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