60 lines
2.1 KiB
C++
60 lines
2.1 KiB
C++
// Declarations for hash functions. -*- C++ -*-
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// Copyright (C) 2010-2020 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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/** @file bits/hash_bytes.h
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* This is an internal header file, included by other library headers.
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* Do not attempt to use it directly. @headername{functional}
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*/
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#ifndef _HASH_BYTES_H
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#define _HASH_BYTES_H 1
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#pragma GCC system_header
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#include <bits/c++config.h>
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namespace std
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{
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_GLIBCXX_BEGIN_NAMESPACE_VERSION
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// Hash function implementation for the nontrivial specialization.
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// All of them are based on a primitive that hashes a pointer to a
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// byte array. The actual hash algorithm is not guaranteed to stay
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// the same from release to release -- it may be updated or tuned to
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// improve hash quality or speed.
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size_t
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_Hash_bytes(const void* __ptr, size_t __len, size_t __seed);
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// A similar hash primitive, using the FNV hash algorithm. This
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// algorithm is guaranteed to stay the same from release to release.
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// (although it might not produce the same values on different
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// machines.)
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size_t
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_Fnv_hash_bytes(const void* __ptr, size_t __len, size_t __seed);
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_GLIBCXX_END_NAMESPACE_VERSION
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} // namespace
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#endif
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