85     ResultError(T&& error_string, int error_errno)  in ResultError()
86         : error_string(std::forward<T>(error_string)), error_errno(error_errno) {}  in ResultError()
88     std::string error_string;  member
93     os << t.error_string;
98     os << std::move(t.error_string);
114         ss_ << result_error.error_string;
120         ss_ << std::move(result_error.error_string);
167         : contents_(std::in_place_index_t<1>(), result_error.error_string,  in Result()
170         : contents_(std::in_place_index_t<1>(), std::move(result_error.error_string),  in Result()
186     const std::string& error_string() const & { return std::get<1>(contents_).error_string; }  in error_string()  function
187     std::string&& error_string() && { return std::get<1>(std::move(contents_)).error_string; }  in error_string()  function
188     const std::string&& error_string() const && {  in error_string()  function
189         return std::get<1>(std::move(contents_)).error_string;  in error_string()