1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_CONTAINERS_HASH_TABLES_H_ 6 #define BASE_CONTAINERS_HASH_TABLES_H_ 7 8 #include <cstddef> 9 #include <unordered_map> 10 #include <unordered_set> 11 #include <utility> 12 13 #include "base/hash.h" 14 15 // This header file is deprecated. Use the corresponding C++11 type 16 // instead. https://crbug.com/576864 17 18 // Use a custom hasher instead. 19 #define BASE_HASH_NAMESPACE base_hash 20 21 namespace BASE_HASH_NAMESPACE { 22 23 // A separate hasher which, by default, forwards to std::hash. This is so legacy 24 // uses of BASE_HASH_NAMESPACE with base::hash_map do not interfere with 25 // std::hash mid-transition. 26 template<typename T> 27 struct hash { 28 std::size_t operator()(const T& value) const { return std::hash<T>()(value); } 29 }; 30 31 // Use base::IntPairHash from base/hash.h as a custom hasher instead. 32 template <typename Type1, typename Type2> 33 struct hash<std::pair<Type1, Type2>> { 34 std::size_t operator()(std::pair<Type1, Type2> value) const { 35 return base::HashInts(value.first, value.second); 36 } 37 }; 38 39 } // namespace BASE_HASH_NAMESPACE 40 41 namespace base { 42 43 // Use std::unordered_map instead. 44 template <class Key, 45 class T, 46 class Hash = BASE_HASH_NAMESPACE::hash<Key>, 47 class Pred = std::equal_to<Key>, 48 class Alloc = std::allocator<std::pair<const Key, T>>> 49 using hash_map = std::unordered_map<Key, T, Hash, Pred, Alloc>; 50 51 // Use std::unordered_multimap instead. 52 template <class Key, 53 class T, 54 class Hash = BASE_HASH_NAMESPACE::hash<Key>, 55 class Pred = std::equal_to<Key>, 56 class Alloc = std::allocator<std::pair<const Key, T>>> 57 using hash_multimap = std::unordered_multimap<Key, T, Hash, Pred, Alloc>; 58 59 // Use std::unordered_multiset instead. 60 template <class Key, 61 class Hash = BASE_HASH_NAMESPACE::hash<Key>, 62 class Pred = std::equal_to<Key>, 63 class Alloc = std::allocator<Key>> 64 using hash_multiset = std::unordered_multiset<Key, Hash, Pred, Alloc>; 65 66 // Use std::unordered_set instead. 67 template <class Key, 68 class Hash = BASE_HASH_NAMESPACE::hash<Key>, 69 class Pred = std::equal_to<Key>, 70 class Alloc = std::allocator<Key>> 71 using hash_set = std::unordered_set<Key, Hash, Pred, Alloc>; 72 73 } // namespace base 74 75 #endif // BASE_CONTAINERS_HASH_TABLES_H_ 76
