perfect task function

perfect_task.cc

template<typename ... MTArg>
struct Task {
  typedef void (*RawFunction)(MTArg...);
//Here we want to forward some set of arguments into a tuple, but the arguments need not match MTArg -- they just have to be convertible:

  template<typename ... Args>
  explicit Task(RawFunction rawFunction, Args&&... args)
    rawFunction(rawFunction),
    args(std::make_tuple(std::forward<Args>(args)...)) {}
//which the above checks. Note I made it explicit, as if Args... is empty, we don't want this to be a converting constructor.

  void run() {
    callFunction(GenIndexSequence<sizeof...(MTArg)>());
  }
private:
  template<unsigned int... argIndexs>
  inline void callFunction() {
    rawFunction(std::forward<MTArg>(std::get<argIndexs>(args))...);
  }
  RawFunction rawFunction;
  std::tuple<MTArg...> args;
};

//and then we write a make_task function:
template<typename ... MTArg, typename... Args>
Task<MTArg...> make_task( void(*raw)(MTArg...), Args...&& args ) {
  return { raw, std::forward<Args>(args)... };
}