ComponentContainer.h

//ComponentContainer.h
#pragma once

#include <vector>

#include <type_traits>
#include <typeinfo>

template<size_t idx, typename T>
struct GetHelper;

template<typename ... T>
struct ComponentContainer {};

template <typename T, typename... Rest>
struct ComponentContainer<T, Rest ...> {

	ComponentContainer() = default;

	ComponentContainer(size_t p_numberOfComponents, const T& first, const Rest& ... rest) :
		numberOfComponents{ p_numberOfComponents },
		first(first),
		rest(rest...) { };

	std::vector<T> first{};
	ComponentContainer<Rest ... > rest;
	size_t numberOfComponents;


	template<size_t idx>
	auto& get()
	{
		return GetHelper<idx, ComponentContainer<T, Rest...>>::get(*this);
	}

	constexpr size_t GetTypeCount() {
		return sizeof...(Rest) + 1;
	}

	void AddElements() {
		GetHelper< sizeof...(Rest), ComponentContainer<T, Rest...>> ::AddElements(*this);
	}

	template<typename U>
	U& GetComponent(EntityId p_entityId) {
		return GetHelper<sizeof...(Rest), ComponentContainer<T, Rest...>>::template GetComponent<U>(*this, p_entityId);
	}

};

template<typename T, typename ... Rest>
struct GetHelper<0, ComponentContainer<T, Rest ... >>
{
	static std::vector<T>& get(ComponentContainer<T, Rest...>& data)
	{
		return data.first;
	}

	static void AddElements(ComponentContainer<T, Rest...>& data) {
		T obj{};
		data.first.push_back(obj);
	}

	template<typename U>
	static U& GetComponent(ComponentContainer<T, Rest...>& data, EntityId p_entityId) {
		typename std::tuple_element<0, std::tuple<T, Rest...> >::type mA;
		std::cout << typeid(mA).name() << '\n';
		std::cout << std::is_same<U, decltype(mA)>::value;

		static_assert (std::is_same<U, decltype(mA)>::value, "Component couldn't be found in GetComponent.");

		if constexpr (std::is_same<T, U>::value) {
			return data.get<0>()[p_entityId];
		}

	}

};

template<size_t idx, typename T, typename ... Rest>
struct GetHelper<idx, ComponentContainer<T, Rest ... >>
{
	static auto& get(ComponentContainer< T, Rest...>& data)
	{
		return GetHelper<idx - 1, ComponentContainer<Rest ...> >::get(data.rest);
	}

	static void AddElements(ComponentContainer<T, Rest...>& data) {
		T obj{};
		data.first.push_back(obj);
		GetHelper<idx - 1, ComponentContainer<Rest...>>::AddElements(data.rest);
	}

	template<typename U>
	static U& GetComponent(ComponentContainer<T, Rest...>& data, EntityId p_entityId) {

		typename std::tuple_element<idx, std::tuple<T, Rest...> >::type mA;

		if constexpr (std::is_same<U, decltype(mA)>::value == true) {
			return data.get<idx>()[p_entityId];
		}
		if constexpr (std::is_same<U, decltype(mA)>::value == false) {
			return GetHelper<idx - 1, ComponentContainer<T, Rest...> >::template GetComponent<U>(data, p_entityId);
		}
	}

};