148fb7bfaSmrg // Declarations for hash functions. -*- C++ -*- 248fb7bfaSmrg 3*b1e83836Smrg // Copyright (C) 2010-2022 Free Software Foundation, Inc. 448fb7bfaSmrg // 548fb7bfaSmrg // This file is part of the GNU ISO C++ Library. This library is free 648fb7bfaSmrg // software; you can redistribute it and/or modify it under the 748fb7bfaSmrg // terms of the GNU General Public License as published by the 848fb7bfaSmrg // Free Software Foundation; either version 3, or (at your option) 948fb7bfaSmrg // any later version. 1048fb7bfaSmrg 1148fb7bfaSmrg // This library is distributed in the hope that it will be useful, 1248fb7bfaSmrg // but WITHOUT ANY WARRANTY; without even the implied warranty of 1348fb7bfaSmrg // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1448fb7bfaSmrg // GNU General Public License for more details. 1548fb7bfaSmrg 1648fb7bfaSmrg // Under Section 7 of GPL version 3, you are granted additional 1748fb7bfaSmrg // permissions described in the GCC Runtime Library Exception, version 1848fb7bfaSmrg // 3.1, as published by the Free Software Foundation. 1948fb7bfaSmrg 2048fb7bfaSmrg // You should have received a copy of the GNU General Public License and 2148fb7bfaSmrg // a copy of the GCC Runtime Library Exception along with this program; 2248fb7bfaSmrg // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 2348fb7bfaSmrg // <http://www.gnu.org/licenses/>. 2448fb7bfaSmrg 2548fb7bfaSmrg /** @file bits/hash_bytes.h 2648fb7bfaSmrg * This is an internal header file, included by other library headers. 2748fb7bfaSmrg * Do not attempt to use it directly. @headername{functional} 2848fb7bfaSmrg */ 2948fb7bfaSmrg 3048fb7bfaSmrg #ifndef _HASH_BYTES_H 3148fb7bfaSmrg #define _HASH_BYTES_H 1 3248fb7bfaSmrg 3348fb7bfaSmrg #pragma GCC system_header 3448fb7bfaSmrg 3548fb7bfaSmrg #include <bits/c++config.h> 3648fb7bfaSmrg 3748fb7bfaSmrg namespace std 3848fb7bfaSmrg { 3948fb7bfaSmrg _GLIBCXX_BEGIN_NAMESPACE_VERSION 4048fb7bfaSmrg 4148fb7bfaSmrg // Hash function implementation for the nontrivial specialization. 4248fb7bfaSmrg // All of them are based on a primitive that hashes a pointer to a 4348fb7bfaSmrg // byte array. The actual hash algorithm is not guaranteed to stay 4448fb7bfaSmrg // the same from release to release -- it may be updated or tuned to 4548fb7bfaSmrg // improve hash quality or speed. 4648fb7bfaSmrg size_t 4748fb7bfaSmrg _Hash_bytes(const void* __ptr, size_t __len, size_t __seed); 4848fb7bfaSmrg 4948fb7bfaSmrg // A similar hash primitive, using the FNV hash algorithm. This 5048fb7bfaSmrg // algorithm is guaranteed to stay the same from release to release. 5148fb7bfaSmrg // (although it might not produce the same values on different 5248fb7bfaSmrg // machines.) 5348fb7bfaSmrg size_t 5448fb7bfaSmrg _Fnv_hash_bytes(const void* __ptr, size_t __len, size_t __seed); 5548fb7bfaSmrg 5648fb7bfaSmrg _GLIBCXX_END_NAMESPACE_VERSION 5748fb7bfaSmrg } // namespace 5848fb7bfaSmrg 5948fb7bfaSmrg #endif 60