Denis Koroskin: > Looks like my message class is a static array: Thank you, this fixes that uncommon bug, I have fixed another similar bug relative to AAs. template IsArray(T) { const bool IsArray = !is(T == class) && is(typeof(T.length)) && is(typeof(T.sort)) && is(typeof(T.reverse)) && is(typeof(T.dup)); } Bye and thank you, bearophile