2 * Copyright (C) 2017 Mentor Graphics Development (Deutschland) GmbH
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 // Created by mfritzsc on 7/12/17.
21 #ifndef TMCAGLWM_RESULT_HPP
22 #define TMCAGLWM_RESULT_HPP
24 #include <experimental/optional>
29 using std::experimental::optional;
30 using std::experimental::nullopt;
32 // We only ever return a string as an error - so just parametrize
33 // this over result type T
39 bool is_ok() const { return this->t != nullopt; }
40 bool is_err() const { return this->e != nullptr; }
43 if (this->e != nullptr) {
44 throw std::logic_error(this->e);
46 return this->t.value();
49 operator T() { return this->unwrap(); }
51 char const *unwrap_err() { return this->e; }
53 optional<T> const &ok() const { return this->t; }
54 optional<char const *> err() const {
55 return this->e ? optional<char const *>(this->e) : nullopt;
58 result<T> map_err(std::function<char const *(char const *)> f);
62 struct result<T> Err(char const *e) {
63 return result<T>{e, nullopt};
67 struct result<T> Ok(T t) {
68 return result<T>{nullptr, t};
72 result<T> result<T>::map_err(std::function<char const *(char const *)> f) {
74 return Err<T>(f(this->e));
81 #endif // TMCAGLWM_RESULT_HPP