Function set_last_error

externals/picojson/picojson.h:1142–1144

template <typename T> std::string last_error_t<T>::s;

inline void set_last_error(const std::string &s) {
  last_error_t<bool>::s = s;
}

inline const std::string &get_last_error() {
  return last_error_t<bool>::s;