1 /* 2 * Copyright (C) 2022 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 CHRE_UTIL_COPYABLE_FIXED_SIZE_VECTOR_H_ 18 #define CHRE_UTIL_COPYABLE_FIXED_SIZE_VECTOR_H_ 19 20 #include <cstring> 21 #include <type_traits> 22 23 #include "chre/util/fixed_size_vector.h" 24 25 namespace chre { 26 27 /** 28 * Equivalent to FixedSizeVector, but for situations where there's an explicit 29 * need for it to be copyable. This implies that we've weighed alternatives and 30 * are OK with the potential overhead involved, for example if we know this is 31 * a small size collection that we'd otherwise use a plain array for. 32 */ 33 template <typename ElementType, size_t kCapacity> 34 class CopyableFixedSizeVector : public FixedSizeVector<ElementType, kCapacity> { 35 public: 36 CopyableFixedSizeVector() = default; 37 CopyableFixedSizeVector(const CopyableFixedSizeVector & other)38 CopyableFixedSizeVector(const CopyableFixedSizeVector &other) { 39 copyFrom(other); 40 } 41 42 CopyableFixedSizeVector &operator=(const CopyableFixedSizeVector &other) { 43 copyFrom(other); 44 return *this; 45 } 46 47 private: copyFrom(const CopyableFixedSizeVector & other)48 void copyFrom(const CopyableFixedSizeVector &other) { 49 this->mSize = other.mSize; 50 if (std::is_trivially_copy_constructible<ElementType>::value) { 51 std::memcpy(this->data(), other.data(), 52 sizeof(ElementType) * this->mSize); 53 } else { 54 for (size_t i = 0; i < this->mSize; i++) { 55 new (&this->data()[i]) ElementType(other[i]); 56 } 57 } 58 } 59 }; 60 61 } // namespace chre 62 63 #endif // CHRE_UTIL_COPYABLE_FIXED_SIZE_VECTOR_H_