সি++ unpacking ফাংশন

#include <iostream>
using namespace std;

template<typename... Numbers>
auto sum(Numbers... numbers) {
  return (numbers + ...);
}

int main() {

  std::tuple numbers = {
    10, 15, 10, 25
  };

  std::cout << std::apply(
    sum<decltype(std::get<0>(numbers)),
        decltype(std::get<1>(numbers)),
        decltype(std::get<2>(numbers)),
        decltype(std::get<3>(numbers))>,
    numbers
  );

  return 0;
}