diff --git a/include/wx/hashmap.h b/include/wx/hashmap.h
index df9092a382..86700f40ca 100644
--- a/include/wx/hashmap.h
+++ b/include/wx/hashmap.h
@@ -678,24 +678,27 @@ public: \
 
 // and these do exactly the same thing but should be used inside the
 // library
+// note: DECL is not used since the class is inline
 #define WX_DECLARE_HASH_MAP_WITH_DECL( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, DECL) \
-    _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, DECL )
+    _WX_DECLARE_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME, class )
 
 #define WX_DECLARE_EXPORTED_HASH_MAP( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, CLASSNAME) \
     WX_DECLARE_HASH_MAP_WITH_DECL( KEY_T, VALUE_T, HASH_T, KEY_EQ_T, \
                                    CLASSNAME, class WXDLLIMPEXP_CORE )
 
+// note: DECL is not used since the class is inline
 #define WX_DECLARE_STRING_HASH_MAP_WITH_DECL( VALUE_T, CLASSNAME, DECL ) \
     _WX_DECLARE_HASH_MAP( wxString, VALUE_T, wxStringHash, wxStringEqual, \
-                          CLASSNAME, DECL )
+                          CLASSNAME, class )
 
 #define WX_DECLARE_EXPORTED_STRING_HASH_MAP( VALUE_T, CLASSNAME ) \
     WX_DECLARE_STRING_HASH_MAP_WITH_DECL( VALUE_T, CLASSNAME, \
                                           class WXDLLIMPEXP_CORE )
 
+// note: DECL is not used since the class is inline
 #define WX_DECLARE_VOIDPTR_HASH_MAP_WITH_DECL( VALUE_T, CLASSNAME, DECL ) \
     _WX_DECLARE_HASH_MAP( void*, VALUE_T, wxPointerHash, wxPointerEqual, \
-                          CLASSNAME, DECL )
+                          CLASSNAME, class )
 
 #define WX_DECLARE_EXPORTED_VOIDPTR_HASH_MAP( VALUE_T, CLASSNAME ) \
     WX_DECLARE_VOIDPTR_HASH_MAP_WITH_DECL( VALUE_T, CLASSNAME, \
diff --git a/include/wx/hashset.h b/include/wx/hashset.h
index bb713b87f4..311aeca9a6 100644
--- a/include/wx/hashset.h
+++ b/include/wx/hashset.h
@@ -159,8 +159,9 @@ public:                                                                      \
 
 // and these do exactly the same thing but should be used inside the
 // library
+// note: DECL is not used since the class is inline
 #define WX_DECLARE_HASH_SET_WITH_DECL( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME, DECL) \
-    _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NORMAL, CLASSNAME, DECL )
+    _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NORMAL, CLASSNAME, class )
 
 #define WX_DECLARE_EXPORTED_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME) \
     WX_DECLARE_HASH_SET_WITH_DECL( KEY_T, HASH_T, KEY_EQ_T, \
@@ -173,8 +174,9 @@ public:                                                                      \
 // common compilers (notably Sun CC).
 #define WX_DECLARE_HASH_SET_PTR( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME) \
     _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NOP, CLASSNAME, class )
+// note: DECL is not used since the class is inline
 #define WX_DECLARE_HASH_SET_WITH_DECL_PTR( KEY_T, HASH_T, KEY_EQ_T, CLASSNAME, DECL) \
-    _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NOP, CLASSNAME, DECL )
+    _WX_DECLARE_HASH_SET( KEY_T, HASH_T, KEY_EQ_T, wxPTROP_NOP, CLASSNAME, class )
 
 // delete all hash elements
 //
diff --git a/include/wx/image.h b/include/wx/image.h
index f2b5866d2d..d53ff0b116 100644
--- a/include/wx/image.h
+++ b/include/wx/image.h
@@ -190,7 +190,7 @@ WX_DECLARE_EXPORTED_HASH_MAP(unsigned long, wxImageHistogramEntry,
                              wxIntegerHash, wxIntegerEqual,
                              wxImageHistogramBase);
 
-class WXDLLIMPEXP_CORE wxImageHistogram : public wxImageHistogramBase
+class wxImageHistogram : public wxImageHistogramBase
 {
 public:
     wxImageHistogram() : wxImageHistogramBase(256) { }
@@ -211,9 +211,43 @@ public:
     bool FindFirstUnusedColour(unsigned char *r,
                                unsigned char *g,
                                unsigned char *b,
-                               unsigned char startR = 1,
-                               unsigned char startG = 0,
-                               unsigned char startB = 0 ) const;
+                               unsigned char r2 = 1,
+                               unsigned char g2 = 0,
+                               unsigned char b2 = 0 ) const
+    {
+        unsigned long key = MakeKey(r2, g2, b2);
+
+        while ( find(key) != end() )
+        {
+            // color already used
+            r2++;
+            if ( r2 >= 255 )
+            {
+                r2 = 0;
+                g2++;
+                if ( g2 >= 255 )
+                {
+                    g2 = 0;
+                    b2++;
+                    if ( b2 >= 255 )
+                    {
+                        return false;
+                    }
+                }
+            }
+
+            key = MakeKey(r2, g2, b2);
+        }
+
+        if ( r )
+            *r = r2;
+        if ( g )
+            *g = g2;
+        if ( b )
+            *b = b2;
+
+        return true;
+    }
 };
 
 //-----------------------------------------------------------------------------
diff --git a/src/common/image.cpp b/src/common/image.cpp
index 096f823f0c..880c1c4ea7 100644
--- a/src/common/image.cpp
+++ b/src/common/image.cpp
@@ -3381,49 +3381,6 @@ wxImageHandler::GetResolutionFromOptions(const wxImage& image, int *x, int *y)
 // image histogram stuff
 // ----------------------------------------------------------------------------
 
-bool
-wxImageHistogram::FindFirstUnusedColour(unsigned char *r,
-                                        unsigned char *g,
-                                        unsigned char *b,
-                                        unsigned char r2,
-                                        unsigned char g2,
-                                        unsigned char b2) const
-{
-    unsigned long key = MakeKey(r2, g2, b2);
-
-    while ( find(key) != end() )
-    {
-        // color already used
-        r2++;
-        if ( r2 >= 255 )
-        {
-            r2 = 0;
-            g2++;
-            if ( g2 >= 255 )
-            {
-                g2 = 0;
-                b2++;
-                if ( b2 >= 255 )
-                {
-                    wxLogError(_("No unused colour in image.") );
-                    return false;
-                }
-            }
-        }
-
-        key = MakeKey(r2, g2, b2);
-    }
-
-    if ( r )
-        *r = r2;
-    if ( g )
-        *g = g2;
-    if ( b )
-        *b = b2;
-
-    return true;
-}
-
 bool
 wxImage::FindFirstUnusedColour(unsigned char *r,
                                unsigned char *g,