upstream/utility/BinaryCopy.hpp

/*
 * Copyright (c) 2015, Intel Corporation
 * All rights reserved.
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 * this list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
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 * may be used to endorse or promote products derived from this software without
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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#include <algorithm>
#include <type_traits>
#include "Iterator.hpp"
#include <cassert>

namespace utility
{

/**
 * Raw copy of one variable to another of the same size
 *
 * This can be regarder as a reinterpret_cast but does a copy and does not
 * break strict-aliasing rules.
 *
 * The source and the destination must have the same storage size (e.g. copying
 * a uint8_t into a uint32_t won't compile)
 *
 * @tparam Source The source type
 * @tparam Destination the destination type (even if it is a reference, this
 *         function returns by copy)
 * @param source Source variable
 * @returns the source, reinterpreted as the destination type
 */
template <class Destination, class Source>
typename std::remove_reference<Destination>::type binaryCopy(const Source source)
{
    static_assert(sizeof(Source) == sizeof(Destination),
                  "Source and Destination must have the same size");

    using Destination_ = decltype(binaryCopy<Destination>(source));

    union
    {
        Source source;
        Destination_ destination;
    } hack;

    hack.source = source;
    return hack.destination;
}

} // namespace utility