Added the conversion to unspecfied_bool to all smart pointers, added T& operator* to wxObjectDataPtr

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@51118 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/ptr_scpd.h

@@ -55,6 +55,14 @@ public:
            delete m_ptr;
     }
                                     
+    // test for pointer validity: defining conversion to unspecified_bool_type
+    // and not more obvious bool to avoid implicit conversions to integer types
+    typedef T *(wxScopedPtr<T>::*unspecified_bool_type)() const;
+    operator unspecified_bool_type() const
+    {
+        return m_ptr ? &wxScopedPtr<T>::get : NULL;
+    }
+
     void reset(T * ptr = NULL)      
     {                               
         if (m_ptr != ptr)