Function unhex

include/tsutil/StringConvert.h:74–95

* Convert input hex string into a string * * The input string must have even size and be comprised of hex digits [0-f]. Each two-digit pair is converted from hex to a * character in the resulting output string. * * @param input Input string view * @return The unhexified result string * * @note this is a specialization of boost::algorithms::unhex */

 * @note this is a specialization of boost::algorithms::unhex
 */
inline std::string
unhex(const std::string_view input)
{
  std::string result;

  if (input.size() % 2 != 0) {
    throw std::invalid_argument("input to unhex needs to be an even size");
  }

  result.resize(input.size() / 2);

  const char *p = input.data();
  for (auto &x : result) {
    if (auto [ptr, err] = std::from_chars(p, p + 2, reinterpret_cast<unsigned char &>(x), 16); err == std::errc()) {
      p = ptr;
    } else {
      throw std::runtime_error(std::make_error_code(err).message().c_str());
    }
  }

  return result;
}

} // namespace ts