add struct to HandleToPropHandle to get an MPropHandle from a MeshHandle

src/OpenMesh/Core/Utils/HandleToPropHandle.hh

@@ -35,6 +35,11 @@ namespace OpenMesh {
         using type = OpenMesh::MPropHandleT<T>;
     };
 
+    template<typename T>
+    struct HandleToPropHandle<OpenMesh::MeshHandle, T> {
+        using type = OpenMesh::MPropHandleT<T>;
+    };
+
 } // namespace OpenMesh
 
 #endif // HANDLETOPROPHANDLE_HH_