szaszm commented on a change in pull request #809: URL: https://github.com/apache/nifi-minifi-cpp/pull/809#discussion_r440079252
########## File path: libminifi/include/utils/OptionalUtils.h ########## @@ -0,0 +1,44 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 LIBMINIFI_INCLUDE_UTILS_OPTIONALUTILS_H_ +#define LIBMINIFI_INCLUDE_UTILS_OPTIONALUTILS_H_ + +#include <utility> + +#include <nonstd/optional.hpp> +#include "utils/GeneralUtils.h" + +namespace org { +namespace apache { +namespace nifi { +namespace minifi { +namespace utils { + +template<typename T> +nonstd::optional<typename remove_cvref<T>::type> optional_from_nullable(T&& obj) { Review comment: I recommend introducing an alias to optional in our namespace and referring to that in our code. This would simplify later extension and migration. ########## File path: libminifi/include/utils/GeneralUtils.h ########## @@ -61,6 +61,17 @@ T exchange(T& obj, U&& new_value) { template<typename...> using void_t = void; +template<class T> +using remove_reference_t = typename std::remove_reference<T>::type; + +template<class T> +using remove_cv_t = typename std::remove_cv<T>::type; + +template<class T> +struct remove_cvref { + typedef remove_cv_t<remove_reference_t<T>> type; +}; Review comment: Please move `remove_cvref` either outside of `#ifdef` checks, or another one that checks for C++20 and falls back to `std::remove_cvref` if >= C++20. ########## File path: libminifi/include/utils/GeneralUtils.h ########## @@ -61,6 +61,17 @@ T exchange(T& obj, U&& new_value) { template<typename...> using void_t = void; +template<class T> +using remove_reference_t = typename std::remove_reference<T>::type; + +template<class T> +using remove_cv_t = typename std::remove_cv<T>::type; Review comment: Please add a fallback to std to the `#else` branch of this `#ifdef` block. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
