adding explicit copy and assignment

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@50795 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/mac/carbon/colour.h

@@ -28,6 +28,7 @@ public:
 
     // default
     wxColour() { }
+    wxColour( const wxColour& col );
     DEFINE_STD_WXCOLOUR_CONSTRUCTORS
 
     // dtor
@@ -59,6 +60,7 @@ public:
     wxColour(const RGBColor& col);
     wxColour& operator=(const RGBColor& col);
     wxColour& operator=(CGColorRef col);
+    wxColour& operator=(const wxColour& col);
 
 protected :