How do I get a template parameter pack to infer pass-by-reference rather than pass-by-value?

Question

In the following class, wrapper takes a pointer to an arbitrary const method and returns the result of a call to that method with const re

Answer 1

You can perfect forward the arguments to the function:

template<typename T, typename... Ts, typename... Args>
auto& wrapper(T const& (C::*f)(Ts...) const, Args&&... args) {
  return const_cast<T&>((this->*f)(std::forward<Args>(args)...));
}

This is achieved by making args a forwarding reference parameter pack. Note that we need to introduce a new Args template parameter pack in order to deduce the arguments correctly.