+ | _, _, (_::_) -> false (* no optional args yet *)
+ | RErr, _, []
+ | RInt _, _, []
+ | RInt64 _, _, [] -> true
+ | RBool _, _, []
+ | RConstString _, _, []
+ | RConstOptString _, _, []
+ | RString _, _, []
+ | RStringList _, _, []
+ | RStruct _, _, []
+ | RStructList _, _, []
+ | RHashtable _, _, []
+ | RBufferOut _, _, [] -> false in