Merge pull request #265 from redboltz/add_base_class_support

Base classes packing/converting/creating object::with_zone support in C+...

include/msgpack/adaptor/detail/cpp11_define.hpp

@@ -43,6 +43,19 @@
         msgpack::type::make_define(__VA_ARGS__).msgpack_object(o, z); \
     }
 
+#define MSGPACK_BASE(base) \
+    static_cast<base &>( \
+        const_cast< \
+            std::add_lvalue_reference< \
+                std::remove_const< \
+                    std::remove_pointer< \
+                        decltype(this) \
+                    >::type \
+                >::type \
+            >::type \
+        >(*this) \
+    )
+
 // MSGPACK_ADD_ENUM must be used in the global namespace.
 #define MSGPACK_ADD_ENUM(enum_name) \
   namespace msgpack { \