23 General utilities library [utilities]

23.14 Function objects [function.objects]

23.14.5 Class template reference_­wrapper [refwrap]

23.14.5.4 reference_­wrapper invocation [refwrap.invoke]

template<class... ArgTypes> invoke_result_t<T&, ArgTypes...> operator()(ArgTypes&&... args) const;
Returns: INVOKE(get(), std​::​forward<ArgTypes>(args)...).