1 // Copyright (C) 2019 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef ICING_LEGACY_CORE_ICING_PACKED_POD_H_ 16 #define ICING_LEGACY_CORE_ICING_PACKED_POD_H_ 17 18 #include <type_traits> 19 20 namespace icing { 21 namespace lib { 22 23 // Any struct whose size is not a multiple of its alignment will lead to a 24 // padding of sizeof(T) % alignof(T) bytes per element when creating an array of 25 // that type. 26 template <typename T> 27 struct no_array_padding 28 : std::integral_constant<bool, sizeof(T) % alignof(T) == 0> {}; 29 30 // See go/icing-ubsan for details on requirements of packed objects. 31 template <typename T> 32 struct icing_is_packed_pod 33 : std::conjunction<std::integral_constant<bool, alignof(T) == 1>, 34 std::is_standard_layout<T>, 35 std::is_trivially_copyable<T>> {}; 36 37 } // namespace lib 38 } // namespace icing 39 40 #endif // ICING_LEGACY_CORE_ICING_PACKED_POD_H_ 41