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libreoffice/include/o3tl/hash_combine.hxx
Daniel Baumann 8e63e14cf6
Adding upstream version 4:25.2.3.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-22 16:20:04 +02:00

55 lines
1.7 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#pragma once
#include <cstddef>
#include <functional>
#include <type_traits>
namespace o3tl
{
template <typename T, typename N>
inline std::enable_if_t<(sizeof(N) == 4)> hash_combine(N& nSeed, T const* pValue, size_t nCount)
{
static_assert(sizeof(nSeed) == 4);
for (size_t i = 0; i < nCount; ++i)
{
nSeed ^= std::hash<T>{}(*pValue) + 0x9E3779B9u + (nSeed << 6) + (nSeed >> 2);
++pValue;
}
}
template <typename T, typename N>
inline std::enable_if_t<(sizeof(N) == 4)> hash_combine(N& nSeed, T const& nValue)
{
static_assert(sizeof(nSeed) == 4);
nSeed ^= std::hash<T>{}(nValue) + 0x9E3779B9u + (nSeed << 6) + (nSeed >> 2);
}
template <typename T, typename N>
inline std::enable_if_t<(sizeof(N) == 8)> hash_combine(N& nSeed, T const* pValue, size_t nCount)
{
static_assert(sizeof(nSeed) == 8);
for (size_t i = 0; i < nCount; ++i)
{
nSeed ^= std::hash<T>{}(*pValue) + 0x9E3779B97F4A7C15llu + (nSeed << 12) + (nSeed >> 4);
++pValue;
}
}
template <typename T, typename N>
inline std::enable_if_t<(sizeof(N) == 8)> hash_combine(N& nSeed, T const& nValue)
{
static_assert(sizeof(nSeed) == 8);
nSeed ^= std::hash<T>{}(nValue) + 0x9E3779B97F4A7C15llu + (nSeed << 12) + (nSeed >> 4);
}
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */