| [1166] | 1 | // Declarations for hash functions. -*- C++ -*-
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| 2 |
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| 3 | // Copyright (C) 2010-2021 Free Software Foundation, Inc.
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| 4 | //
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| 5 | // This file is part of the GNU ISO C++ Library. This library is free
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| 6 | // software; you can redistribute it and/or modify it under the
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| 7 | // terms of the GNU General Public License as published by the
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| 8 | // Free Software Foundation; either version 3, or (at your option)
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| 9 | // any later version.
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| 10 |
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| 11 | // This library is distributed in the hope that it will be useful,
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| 12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 14 | // GNU General Public License for more details.
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| 15 |
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| 16 | // Under Section 7 of GPL version 3, you are granted additional
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| 17 | // permissions described in the GCC Runtime Library Exception, version
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| 18 | // 3.1, as published by the Free Software Foundation.
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| 19 |
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| 20 | // You should have received a copy of the GNU General Public License and
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| 21 | // a copy of the GCC Runtime Library Exception along with this program;
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| 22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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| 23 | // <http://www.gnu.org/licenses/>.
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| 24 |
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| 25 | /** @file bits/hash_bytes.h
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| 26 | * This is an internal header file, included by other library headers.
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| 27 | * Do not attempt to use it directly. @headername{functional}
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| 28 | */
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| 29 |
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| 30 | #ifndef _HASH_BYTES_H
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| 31 | #define _HASH_BYTES_H 1
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| 32 |
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| 33 | #pragma GCC system_header
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| 34 |
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| 35 | #include <bits/c++config.h>
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| 36 |
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| 37 | namespace std
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| 38 | {
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| 39 | _GLIBCXX_BEGIN_NAMESPACE_VERSION
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| 40 |
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| 41 | // Hash function implementation for the nontrivial specialization.
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| 42 | // All of them are based on a primitive that hashes a pointer to a
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| 43 | // byte array. The actual hash algorithm is not guaranteed to stay
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| 44 | // the same from release to release -- it may be updated or tuned to
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| 45 | // improve hash quality or speed.
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| 46 | size_t
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| 47 | _Hash_bytes(const void* __ptr, size_t __len, size_t __seed);
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| 48 |
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| 49 | // A similar hash primitive, using the FNV hash algorithm. This
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| 50 | // algorithm is guaranteed to stay the same from release to release.
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| 51 | // (although it might not produce the same values on different
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| 52 | // machines.)
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| 53 | size_t
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| 54 | _Fnv_hash_bytes(const void* __ptr, size_t __len, size_t __seed);
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| 55 |
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| 56 | _GLIBCXX_END_NAMESPACE_VERSION
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| 57 | } // namespace
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| 58 |
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| 59 | #endif
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