Source/WTF/wtf/EmbeddedFixedVector.h

/*
 * Copyright (C) 2021 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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#pragma once

#include <wtf/Noncopyable.h>
#include <wtf/Nonmovable.h>
#include <wtf/TrailingArray.h>
#include <wtf/UniqueRef.h>

namespace WTF {

template<typename T>
class EmbeddedFixedVector final : public TrailingArray<EmbeddedFixedVector<T>, T> {
    WTF_MAKE_FAST_ALLOCATED(EmbeddedFixedVector);
    WTF_MAKE_NONCOPYABLE(EmbeddedFixedVector);
    WTF_MAKE_NONMOVABLE(EmbeddedFixedVector);
public:
    using Base = TrailingArray<EmbeddedFixedVector<T>, T>;

    static UniqueRef<EmbeddedFixedVector> create(unsigned size)
    {
        return UniqueRef { *new (NotNull, fastMalloc(Base::allocationSize(size))) EmbeddedFixedVector(size) };
    }

    template<typename InputIterator>
    static UniqueRef<EmbeddedFixedVector> create(InputIterator first, InputIterator last)
    {
        unsigned size = Checked<uint32_t> { std::distance(first, last) };
        return UniqueRef { *new (NotNull, fastMalloc(Base::allocationSize(size))) EmbeddedFixedVector(size, first, last) };
    }

    template<size_t inlineCapacity, typename OverflowHandler>
    static UniqueRef<EmbeddedFixedVector> createFromVector(const Vector<T, inlineCapacity, OverflowHandler>& other)
    {
        unsigned size = Checked<uint32_t> { other.size() }.value();
        return UniqueRef { *new (NotNull, fastMalloc(Base::allocationSize(size))) EmbeddedFixedVector(size, other.begin(), other.end()) };
    }

    template<size_t inlineCapacity, typename OverflowHandler>
    static UniqueRef<EmbeddedFixedVector> createFromVector(Vector<T, inlineCapacity, OverflowHandler>&& other)
    {
        Vector<T, inlineCapacity, OverflowHandler> container = WTFMove(other);
        unsigned size = Checked<uint32_t> { container.size() }.value();
        return UniqueRef { *new (NotNull, fastMalloc(Base::allocationSize(size))) EmbeddedFixedVector(size, std::move_iterator { container.begin() }, std::move_iterator { container.end() }) };
    }

    template<typename... Args>
    static UniqueRef<EmbeddedFixedVector> createWithSizeAndConstructorArguments(unsigned size, Args&&... args)
    {
        return UniqueRef { *new (NotNull, fastMalloc(Base::allocationSize(size))) EmbeddedFixedVector(size, std::forward<Args>(args)...) };
    }

    UniqueRef<EmbeddedFixedVector> clone() const
    {
        return create(Base::begin(), Base::end());
    }

    bool operator!=(const EmbeddedFixedVector& other) const
    {
        return !(*this == other);
    }

    bool operator==(const EmbeddedFixedVector& other) const
    {
        if (Base::size() != other.size())
            return false;
        for (unsigned i = 0; i < Base::size(); ++i) {
            if (Base::at(i) != other.at(i))
                return false;
        }
        return true;
    }

private:
    explicit EmbeddedFixedVector(unsigned size)
        : Base(size)
    {
    }


    template<typename InputIterator>
    EmbeddedFixedVector(unsigned size, InputIterator first, InputIterator last)
        : Base(size, first, last)
    {
    }

    template<typename... Args>
    explicit EmbeddedFixedVector(unsigned size, Args&&... args) // create with given size and constructor arguments for all elements
        : Base(size, std::forward<Args>(args)...)
    {
    }
};

} // namespace WTF

using WTF::EmbeddedFixedVector;