V8 API Reference, 7.2.502.16 (for Deno 0.2.4)
hashmap-entry.h
1 // Copyright 2016 the V8 project 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 V8_BASE_HASHMAP_ENTRY_H_
6 #define V8_BASE_HASHMAP_ENTRY_H_
7 
8 #include <cstdint>
9 
10 namespace v8 {
11 namespace base {
12 
13 // HashMap entries are (key, value, hash) triplets, with a boolean indicating if
14 // they are an empty entry. Some clients may not need to use the value slot
15 // (e.g. implementers of sets, where the key is the value).
16 template <typename Key, typename Value>
18  Key key;
19  Value value;
20  uint32_t hash; // The full hash value for key
21 
22  TemplateHashMapEntry(Key key, Value value, uint32_t hash)
23  : key(key), value(value), hash(hash), exists_(true) {}
24 
25  bool exists() const { return exists_; }
26 
27  void clear() { exists_ = false; }
28 
29  private:
30  bool exists_;
31 };
32 
33 // Specialization for pointer-valued keys
34 template <typename Key, typename Value>
35 struct TemplateHashMapEntry<Key*, Value> {
36  Key* key;
37  Value value;
38  uint32_t hash; // The full hash value for key
39 
40  TemplateHashMapEntry(Key* key, Value value, uint32_t hash)
41  : key(key), value(value), hash(hash) {}
42 
43  bool exists() const { return key != nullptr; }
44 
45  void clear() { key = nullptr; }
46 };
47 
48 // TODO(leszeks): There could be a specialisation for void values (e.g. for
49 // sets), which omits the value field
50 
51 } // namespace base
52 } // namespace v8
53 
54 #endif // V8_BASE_HASHMAP_ENTRY_H_
Definition: v8.h:2119
Definition: libplatform.h:13