| 29 | |
| 30 | template <typename T> |
| 31 | class AlignedStorage { |
| 32 | public: |
| 33 | static constexpr bool can_memcpy = std::is_trivially_copyable<T>::value && |
| 34 | std::is_trivially_default_constructible<T>::value; |
| 35 | |
| 36 | constexpr T* get() noexcept { |
| 37 | return arrow::internal::launder(reinterpret_cast<T*>(&data_)); |
| 38 | } |
| 39 | |
| 40 | constexpr const T* get() const noexcept { |
| 41 | // Use fully qualified name to avoid ambiguities with MSVC (ARROW-14800) |
| 42 | return arrow::internal::launder(reinterpret_cast<const T*>(&data_)); |
| 43 | } |
| 44 | |
| 45 | void destroy() noexcept { |
| 46 | if (!std::is_trivially_destructible<T>::value) { |
| 47 | get()->~T(); |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | template <typename... A> |
| 52 | void construct(A&&... args) noexcept { |
| 53 | new (&data_) T(std::forward<A>(args)...); |
| 54 | } |
| 55 | |
| 56 | template <typename V> |
| 57 | void assign(V&& v) noexcept { |
| 58 | *get() = std::forward<V>(v); |
| 59 | } |
| 60 | |
| 61 | void move_construct(AlignedStorage* other) noexcept { |
| 62 | new (&data_) T(std::move(*other->get())); |
| 63 | } |
| 64 | |
| 65 | void move_assign(AlignedStorage* other) noexcept { *get() = std::move(*other->get()); } |
| 66 | |
| 67 | template <bool CanMemcpy = can_memcpy> |
| 68 | static typename std::enable_if<CanMemcpy>::type move_construct_several( |
| 69 | AlignedStorage* ARROW_RESTRICT src, AlignedStorage* ARROW_RESTRICT dest, size_t n, |
| 70 | size_t memcpy_length) noexcept { |
| 71 | memcpy(dest->get(), src->get(), memcpy_length * sizeof(T)); |
| 72 | } |
| 73 | |
| 74 | template <bool CanMemcpy = can_memcpy> |
| 75 | static typename std::enable_if<CanMemcpy>::type |
| 76 | move_construct_several_and_destroy_source(AlignedStorage* ARROW_RESTRICT src, |
| 77 | AlignedStorage* ARROW_RESTRICT dest, size_t n, |
| 78 | size_t memcpy_length) noexcept { |
| 79 | memcpy(dest->get(), src->get(), memcpy_length * sizeof(T)); |
| 80 | } |
| 81 | |
| 82 | template <bool CanMemcpy = can_memcpy> |
| 83 | static typename std::enable_if<!CanMemcpy>::type move_construct_several( |