#include <cassert>
#include <string>

using namespace std::string_literals;

template <typename T> auto sum(T final) { return final; }
template <typename T, typename... Ts> auto sum(T first, Ts... rem) {
  return first + sum<Ts...>(rem...);
}
int main(void) {
  bool dummy = sum<double, int, int, int>(1.5, 2, 3, 10) == 16.5;
  assert(dummy);
  dummy = sum<int, int, int, int, int, int, int>(1, 5, 7, 8, 2, 3, 4) == 30;
  assert(dummy);
  dummy = sum<double>(1.5, 1, 2, 3.5) == 8.0;
  assert(dummy);
  dummy = sum<std::string>("asdf"s, "abcdefghijklmnop"s, "qrstuvwxyz"s) ==
          "asdfabcdefghijklmnopqrstuvwxyz"s;
  assert(dummy);
}