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
24 namespace android {
25
26 template<typename T, typename U>
27 struct 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>
mapALookup34 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>
mapALookup37 inline bool map(const V& from, T *to) const { return rlookup(from, to); }
38
39 private:
40 std::vector<std::pair<T, U>> mTable;
41 };
42
43 template<typename T, typename U>
ALookup(std::initializer_list<std::pair<T,U>> list)44 ALookup<T, U>::ALookup(std::initializer_list<std::pair<T, U>> list)
45 : mTable(list) {
46 }
47
48 template<typename T, typename U>
lookup(const T & from,U * to)49 bool 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
59 template<typename T, typename U>
rlookup(const U & from,T * to)60 bool 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