1 /* 2 * Copyright (C) 2018 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 android_hardware_audio_common_VersionUtils_H_ 18 #define android_hardware_audio_common_VersionUtils_H_ 19 20 #include <hidl/HidlSupport.h> 21 #include <type_traits> 22 23 namespace android { 24 namespace hardware { 25 namespace audio { 26 namespace common { 27 namespace utils { 28 29 /** Similar to static_cast but also casts to hidl_bitfield depending on 30 * return type inference (emulated through user-define conversion). 31 */ 32 template <class Source, class Destination = Source> 33 class EnumConverter { 34 public: 35 static_assert(std::is_enum<Source>::value || std::is_enum<Destination>::value, 36 "Source or destination should be an enum"); 37 38 explicit EnumConverter(Source source) : mSource(source) {} 39 40 operator Destination() const { return static_cast<Destination>(mSource); } 41 42 template <class = std::enable_if_t<std::is_enum<Destination>::value>> 43 operator ::android::hardware::hidl_bitfield<Destination>() { 44 return static_cast<std::underlying_type_t<Destination>>(mSource); 45 } 46 47 private: 48 const Source mSource; 49 }; 50 template <class Destination, class Source> 51 auto mkEnumConverter(Source source) { 52 return EnumConverter<Source, Destination>{source}; 53 } 54 55 /** Allows converting an enum to its bitfield or itself. */ 56 template <class Enum> 57 EnumConverter<Enum> mkBitfield(Enum value) { 58 return EnumConverter<Enum>{value}; 59 } 60 61 } // namespace utils 62 } // namespace common 63 } // namespace audio 64 } // namespace hardware 65 } // namespace android 66 67 #endif // android_hardware_audio_common_VersionUtils_H_ 68
