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/*
* Copyright (C) 2015 The Android Open Source Project
*
* 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 AAPT_UTIL_IMMUTABLEMAP_H
#define AAPT_UTIL_IMMUTABLEMAP_H
#include <utility>
#include <vector>
#include "util/TypeTraits.h"
namespace aapt {
template <typename TKey, typename TValue>
class ImmutableMap {
static_assert(is_comparable<TKey, TKey>::value, "key is not comparable");
public:
using const_iterator =
typename std::vector<std::pair<TKey, TValue>>::const_iterator;
ImmutableMap(ImmutableMap&&) noexcept = default;
ImmutableMap& operator=(ImmutableMap&&) noexcept = default;
static ImmutableMap<TKey, TValue> CreatePreSorted(
std::initializer_list<std::pair<TKey, TValue>> list) {
return ImmutableMap(
std::vector<std::pair<TKey, TValue>>(list.begin(), list.end()));
}
static ImmutableMap<TKey, TValue> CreateAndSort(
std::initializer_list<std::pair<TKey, TValue>> list) {
std::vector<std::pair<TKey, TValue>> data(list.begin(), list.end());
std::sort(data.begin(), data.end());
return ImmutableMap(std::move(data));
}
template <typename TKey2, typename = typename std::enable_if<
is_comparable<TKey, TKey2>::value>::type>
const_iterator find(const TKey2& key) const {
auto cmp = [](const std::pair<TKey, TValue>& candidate,
const TKey2& target) -> bool {
return candidate.first < target;
};
const_iterator end_iter = end();
auto iter = std::lower_bound(data_.begin(), end_iter, key, cmp);
if (iter == end_iter || iter->first == key) {
return iter;
}
return end_iter;
}
const_iterator begin() const { return data_.begin(); }
const_iterator end() const { return data_.end(); }
private:
DISALLOW_COPY_AND_ASSIGN(ImmutableMap);
explicit ImmutableMap(std::vector<std::pair<TKey, TValue>> data)
: data_(std::move(data)) {}
std::vector<std::pair<TKey, TValue>> data_;
};
} // namespace aapt
#endif /* AAPT_UTIL_IMMUTABLEMAP_H */