name : object-size-trait.h // Copyright 2021 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef INCLUDE_CPPGC_OBJECT_SIZE_TRAIT_H_ #define INCLUDE_CPPGC_OBJECT_SIZE_TRAIT_H_ #include <cstddef> #include "cppgc/type-traits.h" #include "v8config.h" // NOLINT(build/include_directory) namespace cppgc { namespace internal { struct V8_EXPORT BaseObjectSizeTrait { protected: static size_t GetObjectSizeForGarbageCollected(const void*); static size_t GetObjectSizeForGarbageCollectedMixin(const void*); }; } // namespace internal namespace subtle { /** * Trait specifying how to get the size of an object that was allocated using * `MakeGarbageCollected()`. Also supports querying the size with an inner * pointer to a mixin. */ template <typename T, bool = IsGarbageCollectedMixinTypeV<T>> struct ObjectSizeTrait; template <typename T> struct ObjectSizeTrait<T, false> : cppgc::internal::BaseObjectSizeTrait { static_assert(sizeof(T), "T must be fully defined"); static_assert(IsGarbageCollectedTypeV<T>, "T must be of type GarbageCollected or GarbageCollectedMixin"); static size_t GetSize(const T& object) { return GetObjectSizeForGarbageCollected(&object); } }; template <typename T> struct ObjectSizeTrait<T, true> : cppgc::internal::BaseObjectSizeTrait { static_assert(sizeof(T), "T must be fully defined"); static size_t GetSize(const T& object) { return GetObjectSizeForGarbageCollectedMixin(&object); } }; } // namespace subtle } // namespace cppgc #endif // INCLUDE_CPPGC_OBJECT_SIZE_TRAIT_H_