1 // -*- C++ -*- 2 3 // Copyright (C) 2005, 2006, 2009, 2011 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the terms 7 // of the GNU General Public License as published by the Free Software 8 // Foundation; either version 3, or (at your option) any later 9 // version. 10 11 // This library is distributed in the hope that it will be useful, but 12 // WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 // General Public License for more details. 15 16 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL. 26 27 // Permission to use, copy, modify, sell, and distribute this software 28 // is hereby granted without fee, provided that the above copyright 29 // notice appears in all copies, and that both that copyright notice 30 // and this permission notice appear in supporting documentation. None 31 // of the above authors, nor IBM Haifa Research Laboratories, make any 32 // representation about the suitability of this software for any 33 // purpose. It is provided "as is" without express or implied 34 // warranty. 35 36 /** 37 * @file hash_eq_fn.hpp 38 * Contains 2 eqivalence functions, one employing a hash value, 39 * and one ignoring it. 40 */ 41 42 #ifndef PB_DS_HASH_EQ_FN_HPP 43 #define PB_DS_HASH_EQ_FN_HPP 44 45 #include <utility> 46 #include <debug/debug.h> 47 48 namespace __gnu_pbds 49 { 50 namespace detail 51 { 52 /// Primary template. 53 template<typename Key, typename Eq_Fn, typename _Alloc, bool Store_Hash> 54 struct hash_eq_fn; 55 56 /// Specialization 1 - The client requests that hash values not be stored. 57 template<typename Key, typename Eq_Fn, typename _Alloc> 58 struct hash_eq_fn<Key, Eq_Fn, _Alloc, false> : public Eq_Fn 59 { 60 typedef Eq_Fn eq_fn_base; 61 typedef typename _Alloc::template rebind<Key>::other key_allocator; 62 typedef typename key_allocator::const_reference key_const_reference; 63 64 hash_eq_fn() { } 65 66 hash_eq_fn(const Eq_Fn& r_eq_fn) : Eq_Fn(r_eq_fn) { } 67 68 bool 69 operator()(key_const_reference r_lhs_key, 70 key_const_reference r_rhs_key) const 71 { return eq_fn_base::operator()(r_lhs_key, r_rhs_key); } 72 73 void 74 swap(const hash_eq_fn& other) 75 { std::swap((Eq_Fn&)(*this), (Eq_Fn&)other); } 76 }; 77 78 79 /// Specialization 2 - The client requests that hash values be stored. 80 template<typename Key, class Eq_Fn, class _Alloc> 81 struct hash_eq_fn<Key, Eq_Fn, _Alloc, true> : public Eq_Fn 82 { 83 typedef typename _Alloc::size_type size_type; 84 typedef Eq_Fn eq_fn_base; 85 typedef typename _Alloc::template rebind<Key>::other key_allocator; 86 typedef typename key_allocator::const_reference key_const_reference; 87 88 hash_eq_fn() { } 89 90 hash_eq_fn(const Eq_Fn& r_eq_fn) : Eq_Fn(r_eq_fn) { } 91 92 bool 93 operator()(key_const_reference r_lhs_key, size_type lhs_hash, 94 key_const_reference r_rhs_key, size_type rhs_hash) const 95 { 96 _GLIBCXX_DEBUG_ASSERT(!eq_fn_base::operator()(r_lhs_key, r_rhs_key) 97 || lhs_hash == rhs_hash); 98 99 return (lhs_hash == rhs_hash && 100 eq_fn_base::operator()(r_lhs_key, r_rhs_key)); 101 } 102 103 void 104 swap(const hash_eq_fn& other) 105 { std::swap((Eq_Fn&)(*this), (Eq_Fn&)(other)); } 106 }; 107 } // namespace detail 108 } // namespace __gnu_pbds 109 110 #endif 111