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Diffstat (limited to 'Firestore/core/src/firebase/firestore/util/range.h')
-rw-r--r-- | Firestore/core/src/firebase/firestore/util/range.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/Firestore/core/src/firebase/firestore/util/range.h b/Firestore/core/src/firebase/firestore/util/range.h new file mode 100644 index 0000000..9e96c67 --- /dev/null +++ b/Firestore/core/src/firebase/firestore/util/range.h @@ -0,0 +1,78 @@ +/* + * Copyright 2018 Google + * + * 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 FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_RANGE_H_ +#define FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_RANGE_H_ + +#include <iterator> +#include <utility> + +namespace firebase { +namespace firestore { +namespace util { + +/** + * Adapts a pair of iterators into a range suitable for use with range-based + * for loops. + */ +template <typename Iterator> +class range { + public: + using value_type = typename std::iterator_traits<Iterator>::value_type; + using iterator = Iterator; + using const_iterator = Iterator; + + /** + * Default range which constructs default begin and end pointers. For most + * implementations where the end pointer is a null pointer or some other + * default value, this ends up constructing the empty range. + */ + range() : begin_{}, end_{} { + } + + /** + * Creates a half-open range starting from begin up to, but not including end. + */ + range(iterator&& begin, iterator&& end) + : begin_{std::move(begin)}, end_{std::move(end)} { + } + + iterator begin() const { + return begin_; + } + + iterator end() const { + return end_; + } + + private: + Iterator begin_; + Iterator end_; +}; + +/** + * Creates ranges with type deduction. + */ +template <typename Iterator> +range<Iterator> make_range(Iterator begin, Iterator end) { + return range<Iterator>{std::move(begin), std::move(end)}; +} + +} // namespace util +} // namespace firestore +} // namespace firebase + +#endif // FIRESTORE_CORE_SRC_FIREBASE_FIRESTORE_UTIL_RANGE_H_ |