl(pos);
+  }

 
   void PosLenToImpl(size_t pos, size_t len, size_t *implPos, size_t *implLen) const;
 
 
   void PosLenToImpl(size_t pos, size_t len, size_t *implPos, size_t *implLen) const;
 


@@ -613,22 +879,26 @@ public:
   typedef size_t size_type;
   typedef wxUniChar const_reference;
 
   typedef size_t size_type;
   typedef wxUniChar const_reference;
 

-#if wxUSE_STL
+#if wxUSE_STD_STRING

   #if wxUSE_UNICODE_UTF8
     // random access is not O(1), as required by Random Access Iterator
     #define WX_STR_ITERATOR_TAG std::bidirectional_iterator_tag
   #else
     #define WX_STR_ITERATOR_TAG std::random_access_iterator_tag
   #endif
   #if wxUSE_UNICODE_UTF8
     // random access is not O(1), as required by Random Access Iterator
     #define WX_STR_ITERATOR_TAG std::bidirectional_iterator_tag
   #else
     #define WX_STR_ITERATOR_TAG std::random_access_iterator_tag
   #endif

+  #define WX_DEFINE_ITERATOR_CATEGORY(cat) typedef cat iterator_category;

 #else
 #else

-  #define WX_STR_ITERATOR_TAG void /* dummy type */
+  // not defining iterator_category at all in this case is better than defining
+  // it as some dummy type -- at least it results in more intelligible error
+  // messages
+  #define WX_DEFINE_ITERATOR_CATEGORY(cat)

 #endif
 
   #define WX_STR_ITERATOR_IMPL(iterator_name, pointer_type, reference_type) \
       private:                                                              \
           typedef wxStringImpl::iterator_name underlying_iterator;          \
       public:                                                               \
 #endif
 
   #define WX_STR_ITERATOR_IMPL(iterator_name, pointer_type, reference_type) \
       private:                                                              \
           typedef wxStringImpl::iterator_name underlying_iterator;          \
       public:                                                               \

-          typedef WX_STR_ITERATOR_TAG iterator_category;                    \
+          WX_DEFINE_ITERATOR_CATEGORY(WX_STR_ITERATOR_TAG)                  \

           typedef wxUniChar value_type;                                     \
           typedef int difference_type;                                      \
           typedef reference_type reference;                                 \
           typedef wxUniChar value_type;                                     \
           typedef int difference_type;                                      \
           typedef reference_type reference;                                 \


@@ -727,18 +997,28 @@ public:
       }
 
       reference operator*()
       }
 
       reference operator*()

-        { return wxUniCharRef::CreateForString(m_node, m_cur); }
+        { return wxUniCharRef::CreateForString(*str(), m_cur); }

 
       iterator operator+(ptrdiff_t n) const
         { return iterator(str(), wxStringOperations::AddToIter(m_cur, n)); }
       iterator operator-(ptrdiff_t n) const
         { return iterator(str(), wxStringOperations::AddToIter(m_cur, -n)); }
 
 
       iterator operator+(ptrdiff_t n) const
         { return iterator(str(), wxStringOperations::AddToIter(m_cur, n)); }
       iterator operator-(ptrdiff_t n) const
         { return iterator(str(), wxStringOperations::AddToIter(m_cur, -n)); }
 

+      // Normal iterators need to be comparable with the const_iterators so
+      // declare the comparison operators and implement them below after the
+      // full const_iterator declaration.
+      bool operator==(const const_iterator& i) const;
+      bool operator!=(const const_iterator& i) const;
+      bool operator<(const const_iterator& i) const;
+      bool operator>(const const_iterator& i) const;
+      bool operator<=(const const_iterator& i) const;
+      bool operator>=(const const_iterator& i) const;
+

   private:
   private:

-      iterator(wxString *str, underlying_iterator ptr)
-          : m_cur(ptr), m_node(str, &m_cur) {}
+      iterator(wxString *wxstr, underlying_iterator ptr)
+          : m_cur(ptr), m_node(wxstr, &m_cur) {}

 
 

-      wxString* str() const { return wx_const_cast(wxString*, m_node.m_str); }
+      wxString* str() const { return const_cast<wxString*>(m_node.m_str); }

 
       wxStringIteratorNode m_node;
 
 
       wxStringIteratorNode m_node;
 


@@ -778,10 +1058,15 @@ public:
       const_iterator operator-(ptrdiff_t n) const
         { return const_iterator(str(), wxStringOperations::AddToIter(m_cur, -n)); }
 
       const_iterator operator-(ptrdiff_t n) const
         { return const_iterator(str(), wxStringOperations::AddToIter(m_cur, -n)); }
 

+      // Notice that comparison operators taking non-const iterator are not
+      // needed here because of the implicit conversion from non-const iterator
+      // to const ones ensure that the versions for const_iterator declared
+      // inside WX_STR_ITERATOR_IMPL can be used.
+

   private:
       // for internal wxString use only:
   private:
       // for internal wxString use only:

-      const_iterator(const wxString *str, underlying_iterator ptr)
-          : m_cur(ptr), m_node(str, &m_cur) {}
+      const_iterator(const wxString *wxstr, underlying_iterator ptr)
+          : m_cur(ptr), m_node(wxstr, &m_cur) {}

 
       const wxString* str() const { return m_node.m_str; }
 
 
       const wxString* str() const { return m_node.m_str; }
 


@@ -791,9 +1076,9 @@ public:
   size_t IterToImplPos(wxString::iterator i) const
     { return wxStringImpl::const_iterator(i.impl()) - m_impl.begin(); }
 
   size_t IterToImplPos(wxString::iterator i) const
     { return wxStringImpl::const_iterator(i.impl()) - m_impl.begin(); }
 

-  iterator GetNthIter(size_t n)
+  iterator GetIterForNthChar(size_t n)

     { return iterator(this, m_impl.begin() + PosToImpl(n)); }
     { return iterator(this, m_impl.begin() + PosToImpl(n)); }

-  const_iterator GetNthIter(size_t n) const
+  const_iterator GetIterForNthChar(size_t n) const

     { return const_iterator(this, m_impl.begin() + PosToImpl(n)); }
 #else // !wxUSE_UNICODE_UTF8
 
     { return const_iterator(this, m_impl.begin() + PosToImpl(n)); }
 #else // !wxUSE_UNICODE_UTF8
 


@@ -813,6 +1098,15 @@ public:
       iterator operator-(ptrdiff_t n) const
         { return iterator(wxStringOperations::AddToIter(m_cur, -n)); }
 
       iterator operator-(ptrdiff_t n) const
         { return iterator(wxStringOperations::AddToIter(m_cur, -n)); }
 

+      // As in UTF-8 case above, define comparison operators taking
+      // const_iterator too.
+      bool operator==(const const_iterator& i) const;
+      bool operator!=(const const_iterator& i) const;
+      bool operator<(const const_iterator& i) const;
+      bool operator>(const const_iterator& i) const;
+      bool operator<=(const const_iterator& i) const;
+      bool operator>=(const const_iterator& i) const;
+

   private:
       // for internal wxString use only:
       iterator(underlying_iterator ptr) : m_cur(ptr) {}
   private:
       // for internal wxString use only:
       iterator(underlying_iterator ptr) : m_cur(ptr) {}


@@ -840,6 +1134,11 @@ public:
       const_iterator operator-(ptrdiff_t n) const
         { return const_iterator(wxStringOperations::AddToIter(m_cur, -n)); }
 
       const_iterator operator-(ptrdiff_t n) const
         { return const_iterator(wxStringOperations::AddToIter(m_cur, -n)); }
 

+      // As in UTF-8 case above, we don't need comparison operators taking
+      // iterator because we have an implicit conversion from iterator to
+      // const_iterator so the operators declared by WX_STR_ITERATOR_IMPL will
+      // be used.
+

   private:
       // for internal wxString use only:
       const_iterator(underlying_iterator ptr) : m_cur(ptr) {}
   private:
       // for internal wxString use only:
       const_iterator(underlying_iterator ptr) : m_cur(ptr) {}


@@ -847,8 +1146,8 @@ public:
           : m_cur(ptr) {}
   };
 
           : m_cur(ptr) {}
   };
 

-  iterator GetNthIter(size_t n) { return begin() + n; }
-  const_iterator GetNthIter(size_t n) const { return begin() + n; }
+  iterator GetIterForNthChar(size_t n) { return begin() + n; }
+  const_iterator GetIterForNthChar(size_t n) const { return begin() + n; }

 #endif // wxUSE_UNICODE_UTF8/!wxUSE_UNICODE_UTF8
 
   #undef WX_STR_ITERATOR_TAG
 #endif // wxUSE_UNICODE_UTF8/!wxUSE_UNICODE_UTF8
 
   #undef WX_STR_ITERATOR_TAG


@@ -863,7 +1162,7 @@ public:
   public:
       typedef T iterator_type;
 
   public:
       typedef T iterator_type;
 

-      typedef typename T::iterator_category iterator_category;
+      WX_DEFINE_ITERATOR_CATEGORY(typename T::iterator_category)

       typedef typename T::value_type value_type;
       typedef typename T::difference_type difference_type;
       typedef typename T::reference reference;
       typedef typename T::value_type value_type;
       typedef typename T::difference_type difference_type;
       typedef typename T::reference reference;


@@ -1014,10 +1313,10 @@ public:
   wxString(const wchar_t *pwz, const wxMBConv& WXUNUSED(conv), size_t nLength)
     { assign(pwz, nLength); }
 
   wxString(const wchar_t *pwz, const wxMBConv& WXUNUSED(conv), size_t nLength)
     { assign(pwz, nLength); }
 

-  wxString(const wxCharBuffer& buf)
-    { assign(buf.data()); } // FIXME-UTF8: fix for embedded NUL and buffer length
-  wxString(const wxWCharBuffer& buf)
-    { assign(buf.data()); } // FIXME-UTF8: fix for embedded NUL and buffer length
+  wxString(const wxScopedCharBuffer& buf)
+    { assign(buf.data(), buf.length()); }
+  wxString(const wxScopedWCharBuffer& buf)
+    { assign(buf.data(), buf.length()); }

 
     // NB: this version uses m_impl.c_str() to force making a copy of the
     //     string, so that "wxString(str.c_str())" idiom for passing strings
 
     // NB: this version uses m_impl.c_str() to force making a copy of the
     //     string, so that "wxString(str.c_str())" idiom for passing strings


@@ -1035,6 +1334,17 @@ public:
   wxString(const wxString& str, size_t nLength)
     { assign(str, nLength); }
 
   wxString(const wxString& str, size_t nLength)
     { assign(str, nLength); }
 

+
+#if wxUSE_STRING_POS_CACHE
+  ~wxString()
+  {
+      // we need to invalidate our cache entry as another string could be
+      // recreated at the same address (unlikely, but still possible, with the
+      // heap-allocated strings but perfectly common with stack-allocated ones)
+      InvalidateCache();
+  }
+#endif // wxUSE_STRING_POS_CACHE
+

   // even if we're not built with wxUSE_STL == 1 it is very convenient to allow
   // implicit conversions from std::string to wxString and vice verse as this
   // allows to use the same strings in non-GUI and GUI code, however we don't
   // even if we're not built with wxUSE_STL == 1 it is very convenient to allow
   // implicit conversions from std::string to wxString and vice verse as this
   // allows to use the same strings in non-GUI and GUI code, however we don't


@@ -1060,29 +1370,57 @@ public:
 
   // Unlike ctor from std::string, we provide conversion to std::string only
   // if wxUSE_STL and not merely wxUSE_STD_STRING (which is on by default),
 
   // Unlike ctor from std::string, we provide conversion to std::string only
   // if wxUSE_STL and not merely wxUSE_STD_STRING (which is on by default),

-  // because it conflicts with operator const char/wchar_t*:
-#if wxUSE_STL
+  // because it conflicts with operator const char/wchar_t* but we still
+  // provide explicit conversions to std::[w]string for convenience in any case
+#if wxUSE_STD_STRING
+  // We can avoid a copy if we already use this string type internally,
+  // otherwise we create a copy on the fly:

   #if wxUSE_UNICODE_WCHAR && wxUSE_STL_BASED_WXSTRING
   #if wxUSE_UNICODE_WCHAR && wxUSE_STL_BASED_WXSTRING

-    // wxStringImpl is std::string in the encoding we want
-    operator const wxStdWideString&() const { return m_impl; }
+    #define wxStringToStdWstringRetType const wxStdWideString&
+    const wxStdWideString& ToStdWstring() const { return m_impl; }

   #else
     // wxStringImpl is either not std::string or needs conversion
   #else
     // wxStringImpl is either not std::string or needs conversion

-    operator wxStdWideString() const
-        // FIXME-UTF8: broken for embedded NULs
-        { return wxStdWideString(wc_str()); }
+    #define wxStringToStdWstringRetType wxStdWideString
+    wxStdWideString ToStdWstring() const
+    {
+#if wxUSE_UNICODE_WCHAR
+        wxScopedWCharBuffer buf =
+            wxScopedWCharBuffer::CreateNonOwned(m_impl.c_str(), m_impl.length());
+#else // !wxUSE_UNICODE_WCHAR
+        wxScopedWCharBuffer buf(wc_str());
+#endif
+
+        return wxStdWideString(buf.data(), buf.length());
+    }

   #endif
 
   #if (!wxUSE_UNICODE || wxUSE_UTF8_LOCALE_ONLY) && wxUSE_STL_BASED_WXSTRING
     // wxStringImpl is std::string in the encoding we want
   #endif
 
   #if (!wxUSE_UNICODE || wxUSE_UTF8_LOCALE_ONLY) && wxUSE_STL_BASED_WXSTRING
     // wxStringImpl is std::string in the encoding we want

-    operator const std::string&() const { return m_impl; }
+    #define wxStringToStdStringRetType const std::string&
+    const std::string& ToStdString() const { return m_impl; }

   #else
     // wxStringImpl is either not std::string or needs conversion
   #else
     // wxStringImpl is either not std::string or needs conversion

-    operator std::string() const
-        // FIXME-UTF8: broken for embedded NULs
-        { return std::string(mb_str()); }
+    #define wxStringToStdStringRetType std::string
+    std::string ToStdString() const
+    {
+        wxScopedCharBuffer buf(mb_str());
+        return std::string(buf.data(), buf.length());
+    }

   #endif
   #endif

+
+#if wxUSE_STL
+  // In wxUSE_STL case we also provide implicit conversions as there is no
+  // ambiguity with the const char/wchar_t* ones as they are disabled in this
+  // build (for consistency with std::basic_string<>)
+  operator wxStringToStdStringRetType() const { return ToStdString(); }
+  operator wxStringToStdWstringRetType() const { return ToStdWstring(); }

 #endif // wxUSE_STL
 
 #endif // wxUSE_STL
 

+#undef wxStringToStdStringRetType
+#undef wxStringToStdWstringRetType
+
+#endif // wxUSE_STD_STRING
+

   wxString Clone() const
   {
       // make a deep copy of the string, i.e. the returned string will have
   wxString Clone() const
   {
       // make a deep copy of the string, i.e. the returned string will have


@@ -1110,7 +1448,32 @@ public:
 
   // std::string methods:
 #if wxUSE_UNICODE_UTF8
 
   // std::string methods:
 #if wxUSE_UNICODE_UTF8

-  size_t length() const { return end() - begin(); } // FIXME-UTF8: optimize!
+  size_t length() const
+  {
+#if wxUSE_STRING_POS_CACHE
+      wxCACHE_PROFILE_FIELD_INC(lentot);
+
+      Cache::Element * const cache = GetCacheElement();
+
+      if ( cache->len == npos )
+      {
+          // it's probably not worth trying to be clever and using cache->pos
+          // here as it's probably 0 anyhow -- you usually call length() before
+          // starting to index the string
+          cache->len = end() - begin();
+      }
+      else
+      {
+          wxCACHE_PROFILE_FIELD_INC(lenhits);
+
+          wxSTRING_CACHE_ASSERT( (int)cache->len == end() - begin() );
+      }
+
+      return cache->len;
+#else // !wxUSE_STRING_POS_CACHE
+      return end() - begin();
+#endif // wxUSE_STRING_POS_CACHE/!wxUSE_STRING_POS_CACHE
+  }

 #else
   size_t length() const { return m_impl.length(); }
 #endif
 #else
   size_t length() const { return m_impl.length(); }
 #endif


@@ -1120,8 +1483,9 @@ public:
 
   bool empty() const { return m_impl.empty(); }
 
 
   bool empty() const { return m_impl.empty(); }
 

-  size_type capacity() const { return m_impl.capacity(); } // FIXME-UTF8
-  void reserve(size_t sz) { m_impl.reserve(sz); } // FIXME-UTF8
+  // NB: these methods don't have a well-defined meaning in UTF-8 case
+  size_type capacity() const { return m_impl.capacity(); }
+  void reserve(size_t sz) { m_impl.reserve(sz); }

 
   void resize(size_t nSize, wxUniChar ch = wxT('\0'))
   {
 
   void resize(size_t nSize, wxUniChar ch = wxT('\0'))
   {


@@ -1132,7 +1496,7 @@ public:
 #if wxUSE_UNICODE_UTF8
     if ( nSize < len )
     {
 #if wxUSE_UNICODE_UTF8
     if ( nSize < len )
     {

-        wxSTRING_INVALIDATE_INDEX_CACHE();
+        wxSTRING_INVALIDATE_CACHE();

 
         // we can't use wxStringImpl::resize() for truncating the string as it
         // counts in bytes, not characters
 
         // we can't use wxStringImpl::resize() for truncating the string as it
         // counts in bytes, not characters


@@ -1143,10 +1507,16 @@ public:
     // we also can't use (presumably more efficient) resize() if we have to
     // append characters taking more than one byte
     if ( !ch.IsAscii() )
     // we also can't use (presumably more efficient) resize() if we have to
     // append characters taking more than one byte
     if ( !ch.IsAscii() )

+    {

         append(nSize - len, ch);
         append(nSize - len, ch);

-    else
+    }
+    else // can use (presumably faster) resize() version

 #endif // wxUSE_UNICODE_UTF8
 #endif // wxUSE_UNICODE_UTF8

+    {
+        wxSTRING_INVALIDATE_CACHED_LENGTH();
+

         m_impl.resize(nSize, (wxStringCharType)ch);
         m_impl.resize(nSize, (wxStringCharType)ch);

+    }

   }
 
   wxString substr(size_t nStart = 0, size_t nLen = npos) const
   }
 
   wxString substr(size_t nStart = 0, size_t nLen = npos) const


@@ -1166,12 +1536,7 @@ public:
     // truncate the string to given length
   wxString& Truncate(size_t uiLen);
     // empty string contents
     // truncate the string to given length
   wxString& Truncate(size_t uiLen);
     // empty string contents

-  void Empty()
-  {
-    Truncate(0);
-
-    wxASSERT_MSG( empty(), _T("string not empty after call to Empty()?") );
-  }
+  void Empty() { clear(); }

     // empty the string and free memory
   void Clear() { clear(); }
 
     // empty the string and free memory
   void Clear() { clear(); }
 


@@ -1191,39 +1556,24 @@ public:
       { return at(n); }
     // read/write access
     wxUniCharRef at(size_t n)
       { return at(n); }
     // read/write access
     wxUniCharRef at(size_t n)

-      { return *GetNthIter(n); }
+      { return *GetIterForNthChar(n); }

     wxUniCharRef GetWritableChar(size_t n)
       { return at(n); }
     // write access
     void SetChar(size_t n, wxUniChar ch)
     wxUniCharRef GetWritableChar(size_t n)
       { return at(n); }
     // write access
     void SetChar(size_t n, wxUniChar ch)

-    {
-        wxUniCharRef ref(at(n));
-
-#if wxUSE_UNICODE_UTF8
-        // if the new character takes the same number of bytes as the old one,
-        // we can avoid invalidating the index cache and it's an important case
-        // as it is exercised by a simple for loop using indices
-        if ( wxStringOperations::GetUtf8CharLength(ref)
-                != wxStringOperations::GetUtf8CharLength(ch) )
-        {
-            wxSTRING_INVALIDATE_INDEX_CACHE();
-        }
-#endif // wxUSE_UNICODE_UTF8
-
-        ref = ch;
-    }
+      { at(n) = ch; }

 
     // get last character
     wxUniChar Last() const
     {
 
     // get last character
     wxUniChar Last() const
     {

-      wxASSERT_MSG( !empty(), _T("wxString: index out of bounds") );
+      wxASSERT_MSG( !empty(), wxT("wxString: index out of bounds") );

       return *rbegin();
     }
 
     // get writable last character
     wxUniCharRef Last()
     {
       return *rbegin();
     }
 
     // get writable last character
     wxUniCharRef Last()
     {

-      wxASSERT_MSG( !empty(), _T("wxString: index out of bounds") );
+      wxASSERT_MSG( !empty(), wxT("wxString: index out of bounds") );

       return *rbegin();
     }
 
       return *rbegin();
     }
 


@@ -1254,11 +1604,53 @@ public:
       { return at(n); }
 #endif // size_t != unsigned int
 
       { return at(n); }
 #endif // size_t != unsigned int
 

-    // explicit conversion to C string (use this with printf()!)
+
+    /*
+        Overview of wxString conversions, implicit and explicit:
+
+        - wxString has a std::[w]string-like c_str() method, however it does
+          not return a C-style string directly but instead returns wxCStrData
+          helper object which is convertible to either "char *" narrow string
+          or "wchar_t *" wide string. Usually the correct conversion will be
+          applied by the compiler automatically but if this doesn't happen you
+          need to explicitly choose one using wxCStrData::AsChar() or AsWChar()
+          methods or another wxString conversion function.
+
+        - One of the places where the conversion does *NOT* happen correctly is
+          when c_str() is passed to a vararg function such as printf() so you
+          must *NOT* use c_str() with them. Either use wxPrintf() (all wx
+          functions do handle c_str() correctly, even if they appear to be
+          vararg (but they're not, really)) or add an explicit AsChar() or, if
+          compatibility with previous wxWidgets versions is important, add a
+          cast to "const char *".
+
+        - In non-STL mode only, wxString is also implicitly convertible to
+          wxCStrData. The same warning as above applies.
+
+        - c_str() is polymorphic as it can be converted to either narrow or
+          wide string. If you explicitly need one or the other, choose to use
+          mb_str() (for narrow) or wc_str() (for wide) instead. Notice that
+          these functions can return either the pointer to string directly (if
+          this is what the string uses internally) or a temporary buffer
+          containing the string and convertible to it. Again, conversion will
+          usually be done automatically by the compiler but beware of the
+          vararg functions: you need an explicit cast when using them.
+
+        - There are also non-const versions of mb_str() and wc_str() called
+          char_str() and wchar_str(). They are only meant to be used with
+          non-const-correct functions and they always return buffers.
+
+        - Finally wx_str() returns whatever string representation is used by
+          wxString internally. It may be either a narrow or wide string
+          depending on wxWidgets build mode but it will always be a raw pointer
+          (and not a buffer).
+     */
+
+    // explicit conversion to wxCStrData

     wxCStrData c_str() const { return wxCStrData(this); }
     wxCStrData data() const { return c_str(); }
 
     wxCStrData c_str() const { return wxCStrData(this); }
     wxCStrData data() const { return c_str(); }
 

-    // implicit conversion to C string
+    // implicit conversion to wxCStrData

     operator wxCStrData() const { return c_str(); }
 
     // the first two operators conflict with operators for conversion to
     operator wxCStrData() const { return c_str(); }
 
     // the first two operators conflict with operators for conversion to


@@ -1310,7 +1702,7 @@ public:
         if ( len )
             *len = length();
 
         if ( len )
             *len = length();
 

-        return wxCharTypeBuffer<T>::CreateNonOwned(wx_str());
+        return wxCharTypeBuffer<T>::CreateNonOwned(wx_str(), length());

 #endif // Unicode build kind
     }
 
 #endif // Unicode build kind
     }
 


@@ -1324,7 +1716,7 @@ public:
     static wxString FromAscii(const char *ascii, size_t len);
     static wxString FromAscii(const char *ascii);
     static wxString FromAscii(char ascii);
     static wxString FromAscii(const char *ascii, size_t len);
     static wxString FromAscii(const char *ascii);
     static wxString FromAscii(char ascii);

-    const wxCharBuffer ToAscii() const;
+    const wxScopedCharBuffer ToAscii() const;

 #else // ANSI
     static wxString FromAscii(const char *ascii) { return wxString( ascii ); }
     static wxString FromAscii(const char *ascii, size_t len)
 #else // ANSI
     static wxString FromAscii(const char *ascii) { return wxString( ascii ); }
     static wxString FromAscii(const char *ascii, size_t len)


@@ -1379,8 +1771,8 @@ public:
         return FromImpl(wxStringImpl(utf8, len));
     }
 
         return FromImpl(wxStringImpl(utf8, len));
     }
 

-    const char* utf8_str() const { return wx_str(); }
-    const char* ToUTF8() const { return wx_str(); }
+    const wxScopedCharBuffer utf8_str() const
+        { return wxCharBuffer::CreateNonOwned(m_impl.c_str(), m_impl.length()); }

 
     // this function exists in UTF-8 build only and returns the length of the
     // internal UTF-8 representation
 
     // this function exists in UTF-8 build only and returns the length of the
     // internal UTF-8 representation


@@ -1395,33 +1787,39 @@ public:
                       "string must be valid UTF-8" );
         return s;
     }
                       "string must be valid UTF-8" );
         return s;
     }

-    const wxCharBuffer utf8_str() const { return mb_str(wxMBConvUTF8()); }
-    const wxCharBuffer ToUTF8() const { return utf8_str(); }
+    const wxScopedCharBuffer utf8_str() const { return mb_str(wxMBConvUTF8()); }

 #else // ANSI
     static wxString FromUTF8(const char *utf8)
       { return wxString(wxMBConvUTF8().cMB2WC(utf8)); }
     static wxString FromUTF8(const char *utf8, size_t len)
     {
         size_t wlen;
 #else // ANSI
     static wxString FromUTF8(const char *utf8)
       { return wxString(wxMBConvUTF8().cMB2WC(utf8)); }
     static wxString FromUTF8(const char *utf8, size_t len)
     {
         size_t wlen;

-        wxWCharBuffer buf(wxMBConvUTF8().cMB2WC(utf8, len == npos ? wxNO_LEN : len, &wlen));
+        wxScopedWCharBuffer buf(wxMBConvUTF8().cMB2WC(utf8, len == npos ? wxNO_LEN : len, &wlen));

         return wxString(buf.data(), wlen);
     }
     static wxString FromUTF8Unchecked(const char *utf8, size_t len = npos)
     {
         size_t wlen;
         return wxString(buf.data(), wlen);
     }
     static wxString FromUTF8Unchecked(const char *utf8, size_t len = npos)
     {
         size_t wlen;

-        wxWCharBuffer buf(wxMBConvUTF8().cMB2WC(utf8,
-                                                len == npos ? wxNO_LEN : len,
-                                                &wlen));
+        wxScopedWCharBuffer buf
+                            (
+                              wxMBConvUTF8().cMB2WC
+                                             (
+                                               utf8,
+                                               len == npos ? wxNO_LEN : len,
+                                               &wlen
+                                             )
+                            );

         wxASSERT_MSG( !utf8 || !*utf8 || wlen,
                       "string must be valid UTF-8" );
 
         return wxString(buf.data(), wlen);
     }
         wxASSERT_MSG( !utf8 || !*utf8 || wlen,
                       "string must be valid UTF-8" );
 
         return wxString(buf.data(), wlen);
     }

-    const wxCharBuffer utf8_str() const
+    const wxScopedCharBuffer utf8_str() const

       { return wxMBConvUTF8().cWC2MB(wc_str()); }
       { return wxMBConvUTF8().cWC2MB(wc_str()); }

-    const wxCharBuffer ToUTF8() const { return utf8_str(); }

 #endif
 
 #endif
 

+    const wxScopedCharBuffer ToUTF8() const { return utf8_str(); }
+

     // functions for storing binary data in wxString:
 #if wxUSE_UNICODE
     static wxString From8BitData(const char *data, size_t len)
     // functions for storing binary data in wxString:
 #if wxUSE_UNICODE
     static wxString From8BitData(const char *data, size_t len)


@@ -1429,14 +1827,16 @@ public:
     // version for NUL-terminated data:
     static wxString From8BitData(const char *data)
       { return wxString(data, wxConvISO8859_1); }
     // version for NUL-terminated data:
     static wxString From8BitData(const char *data)
       { return wxString(data, wxConvISO8859_1); }

-    const wxCharBuffer To8BitData() const { return mb_str(wxConvISO8859_1); }
+    const wxScopedCharBuffer To8BitData() const
+        { return mb_str(wxConvISO8859_1); }

 #else // ANSI
     static wxString From8BitData(const char *data, size_t len)
       { return wxString(data, len); }
     // version for NUL-terminated data:
     static wxString From8BitData(const char *data)
       { return wxString(data); }
 #else // ANSI
     static wxString From8BitData(const char *data, size_t len)
       { return wxString(data, len); }
     // version for NUL-terminated data:
     static wxString From8BitData(const char *data)
       { return wxString(data); }

-    const char *To8BitData() const { return c_str(); }
+    const wxScopedCharBuffer To8BitData() const
+        { return wxScopedCharBuffer::CreateNonOwned(wx_str(), length()); }

 #endif // Unicode/ANSI
 
     // conversions with (possible) format conversions: have to return a
 #endif // Unicode/ANSI
 
     // conversions with (possible) format conversions: have to return a


@@ -1448,53 +1848,67 @@ public:
     // accepting the file names. The return value is always the same, but the
     // type differs because a function may either return pointer to the buffer
     // directly or have to use intermediate buffer for translation.
     // accepting the file names. The return value is always the same, but the
     // type differs because a function may either return pointer to the buffer
     // directly or have to use intermediate buffer for translation.

+

 #if wxUSE_UNICODE
 
 #if wxUSE_UNICODE
 

+    // this is an optimization: even though using mb_str(wxConvLibc) does the
+    // same thing (i.e. returns pointer to internal representation as locale is
+    // always an UTF-8 one) in wxUSE_UTF8_LOCALE_ONLY case, we can avoid the
+    // extra checks and the temporary buffer construction by providing a
+    // separate mb_str() overload

 #if wxUSE_UTF8_LOCALE_ONLY
     const char* mb_str() const { return wx_str(); }
 #if wxUSE_UTF8_LOCALE_ONLY
     const char* mb_str() const { return wx_str(); }

-    const wxCharBuffer mb_str(const wxMBConv& conv) const;
-#else
-    const wxCharBuffer mb_str(const wxMBConv& conv = wxConvLibc) const;
-#endif
+    const wxScopedCharBuffer mb_str(const wxMBConv& conv) const
+    {
+        return AsCharBuf(conv);
+    }
+#else // !wxUSE_UTF8_LOCALE_ONLY
+    const wxScopedCharBuffer mb_str(const wxMBConv& conv = wxConvLibc) const
+    {
+        return AsCharBuf(conv);
+    }
+#endif // wxUSE_UTF8_LOCALE_ONLY/!wxUSE_UTF8_LOCALE_ONLY

 
     const wxWX2MBbuf mbc_str() const { return mb_str(*wxConvCurrent); }
 
 #if wxUSE_UNICODE_WCHAR
     const wchar_t* wc_str() const { return wx_str(); }
 #elif wxUSE_UNICODE_UTF8
 
     const wxWX2MBbuf mbc_str() const { return mb_str(*wxConvCurrent); }
 
 #if wxUSE_UNICODE_WCHAR
     const wchar_t* wc_str() const { return wx_str(); }
 #elif wxUSE_UNICODE_UTF8

-    const wxWCharBuffer wc_str() const;
+    const wxScopedWCharBuffer wc_str() const
+        { return AsWCharBuf(wxMBConvStrictUTF8()); }

 #endif
     // for compatibility with !wxUSE_UNICODE version
     const wxWX2WCbuf wc_str(const wxMBConv& WXUNUSED(conv)) const
       { return wc_str(); }
 
 #if wxMBFILES
 #endif
     // for compatibility with !wxUSE_UNICODE version
     const wxWX2WCbuf wc_str(const wxMBConv& WXUNUSED(conv)) const
       { return wc_str(); }
 
 #if wxMBFILES

-    const wxCharBuffer fn_str() const { return mb_str(wxConvFile); }
+    const wxScopedCharBuffer fn_str() const { return mb_str(wxConvFile); }

 #else // !wxMBFILES
     const wxWX2WCbuf fn_str() const { return wc_str(); }
 #endif // wxMBFILES/!wxMBFILES
 
 #else // ANSI
 #else // !wxMBFILES
     const wxWX2WCbuf fn_str() const { return wc_str(); }
 #endif // wxMBFILES/!wxMBFILES
 
 #else // ANSI

-    const wxChar* mb_str() const { return wx_str(); }
+    const char* mb_str() const { return wx_str(); }

 
     // for compatibility with wxUSE_UNICODE version
     const char* mb_str(const wxMBConv& WXUNUSED(conv)) const { return wx_str(); }
 
     const wxWX2MBbuf mbc_str() const { return mb_str(); }
 
 
     // for compatibility with wxUSE_UNICODE version
     const char* mb_str(const wxMBConv& WXUNUSED(conv)) const { return wx_str(); }
 
     const wxWX2MBbuf mbc_str() const { return mb_str(); }
 

-#if wxUSE_WCHAR_T
-    const wxWCharBuffer wc_str(const wxMBConv& conv = wxConvLibc) const;
-#endif // wxUSE_WCHAR_T
-    const wxCharBuffer fn_str() const { return wxConvFile.cWC2WX( wc_str( wxConvLibc ) ); }
+    const wxScopedWCharBuffer wc_str(const wxMBConv& conv = wxConvLibc) const
+        { return AsWCharBuf(conv); }
+
+    const wxScopedCharBuffer fn_str() const
+        { return wxConvFile.cWC2WX( wc_str( wxConvLibc ) ); }

 #endif // Unicode/ANSI
 
 #if wxUSE_UNICODE_UTF8
 #endif // Unicode/ANSI
 
 #if wxUSE_UNICODE_UTF8

-    const wxWCharBuffer t_str() const { return wc_str(); }
+    const wxScopedWCharBuffer t_str() const { return wc_str(); }

 #elif wxUSE_UNICODE_WCHAR
     const wchar_t* t_str() const { return wx_str(); }
 #else
     const char* t_str() const { return wx_str(); }
 #elif wxUSE_UNICODE_WCHAR
     const wchar_t* t_str() const { return wx_str(); }
 #else
     const char* t_str() const { return wx_str(); }

-#endif 
+#endif

 
 
   // overloaded assignment
 
 
   // overloaded assignment


@@ -1503,7 +1917,7 @@ public:
   {
     if ( this != &stringSrc )
     {
   {
     if ( this != &stringSrc )
     {

-        wxSTRING_INVALIDATE_INDEX_CACHE();
+        wxSTRING_INVALIDATE_CACHE();

 
         m_impl = stringSrc.m_impl;
     }
 
         m_impl = stringSrc.m_impl;
     }


@@ -1516,7 +1930,7 @@ public:
     // from a character
   wxString& operator=(wxUniChar ch)
   {
     // from a character
   wxString& operator=(wxUniChar ch)
   {

-    wxSTRING_INVALIDATE_INDEX_CACHE();
+    wxSTRING_INVALIDATE_CACHE();

 
 #if wxUSE_UNICODE_UTF8
     if ( !ch.IsAscii() )
 
 #if wxUSE_UNICODE_UTF8
     if ( !ch.IsAscii() )


@@ -1540,7 +1954,7 @@ public:
 #if wxUSE_STL_BASED_WXSTRING
   wxString& operator=(const char *psz)
   {
 #if wxUSE_STL_BASED_WXSTRING
   wxString& operator=(const char *psz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       if ( psz )
           m_impl = ImplStr(psz);
 
       if ( psz )
           m_impl = ImplStr(psz);


@@ -1552,7 +1966,7 @@ public:
 
   wxString& operator=(const wchar_t *pwz)
   {
 
   wxString& operator=(const wchar_t *pwz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       if ( pwz )
           m_impl = ImplStr(pwz);
 
       if ( pwz )
           m_impl = ImplStr(pwz);


@@ -1564,7 +1978,7 @@ public:
 #else // !wxUSE_STL_BASED_WXSTRING
   wxString& operator=(const char *psz)
   {
 #else // !wxUSE_STL_BASED_WXSTRING
   wxString& operator=(const char *psz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl = ImplStr(psz);
 
 
       m_impl = ImplStr(psz);
 


@@ -1573,7 +1987,7 @@ public:
 
   wxString& operator=(const wchar_t *pwz)
   {
 
   wxString& operator=(const wchar_t *pwz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl = ImplStr(pwz);
 
 
       m_impl = ImplStr(pwz);
 


@@ -1584,12 +1998,12 @@ public:
   wxString& operator=(const unsigned char *psz)
     { return operator=((const char*)psz); }
 
   wxString& operator=(const unsigned char *psz)
     { return operator=((const char*)psz); }
 

-    // from wxWCharBuffer
-  wxString& operator=(const wxWCharBuffer& s)
-    { return operator=(s.data()); } // FIXME-UTF8: fix for embedded NULs
-    // from wxCharBuffer
-  wxString& operator=(const wxCharBuffer& s)
-    { return operator=(s.data()); } // FIXME-UTF8: fix for embedded NULs
+    // from wxScopedWCharBuffer
+  wxString& operator=(const wxScopedWCharBuffer& s)
+    { return assign(s); }
+    // from wxScopedCharBuffer
+  wxString& operator=(const wxScopedCharBuffer& s)
+    { return assign(s); }

 
   // string concatenation
     // in place concatenation
 
   // string concatenation
     // in place concatenation


@@ -1603,7 +2017,7 @@ public:
   {
 #if WXWIN_COMPATIBILITY_2_8 && !wxUSE_STL_BASED_WXSTRING && !wxUSE_UNICODE_UTF8
     wxASSERT_MSG( s.IsValid(),
   {
 #if WXWIN_COMPATIBILITY_2_8 && !wxUSE_STL_BASED_WXSTRING && !wxUSE_UNICODE_UTF8
     wxASSERT_MSG( s.IsValid(),

-                  _T("did you forget to call UngetWriteBuf()?") );
+                  wxT("did you forget to call UngetWriteBuf()?") );

 #endif
 
     append(s);
 #endif
 
     append(s);


@@ -1624,10 +2038,10 @@ public:
   wxString& operator<<(wchar_t ch) { append(1, ch); return *this; }
 
       // string += buffer (i.e. from wxGetString)
   wxString& operator<<(wchar_t ch) { append(1, ch); return *this; }
 
       // string += buffer (i.e. from wxGetString)

-  wxString& operator<<(const wxWCharBuffer& s)
-    { return operator<<((const wchar_t *)s); }
-  wxString& operator<<(const wxCharBuffer& s)
-    { return operator<<((const char *)s); }
+  wxString& operator<<(const wxScopedWCharBuffer& s)
+    { return append(s); }
+  wxString& operator<<(const wxScopedCharBuffer& s)
+    { return append(s); }

 
     // string += C string
   wxString& Append(const wxString& s)
 
     // string += C string
   wxString& Append(const wxString& s)


@@ -1645,9 +2059,9 @@ public:
     { append(pwz); return *this; }
   wxString& Append(const wxCStrData& psz)
     { append(psz); return *this; }
     { append(pwz); return *this; }
   wxString& Append(const wxCStrData& psz)
     { append(psz); return *this; }

-  wxString& Append(const wxCharBuffer& psz)
+  wxString& Append(const wxScopedCharBuffer& psz)

     { append(psz); return *this; }
     { append(psz); return *this; }

-  wxString& Append(const wxWCharBuffer& psz)
+  wxString& Append(const wxScopedWCharBuffer& psz)

     { append(psz); return *this; }
   wxString& Append(const char* psz, size_t nLen)
     { append(psz, nLen); return *this; }
     { append(psz); return *this; }
   wxString& Append(const char* psz, size_t nLen)
     { append(psz, nLen); return *this; }


@@ -1655,9 +2069,9 @@ public:
     { append(pwz, nLen); return *this; }
   wxString& Append(const wxCStrData& psz, size_t nLen)
     { append(psz, nLen); return *this; }
     { append(pwz, nLen); return *this; }
   wxString& Append(const wxCStrData& psz, size_t nLen)
     { append(psz, nLen); return *this; }

-  wxString& Append(const wxCharBuffer& psz, size_t nLen)
+  wxString& Append(const wxScopedCharBuffer& psz, size_t nLen)

     { append(psz, nLen); return *this; }
     { append(psz, nLen); return *this; }

-  wxString& Append(const wxWCharBuffer& psz, size_t nLen)
+  wxString& Append(const wxScopedWCharBuffer& psz, size_t nLen)

     { append(psz, nLen); return *this; }
     // append count copies of given character
   wxString& Append(wxUniChar ch, size_t count = 1u)
     { append(psz, nLen); return *this; }
     // append count copies of given character
   wxString& Append(wxUniChar ch, size_t count = 1u)


@@ -1697,36 +2111,34 @@ public:
   // stream-like functions
       // insert an int into string
   wxString& operator<<(int i)
   // stream-like functions
       // insert an int into string
   wxString& operator<<(int i)

-    { return (*this) << Format(_T("%d"), i); }
+    { return (*this) << Format(wxT("%d"), i); }

       // insert an unsigned int into string
   wxString& operator<<(unsigned int ui)
       // insert an unsigned int into string
   wxString& operator<<(unsigned int ui)

-    { return (*this) << Format(_T("%u"), ui); }
+    { return (*this) << Format(wxT("%u"), ui); }

       // insert a long into string
   wxString& operator<<(long l)
       // insert a long into string
   wxString& operator<<(long l)

-    { return (*this) << Format(_T("%ld"), l); }
+    { return (*this) << Format(wxT("%ld"), l); }

       // insert an unsigned long into string
   wxString& operator<<(unsigned long ul)
       // insert an unsigned long into string
   wxString& operator<<(unsigned long ul)

-    { return (*this) << Format(_T("%lu"), ul); }
-#if defined wxLongLong_t && !defined wxLongLongIsLong
+    { return (*this) << Format(wxT("%lu"), ul); }
+#ifdef wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG

       // insert a long long if they exist and aren't longs
   wxString& operator<<(wxLongLong_t ll)
     {
       // insert a long long if they exist and aren't longs
   wxString& operator<<(wxLongLong_t ll)
     {

-      const wxChar *fmt = _T("%") wxLongLongFmtSpec _T("d");
-      return (*this) << Format(fmt, ll);
+      return (*this) << Format("%" wxLongLongFmtSpec "d", ll);

     }
       // insert an unsigned long long
   wxString& operator<<(wxULongLong_t ull)
     {
     }
       // insert an unsigned long long
   wxString& operator<<(wxULongLong_t ull)
     {

-      const wxChar *fmt = _T("%") wxLongLongFmtSpec _T("u");
-      return (*this) << Format(fmt , ull);
+      return (*this) << Format("%" wxLongLongFmtSpec "u" , ull);

     }
     }

-#endif // wxLongLong_t && !wxLongLongIsLong
+#endif // wxHAS_LONG_LONG_T_DIFFERENT_FROM_LONG

       // insert a float into string
   wxString& operator<<(float f)
       // insert a float into string
   wxString& operator<<(float f)

-    { return (*this) << Format(_T("%f"), f); }
+    { return (*this) << Format(wxT("%f"), f); }

       // insert a double into string
   wxString& operator<<(double d)
       // insert a double into string
   wxString& operator<<(double d)

-    { return (*this) << Format(_T("%g"), d); }
+    { return (*this) << Format(wxT("%g"), d); }

 
   // string comparison
     // case-sensitive comparison (returns a value < 0, = 0 or > 0)
 
   // string comparison
     // case-sensitive comparison (returns a value < 0, = 0 or > 0)


@@ -1738,9 +2150,9 @@ public:
     { return compare(s); }
   int Cmp(const wxCStrData& s) const
     { return compare(s); }
     { return compare(s); }
   int Cmp(const wxCStrData& s) const
     { return compare(s); }

-  int Cmp(const wxCharBuffer& s) const
+  int Cmp(const wxScopedCharBuffer& s) const

     { return compare(s); }
     { return compare(s); }

-  int Cmp(const wxWCharBuffer& s) const
+  int Cmp(const wxScopedWCharBuffer& s) const

     { return compare(s); }
     // same as Cmp() but not case-sensitive
   int CmpNoCase(const wxString& s) const;
     { return compare(s); }
     // same as Cmp() but not case-sensitive
   int CmpNoCase(const wxString& s) const;


@@ -1763,9 +2175,9 @@ public:
 
   bool IsSameAs(const wxCStrData& str, bool compareWithCase = true) const
     { return IsSameAs(str.AsString(), compareWithCase); }
 
   bool IsSameAs(const wxCStrData& str, bool compareWithCase = true) const
     { return IsSameAs(str.AsString(), compareWithCase); }

-  bool IsSameAs(const wxCharBuffer& str, bool compareWithCase = true) const
+  bool IsSameAs(const wxScopedCharBuffer& str, bool compareWithCase = true) const

     { return IsSameAs(str.data(), compareWithCase); }
     { return IsSameAs(str.data(), compareWithCase); }

-  bool IsSameAs(const wxWCharBuffer& str, bool compareWithCase = true) const
+  bool IsSameAs(const wxScopedWCharBuffer& str, bool compareWithCase = true) const

     { return IsSameAs(str.data(), compareWithCase); }
     // comparison with a single character: returns true if equal
   bool IsSameAs(wxUniChar c, bool compareWithCase = true) const;
     { return IsSameAs(str.data(), compareWithCase); }
     // comparison with a single character: returns true if equal
   bool IsSameAs(wxUniChar c, bool compareWithCase = true) const;


@@ -1803,16 +2215,18 @@ public:
   wxString Left(size_t nCount) const;
       // get last nCount characters
   wxString Right(size_t nCount) const;
   wxString Left(size_t nCount) const;
       // get last nCount characters
   wxString Right(size_t nCount) const;

-      // get all characters before the first occurance of ch
-      // (returns the whole string if ch not found)
-  wxString BeforeFirst(wxUniChar ch) const;
-      // get all characters before the last occurence of ch
-      // (returns empty string if ch not found)
-  wxString BeforeLast(wxUniChar ch) const;
-      // get all characters after the first occurence of ch
+      // get all characters before the first occurrence of ch
+      // (returns the whole string if ch not found) and also put everything
+      // following the first occurrence of ch into rest if it's non-NULL
+  wxString BeforeFirst(wxUniChar ch, wxString *rest = NULL) const;
+      // get all characters before the last occurrence of ch
+      // (returns empty string if ch not found) and also put everything
+      // following the last occurrence of ch into rest if it's non-NULL
+  wxString BeforeLast(wxUniChar ch, wxString *rest = NULL) const;
+      // get all characters after the first occurrence of ch

       // (returns empty string if ch not found)
   wxString AfterFirst(wxUniChar ch) const;
       // (returns empty string if ch not found)
   wxString AfterFirst(wxUniChar ch) const;

-      // get all characters after the last occurence of ch
+      // get all characters after the last occurrence of ch

       // (returns the whole string if ch not found)
   wxString AfterLast(wxUniChar ch) const;
 
       // (returns the whole string if ch not found)
   wxString AfterLast(wxUniChar ch) const;
 


@@ -1872,12 +2286,12 @@ public:
 
   int Find(const wxCStrData& sub) const
     { return Find(sub.AsString()); }
 
   int Find(const wxCStrData& sub) const
     { return Find(sub.AsString()); }

-  int Find(const wxCharBuffer& sub) const
+  int Find(const wxScopedCharBuffer& sub) const

     { return Find(sub.data()); }
     { return Find(sub.data()); }

-  int Find(const wxWCharBuffer& sub) const
+  int Find(const wxScopedWCharBuffer& sub) const

     { return Find(sub.data()); }
 
     { return Find(sub.data()); }
 

-      // replace first (or all of bReplaceAll) occurences of substring with
+      // replace first (or all of bReplaceAll) occurrences of substring with

       // another string, returns the number of replacements made
   size_t Replace(const wxString& strOld,
                  const wxString& strNew,
       // another string, returns the number of replacements made
   size_t Replace(const wxString& strOld,
                  const wxString& strNew,


@@ -1886,24 +2300,38 @@ public:
     // check if the string contents matches a mask containing '*' and '?'
   bool Matches(const wxString& mask) const;
 
     // check if the string contents matches a mask containing '*' and '?'
   bool Matches(const wxString& mask) const;
 

-    // conversion to numbers: all functions return true only if the whole
-    // string is a number and put the value of this number into the pointer
-    // provided, the base is the numeric base in which the conversion should be
-    // done and must be comprised between 2 and 36 or be 0 in which case the
-    // standard C rules apply (leading '0' => octal, "0x" => hex)
-        // convert to a signed integer
-    bool ToLong(long *val, int base = 10) const;
-        // convert to an unsigned integer
-    bool ToULong(unsigned long *val, int base = 10) const;
-        // convert to wxLongLong
+  // conversion to numbers: all functions return true only if the whole
+  // string is a number and put the value of this number into the pointer
+  // provided, the base is the numeric base in which the conversion should be
+  // done and must be comprised between 2 and 36 or be 0 in which case the
+  // standard C rules apply (leading '0' => octal, "0x" => hex)
+      // convert to a signed integer
+  bool ToLong(long *val, int base = 10) const;
+      // convert to an unsigned integer
+  bool ToULong(unsigned long *val, int base = 10) const;
+      // convert to wxLongLong

 #if defined(wxLongLong_t)
 #if defined(wxLongLong_t)

-    bool ToLongLong(wxLongLong_t *val, int base = 10) const;
-        // convert to wxULongLong
-    bool ToULongLong(wxULongLong_t *val, int base = 10) const;
+  bool ToLongLong(wxLongLong_t *val, int base = 10) const;
+      // convert to wxULongLong
+  bool ToULongLong(wxULongLong_t *val, int base = 10) const;

 #endif // wxLongLong_t
 #endif // wxLongLong_t

-        // convert to a double
-    bool ToDouble(double *val) const;
-
+      // convert to a double
+  bool ToDouble(double *val) const;
+
+  // conversions to numbers using C locale
+      // convert to a signed integer
+  bool ToCLong(long *val, int base = 10) const;
+      // convert to an unsigned integer
+  bool ToCULong(unsigned long *val, int base = 10) const;
+      // convert to a double
+  bool ToCDouble(double *val) const;
+
+  // create a string representing the given floating point number
+    // in the current locale
+  static wxString FromDouble(double val)
+    { return wxString::Format(wxS("%g"), val); }
+    // in C locale
+  static wxString FromCDouble(double val);

 
 #ifndef wxNEEDS_WXSTRING_PRINTF_MIXIN
   // formatted input/output
 
 #ifndef wxNEEDS_WXSTRING_PRINTF_MIXIN
   // formatted input/output


@@ -1929,7 +2357,7 @@ public:
 
 #ifndef wxNEEDS_WXSTRING_PRINTF_MIXIN
     // returns the string containing the result of Printf() to it
 
 #ifndef wxNEEDS_WXSTRING_PRINTF_MIXIN
     // returns the string containing the result of Printf() to it

-  // static wxString Format(const wxString& format, ...) ATTRIBUTE_PRINTF_1;
+  // static wxString Format(const wxString& format, ...) WX_ATTRIBUTE_PRINTF_1;

   WX_DEFINE_VARARG_FUNC(static wxString, Format, 1, (const wxFormatString&),
                         DoFormatWchar, DoFormatUtf8)
 #ifdef __WATCOMC__
   WX_DEFINE_VARARG_FUNC(static wxString, Format, 1, (const wxFormatString&),
                         DoFormatWchar, DoFormatUtf8)
 #ifdef __WATCOMC__


@@ -1978,7 +2406,7 @@ public:
 #ifndef wxNEEDS_WXSTRING_PRINTF_MIXIN
   // use Printf()
   // (take 'this' into account in attribute parameter count)
 #ifndef wxNEEDS_WXSTRING_PRINTF_MIXIN
   // use Printf()
   // (take 'this' into account in attribute parameter count)

-  // int sprintf(const wxString& format, ...) ATTRIBUTE_PRINTF_2;
+  // int sprintf(const wxString& format, ...) WX_ATTRIBUTE_PRINTF_2;

   WX_DEFINE_VARARG_FUNC(int, sprintf, 1, (const wxFormatString&),
                         DoPrintfWchar, DoPrintfUtf8)
 #ifdef __WATCOMC__
   WX_DEFINE_VARARG_FUNC(int, sprintf, 1, (const wxFormatString&),
                         DoPrintfWchar, DoPrintfUtf8)
 #ifdef __WATCOMC__


@@ -2059,7 +2487,7 @@ public:
                CreateConstIterator(last).impl())
   {
       wxASSERT_MSG( first.m_str == last.m_str,
                CreateConstIterator(last).impl())
   {
       wxASSERT_MSG( first.m_str == last.m_str,

-                    _T("pointers must be into the same string") );
+                    wxT("pointers must be into the same string") );

   }
 #endif // WXWIN_COMPATIBILITY_STRING_PTR_AS_ITER
 
   }
 #endif // WXWIN_COMPATIBILITY_STRING_PTR_AS_ITER
 


@@ -2067,56 +2495,90 @@ public:
     // append elements str[pos], ..., str[pos+n]
   wxString& append(const wxString& str, size_t pos, size_t n)
   {
     // append elements str[pos], ..., str[pos+n]
   wxString& append(const wxString& str, size_t pos, size_t n)
   {

-    size_t from, len;
-    str.PosLenToImpl(pos, n, &from, &len);
-    m_impl.append(str.m_impl, from, len);
-    return *this;
+      wxSTRING_UPDATE_CACHED_LENGTH(n);
+
+      size_t from, len;
+      str.PosLenToImpl(pos, n, &from, &len);
+      m_impl.append(str.m_impl, from, len);
+      return *this;

   }
     // append a string
   wxString& append(const wxString& str)
   }
     // append a string
   wxString& append(const wxString& str)

-    { m_impl.append(str.m_impl); return *this; }
+  {
+      wxSTRING_UPDATE_CACHED_LENGTH(str.length());
+
+      m_impl.append(str.m_impl);
+      return *this;
+  }
+

     // append first n (or all if n == npos) characters of sz
   wxString& append(const char *sz)
     // append first n (or all if n == npos) characters of sz
   wxString& append(const char *sz)

-    { m_impl.append(ImplStr(sz)); return *this; }
+  {
+      wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+      m_impl.append(ImplStr(sz));
+      return *this;
+  }
+

   wxString& append(const wchar_t *sz)
   wxString& append(const wchar_t *sz)

-    { m_impl.append(ImplStr(sz)); return *this; }
+  {
+      wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+      m_impl.append(ImplStr(sz));
+      return *this;
+  }
+

   wxString& append(const char *sz, size_t n)
   {
   wxString& append(const char *sz, size_t n)
   {

-    SubstrBufFromMB str(ImplStr(sz, n));
-    m_impl.append(str.data, str.len);
-    return *this;
+      wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+      SubstrBufFromMB str(ImplStr(sz, n));
+      m_impl.append(str.data, str.len);
+      return *this;

   }
   wxString& append(const wchar_t *sz, size_t n)
   {
   }
   wxString& append(const wchar_t *sz, size_t n)
   {

-    SubstrBufFromWC str(ImplStr(sz, n));
-    m_impl.append(str.data, str.len);
-    return *this;
+      wxSTRING_UPDATE_CACHED_LENGTH(n);
+
+      SubstrBufFromWC str(ImplStr(sz, n));
+      m_impl.append(str.data, str.len);
+      return *this;

   }
 
   wxString& append(const wxCStrData& str)
     { return append(str.AsString()); }
   }
 
   wxString& append(const wxCStrData& str)
     { return append(str.AsString()); }

-  wxString& append(const wxCharBuffer& str)
-    { return append(str.data()); }
-  wxString& append(const wxWCharBuffer& str)
-    { return append(str.data()); }
+  wxString& append(const wxScopedCharBuffer& str)
+    { return append(str.data(), str.length()); }
+  wxString& append(const wxScopedWCharBuffer& str)
+    { return append(str.data(), str.length()); }

   wxString& append(const wxCStrData& str, size_t n)
     { return append(str.AsString(), 0, n); }
   wxString& append(const wxCStrData& str, size_t n)
     { return append(str.AsString(), 0, n); }

-  wxString& append(const wxCharBuffer& str, size_t n)
+  wxString& append(const wxScopedCharBuffer& str, size_t n)

     { return append(str.data(), n); }
     { return append(str.data(), n); }

-  wxString& append(const wxWCharBuffer& str, size_t n)
+  wxString& append(const wxScopedWCharBuffer& str, size_t n)

     { return append(str.data(), n); }
 
     // append n copies of ch
   wxString& append(size_t n, wxUniChar ch)
   {
 #if wxUSE_UNICODE_UTF8
     { return append(str.data(), n); }
 
     // append n copies of ch
   wxString& append(size_t n, wxUniChar ch)
   {
 #if wxUSE_UNICODE_UTF8

-    if ( !ch.IsAscii() )
-        m_impl.append(wxStringOperations::EncodeNChars(n, ch));
-    else
+      if ( !ch.IsAscii() )
+      {
+          wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+          m_impl.append(wxStringOperations::EncodeNChars(n, ch));
+      }
+      else // ASCII

 #endif
 #endif

-        m_impl.append(n, (wxStringCharType)ch);
-    return *this;
+      {
+          wxSTRING_UPDATE_CACHED_LENGTH(n);
+
+          m_impl.append(n, (wxStringCharType)ch);
+      }
+
+      return *this;

   }
   }

+

   wxString& append(size_t n, wxUniCharRef ch)
     { return append(n, wxUniChar(ch)); }
   wxString& append(size_t n, char ch)
   wxString& append(size_t n, wxUniCharRef ch)
     { return append(n, wxUniChar(ch)); }
   wxString& append(size_t n, char ch)


@@ -2128,7 +2590,12 @@ public:
 
     // append from first to last
   wxString& append(const_iterator first, const_iterator last)
 
     // append from first to last
   wxString& append(const_iterator first, const_iterator last)

-    { m_impl.append(first.impl(), last.impl()); return *this; }
+  {
+      wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+      m_impl.append(first.impl(), last.impl());
+      return *this;
+  }

 #if WXWIN_COMPATIBILITY_STRING_PTR_AS_ITER
   wxString& append(const char *first, const char *last)
     { return append(first, last - first); }
 #if WXWIN_COMPATIBILITY_STRING_PTR_AS_ITER
   wxString& append(const char *first, const char *last)
     { return append(first, last - first); }


@@ -2141,7 +2608,7 @@ public:
     // same as `this_string = str'
   wxString& assign(const wxString& str)
   {
     // same as `this_string = str'
   wxString& assign(const wxString& str)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_SET_CACHED_LENGTH(str.length());

 
       m_impl = str.m_impl;
 
 
       m_impl = str.m_impl;
 


@@ -2150,7 +2617,7 @@ public:
 
   wxString& assign(const wxString& str, size_t len)
   {
 
   wxString& assign(const wxString& str, size_t len)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_SET_CACHED_LENGTH(len);

 
       m_impl.assign(str.m_impl, 0, str.LenToImpl(len));
 
 
       m_impl.assign(str.m_impl, 0, str.LenToImpl(len));
 


@@ -2160,18 +2627,21 @@ public:
     // same as ` = str[pos..pos + n]
   wxString& assign(const wxString& str, size_t pos, size_t n)
   {
     // same as ` = str[pos..pos + n]
   wxString& assign(const wxString& str, size_t pos, size_t n)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
-

       size_t from, len;
       str.PosLenToImpl(pos, n, &from, &len);
       m_impl.assign(str.m_impl, from, len);
       size_t from, len;
       str.PosLenToImpl(pos, n, &from, &len);
       m_impl.assign(str.m_impl, from, len);

+
+      // it's important to call this after PosLenToImpl() above in case str is
+      // the same string as this one
+      wxSTRING_SET_CACHED_LENGTH(n);
+

       return *this;
   }
 
     // same as `= first n (or all if n == npos) characters of sz'
   wxString& assign(const char *sz)
   {
       return *this;
   }
 
     // same as `= first n (or all if n == npos) characters of sz'
   wxString& assign(const char *sz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.assign(ImplStr(sz));
 
 
       m_impl.assign(ImplStr(sz));
 


@@ -2180,7 +2650,7 @@ public:
 
   wxString& assign(const wchar_t *sz)
   {
 
   wxString& assign(const wchar_t *sz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.assign(ImplStr(sz));
 
 
       m_impl.assign(ImplStr(sz));
 


@@ -2189,7 +2659,7 @@ public:
 
   wxString& assign(const char *sz, size_t n)
   {
 
   wxString& assign(const char *sz, size_t n)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_SET_CACHED_LENGTH(n);

 
       SubstrBufFromMB str(ImplStr(sz, n));
       m_impl.assign(str.data, str.len);
 
       SubstrBufFromMB str(ImplStr(sz, n));
       m_impl.assign(str.data, str.len);


@@ -2199,7 +2669,7 @@ public:
 
   wxString& assign(const wchar_t *sz, size_t n)
   {
 
   wxString& assign(const wchar_t *sz, size_t n)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_SET_CACHED_LENGTH(n);

 
       SubstrBufFromWC str(ImplStr(sz, n));
       m_impl.assign(str.data, str.len);
 
       SubstrBufFromWC str(ImplStr(sz, n));
       m_impl.assign(str.data, str.len);


@@ -2209,29 +2679,30 @@ public:
 
   wxString& assign(const wxCStrData& str)
     { return assign(str.AsString()); }
 
   wxString& assign(const wxCStrData& str)
     { return assign(str.AsString()); }

-  wxString& assign(const wxCharBuffer& str)
-    { return assign(str.data()); }
-  wxString& assign(const wxWCharBuffer& str)
-    { return assign(str.data()); }
+  wxString& assign(const wxScopedCharBuffer& str)
+    { return assign(str.data(), str.length()); }
+  wxString& assign(const wxScopedWCharBuffer& str)
+    { return assign(str.data(), str.length()); }

   wxString& assign(const wxCStrData& str, size_t len)
     { return assign(str.AsString(), len); }
   wxString& assign(const wxCStrData& str, size_t len)
     { return assign(str.AsString(), len); }

-  wxString& assign(const wxCharBuffer& str, size_t len)
+  wxString& assign(const wxScopedCharBuffer& str, size_t len)

     { return assign(str.data(), len); }
     { return assign(str.data(), len); }

-  wxString& assign(const wxWCharBuffer& str, size_t len)
+  wxString& assign(const wxScopedWCharBuffer& str, size_t len)

     { return assign(str.data(), len); }
 
     // same as `= n copies of ch'
   wxString& assign(size_t n, wxUniChar ch)
   {
     { return assign(str.data(), len); }
 
     // same as `= n copies of ch'
   wxString& assign(size_t n, wxUniChar ch)
   {

-    wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_SET_CACHED_LENGTH(n);

 
 #if wxUSE_UNICODE_UTF8
 
 #if wxUSE_UNICODE_UTF8

-    if ( !ch.IsAscii() )
-        m_impl.assign(wxStringOperations::EncodeNChars(n, ch));
-    else
+      if ( !ch.IsAscii() )
+          m_impl.assign(wxStringOperations::EncodeNChars(n, ch));
+      else

 #endif
 #endif

-        m_impl.assign(n, (wxStringCharType)ch);
-    return *this;
+          m_impl.assign(n, (wxStringCharType)ch);
+
+      return *this;

   }
 
   wxString& assign(size_t n, wxUniCharRef ch)
   }
 
   wxString& assign(size_t n, wxUniCharRef ch)


@@ -2246,7 +2717,7 @@ public:
     // assign from first to last
   wxString& assign(const_iterator first, const_iterator last)
   {
     // assign from first to last
   wxString& assign(const_iterator first, const_iterator last)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.assign(first.impl(), last.impl());
 
 
       m_impl.assign(first.impl(), last.impl());
 


@@ -2267,9 +2738,9 @@ public:
   int compare(const wchar_t* sz) const;
   int compare(const wxCStrData& str) const
     { return compare(str.AsString()); }
   int compare(const wchar_t* sz) const;
   int compare(const wxCStrData& str) const
     { return compare(str.AsString()); }

-  int compare(const wxCharBuffer& str) const
+  int compare(const wxScopedCharBuffer& str) const

     { return compare(str.data()); }
     { return compare(str.data()); }

-  int compare(const wxWCharBuffer& str) const
+  int compare(const wxScopedWCharBuffer& str) const

     { return compare(str.data()); }
     // comparison with a substring
   int compare(size_t nStart, size_t nLen, const wxString& str) const;
     { return compare(str.data()); }
     // comparison with a substring
   int compare(size_t nStart, size_t nLen, const wxString& str) const;


@@ -2284,11 +2755,11 @@ public:
 
     // insert another string
   wxString& insert(size_t nPos, const wxString& str)
 
     // insert another string
   wxString& insert(size_t nPos, const wxString& str)

-    { insert(GetNthIter(nPos), str.begin(), str.end()); return *this; }
+    { insert(GetIterForNthChar(nPos), str.begin(), str.end()); return *this; }

     // insert n chars of str starting at nStart (in str)
   wxString& insert(size_t nPos, const wxString& str, size_t nStart, size_t n)
   {
     // insert n chars of str starting at nStart (in str)
   wxString& insert(size_t nPos, const wxString& str, size_t nStart, size_t n)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_UPDATE_CACHED_LENGTH(n);

 
       size_t from, len;
       str.PosLenToImpl(nStart, n, &from, &len);
 
       size_t from, len;
       str.PosLenToImpl(nStart, n, &from, &len);


@@ -2300,7 +2771,7 @@ public:
     // insert first n (or all if n == npos) characters of sz
   wxString& insert(size_t nPos, const char *sz)
   {
     // insert first n (or all if n == npos) characters of sz
   wxString& insert(size_t nPos, const char *sz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.insert(PosToImpl(nPos), ImplStr(sz));
 
 
       m_impl.insert(PosToImpl(nPos), ImplStr(sz));
 


@@ -2309,14 +2780,14 @@ public:
 
   wxString& insert(size_t nPos, const wchar_t *sz)
   {
 
   wxString& insert(size_t nPos, const wchar_t *sz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.insert(PosToImpl(nPos), ImplStr(sz)); return *this;
   }
 
   wxString& insert(size_t nPos, const char *sz, size_t n)
   {
 
       m_impl.insert(PosToImpl(nPos), ImplStr(sz)); return *this;
   }
 
   wxString& insert(size_t nPos, const char *sz, size_t n)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_UPDATE_CACHED_LENGTH(n);

 
       SubstrBufFromMB str(ImplStr(sz, n));
       m_impl.insert(PosToImpl(nPos), str.data, str.len);
 
       SubstrBufFromMB str(ImplStr(sz, n));
       m_impl.insert(PosToImpl(nPos), str.data, str.len);


@@ -2326,7 +2797,7 @@ public:
 
   wxString& insert(size_t nPos, const wchar_t *sz, size_t n)
   {
 
   wxString& insert(size_t nPos, const wchar_t *sz, size_t n)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_UPDATE_CACHED_LENGTH(n);

 
       SubstrBufFromWC str(ImplStr(sz, n));
       m_impl.insert(PosToImpl(nPos), str.data, str.len);
 
       SubstrBufFromWC str(ImplStr(sz, n));
       m_impl.insert(PosToImpl(nPos), str.data, str.len);


@@ -2337,36 +2808,36 @@ public:
     // insert n copies of ch
   wxString& insert(size_t nPos, size_t n, wxUniChar ch)
   {
     // insert n copies of ch
   wxString& insert(size_t nPos, size_t n, wxUniChar ch)
   {

-    wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_UPDATE_CACHED_LENGTH(n);

 
 #if wxUSE_UNICODE_UTF8
 
 #if wxUSE_UNICODE_UTF8

-    if ( !ch.IsAscii() )
-        m_impl.insert(PosToImpl(nPos), wxStringOperations::EncodeNChars(n, ch));
-    else
+      if ( !ch.IsAscii() )
+          m_impl.insert(PosToImpl(nPos), wxStringOperations::EncodeNChars(n, ch));
+      else

 #endif
 #endif

-        m_impl.insert(PosToImpl(nPos), n, (wxStringCharType)ch);
-    return *this;
+          m_impl.insert(PosToImpl(nPos), n, (wxStringCharType)ch);
+      return *this;

   }
 
   iterator insert(iterator it, wxUniChar ch)
   {
   }
 
   iterator insert(iterator it, wxUniChar ch)
   {

-    wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_UPDATE_CACHED_LENGTH(1);

 
 #if wxUSE_UNICODE_UTF8
 
 #if wxUSE_UNICODE_UTF8

-    if ( !ch.IsAscii() )
-    {
-        size_t pos = IterToImplPos(it);
-        m_impl.insert(pos, wxStringOperations::EncodeChar(ch));
-        return iterator(this, m_impl.begin() + pos);
-    }
-    else
+      if ( !ch.IsAscii() )
+      {
+          size_t pos = IterToImplPos(it);
+          m_impl.insert(pos, wxStringOperations::EncodeChar(ch));
+          return iterator(this, m_impl.begin() + pos);
+      }
+      else

 #endif
 #endif

-        return iterator(this, m_impl.insert(it.impl(), (wxStringCharType)ch));
+          return iterator(this, m_impl.insert(it.impl(), (wxStringCharType)ch));

   }
 
   void insert(iterator it, const_iterator first, const_iterator last)
   {
   }
 
   void insert(iterator it, const_iterator first, const_iterator last)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.insert(it.impl(), first.impl(), last.impl());
   }
 
       m_impl.insert(it.impl(), first.impl(), last.impl());
   }


@@ -2382,20 +2853,20 @@ public:
 
   void insert(iterator it, size_type n, wxUniChar ch)
   {
 
   void insert(iterator it, size_type n, wxUniChar ch)
   {

-    wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_UPDATE_CACHED_LENGTH(n);

 
 #if wxUSE_UNICODE_UTF8
 
 #if wxUSE_UNICODE_UTF8

-    if ( !ch.IsAscii() )
-        m_impl.insert(IterToImplPos(it), wxStringOperations::EncodeNChars(n, ch));
-    else
+      if ( !ch.IsAscii() )
+          m_impl.insert(IterToImplPos(it), wxStringOperations::EncodeNChars(n, ch));
+      else

 #endif
 #endif

-        m_impl.insert(it.impl(), n, (wxStringCharType)ch);
+          m_impl.insert(it.impl(), n, (wxStringCharType)ch);

   }
 
     // delete characters from nStart to nStart + nLen
   wxString& erase(size_type pos = 0, size_type n = npos)
   {
   }
 
     // delete characters from nStart to nStart + nLen
   wxString& erase(size_type pos = 0, size_type n = npos)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(pos, n, &from, &len);
 
       size_t from, len;
       PosLenToImpl(pos, n, &from, &len);


@@ -2407,14 +2878,14 @@ public:
     // delete characters from first up to last
   iterator erase(iterator first, iterator last)
   {
     // delete characters from first up to last
   iterator erase(iterator first, iterator last)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       return iterator(this, m_impl.erase(first.impl(), last.impl()));
   }
 
   iterator erase(iterator first)
   {
 
       return iterator(this, m_impl.erase(first.impl(), last.impl()));
   }
 
   iterator erase(iterator first)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_UPDATE_CACHED_LENGTH(-1);

 
       return iterator(this, m_impl.erase(first.impl()));
   }
 
       return iterator(this, m_impl.erase(first.impl()));
   }


@@ -2424,7 +2895,7 @@ public:
 #else
   void clear()
   {
 #else
   void clear()
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_SET_CACHED_LENGTH(0);

 
       m_impl.clear();
   }
 
       m_impl.clear();
   }


@@ -2433,7 +2904,7 @@ public:
     // replaces the substring of length nLen starting at nStart
   wxString& replace(size_t nStart, size_t nLen, const char* sz)
   {
     // replaces the substring of length nLen starting at nStart
   wxString& replace(size_t nStart, size_t nLen, const char* sz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);
 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);


@@ -2444,7 +2915,7 @@ public:
 
   wxString& replace(size_t nStart, size_t nLen, const wchar_t* sz)
   {
 
   wxString& replace(size_t nStart, size_t nLen, const wchar_t* sz)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);
 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);


@@ -2456,7 +2927,7 @@ public:
     // replaces the substring of length nLen starting at nStart
   wxString& replace(size_t nStart, size_t nLen, const wxString& str)
   {
     // replaces the substring of length nLen starting at nStart
   wxString& replace(size_t nStart, size_t nLen, const wxString& str)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);
 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);


@@ -2468,7 +2939,7 @@ public:
     // replaces the substring with nCount copies of ch
   wxString& replace(size_t nStart, size_t nLen, size_t nCount, wxUniChar ch)
   {
     // replaces the substring with nCount copies of ch
   wxString& replace(size_t nStart, size_t nLen, size_t nCount, wxUniChar ch)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);
 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);


@@ -2486,7 +2957,7 @@ public:
   wxString& replace(size_t nStart, size_t nLen,
                     const wxString& str, size_t nStart2, size_t nLen2)
   {
   wxString& replace(size_t nStart, size_t nLen,
                     const wxString& str, size_t nStart2, size_t nLen2)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);
 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);


@@ -2503,7 +2974,7 @@ public:
   wxString& replace(size_t nStart, size_t nLen,
                     const char* sz, size_t nCount)
   {
   wxString& replace(size_t nStart, size_t nLen,
                     const char* sz, size_t nCount)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);
 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);


@@ -2518,7 +2989,7 @@ public:
   wxString& replace(size_t nStart, size_t nLen,
                     const wchar_t* sz, size_t nCount)
   {
   wxString& replace(size_t nStart, size_t nLen,
                     const wchar_t* sz, size_t nCount)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);
 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);


@@ -2533,7 +3004,7 @@ public:
   wxString& replace(size_t nStart, size_t nLen,
                     const wxString& s, size_t nCount)
   {
   wxString& replace(size_t nStart, size_t nLen,
                     const wxString& s, size_t nCount)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);
 
       size_t from, len;
       PosLenToImpl(nStart, nLen, &from, &len);


@@ -2544,7 +3015,7 @@ public:
 
   wxString& replace(iterator first, iterator last, const char* s)
   {
 
   wxString& replace(iterator first, iterator last, const char* s)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.replace(first.impl(), last.impl(), ImplStr(s));
 
 
       m_impl.replace(first.impl(), last.impl(), ImplStr(s));
 


@@ -2553,7 +3024,7 @@ public:
 
   wxString& replace(iterator first, iterator last, const wchar_t* s)
   {
 
   wxString& replace(iterator first, iterator last, const wchar_t* s)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.replace(first.impl(), last.impl(), ImplStr(s));
 
 
       m_impl.replace(first.impl(), last.impl(), ImplStr(s));
 


@@ -2562,7 +3033,7 @@ public:
 
   wxString& replace(iterator first, iterator last, const char* s, size_type n)
   {
 
   wxString& replace(iterator first, iterator last, const char* s, size_type n)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       SubstrBufFromMB str(ImplStr(s, n));
       m_impl.replace(first.impl(), last.impl(), str.data, str.len);
 
       SubstrBufFromMB str(ImplStr(s, n));
       m_impl.replace(first.impl(), last.impl(), str.data, str.len);


@@ -2572,7 +3043,7 @@ public:
 
   wxString& replace(iterator first, iterator last, const wchar_t* s, size_type n)
   {
 
   wxString& replace(iterator first, iterator last, const wchar_t* s, size_type n)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       SubstrBufFromWC str(ImplStr(s, n));
       m_impl.replace(first.impl(), last.impl(), str.data, str.len);
 
       SubstrBufFromWC str(ImplStr(s, n));
       m_impl.replace(first.impl(), last.impl(), str.data, str.len);


@@ -2582,7 +3053,7 @@ public:
 
   wxString& replace(iterator first, iterator last, const wxString& s)
   {
 
   wxString& replace(iterator first, iterator last, const wxString& s)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.replace(first.impl(), last.impl(), s.m_impl);
 
 
       m_impl.replace(first.impl(), last.impl(), s.m_impl);
 


@@ -2591,7 +3062,7 @@ public:
 
   wxString& replace(iterator first, iterator last, size_type n, wxUniChar ch)
   {
 
   wxString& replace(iterator first, iterator last, size_type n, wxUniChar ch)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
 #if wxUSE_UNICODE_UTF8
       if ( !ch.IsAscii() )
 
 #if wxUSE_UNICODE_UTF8
       if ( !ch.IsAscii() )


@@ -2607,7 +3078,7 @@ public:
   wxString& replace(iterator first, iterator last,
                     const_iterator first1, const_iterator last1)
   {
   wxString& replace(iterator first, iterator last,
                     const_iterator first1, const_iterator last1)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.replace(first.impl(), last.impl(), first1.impl(), last1.impl());
 
 
       m_impl.replace(first.impl(), last.impl(), first1.impl(), last1.impl());
 


@@ -2624,7 +3095,13 @@ public:
   // swap two strings
   void swap(wxString& str)
   {
   // swap two strings
   void swap(wxString& str)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+#if wxUSE_STRING_POS_CACHE
+      // we modify not only this string but also the other one directly so we
+      // need to invalidate cache for both of them (we could also try to
+      // exchange their cache entries but it seems unlikely to be worth it)
+      InvalidateCache();
+      str.InvalidateCache();
+#endif // wxUSE_STRING_POS_CACHE

 
       m_impl.swap(str.m_impl);
   }
 
       m_impl.swap(str.m_impl);
   }


@@ -2644,14 +3121,14 @@ public:
       SubstrBufFromWC str(ImplStr(sz, n));
       return PosFromImpl(m_impl.find(str.data, PosToImpl(nStart), str.len));
   }
       SubstrBufFromWC str(ImplStr(sz, n));
       return PosFromImpl(m_impl.find(str.data, PosToImpl(nStart), str.len));
   }

-  size_t find(const wxCharBuffer& s, size_t nStart = 0, size_t n = npos) const
+  size_t find(const wxScopedCharBuffer& s, size_t nStart = 0, size_t n = npos) const

     { return find(s.data(), nStart, n); }
     { return find(s.data(), nStart, n); }

-  size_t find(const wxWCharBuffer& s, size_t nStart = 0, size_t n = npos) const
+  size_t find(const wxScopedWCharBuffer& s, size_t nStart = 0, size_t n = npos) const

     { return find(s.data(), nStart, n); }
   size_t find(const wxCStrData& s, size_t nStart = 0, size_t n = npos) const
     { return find(s.AsWChar(), nStart, n); }
 
     { return find(s.data(), nStart, n); }
   size_t find(const wxCStrData& s, size_t nStart = 0, size_t n = npos) const
     { return find(s.AsWChar(), nStart, n); }
 

-    // find the first occurence of character ch after nStart
+    // find the first occurrence of character ch after nStart

   size_t find(wxUniChar ch, size_t nStart = 0) const
   {
 #if wxUSE_UNICODE_UTF8
   size_t find(wxUniChar ch, size_t nStart = 0) const
   {
 #if wxUSE_UNICODE_UTF8


@@ -2690,9 +3167,9 @@ public:
       SubstrBufFromWC str(ImplStr(sz, n));
       return PosFromImpl(m_impl.rfind(str.data, PosToImpl(nStart), str.len));
   }
       SubstrBufFromWC str(ImplStr(sz, n));
       return PosFromImpl(m_impl.rfind(str.data, PosToImpl(nStart), str.len));
   }

-  size_t rfind(const wxCharBuffer& s, size_t nStart = npos, size_t n = npos) const
+  size_t rfind(const wxScopedCharBuffer& s, size_t nStart = npos, size_t n = npos) const

     { return rfind(s.data(), nStart, n); }
     { return rfind(s.data(), nStart, n); }

-  size_t rfind(const wxWCharBuffer& s, size_t nStart = npos, size_t n = npos) const
+  size_t rfind(const wxScopedWCharBuffer& s, size_t nStart = npos, size_t n = npos) const

     { return rfind(s.data(), nStart, n); }
   size_t rfind(const wxCStrData& s, size_t nStart = npos, size_t n = npos) const
     { return rfind(s.AsWChar(), nStart, n); }
     { return rfind(s.data(), nStart, n); }
   size_t rfind(const wxCStrData& s, size_t nStart = npos, size_t n = npos) const
     { return rfind(s.AsWChar(), nStart, n); }


@@ -2717,7 +3194,7 @@ public:
   size_t rfind(wchar_t ch, size_t nStart = npos) const
     {  return rfind(wxUniChar(ch), nStart); }
 
   size_t rfind(wchar_t ch, size_t nStart = npos) const
     {  return rfind(wxUniChar(ch), nStart); }
 

-  // find first/last occurence of any character (not) in the set:
+  // find first/last occurrence of any character (not) in the set:

 #if wxUSE_STL_BASED_WXSTRING && !wxUSE_UNICODE_UTF8
   // FIXME-UTF8: this is not entirely correct, because it doesn't work if
   //             sizeof(wchar_t)==2 and surrogates are present in the string;
 #if wxUSE_STL_BASED_WXSTRING && !wxUSE_UNICODE_UTF8
   // FIXME-UTF8: this is not entirely correct, because it doesn't work if
   //             sizeof(wchar_t)==2 and surrogates are present in the string;


@@ -2808,7 +3285,7 @@ public:
   size_t find_last_of(wxUniChar c, size_t nStart = npos) const
     { return rfind(c, nStart); }
 
   size_t find_last_of(wxUniChar c, size_t nStart = npos) const
     { return rfind(c, nStart); }
 

-    // find first/last occurence of any character not in the set
+    // find first/last occurrence of any character not in the set

 
     // as strspn() (starting from nStart), returns npos on failure
   size_t find_first_not_of(const wxString& str, size_t nStart = 0) const
 
     // as strspn() (starting from nStart), returns npos on failure
   size_t find_first_not_of(const wxString& str, size_t nStart = 0) const


@@ -2878,80 +3355,102 @@ public:
   // and additional overloads for the versions taking strings:
   size_t find_first_of(const wxCStrData& sz, size_t nStart = 0) const
     { return find_first_of(sz.AsString(), nStart); }
   // and additional overloads for the versions taking strings:
   size_t find_first_of(const wxCStrData& sz, size_t nStart = 0) const
     { return find_first_of(sz.AsString(), nStart); }

-  size_t find_first_of(const wxCharBuffer& sz, size_t nStart = 0) const
+  size_t find_first_of(const wxScopedCharBuffer& sz, size_t nStart = 0) const

     { return find_first_of(sz.data(), nStart); }
     { return find_first_of(sz.data(), nStart); }

-  size_t find_first_of(const wxWCharBuffer& sz, size_t nStart = 0) const
+  size_t find_first_of(const wxScopedWCharBuffer& sz, size_t nStart = 0) const

     { return find_first_of(sz.data(), nStart); }
   size_t find_first_of(const wxCStrData& sz, size_t nStart, size_t n) const
     { return find_first_of(sz.AsWChar(), nStart, n); }
     { return find_first_of(sz.data(), nStart); }
   size_t find_first_of(const wxCStrData& sz, size_t nStart, size_t n) const
     { return find_first_of(sz.AsWChar(), nStart, n); }

-  size_t find_first_of(const wxCharBuffer& sz, size_t nStart, size_t n) const
+  size_t find_first_of(const wxScopedCharBuffer& sz, size_t nStart, size_t n) const

     { return find_first_of(sz.data(), nStart, n); }
     { return find_first_of(sz.data(), nStart, n); }

-  size_t find_first_of(const wxWCharBuffer& sz, size_t nStart, size_t n) const
+  size_t find_first_of(const wxScopedWCharBuffer& sz, size_t nStart, size_t n) const

     { return find_first_of(sz.data(), nStart, n); }
 
   size_t find_last_of(const wxCStrData& sz, size_t nStart = 0) const
     { return find_last_of(sz.AsString(), nStart); }
     { return find_first_of(sz.data(), nStart, n); }
 
   size_t find_last_of(const wxCStrData& sz, size_t nStart = 0) const
     { return find_last_of(sz.AsString(), nStart); }

-  size_t find_last_of(const wxCharBuffer& sz, size_t nStart = 0) const
+  size_t find_last_of(const wxScopedCharBuffer& sz, size_t nStart = 0) const

     { return find_last_of(sz.data(), nStart); }
     { return find_last_of(sz.data(), nStart); }

-  size_t find_last_of(const wxWCharBuffer& sz, size_t nStart = 0) const
+  size_t find_last_of(const wxScopedWCharBuffer& sz, size_t nStart = 0) const

     { return find_last_of(sz.data(), nStart); }
   size_t find_last_of(const wxCStrData& sz, size_t nStart, size_t n) const
     { return find_last_of(sz.AsWChar(), nStart, n); }
     { return find_last_of(sz.data(), nStart); }
   size_t find_last_of(const wxCStrData& sz, size_t nStart, size_t n) const
     { return find_last_of(sz.AsWChar(), nStart, n); }

-  size_t find_last_of(const wxCharBuffer& sz, size_t nStart, size_t n) const
+  size_t find_last_of(const wxScopedCharBuffer& sz, size_t nStart, size_t n) const

     { return find_last_of(sz.data(), nStart, n); }
     { return find_last_of(sz.data(), nStart, n); }

-  size_t find_last_of(const wxWCharBuffer& sz, size_t nStart, size_t n) const
+  size_t find_last_of(const wxScopedWCharBuffer& sz, size_t nStart, size_t n) const

     { return find_last_of(sz.data(), nStart, n); }
 
   size_t find_first_not_of(const wxCStrData& sz, size_t nStart = 0) const
     { return find_first_not_of(sz.AsString(), nStart); }
     { return find_last_of(sz.data(), nStart, n); }
 
   size_t find_first_not_of(const wxCStrData& sz, size_t nStart = 0) const
     { return find_first_not_of(sz.AsString(), nStart); }

-  size_t find_first_not_of(const wxCharBuffer& sz, size_t nStart = 0) const
+  size_t find_first_not_of(const wxScopedCharBuffer& sz, size_t nStart = 0) const

     { return find_first_not_of(sz.data(), nStart); }
     { return find_first_not_of(sz.data(), nStart); }

-  size_t find_first_not_of(const wxWCharBuffer& sz, size_t nStart = 0) const
+  size_t find_first_not_of(const wxScopedWCharBuffer& sz, size_t nStart = 0) const

     { return find_first_not_of(sz.data(), nStart); }
   size_t find_first_not_of(const wxCStrData& sz, size_t nStart, size_t n) const
     { return find_first_not_of(sz.AsWChar(), nStart, n); }
     { return find_first_not_of(sz.data(), nStart); }
   size_t find_first_not_of(const wxCStrData& sz, size_t nStart, size_t n) const
     { return find_first_not_of(sz.AsWChar(), nStart, n); }

-  size_t find_first_not_of(const wxCharBuffer& sz, size_t nStart, size_t n) const
+  size_t find_first_not_of(const wxScopedCharBuffer& sz, size_t nStart, size_t n) const

     { return find_first_not_of(sz.data(), nStart, n); }
     { return find_first_not_of(sz.data(), nStart, n); }

-  size_t find_first_not_of(const wxWCharBuffer& sz, size_t nStart, size_t n) const
+  size_t find_first_not_of(const wxScopedWCharBuffer& sz, size_t nStart, size_t n) const

     { return find_first_not_of(sz.data(), nStart, n); }
 
   size_t find_last_not_of(const wxCStrData& sz, size_t nStart = 0) const
     { return find_last_not_of(sz.AsString(), nStart); }
     { return find_first_not_of(sz.data(), nStart, n); }
 
   size_t find_last_not_of(const wxCStrData& sz, size_t nStart = 0) const
     { return find_last_not_of(sz.AsString(), nStart); }

-  size_t find_last_not_of(const wxCharBuffer& sz, size_t nStart = 0) const
+  size_t find_last_not_of(const wxScopedCharBuffer& sz, size_t nStart = 0) const

     { return find_last_not_of(sz.data(), nStart); }
     { return find_last_not_of(sz.data(), nStart); }

-  size_t find_last_not_of(const wxWCharBuffer& sz, size_t nStart = 0) const
+  size_t find_last_not_of(const wxScopedWCharBuffer& sz, size_t nStart = 0) const

     { return find_last_not_of(sz.data(), nStart); }
   size_t find_last_not_of(const wxCStrData& sz, size_t nStart, size_t n) const
     { return find_last_not_of(sz.AsWChar(), nStart, n); }
     { return find_last_not_of(sz.data(), nStart); }
   size_t find_last_not_of(const wxCStrData& sz, size_t nStart, size_t n) const
     { return find_last_not_of(sz.AsWChar(), nStart, n); }

-  size_t find_last_not_of(const wxCharBuffer& sz, size_t nStart, size_t n) const
+  size_t find_last_not_of(const wxScopedCharBuffer& sz, size_t nStart, size_t n) const

     { return find_last_not_of(sz.data(), nStart, n); }
     { return find_last_not_of(sz.data(), nStart, n); }

-  size_t find_last_not_of(const wxWCharBuffer& sz, size_t nStart, size_t n) const
+  size_t find_last_not_of(const wxScopedWCharBuffer& sz, size_t nStart, size_t n) const

     { return find_last_not_of(sz.data(), nStart, n); }
 
       // string += string
   wxString& operator+=(const wxString& s)
     { return find_last_not_of(sz.data(), nStart, n); }
 
       // string += string
   wxString& operator+=(const wxString& s)

-    { m_impl += s.m_impl; return *this; }
+  {
+      wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+      m_impl += s.m_impl;
+      return *this;
+  }

       // string += C string
   wxString& operator+=(const char *psz)
       // string += C string
   wxString& operator+=(const char *psz)

-    { m_impl += ImplStr(psz); return *this; }
+  {
+      wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+      m_impl += ImplStr(psz);
+      return *this;
+  }

   wxString& operator+=(const wchar_t *pwz)
   wxString& operator+=(const wchar_t *pwz)

-    { m_impl += ImplStr(pwz); return *this; }
+  {
+      wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+      m_impl += ImplStr(pwz);
+      return *this;
+  }

   wxString& operator+=(const wxCStrData& s)
   wxString& operator+=(const wxCStrData& s)

-    { m_impl += s.AsString().m_impl; return *this; }
-  wxString& operator+=(const wxCharBuffer& s)
-    { return operator+=(s.data()); }
-  wxString& operator+=(const wxWCharBuffer& s)
-    { return operator+=(s.data()); }
+  {
+      wxSTRING_INVALIDATE_CACHED_LENGTH();
+
+      m_impl += s.AsString().m_impl;
+      return *this;
+  }
+  wxString& operator+=(const wxScopedCharBuffer& s)
+    { return append(s); }
+  wxString& operator+=(const wxScopedWCharBuffer& s)
+    { return append(s); }

       // string += char
   wxString& operator+=(wxUniChar ch)
   {
       // string += char
   wxString& operator+=(wxUniChar ch)
   {

+      wxSTRING_UPDATE_CACHED_LENGTH(1);
+

 #if wxUSE_UNICODE_UTF8
 #if wxUSE_UNICODE_UTF8

-    if ( !ch.IsAscii() )
-        m_impl += wxStringOperations::EncodeChar(ch);
-    else
+      if ( !ch.IsAscii() )
+          m_impl += wxStringOperations::EncodeChar(ch);
+      else

 #endif
 #endif

-        m_impl += (wxStringCharType)ch;
-    return *this;
+          m_impl += (wxStringCharType)ch;
+      return *this;

   }
   wxString& operator+=(wxUniCharRef ch) { return *this += wxUniChar(ch); }
   wxString& operator+=(int ch) { return *this += wxUniChar(ch); }
   }
   wxString& operator+=(wxUniCharRef ch) { return *this += wxUniChar(ch); }
   wxString& operator+=(int ch) { return *this += wxUniChar(ch); }


@@ -2969,14 +3468,14 @@ private:
 
   void DoUngetWriteBuf()
   {
 
   void DoUngetWriteBuf()
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_INVALIDATE_CACHE();

 
       m_impl.DoUngetWriteBuf();
   }
 
   void DoUngetWriteBuf(size_t nLen)
   {
 
       m_impl.DoUngetWriteBuf();
   }
 
   void DoUngetWriteBuf(size_t nLen)
   {

-      wxSTRING_INVALIDATE_INDEX_CACHE();
+      wxSTRING_SET_CACHED_LENGTH(nLen);

 
       m_impl.DoUngetWriteBuf(nLen);
   }
 
       m_impl.DoUngetWriteBuf(nLen);
   }


@@ -3002,36 +3501,117 @@ private:
   wxStringImpl m_impl;
 
   // buffers for compatibility conversion from (char*)c_str() and
   wxStringImpl m_impl;
 
   // buffers for compatibility conversion from (char*)c_str() and

-  // (wchar_t*)c_str():
-  // FIXME-UTF8: bechmark various approaches to keeping compatibility buffers
+  // (wchar_t*)c_str(): the pointers returned by these functions should remain
+  // valid until the string itself is modified for compatibility with the
+  // existing code and consistency with std::string::c_str() so returning a
+  // temporary buffer won't do and we need to cache the conversion results
+
+  // TODO-UTF8: benchmark various approaches to keeping compatibility buffers

   template<typename T>
   struct ConvertedBuffer
   {
   template<typename T>
   struct ConvertedBuffer
   {

-      ConvertedBuffer() : m_buf(NULL) {}
+      // notice that there is no need to initialize m_len here as it's unused
+      // as long as m_str is NULL
+      ConvertedBuffer() : m_str(NULL) {}

       ~ConvertedBuffer()
       ~ConvertedBuffer()

-          { free(m_buf); }
+          { free(m_str); }

 
 

-      operator T*() const { return m_buf; }
+      bool Extend(size_t len)
+      {
+          // add extra 1 for the trailing NUL
+          void * const str = realloc(m_str, sizeof(T)*(len + 1));
+          if ( !str )
+              return false;
+
+          m_str = static_cast<T *>(str);
+          m_len = len;

 
 

-      ConvertedBuffer& operator=(T *str)
+          return true;
+      }
+
+      const wxScopedCharTypeBuffer<T> AsScopedBuffer() const

       {
       {

-          free(m_buf);
-          m_buf = str;
-          return *this;
+          return wxScopedCharTypeBuffer<T>::CreateNonOwned(m_str, m_len);

       }
 
       }
 

-      T *m_buf;
+      T *m_str;     // pointer to the string data
+      size_t m_len; // length, not size, i.e. in chars and without last NUL

   };
   };

-#if wxUSE_UNICODE && !wxUSE_UTF8_LOCALE_ONLY
+
+
+#if wxUSE_UNICODE
+  // common mb_str() and wxCStrData::AsChar() helper: performs the conversion
+  // and returns either m_convertedToChar.m_str (in which case its m_len is
+  // also updated) or NULL if it failed
+  //
+  // there is an important exception: in wxUSE_UNICODE_UTF8 build if conv is a
+  // UTF-8 one, we return m_impl.c_str() directly, without doing any conversion
+  // as optimization and so the caller needs to check for this before using
+  // m_convertedToChar
+  //
+  // NB: AsChar() returns char* in any build, unlike mb_str()
+  const char *AsChar(const wxMBConv& conv) const;
+
+  // mb_str() implementation helper
+  wxScopedCharBuffer AsCharBuf(const wxMBConv& conv) const
+  {
+#if wxUSE_UNICODE_UTF8
+      // avoid conversion if we can
+      if ( conv.IsUTF8() )
+      {
+          return wxScopedCharBuffer::CreateNonOwned(m_impl.c_str(),
+                  m_impl.length());
+      }
+#endif // wxUSE_UNICODE_UTF8
+
+      // call this solely in order to fill in m_convertedToChar as AsChar()
+      // updates it as a side effect: this is a bit ugly but it's a completely
+      // internal function so the users of this class shouldn't care or know
+      // about it and doing it like this, i.e. having a separate AsChar(),
+      // allows us to avoid the creation and destruction of a temporary buffer
+      // when using wxCStrData without duplicating any code
+      if ( !AsChar(conv) )
+      {
+          // although it would be probably more correct to return NULL buffer
+          // from here if the conversion fails, a lot of existing code doesn't
+          // expect mb_str() (or wc_str()) to ever return NULL so return an
+          // empty string otherwise to avoid crashes in it
+          //
+          // also, some existing code does check for the conversion success and
+          // so asserting here would be bad too -- even if it does mean that
+          // silently losing data is possible for badly written code
+          return wxScopedCharBuffer::CreateNonOwned("", 0);
+      }
+
+      return m_convertedToChar.AsScopedBuffer();
+  }
+

   ConvertedBuffer<char> m_convertedToChar;
   ConvertedBuffer<char> m_convertedToChar;

-#endif
+#endif // !wxUSE_UNICODE
+

 #if !wxUSE_UNICODE_WCHAR
 #if !wxUSE_UNICODE_WCHAR

+  // common wc_str() and wxCStrData::AsWChar() helper for both UTF-8 and ANSI
+  // builds: converts the string contents into m_convertedToWChar and returns
+  // NULL if the conversion failed (this can only happen in ANSI build)
+  //
+  // NB: AsWChar() returns wchar_t* in any build, unlike wc_str()
+  const wchar_t *AsWChar(const wxMBConv& conv) const;
+
+  // wc_str() implementation helper
+  wxScopedWCharBuffer AsWCharBuf(const wxMBConv& conv) const
+  {
+      if ( !AsWChar(conv) )
+          return wxScopedWCharBuffer::CreateNonOwned(L"", 0);
+
+      return m_convertedToWChar.AsScopedBuffer();
+  }
+

   ConvertedBuffer<wchar_t> m_convertedToWChar;
   ConvertedBuffer<wchar_t> m_convertedToWChar;

-#endif
+#endif // !wxUSE_UNICODE_WCHAR

 
 #if wxUSE_UNICODE_UTF8
   // FIXME-UTF8: (try to) move this elsewhere (TLS) or solve differently
 
 #if wxUSE_UNICODE_UTF8
   // FIXME-UTF8: (try to) move this elsewhere (TLS) or solve differently

-  //             assigning to character pointer to by wxString::interator may
+  //             assigning to character pointer to by wxString::iterator may

   //             change the underlying wxStringImpl iterator, so we have to
   //             keep track of all iterators and update them as necessary:
   struct wxStringIteratorNodeHead
   //             change the underlying wxStringImpl iterator, so we have to
   //             keep track of all iterators and update them as necessary:
   struct wxStringIteratorNodeHead


@@ -3041,7 +3621,7 @@ private:
 
       // copying is disallowed as it would result in more than one pointer into
       // the same linked list
 
       // copying is disallowed as it would result in more than one pointer into
       // the same linked list

-      DECLARE_NO_COPY_CLASS(wxStringIteratorNodeHead)
+      wxDECLARE_NO_COPY_CLASS(wxStringIteratorNodeHead);

   };
 
   wxStringIteratorNodeHead m_iterators;
   };
 
   wxStringIteratorNodeHead m_iterators;


@@ -3056,7 +3636,7 @@ private:
 };
 
 #ifdef wxNEEDS_WXSTRING_PRINTF_MIXIN
 };
 
 #ifdef wxNEEDS_WXSTRING_PRINTF_MIXIN

-    #pragma warning (default:4275)
+    #pragma warning (pop)

 #endif
 
 // string iterator operators that satisfy STL Random Access Iterator
 #endif
 
 // string iterator operators that satisfy STL Random Access Iterator


@@ -3111,9 +3691,9 @@ namespace wxPrivate
 template <>
 struct wxStringAsBufHelper<char>
 {
 template <>
 struct wxStringAsBufHelper<char>
 {

-    static wxCharBuffer Get(const wxString& s, size_t *len)
+    static wxScopedCharBuffer Get(const wxString& s, size_t *len)

     {
     {

-        wxCharBuffer buf(s.mb_str());
+        wxScopedCharBuffer buf(s.mb_str());

         if ( len )
             *len = buf ? strlen(buf) : 0;
         return buf;
         if ( len )
             *len = buf ? strlen(buf) : 0;
         return buf;


@@ -3123,11 +3703,12 @@ struct wxStringAsBufHelper<char>
 template <>
 struct wxStringAsBufHelper<wchar_t>
 {
 template <>
 struct wxStringAsBufHelper<wchar_t>
 {

-    static wxWCharBuffer Get(const wxString& s, size_t *len)
+    static wxScopedWCharBuffer Get(const wxString& s, size_t *len)

     {
     {

+        const size_t length = s.length();

         if ( len )
         if ( len )

-            *len = s.length();
-        return wxWCharBuffer::CreateNonOwned(s.wx_str());
+            *len = length;
+        return wxScopedWCharBuffer::CreateNonOwned(s.wx_str(), length);

     }
 };
 
     }
 };
 


@@ -3136,20 +3717,21 @@ struct wxStringAsBufHelper<wchar_t>
 template <>
 struct wxStringAsBufHelper<char>
 {
 template <>
 struct wxStringAsBufHelper<char>
 {

-    static wxCharBuffer Get(const wxString& s, size_t *len)
+    static wxScopedCharBuffer Get(const wxString& s, size_t *len)

     {
     {

+        const size_t length = s.utf8_length();

         if ( len )
         if ( len )

-            *len = s.utf8_length();
-        return wxCharBuffer::CreateNonOwned(s.wx_str());
+            *len = length;
+        return wxScopedCharBuffer::CreateNonOwned(s.wx_str(), length);

     }
 };
 
 template <>
 struct wxStringAsBufHelper<wchar_t>
 {
     }
 };
 
 template <>
 struct wxStringAsBufHelper<wchar_t>
 {

-    static wxWCharBuffer Get(const wxString& s, size_t *len)
+    static wxScopedWCharBuffer Get(const wxString& s, size_t *len)

     {
     {

-        wxWCharBuffer wbuf(s.wc_str());
+        wxScopedWCharBuffer wbuf(s.wc_str());

         if ( len )
             *len = wxWcslen(wbuf);
         return wbuf;
         if ( len )
             *len = wxWcslen(wbuf);
         return wbuf;


@@ -3184,7 +3766,7 @@ private:
     wxString&         m_str;
     wxStringCharType *m_buf;
 
     wxString&         m_str;
     wxStringCharType *m_buf;
 

-    DECLARE_NO_COPY_CLASS(wxStringInternalBuffer)
+    wxDECLARE_NO_COPY_CLASS(wxStringInternalBuffer);

 };
 
 class wxStringInternalBufferLength
 };
 
 class wxStringInternalBufferLength


@@ -3214,13 +3796,13 @@ private:
     size_t            m_len;
     bool              m_lenSet;
 
     size_t            m_len;
     bool              m_lenSet;
 

-    DECLARE_NO_COPY_CLASS(wxStringInternalBufferLength)
+    wxDECLARE_NO_COPY_CLASS(wxStringInternalBufferLength);

 };
 
 #endif // !wxUSE_STL_BASED_WXSTRING
 
 template<typename T>
 };
 
 #endif // !wxUSE_STL_BASED_WXSTRING
 
 template<typename T>

-class WXDLLIMPEXP_BASE wxStringTypeBufferBase
+class wxStringTypeBufferBase

 {
 public:
     typedef T CharType;
 {
 public:
     typedef T CharType;


@@ -3260,8 +3842,7 @@ protected:
 };
 
 template<typename T>
 };
 
 template<typename T>

-class WXDLLIMPEXP_BASE wxStringTypeBufferLengthBase
-    : public wxStringTypeBufferBase<T>
+class wxStringTypeBufferLengthBase : public wxStringTypeBufferBase<T>

 {
 public:
     wxStringTypeBufferLengthBase(wxString& str, size_t lenWanted = 1024)
 {
 public:
     wxStringTypeBufferLengthBase(wxString& str, size_t lenWanted = 1024)


@@ -3295,7 +3876,7 @@ public:
         this->m_str.assign(this->m_buf.data());
     }
 
         this->m_str.assign(this->m_buf.data());
     }
 

-    DECLARE_NO_COPY_CLASS(wxStringTypeBuffer)
+    wxDECLARE_NO_COPY_CLASS(wxStringTypeBuffer);

 };
 
 template<typename T>
 };
 
 template<typename T>


@@ -3311,7 +3892,7 @@ public:
         this->m_str.assign(this->m_buf.data(), this->m_len);
     }
 
         this->m_str.assign(this->m_buf.data(), this->m_len);
     }
 

-    DECLARE_NO_COPY_CLASS(wxStringTypeBufferLength)
+    wxDECLARE_NO_COPY_CLASS(wxStringTypeBufferLength);

 };
 
 #if wxUSE_STL_BASED_WXSTRING
 };
 
 #if wxUSE_STL_BASED_WXSTRING


@@ -3326,7 +3907,7 @@ public:
     ~wxStringInternalBuffer()
         { m_str.m_impl.assign(m_buf.data()); }
 
     ~wxStringInternalBuffer()
         { m_str.m_impl.assign(m_buf.data()); }
 

-    DECLARE_NO_COPY_CLASS(wxStringInternalBuffer)
+    wxDECLARE_NO_COPY_CLASS(wxStringInternalBuffer);

 };
 
 WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE(
 };
 
 WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE(


@@ -3344,7 +3925,7 @@ public:
         m_str.m_impl.assign(m_buf.data(), m_len);
     }
 
         m_str.m_impl.assign(m_buf.data(), m_len);
     }
 

-    DECLARE_NO_COPY_CLASS(wxStringInternalBufferLength)
+    wxDECLARE_NO_COPY_CLASS(wxStringInternalBufferLength);

 };
 
 #endif // wxUSE_STL_BASED_WXSTRING
 };
 
 #endif // wxUSE_STL_BASED_WXSTRING


@@ -3365,27 +3946,59 @@ typedef wxStringInternalBufferLength          wxUTF8StringBufferLength;
 
 WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxStringTypeBufferBase<char> )
 
 
 WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxStringTypeBufferBase<char> )
 

-class WXDLLIMPEXP_BASE wxUTF8StringBuffer : public wxStringTypeBufferBase<char>
+// Note about inlined dtors in the classes below: this is done not for
+// performance reasons but just to avoid linking errors in the MSVC DLL build
+// under Windows: if a class has non-inline methods it must be declared as
+// being DLL-exported but, due to an extremely interesting feature of MSVC 7
+// and later, any template class which is used as a base of a DLL-exported
+// class is implicitly made DLL-exported too, as explained at the bottom of
+// http://msdn.microsoft.com/en-us/library/twa2aw10.aspx (just to confirm: yes,
+// _inheriting_ from a class can change whether it is being exported from DLL)
+//
+// But this results in link errors because the base template class is not DLL-
+// exported, whether it is declared with WXDLLIMPEXP_BASE or not, because it
+// does have only inline functions. So the simplest fix is to just make all the
+// functions of these classes inline too.
+
+class wxUTF8StringBuffer : public wxStringTypeBufferBase<char>

 {
 public:
     wxUTF8StringBuffer(wxString& str, size_t lenWanted = 1024)
         : wxStringTypeBufferBase<char>(str, lenWanted) {}
 {
 public:
     wxUTF8StringBuffer(wxString& str, size_t lenWanted = 1024)
         : wxStringTypeBufferBase<char>(str, lenWanted) {}

-    ~wxUTF8StringBuffer();
+    ~wxUTF8StringBuffer()
+    {
+        wxMBConvStrictUTF8 conv;
+        size_t wlen = conv.ToWChar(NULL, 0, m_buf);
+        wxCHECK_RET( wlen != wxCONV_FAILED, "invalid UTF-8 data in string buffer?" );
+
+        wxStringInternalBuffer wbuf(m_str, wlen);
+        conv.ToWChar(wbuf, wlen, m_buf);
+    }

 
 

-    DECLARE_NO_COPY_CLASS(wxUTF8StringBuffer)
+    wxDECLARE_NO_COPY_CLASS(wxUTF8StringBuffer);

 };
 
 WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxStringTypeBufferLengthBase<char> )
 
 };
 
 WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxStringTypeBufferLengthBase<char> )
 

-class WXDLLIMPEXP_BASE wxUTF8StringBufferLength
-    : public wxStringTypeBufferLengthBase<char>
+class wxUTF8StringBufferLength : public wxStringTypeBufferLengthBase<char>

 {
 public:
     wxUTF8StringBufferLength(wxString& str, size_t lenWanted = 1024)
         : wxStringTypeBufferLengthBase<char>(str, lenWanted) {}
 {
 public:
     wxUTF8StringBufferLength(wxString& str, size_t lenWanted = 1024)
         : wxStringTypeBufferLengthBase<char>(str, lenWanted) {}

-    ~wxUTF8StringBufferLength();
+    ~wxUTF8StringBufferLength()
+    {
+        wxCHECK_RET(m_lenSet, "length not set");
+
+        wxMBConvStrictUTF8 conv;
+        size_t wlen = conv.ToWChar(NULL, 0, m_buf, m_len);
+        wxCHECK_RET( wlen != wxCONV_FAILED, "invalid UTF-8 data in string buffer?" );

 
 

-    DECLARE_NO_COPY_CLASS(wxUTF8StringBufferLength)
+        wxStringInternalBufferLength wbuf(m_str, wlen);
+        conv.ToWChar(wbuf, wlen, m_buf, m_len);
+        wbuf.SetLength(wlen);
+    }
+
+    wxDECLARE_NO_COPY_CLASS(wxUTF8StringBufferLength);

 };
 #endif // wxUSE_UNICODE_UTF8/wxUSE_UNICODE_WCHAR
 
 };
 #endif // wxUSE_UNICODE_UTF8/wxUSE_UNICODE_WCHAR
 


@@ -3422,32 +4035,32 @@ inline bool operator!=(const wxString& s1, const wxCStrData& s2)
 inline bool operator!=(const wxCStrData& s1, const wxString& s2)
     { return s1.AsString() != s2; }
 
 inline bool operator!=(const wxCStrData& s1, const wxString& s2)
     { return s1.AsString() != s2; }
 

-inline bool operator==(const wxString& s1, const wxWCharBuffer& s2)
+inline bool operator==(const wxString& s1, const wxScopedWCharBuffer& s2)

     { return (s1.Cmp((const wchar_t *)s2) == 0); }
     { return (s1.Cmp((const wchar_t *)s2) == 0); }

-inline bool operator==(const wxWCharBuffer& s1, const wxString& s2)
+inline bool operator==(const wxScopedWCharBuffer& s1, const wxString& s2)

     { return (s2.Cmp((const wchar_t *)s1) == 0); }
     { return (s2.Cmp((const wchar_t *)s1) == 0); }

-inline bool operator!=(const wxString& s1, const wxWCharBuffer& s2)
+inline bool operator!=(const wxString& s1, const wxScopedWCharBuffer& s2)

     { return (s1.Cmp((const wchar_t *)s2) != 0); }
     { return (s1.Cmp((const wchar_t *)s2) != 0); }

-inline bool operator!=(const wxWCharBuffer& s1, const wxString& s2)
+inline bool operator!=(const wxScopedWCharBuffer& s1, const wxString& s2)

     { return (s2.Cmp((const wchar_t *)s1) != 0); }
 
     { return (s2.Cmp((const wchar_t *)s1) != 0); }
 

-inline bool operator==(const wxString& s1, const wxCharBuffer& s2)
+inline bool operator==(const wxString& s1, const wxScopedCharBuffer& s2)

     { return (s1.Cmp((const char *)s2) == 0); }
     { return (s1.Cmp((const char *)s2) == 0); }

-inline bool operator==(const wxCharBuffer& s1, const wxString& s2)
+inline bool operator==(const wxScopedCharBuffer& s1, const wxString& s2)

     { return (s2.Cmp((const char *)s1) == 0); }
     { return (s2.Cmp((const char *)s1) == 0); }

-inline bool operator!=(const wxString& s1, const wxCharBuffer& s2)
+inline bool operator!=(const wxString& s1, const wxScopedCharBuffer& s2)

     { return (s1.Cmp((const char *)s2) != 0); }
     { return (s1.Cmp((const char *)s2) != 0); }

-inline bool operator!=(const wxCharBuffer& s1, const wxString& s2)
+inline bool operator!=(const wxScopedCharBuffer& s1, const wxString& s2)

     { return (s2.Cmp((const char *)s1) != 0); }
 
     { return (s2.Cmp((const char *)s1) != 0); }
 

-inline wxString operator+(const wxString& string, const wxWCharBuffer& buf)
+inline wxString operator+(const wxString& string, const wxScopedWCharBuffer& buf)

     { return string + (const wchar_t *)buf; }
     { return string + (const wchar_t *)buf; }

-inline wxString operator+(const wxWCharBuffer& buf, const wxString& string)
+inline wxString operator+(const wxScopedWCharBuffer& buf, const wxString& string)

     { return (const wchar_t *)buf + string; }
 
     { return (const wchar_t *)buf + string; }
 

-inline wxString operator+(const wxString& string, const wxCharBuffer& buf)
+inline wxString operator+(const wxString& string, const wxScopedCharBuffer& buf)

     { return string + (const char *)buf; }
     { return string + (const char *)buf; }

-inline wxString operator+(const wxCharBuffer& buf, const wxString& string)
+inline wxString operator+(const wxScopedCharBuffer& buf, const wxString& string)

     { return (const char *)buf + string; }
 
 // comparison with char
     { return (const char *)buf + string; }
 
 // comparison with char


@@ -3470,6 +4083,21 @@ inline bool operator!=(const wxString& s, const wxUniCharRef& c) { return !s.IsS
 inline bool operator!=(const wxString& s, char c) { return !s.IsSameAs(c); }
 inline bool operator!=(const wxString& s, wchar_t c) { return !s.IsSameAs(c); }
 
 inline bool operator!=(const wxString& s, char c) { return !s.IsSameAs(c); }
 inline bool operator!=(const wxString& s, wchar_t c) { return !s.IsSameAs(c); }
 

+
+// wxString iterators comparisons
+inline bool wxString::iterator::operator==(const const_iterator& i) const
+    { return i == *this; }
+inline bool wxString::iterator::operator!=(const const_iterator& i) const
+    { return i != *this; }
+inline bool wxString::iterator::operator<(const const_iterator& i) const
+    { return i > *this; }
+inline bool wxString::iterator::operator>(const const_iterator& i) const
+    { return i < *this; }
+inline bool wxString::iterator::operator<=(const const_iterator& i) const
+    { return i >= *this; }
+inline bool wxString::iterator::operator>=(const const_iterator& i) const
+    { return i <= *this; }
+

 // comparison with C string in Unicode build
 #if wxUSE_UNICODE
 
 // comparison with C string in Unicode build
 #if wxUSE_UNICODE
 


@@ -3505,16 +4133,16 @@ wxDEFINE_ALL_COMPARISONS(const char *, const wxCStrData&, wxCMP_CHAR_CSTRDATA)
 
 WXDLLIMPEXP_BASE wxSTD ostream& operator<<(wxSTD ostream&, const wxString&);
 WXDLLIMPEXP_BASE wxSTD ostream& operator<<(wxSTD ostream&, const wxCStrData&);
 
 WXDLLIMPEXP_BASE wxSTD ostream& operator<<(wxSTD ostream&, const wxString&);
 WXDLLIMPEXP_BASE wxSTD ostream& operator<<(wxSTD ostream&, const wxCStrData&);

-WXDLLIMPEXP_BASE wxSTD ostream& operator<<(wxSTD ostream&, const wxCharBuffer&);
+WXDLLIMPEXP_BASE wxSTD ostream& operator<<(wxSTD ostream&, const wxScopedCharBuffer&);

 #ifndef __BORLANDC__
 #ifndef __BORLANDC__

-WXDLLIMPEXP_BASE wxSTD ostream& operator<<(wxSTD ostream&, const wxWCharBuffer&);
+WXDLLIMPEXP_BASE wxSTD ostream& operator<<(wxSTD ostream&, const wxScopedWCharBuffer&);

 #endif
 
 #if wxUSE_UNICODE && defined(HAVE_WOSTREAM)
 
 WXDLLIMPEXP_BASE wxSTD wostream& operator<<(wxSTD wostream&, const wxString&);
 WXDLLIMPEXP_BASE wxSTD wostream& operator<<(wxSTD wostream&, const wxCStrData&);
 #endif
 
 #if wxUSE_UNICODE && defined(HAVE_WOSTREAM)
 
 WXDLLIMPEXP_BASE wxSTD wostream& operator<<(wxSTD wostream&, const wxString&);
 WXDLLIMPEXP_BASE wxSTD wostream& operator<<(wxSTD wostream&, const wxCStrData&);

-WXDLLIMPEXP_BASE wxSTD wostream& operator<<(wxSTD wostream&, const wxWCharBuffer&);
+WXDLLIMPEXP_BASE wxSTD wostream& operator<<(wxSTD wostream&, const wxScopedWCharBuffer&);

 
 #endif  // wxUSE_UNICODE && defined(HAVE_WOSTREAM)
 
 
 #endif  // wxUSE_UNICODE && defined(HAVE_WOSTREAM)
 


@@ -3539,48 +4167,56 @@ inline wxCStrData::wxCStrData(const wxCStrData& data)
 inline wxCStrData::~wxCStrData()
 {
     if ( m_owned )
 inline wxCStrData::~wxCStrData()
 {
     if ( m_owned )

-        delete wx_const_cast(wxString*, m_str); // cast to silence warnings
+        delete const_cast<wxString*>(m_str); // cast to silence warnings

 }
 
 }
 

-// simple cases for AsChar() and AsWChar(), the complicated ones are
-// in string.cpp
-#if wxUSE_UNICODE_WCHAR
+// AsChar() and AsWChar() implementations simply forward to wxString methods
+

 inline const wchar_t* wxCStrData::AsWChar() const
 {
 inline const wchar_t* wxCStrData::AsWChar() const
 {

-    return m_str->wx_str() + m_offset;
-}
-#endif // wxUSE_UNICODE_WCHAR
+    const wchar_t * const p =
+#if wxUSE_UNICODE_WCHAR
+        m_str->wc_str();
+#elif wxUSE_UNICODE_UTF8
+        m_str->AsWChar(wxMBConvStrictUTF8());
+#else
+        m_str->AsWChar(wxConvLibc);
+#endif

 
 

+    // in Unicode build the string always has a valid Unicode representation
+    // and even if a conversion is needed (as in UTF8 case) it can't fail
+    //
+    // but in ANSI build the string contents might be not convertible to
+    // Unicode using the current locale encoding so we do need to check for
+    // errors

 #if !wxUSE_UNICODE
 #if !wxUSE_UNICODE

-inline const char* wxCStrData::AsChar() const
-{
-    return m_str->wx_str() + m_offset;
-}
+    if ( !p )
+    {
+        // if conversion fails, return empty string and not NULL to avoid
+        // crashes in code written with either wxWidgets 2 wxString or
+        // std::string behaviour in mind: neither of them ever returns NULL
+        // from its c_str() and so we shouldn't neither
+        //
+        // notice that the same is done in AsChar() below and
+        // wxString::wc_str() and mb_str() for the same reasons
+        return L"";
+    }

 #endif // !wxUSE_UNICODE
 
 #endif // !wxUSE_UNICODE
 

-#if wxUSE_UTF8_LOCALE_ONLY
-inline const char* wxCStrData::AsChar() const
-{
-    return wxStringOperations::AddToIter(m_str->wx_str(), m_offset);
-}
-#endif // wxUSE_UTF8_LOCALE_ONLY
-
-inline const wxCharBuffer wxCStrData::AsCharBuf() const
-{
-#if !wxUSE_UNICODE
-    return wxCharBuffer::CreateNonOwned(AsChar());
-#else
-    return AsString().mb_str();
-#endif
+    return p + m_offset;

 }
 
 }
 

-inline const wxWCharBuffer wxCStrData::AsWCharBuf() const
+inline const char* wxCStrData::AsChar() const

 {
 {

-#if wxUSE_UNICODE_WCHAR
-    return wxWCharBuffer::CreateNonOwned(AsWChar());
-#else
-    return AsString().wc_str();
-#endif
+#if wxUSE_UNICODE && !wxUSE_UTF8_LOCALE_ONLY
+    const char * const p = m_str->AsChar(wxConvLibc);
+    if ( !p )
+        return "";
+#else // !wxUSE_UNICODE || wxUSE_UTF8_LOCALE_ONLY
+    const char * const p = m_str->mb_str();
+#endif // wxUSE_UNICODE && !wxUSE_UTF8_LOCALE_ONLY
+
+    return p + m_offset;

 }
 
 inline wxString wxCStrData::AsString() const
 }
 
 inline wxString wxCStrData::AsString() const


@@ -3603,7 +4239,7 @@ inline const wxStringCharType *wxCStrData::AsInternal() const
 inline wxUniChar wxCStrData::operator*() const
 {
     if ( m_str->empty() )
 inline wxUniChar wxCStrData::operator*() const
 {
     if ( m_str->empty() )

-        return wxUniChar(_T('\0'));
+        return wxUniChar(wxT('\0'));

     else
         return (*m_str)[m_offset];
 }
     else
         return (*m_str)[m_offset];
 }


@@ -3662,7 +4298,7 @@ void wxStringIteratorNode::DoSet(const wxString *str,
     if ( str )
     {
         m_next = str->m_iterators.ptr;
     if ( str )
     {
         m_next = str->m_iterators.ptr;

-        wx_const_cast(wxString*, m_str)->m_iterators.ptr = this;
+        const_cast<wxString*>(m_str)->m_iterators.ptr = this;

         if ( m_next )
             m_next->m_prev = this;
     }
         if ( m_next )
             m_next->m_prev = this;
     }


@@ -3679,7 +4315,7 @@ void wxStringIteratorNode::clear()
     if ( m_prev )
         m_prev->m_next = m_next;
     else if ( m_str ) // first in the list
     if ( m_prev )
         m_prev->m_next = m_next;
     else if ( m_str ) // first in the list

-        wx_const_cast(wxString*, m_str)->m_iterators.ptr = m_next;
+        const_cast<wxString*>(m_str)->m_iterators.ptr = m_next;

 
     m_next = m_prev = NULL;
     m_citer = NULL;
 
     m_next = m_prev = NULL;
     m_citer = NULL;


@@ -3696,4 +4332,19 @@ void wxStringIteratorNode::clear()
     #include "wx/crt.h"
 #endif
 
     #include "wx/crt.h"
 #endif
 

+// ----------------------------------------------------------------------------
+// Checks on wxString characters
+// ----------------------------------------------------------------------------
+
+template<bool (T)(const wxUniChar& c)>
+    inline bool wxStringCheck(const wxString& val)
+    {
+        for ( wxString::const_iterator i = val.begin();
+              i != val.end();
+              ++i )
+            if (T(*i) == 0)
+                return false;
+        return true;
+    }
+

 #endif  // _WX_WXSTRING_H_
 #endif  // _WX_WXSTRING_H_