hash.h

/*****************************************************************************
 * VCLib                                                                     *
 * Visual Computing Library                                                  *
 *                                                                           *
 * Copyright(C) 2021-2025                                                    *
 * Visual Computing Lab                                                      *
 * ISTI - Italian National Research Council                                  *
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 * This program is free software; you can redistribute it and/or modify      *
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 * This program is distributed in the hope that it will be useful,           *
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the              *
 * Mozilla Public License Version 2.0                                        *
 * (https://www.mozilla.org/en-US/MPL/2.0/) for more details.                *
 ****************************************************************************/
 
#ifndef VCL_BASE_HASH_H
#define VCL_BASE_HASH_H
 
#include <functional>
 
namespace vcl {
 
template<typename T, typename... Rest>
void hashCombine(std::size_t& seed, const T& v, const Rest&... rest)
{
    seed ^= std::hash<T> {}(v) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
    (hashCombine(seed, rest), ...);
}
 
} // namespace vcl
 
#endif // VCL_BASE_HASH_H