Fixed wxPGMultiButton (event handling, FinalizePosition() -> Finalize(), no longer...

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

diff --git a/include/wx/string.h b/include/wx/string.h
index 1e8be0ca2371446f7bba615c3613335fc75a6b3c..44e0d7d2ae009cd9d4248672da854d0a5dc59cd2 100644 (file)
--- a/include/wx/string.h
+++ b/include/wx/string.h
@@ -607,13 +607,13 @@ private:
   // 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
-  static Cache& GetCache()
+  WXEXPORT static Cache& GetCache()
   {
       static wxTLS_TYPE(Cache) s_cache;
 
       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
@@ -671,7 +671,15 @@ private:
       // 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...)
-      for ( Cache::Element *c = GetCacheBegin(); c != GetCacheEnd(); c++ )
+      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;
@@ -1518,11 +1526,53 @@ public:
       { 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(); }
 
-    // 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