vector_traits.h | Explore in Territory

/*
 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_VECTOR_TRAITS_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_VECTOR_TRAITS_H_

#include <memory>
#include <type_traits>
#include <utility>
#include "base/memory/scoped_refptr.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/type_traits.h"

namespace WTF {

// Vector traits serve two purposes:
// 1. Faster bulk operations: Instead of invoking proper constructors,
//    destructors, copy operators, and move operators on individual elements,
//    the vector implementation will just use `memcpy()` and friends where
//    possible.
// 2. Garbage collection support: HeapVector requires certain traits to be set
//    which is used to acknowledge that semantics are different from regular
//    `WTF::Vector` and `std::vector`.
template <typename T>
struct VectorTraitsBase { … };

template <typename T>
struct VectorTraits : VectorTraitsBase<T> { … };

// Classes marked with SimpleVectorTraits will use memmov, memcpy, memcmp
// instead of constructors, copy operators, etc for initialization, move and
// comparison.
template <typename T>
struct SimpleClassVectorTraits : VectorTraitsBase<T> { … };

// We know std::unique_ptr and RefPtr are simple enough that initializing to 0
// and moving with memcpy (and then not destructing the original) will totally
// work.
VectorTraits<scoped_refptr<P>>;

VectorTraits<std::unique_ptr<P>>;
static_assert …;
static_assert …;
static_assert …;
static_assert …;
static_assert …;
static_assert …;

VectorTraits<std::pair<First, Second>>;

}  // namespace WTF

#define WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(ClassName) …

#define WTF_ALLOW_MOVE_AND_INIT_WITH_MEM_FUNCTIONS(ClassName) …

#define WTF_ALLOW_INIT_WITH_MEM_FUNCTIONS(ClassName) …

#define WTF_ALLOW_CLEAR_UNUSED_SLOTS_WITH_MEM_FUNCTIONS(ClassName) …

VectorTraits;
SimpleClassVectorTraits;

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_VECTOR_TRAITS_H_
chromium/third_party/blink/renderer/platform/wtf/vector_traits.h
