text: #include <array>
  #include <iostream>
  #include <string_view>
  #include <tuple>
  #include <type_traits>
  
  namespace a::b::c
  {
      inline constexpr std::string_view str{ "hello" };
  }
  
  template <class... T>
  std::tuple<std::size_t, std::common_type_t<T...>> sum(T... args)
  {
      return { sizeof...(T), (args + ...) };
  }
  
  int main()
  {
      auto [iNumbers, iSum]{ sum(1, 2, 3) };
      std::cout << a::b::c::str << ' ' << iNumbers << ' ' << iSum << '\n';
  
      std::array arr{ 1, 2, 3 };
  
      std::cout << std::size(arr) << '\n';
  
      return 0;
  }