template <class F, class C, class ErrorHandler, class R, class RV, class... Args>
struct marshalled_func_imp<F, C, RV(R &, Args...), ErrorHandler> {
static inline handler *wrap(F f, C *c=nullptr) {
template <class F, class C, class ErrorHandler, class R, class RV, class... Args>
struct marshalled_func_imp<F, C, RV(R &, Args...), ErrorHandler> {
static inline handler *wrap(F f, C *c=nullptr) {