chromium/third_party/blink/renderer/core/typed_arrays/array_buffer_view_helpers.h

// Copyright 2017 The Chromium Authors
// 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_CORE_TYPED_ARRAYS_ARRAY_BUFFER_VIEW_HELPERS_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_TYPED_ARRAYS_ARRAY_BUFFER_VIEW_HELPERS_H_

#include <type_traits>

#include "third_party/blink/renderer/core/typed_arrays/dom_array_buffer_view.h"
#include "third_party/blink/renderer/platform/heap/collection_support/heap_vector.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/heap/member.h"
#include "third_party/blink/renderer/platform/wtf/type_traits.h"

namespace blink {

// A wrapper template type that is used to ensure that a TypedArray is not
// backed by a SharedArrayBuffer.  It is usable like a smart pointer.
//
//   void Foo(NotShared<DOMUint32Array> param) {
//     size_t length = param->length();
//     ...
//   }
template <typename T>
class NotShared { … };

// A wrapper template type that specifies that a TypedArray *may* be backed by
// a SharedArrayBuffer.  It is usable like a smart pointer.
//
//   void Foo(MaybeShared<DOMUint32Array> param) {
//     DOMArrayBuffer* buffer = param->buffer();
//     ...
//   }
template <typename T>
class MaybeShared { … };

}  // namespace blink

namespace WTF {

// NotShared<T> is essentially Member<T> from the perspective of HeapVector.
VectorTraits<blink::NotShared<T>>;

// MaybeShared<T> is essentially Member<T> from the perspective of HeapVector.
VectorTraits<blink::MaybeShared<T>>;

}  // namespace WTF

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_TYPED_ARRAYS_ARRAY_BUFFER_VIEW_HELPERS_H_