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// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_BASE_HASHMAP_ENTRY_H_
#define V8_BASE_HASHMAP_ENTRY_H_
#include <cstdint>
namespace v8 {
namespace base {
// HashMap entries are (key, value, hash) triplets, with a boolean indicating if
// they are an empty entry. Some clients may not need to use the value slot
// (e.g. implementers of sets, where the key is the value).
template <typename Key, typename Value>
struct TemplateHashMapEntry {
Key key;
Value value;
uint32_t hash; // The full hash value for key
TemplateHashMapEntry(Key key, Value value, uint32_t hash)
: key(key), value(value), hash(hash), exists_(true) {}
bool exists() const { return exists_; }
void clear() { exists_ = false; }
private:
bool exists_;
};
// Specialization for pointer-valued keys
template <typename Key, typename Value>
struct TemplateHashMapEntry<Key*, Value> {
Key* key;
Value value;
uint32_t hash; // The full hash value for key
TemplateHashMapEntry(Key* key, Value value, uint32_t hash)
: key(key), value(value), hash(hash) {}
bool exists() const { return key != nullptr; }
void clear() { key = nullptr; }
};
// TODO(leszeks): There could be a specialisation for void values (e.g. for
// sets), which omits the value field
} // namespace base
} // namespace v8
#endif // V8_BASE_HASHMAP_ENTRY_H_
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