1 /*
2  * Copyright (C) 2019 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 /**
18  * @addtogroup NdkBinder
19  * @{
20  */
21 
22 /**
23  * @file binder_enums.h
24  * @brief Helpers for AIDL enum types.
25  */
26 
27 #pragma once
28 
29 #include <iterator>
30 #include <type_traits>
31 
32 namespace ndk {
33 
34 namespace internal {
35 /**
36  * Never instantiated. Used as a placeholder for template variables.
37  */
38 template <typename T>
39 struct invalid_type;
40 
41 /**
42  * AIDL generates specializations of this for enums.
43  */
44 template <typename EnumType, typename = std::enable_if_t<std::is_enum<EnumType>::value>>
45 constexpr invalid_type<EnumType> enum_values;
46 }  // namespace internal
47 
48 /**
49  * Iterable interface to enumerate all values of AIDL enum types.
50  */
51 template <typename EnumType, typename = std::enable_if_t<std::is_enum<EnumType>::value>>
52 struct enum_range {
53     /**
54      * Return an iterator pointing to the first enum value.
55      */
beginenum_range56     constexpr auto begin() const { return std::begin(internal::enum_values<EnumType>); }
57     /**
58      * Return an iterator pointing to one past the last enum value.
59      */
endenum_range60     constexpr auto end() const { return std::end(internal::enum_values<EnumType>); }
61 };
62 
63 }  // namespace ndk
64 
65 /** @} */