Arduino-compatable Tuple implementation (not std compatable). Need to make a proper adruino lib for this.

Tuple.ino

#include <ArduinoSTL.h>
#include <iostream>

// helpers
template <typename T>
struct id { using type = T; };

template <typename T>
using type_of = typename T::type;

template <size_t... N>
struct sizes : id <sizes <N...> > { };

// choose N-th element in list <T...>
template <size_t N, typename... T>
struct Choose;

template <size_t N, typename H, typename... T>
struct Choose <N, H, T...> : Choose <N-1, T...> { };

template <typename H, typename... T>
struct Choose <0, H, T...> : id <H> { };

template <size_t N, typename... T>
using choose = type_of <Choose <N, T...> >;

// given L>=0, generate sequence <0, ..., L-1>
template <size_t L, size_t I = 0, typename S = sizes <> >
struct Range;

template <size_t L, size_t I, size_t... N>
struct Range <L, I, sizes <N...> > : Range <L, I+1, sizes <N..., I> > { };

template <size_t L, size_t... N>
struct Range <L, L, sizes <N...> > : sizes <N...> { };

template <size_t L>
using range = type_of <Range <L> >;

// single tuple element
template <size_t N, typename T>
class TupleElem
{
    T elem;
public:
  T&       get()       { return elem; }
  const T& get() const { return elem; }
};

// tuple implementation
template <typename N, typename... T>
class TupleImpl;

template <size_t... N, typename... T>
class TupleImpl <sizes <N...>, T...> : TupleElem <N, T>...
{
  template <size_t M> using pick = choose <M, T...>;
  template <size_t M> using elem = TupleElem <M, pick <M> >;

public:
  template <size_t M>
  pick <M>& get() { return elem <M>::get(); }

  template <size_t M>
  const pick <M>& get() const { return elem <M>::get(); }
};

template <typename... T>
struct Tuple : TupleImpl <range <sizeof...(T)>, T...>
{
    static constexpr std::size_t size() { return sizeof...(T); }
};

void setup() {
  Serial.begin(115200);
  while(!Serial);
    using namespace std;

    Tuple<unsigned long, uint32_t> test;
    Tuple<> test2;



    test.get<0>() = 1;
    test.get<1>() = 2;

    cout << test.size() << endl;
    cout << test.get<0>() << endl;
    cout << test.get<1>() << endl;
}

void loop() {
  // put your main code here, to run repeatedly:

}