passlambda.cpp

#include <functional>
#include <iostream>

template<typename...Ts>
struct TypeList {
};

template<typename T, typename...Ts>
using Tail = TypeList<Ts...>;

//template<typename T>
//struct FunctionTraits
//  : public FunctionTraits<decltype(&T::operator())> {
//};

template<typename T>
struct FunctionTraits
: public FunctionTraits<decltype(&std::remove_pointer_t<T>::operator())> {
};


template<typename C, typename R, typename... Ts>
struct FunctionTraits<R(C::*)(Ts...) const> {
  enum {
    Arity = sizeof...(Ts)
  };

  using ResultType = R;
  using Params = TypeList<Ts...>;

  template<size_t i>
  struct Param {
    typedef typename std::tuple_element<i, std::tuple<Ts...>>::type Type;
  };
};

template<typename F>
auto getParams(F &&) {
  typedef FunctionTraits<F> Traits;

  return typename Traits::Params{};
}
//struct Entity {
//};
//
//template<class... PickComponents, size_t... PickComponentIndices>
//void iterateEntitiesInternal(
//  const std::function<void(Entity, const PickComponents &...)> iterFn,
//  std::index_sequence<PickComponentIndices...> sequence);
//
//template<class... PickComponents>
//void iterateEntities(std::function<void(Entity, const PickComponents &...)> iterFn) {
//  iterateEntitiesInternal(iterFn, std::index_sequence_for<PickComponents...>{});
//}

int main() {
  getParams([](Entity entity, const auto &c1, const auto &c2, const auto &c3) -> void {

  });


  return 0;
}