#include <iostream>
#include <tuple>
#include <vector>
#include <string>
#include <type_traits>
#define ID(X)       X
#define ID_(X)		ID(X),
#define NOTHING(X)
#define SPACE
#define COMMA       ,
#define TYPE_LIST_G(G, X, A1, L1, A2, L2) \
	G(A1(int)    X  A2("int")) \
	G(A1(double) X  A2("double")) \
	G(L1(char)   X  L2("char"))
	
#define TYPE_LIST(A1, L1, A2, L2) \
	TYPE_LIST_G(ID, SPACE, A1, L1, A2, L2)
#define TYPE_LIST2_G(G, A1, A2) \
	TYPE_LIST_G(G, COMMA, A1, A1, A2, A2)
int main() {
	// Example 1: generate a tuple from our type list
	// A1 is identity plus ','
	// L1 is identity (no comma)
	// A2 is nothing
	// L2 is nothing
	using T = std::tuple< TYPE_LIST(ID_, ID, NOTHING, NOTHING) >;
	static_assert(std::is_same<int,	   std::tuple_element<0, T>::type>::value, "First type is int");
	static_assert(std::is_same<double, std::tuple_element<1, T>::type>::value, "Second type is double");
	
	// Example 2: generate a string list from our type list
	// A1 is nothing
	// L1 is nothing
	// A2 is identity plus ','
	// L2 is identity (no comma)
	std::vector<std::string> names = {
		TYPE_LIST(NOTHING, NOTHING, ID_, ID)
	};
	for (const auto &s : names) std::cout << s << std::endl;
	
	// Example 3: generate code around elements
	// Functors for all and terminating elements are the same
#define HANDLE_CASE(T, S) std::cout << "sizeof(" << S << ") is " << sizeof(T) << std::endl; 
	TYPE_LIST2_G(HANDLE_CASE, ID, ID)
	return 0;
}