-//
-// Created by mfritzsc on 7/12/17.
-//
+/*
+ * Copyright (C) 2017 Mentor Graphics Development (Deutschland) GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
#ifndef TMCAGLWM_RESULT_HPP
#define TMCAGLWM_RESULT_HPP
#include <experimental/optional>
+#include <functional>
namespace wm {
- using std::experimental::optional;
- using std::experimental::nullopt;
+using std::experimental::optional;
+using std::experimental::nullopt;
- // We only ever return a string as an error - so just parametrize
- // this over result type T
- template<typename T>
- struct result {
- char const *e;
- optional<T> t;
+// We only ever return a string as an error - so just parametrize
+// this over result type T
+template <typename T>
+struct result {
+ char const *e;
+ optional<T> t;
- bool is_ok() const { return this->t != nullopt; }
- bool is_err() const { return this->e != nullptr; }
+ bool is_ok() const { return this->t != nullopt; }
+ bool is_err() const { return this->e != nullptr; }
- T unwrap() { return this->t.value(); }
+ T unwrap() {
+ if (this->e != nullptr) {
+ throw std::logic_error(this->e);
+ }
+ return this->t.value();
+ }
- char const *unwrap_err() { return this->e; }
- };
+ operator T() { return this->unwrap(); }
- template<typename T>
- struct result<T> Err(char const *e) { return result<T>{e, nullopt}; }
+ char const *unwrap_err() { return this->e; }
- template<typename T>
- struct result<T> Ok(T t) { return result<T>{nullptr, t}; }
+ optional<T> const &ok() const { return this->t; }
+ optional<char const *> err() const {
+ return this->e ? optional<char const *>(this->e) : nullopt;
+ }
-} // namespace wm
+ result<T> map_err(std::function<char const *(char const *)> f);
+};
-#endif //TMCAGLWM_RESULT_HPP
+template <typename T>
+struct result<T> Err(char const *e) {
+ return result<T>{e, nullopt};
+}
+
+template <typename T>
+struct result<T> Ok(T t) {
+ return result<T>{nullptr, t};
+}
+
+template <typename T>
+result<T> result<T>::map_err(std::function<char const *(char const *)> f) {
+ if (this->is_err()) {
+ return Err<T>(f(this->e));
+ }
+ return *this;
+}
+
+} // namespace wm
+
+#endif // TMCAGLWM_RESULT_HPP