1/*! *****************************************************************************
2Copyright (c) Microsoft Corporation. All rights reserved.
3Licensed under the Apache License, Version 2.0 (the "License"); you may not use
4this file except in compliance with the License. You may obtain a copy of the
5License at http://www.apache.org/licenses/LICENSE-2.0
6
7THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
8KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
9WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
10MERCHANTABLITY OR NON-INFRINGEMENT.
11
12See the Apache Version 2.0 License for specific language governing permissions
13and limitations under the License.
14***************************************************************************** */
15
16
17
18/// <reference no-default-lib="true"/>
19
20
21interface WeakRef<T extends object> {
22    readonly [Symbol.toStringTag]: "WeakRef";
23
24    /**
25     * Returns the WeakRef instance's target object, or undefined if the target object has been
26     * reclaimed.
27     */
28    deref(): T | undefined;
29}
30
31interface WeakRefConstructor {
32    readonly prototype: WeakRef<any>;
33
34    /**
35     * Creates a WeakRef instance for the given target object.
36     * @param target The target object for the WeakRef instance.
37     */
38    new<T extends object>(target?: T): WeakRef<T>;
39}
40
41declare var WeakRef: WeakRefConstructor;
42
43interface FinalizationRegistry {
44    readonly [Symbol.toStringTag]: "FinalizationRegistry";
45
46    /**
47     * Registers an object with the registry.
48     * @param target The target object to register.
49     * @param heldValue The value to pass to the finalizer for this object. This cannot be the
50     * target object.
51     * @param unregisterToken The token to pass to the unregister method to unregister the target
52     * object. If provided (and not undefined), this must be an object. If not provided, the target
53     * cannot be unregistered.
54     */
55    register(target: object, heldValue: any, unregisterToken?: object): void;
56
57    /**
58     * Unregisters an object from the registry.
59     * @param unregisterToken The token that was used as the unregisterToken argument when calling
60     * register to register the target object.
61     */
62    unregister(unregisterToken: object): void;
63}
64
65interface FinalizationRegistryConstructor {
66    readonly prototype: FinalizationRegistry;
67
68    /**
69     * Creates a finalization registry with an associated cleanup callback
70     * @param cleanupCallback The callback to call after an object in the registry has been reclaimed.
71     */
72    new(cleanupCallback: (heldValue: any) => void): FinalizationRegistry;
73}
74
75declare var FinalizationRegistry: FinalizationRegistryConstructor;
76