Source/WTF/wtf/RawValueTraits.h

/*
 * Copyright (C) 2018 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
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 */

#pragma once

#include <cstdint>
#include <utility>

namespace WTF {

template<typename T>
struct RawValueTraits {
    template<typename U> using RebindTraits = RawValueTraits<U>;

    using StorageType = T;

    template<typename U>
    static ALWAYS_INLINE T exchange(StorageType& val, U&& newValue) { return std::exchange(val, newValue); }

    static ALWAYS_INLINE void swap(StorageType& a, StorageType& b) { std::swap(a, b); }
    static ALWAYS_INLINE T unwrap(const StorageType& val) { return val; }
};

} // namespace WTF

using WTF::RawValueTraits;