| /* |
| * 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 CONDITIONAL_BACK_INSERTER_HPP_ |
| #define CONDITIONAL_BACK_INSERTER_HPP_ |
| |
| #include <iterator> |
| #include <functional> |
| |
| namespace datasketches { |
| |
| template <typename Container, typename Predicate> |
| class conditional_back_insert_iterator: public std::back_insert_iterator<Container> { |
| public: |
| template<typename P> |
| conditional_back_insert_iterator(Container& c, P&& p): std::back_insert_iterator<Container>(c), p(std::forward<P>(p)) {} |
| |
| // MSVC seems to insist on having copy constructor and assignment |
| conditional_back_insert_iterator(const conditional_back_insert_iterator& other): |
| std::back_insert_iterator<Container>(other), p(other.p) {} |
| conditional_back_insert_iterator& operator=(const conditional_back_insert_iterator& other) { |
| std::back_insert_iterator<Container>::operator=(other); |
| p = other.p; |
| return *this; |
| } |
| |
| conditional_back_insert_iterator& operator=(const typename Container::value_type& value) { |
| if (p(value)) std::back_insert_iterator<Container>::operator=(value); |
| return *this; |
| } |
| |
| conditional_back_insert_iterator& operator=(typename Container::value_type&& value) { |
| if (p(value)) std::back_insert_iterator<Container>::operator=(std::move(value)); |
| return *this; |
| } |
| |
| conditional_back_insert_iterator& operator*() { return *this; } |
| conditional_back_insert_iterator& operator++() { return *this; } |
| conditional_back_insert_iterator& operator++(int) { return *this; } |
| |
| private: |
| Predicate p; |
| }; |
| |
| template<typename Container, typename Predicate> |
| conditional_back_insert_iterator<Container, Predicate> conditional_back_inserter(Container& c, Predicate&& p) { |
| return conditional_back_insert_iterator<Container, Predicate>(c, std::forward<Predicate>(p)); |
| } |
| |
| } /* namespace datasketches */ |
| |
| #endif |