text: #include <system_error>
  
  int main()
  {
    bool res(false);
    try {
      throw std::system_error(std::make_error_code(std::errc::io_error), "i must be thrown");
    } catch (const std::system_error& e) {
      res = true;
    }
    return res ? 0 : 1;
  }
  