1*38fd1498Szrj // Declarations for hash functions. -*- C++ -*- 2*38fd1498Szrj 3*38fd1498Szrj // Copyright (C) 2010-2018 Free Software Foundation, Inc. 4*38fd1498Szrj // 5*38fd1498Szrj // This file is part of the GNU ISO C++ Library. This library is free 6*38fd1498Szrj // software; you can redistribute it and/or modify it under the 7*38fd1498Szrj // terms of the GNU General Public License as published by the 8*38fd1498Szrj // Free Software Foundation; either version 3, or (at your option) 9*38fd1498Szrj // any later version. 10*38fd1498Szrj 11*38fd1498Szrj // This library is distributed in the hope that it will be useful, 12*38fd1498Szrj // but WITHOUT ANY WARRANTY; without even the implied warranty of 13*38fd1498Szrj // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14*38fd1498Szrj // GNU General Public License for more details. 15*38fd1498Szrj 16*38fd1498Szrj // Under Section 7 of GPL version 3, you are granted additional 17*38fd1498Szrj // permissions described in the GCC Runtime Library Exception, version 18*38fd1498Szrj // 3.1, as published by the Free Software Foundation. 19*38fd1498Szrj 20*38fd1498Szrj // You should have received a copy of the GNU General Public License and 21*38fd1498Szrj // a copy of the GCC Runtime Library Exception along with this program; 22*38fd1498Szrj // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23*38fd1498Szrj // <http://www.gnu.org/licenses/>. 24*38fd1498Szrj 25*38fd1498Szrj /** @file bits/hash_bytes.h 26*38fd1498Szrj * This is an internal header file, included by other library headers. 27*38fd1498Szrj * Do not attempt to use it directly. @headername{functional} 28*38fd1498Szrj */ 29*38fd1498Szrj 30*38fd1498Szrj #ifndef _HASH_BYTES_H 31*38fd1498Szrj #define _HASH_BYTES_H 1 32*38fd1498Szrj 33*38fd1498Szrj #pragma GCC system_header 34*38fd1498Szrj 35*38fd1498Szrj #include <bits/c++config.h> 36*38fd1498Szrj 37*38fd1498Szrj namespace std 38*38fd1498Szrj { 39*38fd1498Szrj _GLIBCXX_BEGIN_NAMESPACE_VERSION 40*38fd1498Szrj 41*38fd1498Szrj // Hash function implementation for the nontrivial specialization. 42*38fd1498Szrj // All of them are based on a primitive that hashes a pointer to a 43*38fd1498Szrj // byte array. The actual hash algorithm is not guaranteed to stay 44*38fd1498Szrj // the same from release to release -- it may be updated or tuned to 45*38fd1498Szrj // improve hash quality or speed. 46*38fd1498Szrj size_t 47*38fd1498Szrj _Hash_bytes(const void* __ptr, size_t __len, size_t __seed); 48*38fd1498Szrj 49*38fd1498Szrj // A similar hash primitive, using the FNV hash algorithm. This 50*38fd1498Szrj // algorithm is guaranteed to stay the same from release to release. 51*38fd1498Szrj // (although it might not produce the same values on different 52*38fd1498Szrj // machines.) 53*38fd1498Szrj size_t 54*38fd1498Szrj _Fnv_hash_bytes(const void* __ptr, size_t __len, size_t __seed); 55*38fd1498Szrj 56*38fd1498Szrj _GLIBCXX_END_NAMESPACE_VERSION 57*38fd1498Szrj } // namespace 58*38fd1498Szrj 59*38fd1498Szrj #endif 60