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// Copyright 2020 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 INCLUDE_CPPGC_EPHEMERON_PAIR_H_
#define INCLUDE_CPPGC_EPHEMERON_PAIR_H_
#include "cppgc/liveness-broker.h"
#include "cppgc/member.h"
namespace cppgc {
/**
* An ephemeron pair is used to conditionally retain an object.
* The `value` will be kept alive only if the `key` is alive.
*/
template <typename K, typename V>
struct EphemeronPair {
EphemeronPair(K* k, V* v) : key(k), value(v) {}
WeakMember<K> key;
Member<V> value;
void ClearValueIfKeyIsDead(const LivenessBroker& broker) {
if (!broker.IsHeapObjectAlive(key)) value = nullptr;
}
};
} // namespace cppgc
#endif // INCLUDE_CPPGC_EPHEMERON_PAIR_H_
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