... to be a pair< variant<XXX>, Primitive_id > rather than pair<optional<variant<XXX> >, Primitive_id > The rational is that the optional around the variant here is not needed since there is one around the pair.
... to be a pair< variant<XXX>, Primitive_id > rather than pair<optional<variant<XXX> >, Primitive_id > The rational is that the optional around the variant here is not needed since there is one around the pair.