83 struct ResultError {  struct
85     ResultError(T&& error_string, int error_errno)  in ResultError()  function
92 inline std::ostream& operator<<(std::ostream& os, const ResultError& t) {  argument
97 inline std::ostream& operator<<(std::ostream& os, ResultError&& t) {
113     Error&& operator<<(const ResultError& result_error) {
119     Error&& operator<<(ResultError&& result_error) {
166     Result(const ResultError& result_error)  in Result()
169     Result(ResultError&& result_error)  in Result()
182     const ResultError& error() const & { return std::get<1>(contents_); }  in error()
183     ResultError&& error() && { return std::get<1>(std::move(contents_)); }  in error()
184     const ResultError&& error() const && { return std::get<1>(std::move(contents_)); }  in error()
205     std::variant<T, ResultError> contents_;