1/*
2 * Copyright 2016 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 A_LOOKUP_H_
18
19#define A_LOOKUP_H_
20
21#include <utility>
22#include <vector>
23
24namespace android {
25
26template<typename T, typename U>
27struct ALookup {
28    ALookup(std::initializer_list<std::pair<T, U>> list);
29
30    bool lookup(const T& from, U *to) const;
31    bool rlookup(const U& from, T *to) const;
32
33    template<typename V, typename = typename std::enable_if<!std::is_same<T, V>::value>::type>
34    inline bool map(const T& from, V *to) const { return lookup(from, to); }
35
36    template<typename V, typename = typename std::enable_if<!std::is_same<T, V>::value>::type>
37    inline bool map(const V& from, T *to) const { return rlookup(from, to); }
38
39private:
40    std::vector<std::pair<T, U>> mTable;
41};
42
43template<typename T, typename U>
44ALookup<T, U>::ALookup(std::initializer_list<std::pair<T, U>> list)
45    : mTable(list) {
46}
47
48template<typename T, typename U>
49bool ALookup<T, U>::lookup(const T& from, U *to) const {
50    for (auto elem : mTable) {
51        if (elem.first == from) {
52            *to = elem.second;
53            return true;
54        }
55    }
56    return false;
57}
58
59template<typename T, typename U>
60bool ALookup<T, U>::rlookup(const U& from, T *to) const {
61    for (auto elem : mTable) {
62        if (elem.second == from) {
63            *to = elem.first;
64            return true;
65        }
66    }
67    return false;
68}
69
70} // namespace android
71
72#endif  // A_UTILS_H_
73