chromium/src/third_party/blink/renderer/platform/heap/collection_support/heap_deque.h

// Copyright 2021 The Chromium 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 THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_COLLECTION_SUPPORT_HEAP_DEQUE_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_COLLECTION_SUPPORT_HEAP_DEQUE_H_

#include "third_party/blink/renderer/platform/heap/heap.h"
#include "third_party/blink/renderer/platform/heap/heap_allocator_impl.h"
#include "third_party/blink/renderer/platform/heap/visitor.h"
#include "third_party/blink/renderer/platform/wtf/deque.h"
#include "third_party/blink/renderer/platform/wtf/type_traits.h"

namespace blink {

template <typename T>
class HeapDeque final : public GarbageCollected<HeapDeque<T>>,
                        public Deque<T, 0, HeapAllocator> {
  DISALLOW_NEW();

 public:
  HeapDeque() = default;

  explicit HeapDeque(wtf_size_t size) : Deque<T, 0, HeapAllocator>(size) {
  }

  HeapDeque(wtf_size_t size, const T& val)
      : Deque<T, 0, HeapAllocator>(size, val) {
  }

  HeapDeque& operator=(const HeapDeque& other) {
    HeapDeque<T> copy(other);
    Deque<T, 0, HeapAllocator>::Swap(copy);
    return *this;
  }

  HeapDeque(const HeapDeque<T>& other) : Deque<T, 0, HeapAllocator>(other) {}

  void Trace(Visitor* visitor) const {
    CheckType();
    Deque<T, 0, HeapAllocator>::Trace(visitor);
  }

 private:
  static constexpr void CheckType() {
    static_assert(WTF::IsMemberType<T>::value,
                  "HeapDeque supports only Member.");
    static_assert(std::is_trivially_destructible<HeapDeque>::value,
                  "HeapDeque must be trivially destructible.");
    static_assert(WTF::IsTraceable<T>::value,
                  "For vectors without traceable elements, use Deque<> instead "
                  "of HeapDeque<>");
  }
};

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_COLLECTION_SUPPORT_HEAP_DEQUE_H_