Fairphone ODM | 25c12f5 | 2023-12-15 17:24:06 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2015 The Android Open Source Project |
| 3 | * |
| 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 |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 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. |
| 15 | */ |
| 16 | |
| 17 | #ifndef ART_LIBARTBASE_BASE_ITERATION_RANGE_H_ |
| 18 | #define ART_LIBARTBASE_BASE_ITERATION_RANGE_H_ |
| 19 | |
| 20 | #include <iterator> |
| 21 | #include <type_traits> |
| 22 | |
| 23 | namespace art { |
| 24 | |
| 25 | // Helper class that acts as a container for range-based loops, given an iteration |
| 26 | // range [first, last) defined by two iterators. |
| 27 | template <typename Iter> |
| 28 | class IterationRange { |
| 29 | public: |
| 30 | using iterator = Iter; |
| 31 | using difference_type = typename std::iterator_traits<Iter>::difference_type; |
| 32 | using value_type = typename std::iterator_traits<Iter>::value_type; |
| 33 | using pointer = typename std::iterator_traits<Iter>::pointer; |
| 34 | using reference = typename std::iterator_traits<Iter>::reference; |
| 35 | |
| 36 | IterationRange(iterator first, iterator last) : first_(first), last_(last) { } |
| 37 | |
| 38 | iterator begin() const { return first_; } |
| 39 | iterator end() const { return last_; } |
| 40 | iterator cbegin() const { return first_; } |
| 41 | iterator cend() const { return last_; } |
| 42 | |
| 43 | protected: |
| 44 | iterator first_; |
| 45 | iterator last_; |
| 46 | }; |
| 47 | |
| 48 | template <typename Iter> |
| 49 | inline IterationRange<Iter> MakeIterationRange(const Iter& begin_it, const Iter& end_it) { |
| 50 | return IterationRange<Iter>(begin_it, end_it); |
| 51 | } |
| 52 | |
| 53 | template <typename List> |
| 54 | inline auto MakeIterationRange(List& list) -> IterationRange<decltype(list.begin())> { |
| 55 | static_assert(std::is_same_v<decltype(list.begin()), decltype(list.end())>, |
| 56 | "Different iterator types"); |
| 57 | return MakeIterationRange(list.begin(), list.end()); |
| 58 | } |
| 59 | |
| 60 | template <typename Iter> |
| 61 | inline IterationRange<Iter> MakeEmptyIterationRange(const Iter& it) { |
| 62 | return IterationRange<Iter>(it, it); |
| 63 | } |
| 64 | |
| 65 | template <typename Container> |
| 66 | inline auto ReverseRange(Container&& c) { |
| 67 | using riter = typename std::reverse_iterator<decltype(c.begin())>; |
| 68 | return MakeIterationRange(riter(c.end()), riter(c.begin())); |
| 69 | } |
| 70 | |
| 71 | template <typename T, size_t size> |
| 72 | inline auto ReverseRange(T (&array)[size]) { |
| 73 | return ReverseRange(MakeIterationRange<T*>(array, array+size)); |
| 74 | } |
| 75 | |
| 76 | } // namespace art |
| 77 | |
| 78 | #endif // ART_LIBARTBASE_BASE_ITERATION_RANGE_H_ |