2 * Copyright 2015 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
16 // Copyright 2013-present Facebook. All Rights Reserved.
17 // @author: Pavlo Kushnir (pavlo)
19 #ifndef FOLLY_EXPERIMENTAL_STRINGKEYEDSET_H_
20 #define FOLLY_EXPERIMENTAL_STRINGKEYEDSET_H_
22 #include <initializer_list>
25 #include <folly/Range.h>
26 #include <folly/experimental/StringKeyedCommon.h>
31 * Wrapper class for set<string> that can
32 * perform lookup operations with StringPiece, not only string.
34 * It uses kind of hack: string pointed by StringPiece is copied when
35 * StringPiece is inserted into set
37 template <class Compare = std::less<StringPiece>,
38 class Alloc = std::allocator<StringPiece>>
39 class StringKeyedSetBase
40 : private std::set<StringPiece, Compare, Alloc> {
42 using Base = std::set<StringPiece, Compare, Alloc>;
45 typedef typename Base::key_type key_type;
46 typedef typename Base::value_type value_type;
47 typedef typename Base::key_compare key_compare;
48 typedef typename Base::allocator_type allocator_type;
49 typedef typename Base::reference reference;
50 typedef typename Base::const_reference const_reference;
51 typedef typename Base::pointer pointer;
52 typedef typename Base::const_pointer const_pointer;
53 typedef typename Base::iterator iterator;
54 typedef typename Base::const_iterator const_iterator;
55 typedef typename Base::reverse_iterator reverse_iterator;
56 typedef typename Base::const_reverse_iterator const_reverse_iterator;
57 typedef typename Base::size_type size_type;
58 typedef typename Base::difference_type difference_type;
60 explicit StringKeyedSetBase(
61 const key_compare& comp = key_compare(),
62 const allocator_type& alloc = allocator_type())
66 explicit StringKeyedSetBase(const allocator_type& alloc)
70 template <class InputIterator>
72 InputIterator b, InputIterator e,
73 const key_compare& comp = key_compare(),
74 const allocator_type& alloc = allocator_type())
81 StringKeyedSetBase(const StringKeyedSetBase& rhs)
82 : StringKeyedSetBase(rhs, rhs.get_allocator()) {
85 StringKeyedSetBase(const StringKeyedSetBase& rhs,
86 const allocator_type& a)
87 : StringKeyedSetBase(rhs.begin(), rhs.end(), rhs.key_comp(), a) {
90 StringKeyedSetBase(StringKeyedSetBase&& other) noexcept
91 : Base(std::move(other)) {
92 assert(other.empty());
95 StringKeyedSetBase(StringKeyedSetBase&& other,
96 const allocator_type& alloc) noexcept
97 : Base(std::move(other), alloc) {
98 assert(other.empty());
102 std::initializer_list<value_type> il,
103 const key_compare& comp = key_compare(),
104 const allocator_type& alloc = allocator_type())
105 : StringKeyedSetBase(il.begin(), il.end(), comp, alloc) {
108 StringKeyedSetBase& operator=(const StringKeyedSetBase& other) {
109 if (this == &other) {
112 return *this = StringKeyedSetBase(other);
115 StringKeyedSetBase& operator=(StringKeyedSetBase&& other) noexcept {
116 assert(this != &other);
118 Base::operator=(std::move(other));
119 assert(other.empty());
125 using Base::max_size;
131 using Base::lower_bound;
132 using Base::upper_bound;
134 template <class... Args>
135 std::pair<iterator, bool> emplace(Args&&... args) {
136 auto key = StringPiece(std::forward<Args>(args)...);
141 return Base::emplace(stringPieceDup(key, get_allocator()));
144 std::pair<iterator, bool> insert(value_type val) {
149 return Base::insert(stringPieceDup(val, get_allocator()));
152 iterator erase(const_iterator position) {
153 auto key = *position;
154 auto result = Base::erase(position);
155 stringPieceDel(key, get_allocator());
159 size_type erase(StringPiece key) {
168 void clear() noexcept {
169 for (auto it : *this) {
170 stringPieceDel(it, get_allocator());
175 using Base::get_allocator;
177 ~StringKeyedSetBase() {
178 // Here we assume that set doesn't use keys in destructor
179 for (auto it : *this) {
180 stringPieceDel(it, get_allocator());
185 using StringKeyedSet = StringKeyedSetBase<>;
189 #endif /* FOLLY_EXPERIMENTAL_STRINGKEYEDSET_H_ */