type ObjectKeyAny = { [key: string]: any };

/*! *****************************************************************************
Copyright (C) Microsoft. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use
this file except in compliance with the License. You may obtain a copy of the
License at http://www.apache.org/licenses/LICENSE-2.0

THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
MERCHANTABLITY OR NON-INFRINGEMENT.

See the Apache Version 2.0 License for specific language governing permissions
and limitations under the License.
***************************************************************************** */
export namespace Reflect {
    // Metadata Proposal
    // https://rbuckton.github.io/reflect-metadata/

    type HashMap<V> = Record<string, V>;

    interface BufferLike {
        [offset: number]: number;
        length: number;
    }

    type IteratorResult<T> = { value: T; done: false } | {
        value: never;
        done: true;
    };

    interface Iterator<T> {
        next(value?: any): IteratorResult<T>;
        throw?(value: any): IteratorResult<T>;
        return?(value?: T): IteratorResult<T>;
    }

    interface Iterable<T> {
        "@@iterator"(): Iterator<T>;
    }

    interface IterableIterator<T> extends Iterator<T> {
        "@@iterator"(): IterableIterator<T>;
    }

    interface Map<K, V> extends Iterable<[K, V]> {
        size: number;
        has(key: K): boolean;
        get(key: K): V;
        set(key: K, value?: V): this;
        delete(key: K): boolean;
        clear(): void;
        keys(): IterableIterator<K>;
        values(): IterableIterator<V>;
        entries(): IterableIterator<[K, V]>;
    }

    interface MapConstructor {
        new (): Map<any, any>;
        new <K, V>(): Map<K, V>;
        prototype: Map<any, any>;
    }

    interface Set<T> extends Iterable<T> {
        size: number;
        has(value: T): boolean;
        add(value: T): this;
        delete(value: T): boolean;
        clear(): void;
        keys(): IterableIterator<T>;
        values(): IterableIterator<T>;
        entries(): IterableIterator<[T, T]>;
    }

    interface SetConstructor {
        new (): Set<any>;
        new <T>(): Set<T>;
        prototype: Set<any>;
    }

    interface WeakMap<K, V> {
        clear(): void;
        delete(key: K): boolean;
        get(key: K): V;
        has(key: K): boolean;
        set(key: K, value?: V): WeakMap<K, V>;
    }

    interface WeakMapConstructor {
        new (): WeakMap<any, any>;
        new <K, V>(): WeakMap<K, V>;
        prototype: WeakMap<any, any>;
    }

    type MemberDecorator = <T>(
        target: Object,
        propertyKey: string | symbol,
        descriptor?: TypedPropertyDescriptor<T>,
    ) => TypedPropertyDescriptor<T> | void;
    declare const Symbol: { iterator: symbol; toPrimitive: symbol };
    declare const Set: SetConstructor;
    declare const WeakMap: WeakMapConstructor;
    declare const Map: MapConstructor;
    declare const global: any;
    declare const crypto: Crypto;
    declare const msCrypto: Crypto;
    declare const process: any;

    /**
     * Applies a set of decorators to a target object.
     * @param decorators An array of decorators.
     * @param target The target object.
     * @returns The result of applying the provided decorators.
     * @remarks Decorators are applied in reverse order of their positions in the array.
     * @example
     *
     *     class Example { }
     *
     *     // constructor
     *     Example = Reflect.decorate(decoratorsArray, Example);
     *
     */
    export declare function decorate(
        decorators: ClassDecorator[],
        target: Function,
    ): Function;

    /**
     * Applies a set of decorators to a property of a target object.
     * @param decorators An array of decorators.
     * @param target The target object.
     * @param propertyKey The property key to decorate.
     * @param attributes A property descriptor.
     * @remarks Decorators are applied in reverse order.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod() { }
     *         method() { }
     *     }
     *
     *     // property (on constructor)
     *     Reflect.decorate(decoratorsArray, Example, "staticProperty");
     *
     *     // property (on prototype)
     *     Reflect.decorate(decoratorsArray, Example.prototype, "property");
     *
     *     // method (on constructor)
     *     Object.defineProperty(Example, "staticMethod",
     *         Reflect.decorate(decoratorsArray, Example, "staticMethod",
     *             Object.getOwnPropertyDescriptor(Example, "staticMethod")));
     *
     *     // method (on prototype)
     *     Object.defineProperty(Example.prototype, "method",
     *         Reflect.decorate(decoratorsArray, Example.prototype, "method",
     *             Object.getOwnPropertyDescriptor(Example.prototype, "method")));
     *
     */
    export declare function decorate(
        decorators: (PropertyDecorator | MethodDecorator)[],
        target: any,
        propertyKey: string | symbol,
        attributes?: PropertyDescriptor | null,
    ): PropertyDescriptor | undefined;

    /**
     * Applies a set of decorators to a property of a target object.
     * @param decorators An array of decorators.
     * @param target The target object.
     * @param propertyKey The property key to decorate.
     * @param attributes A property descriptor.
     * @remarks Decorators are applied in reverse order.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod() { }
     *         method() { }
     *     }
     *
     *     // property (on constructor)
     *     Reflect.decorate(decoratorsArray, Example, "staticProperty");
     *
     *     // property (on prototype)
     *     Reflect.decorate(decoratorsArray, Example.prototype, "property");
     *
     *     // method (on constructor)
     *     Object.defineProperty(Example, "staticMethod",
     *         Reflect.decorate(decoratorsArray, Example, "staticMethod",
     *             Object.getOwnPropertyDescriptor(Example, "staticMethod")));
     *
     *     // method (on prototype)
     *     Object.defineProperty(Example.prototype, "method",
     *         Reflect.decorate(decoratorsArray, Example.prototype, "method",
     *             Object.getOwnPropertyDescriptor(Example.prototype, "method")));
     *
     */
    export declare function decorate(
        decorators: (PropertyDecorator | MethodDecorator)[],
        target: any,
        propertyKey: string | symbol,
        attributes: PropertyDescriptor,
    ): PropertyDescriptor;

    /**
     * A default metadata decorator factory that can be used on a class, class member, or parameter.
     * @param metadataKey The key for the metadata entry.
     * @param metadataValue The value for the metadata entry.
     * @returns A decorator function.
     * @remarks
     * If `metadataKey` is already defined for the target and target key, the
     * metadataValue for that key will be overwritten.
     * @example
     *
     *     // constructor
     *     @Reflect.metadata(key, value)
     *     class Example {
     *     }
     *
     *     // property (on constructor, TypeScript only)
     *     class Example {
     *         @Reflect.metadata(key, value)
     *         static staticProperty;
     *     }
     *
     *     // property (on prototype, TypeScript only)
     *     class Example {
     *         @Reflect.metadata(key, value)
     *         property;
     *     }
     *
     *     // method (on constructor)
     *     class Example {
     *         @Reflect.metadata(key, value)
     *         static staticMethod() { }
     *     }
     *
     *     // method (on prototype)
     *     class Example {
     *         @Reflect.metadata(key, value)
     *         method() { }
     *     }
     *
     */
    export declare function metadata(
        metadataKey: any,
        metadataValue: any,
    ): {
        (target: Function): void;
        (target: any, propertyKey: string | symbol): void;
    };

    /**
     * Define a unique metadata entry on the target.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param metadataValue A value that contains attached metadata.
     * @param target The target object on which to define metadata.
     * @example
     *
     *     class Example {
     *     }
     *
     *     // constructor
     *     Reflect.defineMetadata("custom:annotation", options, Example);
     *
     *     // decorator factory as metadata-producing annotation.
     *     function MyAnnotation(options): ClassDecorator {
     *         return target => Reflect.defineMetadata("custom:annotation", options, target);
     *     }
     *
     */
    export declare function defineMetadata(
        metadataKey: any,
        metadataValue: any,
        target: any,
    ): void;

    /**
     * Define a unique metadata entry on the target.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param metadataValue A value that contains attached metadata.
     * @param target The target object on which to define metadata.
     * @param propertyKey The property key for the target.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod(p) { }
     *         method(p) { }
     *     }
     *
     *     // property (on constructor)
     *     Reflect.defineMetadata("custom:annotation", Number, Example, "staticProperty");
     *
     *     // property (on prototype)
     *     Reflect.defineMetadata("custom:annotation", Number, Example.prototype, "property");
     *
     *     // method (on constructor)
     *     Reflect.defineMetadata("custom:annotation", Number, Example, "staticMethod");
     *
     *     // method (on prototype)
     *     Reflect.defineMetadata("custom:annotation", Number, Example.prototype, "method");
     *
     *     // decorator factory as metadata-producing annotation.
     *     function MyAnnotation(options): PropertyDecorator {
     *         return (target, key) => Reflect.defineMetadata("custom:annotation", options, target, key);
     *     }
     *
     */
    export declare function defineMetadata(
        metadataKey: any,
        metadataValue: any,
        target: any,
        propertyKey: string | symbol,
    ): void;

    /**
     * Gets a value indicating whether the target object or its prototype chain has the provided metadata key defined.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @returns `true` if the metadata key was defined on the target object or its prototype chain; otherwise, `false`.
     * @example
     *
     *     class Example {
     *     }
     *
     *     // constructor
     *     result = Reflect.hasMetadata("custom:annotation", Example);
     *
     */
    export declare function hasMetadata(metadataKey: any, target: any): boolean;

    /**
     * Gets a value indicating whether the target object or its prototype chain has the provided metadata key defined.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @param propertyKey The property key for the target.
     * @returns `true` if the metadata key was defined on the target object or its prototype chain; otherwise, `false`.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod(p) { }
     *         method(p) { }
     *     }
     *
     *     // property (on constructor)
     *     result = Reflect.hasMetadata("custom:annotation", Example, "staticProperty");
     *
     *     // property (on prototype)
     *     result = Reflect.hasMetadata("custom:annotation", Example.prototype, "property");
     *
     *     // method (on constructor)
     *     result = Reflect.hasMetadata("custom:annotation", Example, "staticMethod");
     *
     *     // method (on prototype)
     *     result = Reflect.hasMetadata("custom:annotation", Example.prototype, "method");
     *
     */
    export declare function hasMetadata(
        metadataKey: any,
        target: any,
        propertyKey: string | symbol,
    ): boolean;

    /**
     * Gets a value indicating whether the target object has the provided metadata key defined.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @returns `true` if the metadata key was defined on the target object; otherwise, `false`.
     * @example
     *
     *     class Example {
     *     }
     *
     *     // constructor
     *     result = Reflect.hasOwnMetadata("custom:annotation", Example);
     *
     */
    export declare function hasOwnMetadata(
        metadataKey: any,
        target: any,
    ): boolean;

    /**
     * Gets a value indicating whether the target object has the provided metadata key defined.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @param propertyKey The property key for the target.
     * @returns `true` if the metadata key was defined on the target object; otherwise, `false`.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod(p) { }
     *         method(p) { }
     *     }
     *
     *     // property (on constructor)
     *     result = Reflect.hasOwnMetadata("custom:annotation", Example, "staticProperty");
     *
     *     // property (on prototype)
     *     result = Reflect.hasOwnMetadata("custom:annotation", Example.prototype, "property");
     *
     *     // method (on constructor)
     *     result = Reflect.hasOwnMetadata("custom:annotation", Example, "staticMethod");
     *
     *     // method (on prototype)
     *     result = Reflect.hasOwnMetadata("custom:annotation", Example.prototype, "method");
     *
     */
    export declare function hasOwnMetadata(
        metadataKey: any,
        target: any,
        propertyKey: string | symbol,
    ): boolean;

    /**
     * Gets the metadata value for the provided metadata key on the target object or its prototype chain.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
     * @example
     *
     *     class Example {
     *     }
     *
     *     // constructor
     *     result = Reflect.getMetadata("custom:annotation", Example);
     *
     */
    export declare function getMetadata(metadataKey: any, target: any): any;

    /**
     * Gets the metadata value for the provided metadata key on the target object or its prototype chain.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @param propertyKey The property key for the target.
     * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod(p) { }
     *         method(p) { }
     *     }
     *
     *     // property (on constructor)
     *     result = Reflect.getMetadata("custom:annotation", Example, "staticProperty");
     *
     *     // property (on prototype)
     *     result = Reflect.getMetadata("custom:annotation", Example.prototype, "property");
     *
     *     // method (on constructor)
     *     result = Reflect.getMetadata("custom:annotation", Example, "staticMethod");
     *
     *     // method (on prototype)
     *     result = Reflect.getMetadata("custom:annotation", Example.prototype, "method");
     *
     */
    export declare function getMetadata(
        metadataKey: any,
        target: any,
        propertyKey: string | symbol,
    ): any;

    /**
     * Gets the metadata value for the provided metadata key on the target object.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
     * @example
     *
     *     class Example {
     *     }
     *
     *     // constructor
     *     result = Reflect.getOwnMetadata("custom:annotation", Example);
     *
     */
    export declare function getOwnMetadata(metadataKey: any, target: any): any;

    /**
     * Gets the metadata value for the provided metadata key on the target object.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @param propertyKey The property key for the target.
     * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod(p) { }
     *         method(p) { }
     *     }
     *
     *     // property (on constructor)
     *     result = Reflect.getOwnMetadata("custom:annotation", Example, "staticProperty");
     *
     *     // property (on prototype)
     *     result = Reflect.getOwnMetadata("custom:annotation", Example.prototype, "property");
     *
     *     // method (on constructor)
     *     result = Reflect.getOwnMetadata("custom:annotation", Example, "staticMethod");
     *
     *     // method (on prototype)
     *     result = Reflect.getOwnMetadata("custom:annotation", Example.prototype, "method");
     *
     */
    export declare function getOwnMetadata(
        metadataKey: any,
        target: any,
        propertyKey: string | symbol,
    ): any;

    /**
     * Gets the metadata keys defined on the target object or its prototype chain.
     * @param target The target object on which the metadata is defined.
     * @returns An array of unique metadata keys.
     * @example
     *
     *     class Example {
     *     }
     *
     *     // constructor
     *     result = Reflect.getMetadataKeys(Example);
     *
     */
    export declare function getMetadataKeys(target: any): any[];

    /**
     * Gets the metadata keys defined on the target object or its prototype chain.
     * @param target The target object on which the metadata is defined.
     * @param propertyKey The property key for the target.
     * @returns An array of unique metadata keys.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod(p) { }
     *         method(p) { }
     *     }
     *
     *     // property (on constructor)
     *     result = Reflect.getMetadataKeys(Example, "staticProperty");
     *
     *     // property (on prototype)
     *     result = Reflect.getMetadataKeys(Example.prototype, "property");
     *
     *     // method (on constructor)
     *     result = Reflect.getMetadataKeys(Example, "staticMethod");
     *
     *     // method (on prototype)
     *     result = Reflect.getMetadataKeys(Example.prototype, "method");
     *
     */
    export declare function getMetadataKeys(
        target: any,
        propertyKey: string | symbol,
    ): any[];

    /**
     * Gets the unique metadata keys defined on the target object.
     * @param target The target object on which the metadata is defined.
     * @returns An array of unique metadata keys.
     * @example
     *
     *     class Example {
     *     }
     *
     *     // constructor
     *     result = Reflect.getOwnMetadataKeys(Example);
     *
     */
    export declare function getOwnMetadataKeys(target: any): any[];

    /**
     * Gets the unique metadata keys defined on the target object.
     * @param target The target object on which the metadata is defined.
     * @param propertyKey The property key for the target.
     * @returns An array of unique metadata keys.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod(p) { }
     *         method(p) { }
     *     }
     *
     *     // property (on constructor)
     *     result = Reflect.getOwnMetadataKeys(Example, "staticProperty");
     *
     *     // property (on prototype)
     *     result = Reflect.getOwnMetadataKeys(Example.prototype, "property");
     *
     *     // method (on constructor)
     *     result = Reflect.getOwnMetadataKeys(Example, "staticMethod");
     *
     *     // method (on prototype)
     *     result = Reflect.getOwnMetadataKeys(Example.prototype, "method");
     *
     */
    export declare function getOwnMetadataKeys(
        target: any,
        propertyKey: string | symbol,
    ): any[];

    /**
     * Deletes the metadata entry from the target object with the provided key.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @returns `true` if the metadata entry was found and deleted; otherwise, false.
     * @example
     *
     *     class Example {
     *     }
     *
     *     // constructor
     *     result = Reflect.deleteMetadata("custom:annotation", Example);
     *
     */
    export declare function deleteMetadata(
        metadataKey: any,
        target: any,
    ): boolean;

    /**
     * Deletes the metadata entry from the target object with the provided key.
     * @param metadataKey A key used to store and retrieve metadata.
     * @param target The target object on which the metadata is defined.
     * @param propertyKey The property key for the target.
     * @returns `true` if the metadata entry was found and deleted; otherwise, false.
     * @example
     *
     *     class Example {
     *         // property declarations are not part of ES6, though they are valid in TypeScript:
     *         // static staticProperty;
     *         // property;
     *
     *         static staticMethod(p) { }
     *         method(p) { }
     *     }
     *
     *     // property (on constructor)
     *     result = Reflect.deleteMetadata("custom:annotation", Example, "staticProperty");
     *
     *     // property (on prototype)
     *     result = Reflect.deleteMetadata("custom:annotation", Example.prototype, "property");
     *
     *     // method (on constructor)
     *     result = Reflect.deleteMetadata("custom:annotation", Example, "staticMethod");
     *
     *     // method (on prototype)
     *     result = Reflect.deleteMetadata("custom:annotation", Example.prototype, "method");
     *
     */
    export declare function deleteMetadata(
        metadataKey: any,
        target: any,
        propertyKey: string | symbol,
    ): boolean;
    declare var self: ObjectKeyAny;
    (function (
        this: any,
        factory: (
            exporter: <K extends keyof typeof Reflect>(
                key: K,
                value: typeof Reflect[K],
            ) => void,
        ) => void,
    ) {
        const root = typeof global === "object"
            ? global
            : typeof self === "object"
                ? self
                : typeof this === "object"
                    ? this
                    : Function("return this;")();

        let exporter = makeExporter(Reflect);
        if (typeof root.Reflect === "undefined") {
            root.Reflect = Reflect;
        } else {
            exporter = makeExporter(root.Reflect, exporter);
        }

        factory(exporter);

        function makeExporter(
            target: typeof Reflect,
            previous?: <K extends keyof typeof Reflect>(
                key: K,
                value: typeof Reflect[K],
            ) => void,
        ) {
            return <K extends keyof typeof Reflect>(
                key: K,
                value: typeof Reflect[K],
            ) => {
                if (typeof target[key] !== "function") {
                    Object.defineProperty(
                        target,
                        key,
                        { configurable: true, writable: true, value },
                    );
                }
                if (previous) previous(key, value);
            };
        }
    })(function (exporter) {
        const hasOwn = Object.prototype.hasOwnProperty;

        // feature test for Symbol support
        const supportsSymbol = typeof Symbol === "function";
        const toPrimitiveSymbol =
            supportsSymbol && typeof Symbol.toPrimitive !== "undefined"
                ? Symbol.toPrimitive
                : "@@toPrimitive";
        const iteratorSymbol =
            supportsSymbol && typeof Symbol.iterator !== "undefined"
                ? Symbol.iterator
                : "@@iterator";
        const supportsCreate = typeof Object.create === "function"; // feature test for Object.create support
        const supportsProto = { __proto__: [] } instanceof Array; // feature test for __proto__ support
        const downLevel = !supportsCreate && !supportsProto;

        const HashMap = {
            // create an object in dictionary mode (a.k.a. "slow" mode in v8)
            create: supportsCreate
                ? <V>() => MakeDictionary(Object.create(null) as HashMap<V>)
                : supportsProto
                    ? <V>() => MakeDictionary({ __proto__: null as any } as HashMap<V>)
                    : <V>() => MakeDictionary({} as HashMap<V>),

            has: downLevel
                ? <V>(map: HashMap<V>, key: string | number | symbol) =>
                    hasOwn.call(map, key)
                : <V>(map: HashMap<V>, key: string | number | symbol) => key in map,

            get: downLevel
                ? <V>(map: HashMap<V>, key: string | number | symbol): V | undefined =>
                    hasOwn.call(map, key) ? map[key as string | number] : undefined
                : <V>(map: HashMap<V>, key: string | number | symbol): V | undefined =>
                    map[key as string | number],
        };

        // Load global or shim versions of Map, Set, and WeakMap
        const functionPrototype = Object.getPrototypeOf(Function);
        const usePolyfill = typeof process === "object" && process.env &&
            process.env["REFLECT_METADATA_USE_MAP_POLYFILL"] === "true";
        const _Map: typeof Map = !usePolyfill && typeof Map === "function" &&
        typeof Map.prototype.entries === "function"
            ? Map
            : CreateMapPolyfill();
        const _Set: typeof Set = !usePolyfill && typeof Set === "function" &&
        typeof Set.prototype.entries === "function"
            ? Set
            : CreateSetPolyfill();
        const _WeakMap: typeof WeakMap =
            !usePolyfill && typeof WeakMap === "function"
                ? WeakMap
                : CreateWeakMapPolyfill();

        // [[Metadata]] internal slot
        // https://rbuckton.github.io/reflect-metadata/#ordinary-object-internal-methods-and-internal-slots
        const Metadata = new _WeakMap<
            any,
            Map<string | symbol | undefined, Map<any, any>>
            >();

        // function decorate(decorators: ClassDecorator[], target: Function): Function;
        // function decorate(decorators: (PropertyDecorator | MethodDecorator)[], target: any, propertyKey: string | symbol, attributes?: PropertyDescriptor | null): PropertyDescriptor | undefined;
        // function decorate(decorators: (PropertyDecorator | MethodDecorator)[], target: any, propertyKey: string | symbol, attributes: PropertyDescriptor): PropertyDescriptor;

        /**
         * Applies a set of decorators to a property of a target object.
         * @param decorators An array of decorators.
         * @param target The target object.
         * @param propertyKey (Optional) The property key to decorate.
         * @param attributes (Optional) The property descriptor for the target key.
         * @remarks Decorators are applied in reverse order.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     Example = Reflect.decorate(decoratorsArray, Example);
         *
         *     // property (on constructor)
         *     Reflect.decorate(decoratorsArray, Example, "staticProperty");
         *
         *     // property (on prototype)
         *     Reflect.decorate(decoratorsArray, Example.prototype, "property");
         *
         *     // method (on constructor)
         *     Object.defineProperty(Example, "staticMethod",
         *         Reflect.decorate(decoratorsArray, Example, "staticMethod",
         *             Object.getOwnPropertyDescriptor(Example, "staticMethod")));
         *
         *     // method (on prototype)
         *     Object.defineProperty(Example.prototype, "method",
         *         Reflect.decorate(decoratorsArray, Example.prototype, "method",
         *             Object.getOwnPropertyDescriptor(Example.prototype, "method")));
         *
         */
        function decorate(
            decorators: (ClassDecorator | MemberDecorator)[],
            target: any,
            propertyKey?: string | symbol,
            attributes?: PropertyDescriptor | null,
        ): PropertyDescriptor | Function | undefined {
            if (!IsUndefined(propertyKey)) {
                if (!IsArray(decorators)) throw new TypeError();
                if (!IsObject(target)) throw new TypeError();
                if (
                    !IsObject(attributes) && !IsUndefined(attributes) &&
                    !IsNull(attributes)
                ) {
                    throw new TypeError();
                }
                if (IsNull(attributes)) attributes = undefined;
                propertyKey = ToPropertyKey(propertyKey);
                return DecorateProperty(
                    <MemberDecorator[]> decorators,
                    target,
                    propertyKey,
                    attributes,
                );
            } else {
                if (!IsArray(decorators)) throw new TypeError();
                if (!IsConstructor(target)) throw new TypeError();
                return DecorateConstructor(
                    <ClassDecorator[]> decorators,
                    <Function> target,
                );
            }
        }

        exporter("decorate", <any> decorate);

        // 4.1.2 Reflect.metadata(metadataKey, metadataValue)
        // https://rbuckton.github.io/reflect-metadata/#reflect.metadata

        /**
         * A default metadata decorator factory that can be used on a class, class member, or parameter.
         * @param metadataKey The key for the metadata entry.
         * @param metadataValue The value for the metadata entry.
         * @returns A decorator function.
         * @remarks
         * If `metadataKey` is already defined for the target and target key, the
         * metadataValue for that key will be overwritten.
         * @example
         *
         *     // constructor
         *     @Reflect.metadata(key, value)
         *     class Example {
         *     }
         *
         *     // property (on constructor, TypeScript only)
         *     class Example {
         *         @Reflect.metadata(key, value)
         *         static staticProperty;
         *     }
         *
         *     // property (on prototype, TypeScript only)
         *     class Example {
         *         @Reflect.metadata(key, value)
         *         property;
         *     }
         *
         *     // method (on constructor)
         *     class Example {
         *         @Reflect.metadata(key, value)
         *         static staticMethod() { }
         *     }
         *
         *     // method (on prototype)
         *     class Example {
         *         @Reflect.metadata(key, value)
         *         method() { }
         *     }
         *
         */
        function metadata(metadataKey: any, metadataValue: any) {
            function decorator(target: Function): void;
            function decorator(target: any, propertyKey: string | symbol): void;
            function decorator(target: any, propertyKey?: string | symbol): void {
                if (!IsObject(target)) throw new TypeError();
                if (
                    !IsUndefined(propertyKey) && !IsPropertyKey(propertyKey)
                ) {
                    throw new TypeError();
                }
                OrdinaryDefineOwnMetadata(
                    metadataKey,
                    metadataValue,
                    target,
                    propertyKey,
                );
            }
            return decorator;
        }

        exporter("metadata", metadata);

        // 4.1.3 Reflect.defineMetadata(metadataKey, metadataValue, target [, propertyKey])
        // https://rbuckton.github.io/reflect-metadata/#reflect.definemetadata

        function defineMetadata(
            metadataKey: any,
            metadataValue: any,
            target: any,
        ): void;
        function defineMetadata(
            metadataKey: any,
            metadataValue: any,
            target: any,
            propertyKey: string | symbol,
        ): void;

        /**
         * Define a unique metadata entry on the target.
         * @param metadataKey A key used to store and retrieve metadata.
         * @param metadataValue A value that contains attached metadata.
         * @param target The target object on which to define metadata.
         * @param propertyKey (Optional) The property key for the target.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     Reflect.defineMetadata("custom:annotation", options, Example);
         *
         *     // property (on constructor)
         *     Reflect.defineMetadata("custom:annotation", options, Example, "staticProperty");
         *
         *     // property (on prototype)
         *     Reflect.defineMetadata("custom:annotation", options, Example.prototype, "property");
         *
         *     // method (on constructor)
         *     Reflect.defineMetadata("custom:annotation", options, Example, "staticMethod");
         *
         *     // method (on prototype)
         *     Reflect.defineMetadata("custom:annotation", options, Example.prototype, "method");
         *
         *     // decorator factory as metadata-producing annotation.
         *     function MyAnnotation(options): Decorator {
         *         return (target, key?) => Reflect.defineMetadata("custom:annotation", options, target, key);
         *     }
         *
         */
        function defineMetadata(
            metadataKey: any,
            metadataValue: any,
            target: any,
            propertyKey?: string | symbol,
        ): void {
            if (!IsObject(target)) throw new TypeError();
            if (!IsUndefined(propertyKey)) propertyKey = ToPropertyKey(propertyKey);
            return OrdinaryDefineOwnMetadata(
                metadataKey,
                metadataValue,
                target,
                propertyKey,
            );
        }

        exporter("defineMetadata", defineMetadata);

        // 4.1.4 Reflect.hasMetadata(metadataKey, target [, propertyKey])
        // https://rbuckton.github.io/reflect-metadata/#reflect.hasmetadata

        function hasMetadata(metadataKey: any, target: any): boolean;
        function hasMetadata(
            metadataKey: any,
            target: any,
            propertyKey: string | symbol,
        ): boolean;

        /**
         * Gets a value indicating whether the target object or its prototype chain has the provided metadata key defined.
         * @param metadataKey A key used to store and retrieve metadata.
         * @param target The target object on which the metadata is defined.
         * @param propertyKey (Optional) The property key for the target.
         * @returns `true` if the metadata key was defined on the target object or its prototype chain; otherwise, `false`.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     result = Reflect.hasMetadata("custom:annotation", Example);
         *
         *     // property (on constructor)
         *     result = Reflect.hasMetadata("custom:annotation", Example, "staticProperty");
         *
         *     // property (on prototype)
         *     result = Reflect.hasMetadata("custom:annotation", Example.prototype, "property");
         *
         *     // method (on constructor)
         *     result = Reflect.hasMetadata("custom:annotation", Example, "staticMethod");
         *
         *     // method (on prototype)
         *     result = Reflect.hasMetadata("custom:annotation", Example.prototype, "method");
         *
         */
        function hasMetadata(
            metadataKey: any,
            target: any,
            propertyKey?: string | symbol,
        ): boolean {
            if (!IsObject(target)) throw new TypeError();
            if (!IsUndefined(propertyKey)) propertyKey = ToPropertyKey(propertyKey);
            return OrdinaryHasMetadata(metadataKey, target, propertyKey);
        }

        exporter("hasMetadata", hasMetadata);

        // 4.1.5 Reflect.hasOwnMetadata(metadataKey, target [, propertyKey])
        // https://rbuckton.github.io/reflect-metadata/#reflect-hasownmetadata

        function hasOwnMetadata(metadataKey: any, target: any): boolean;
        function hasOwnMetadata(
            metadataKey: any,
            target: any,
            propertyKey: string | symbol,
        ): boolean;

        /**
         * Gets a value indicating whether the target object has the provided metadata key defined.
         * @param metadataKey A key used to store and retrieve metadata.
         * @param target The target object on which the metadata is defined.
         * @param propertyKey (Optional) The property key for the target.
         * @returns `true` if the metadata key was defined on the target object; otherwise, `false`.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     result = Reflect.hasOwnMetadata("custom:annotation", Example);
         *
         *     // property (on constructor)
         *     result = Reflect.hasOwnMetadata("custom:annotation", Example, "staticProperty");
         *
         *     // property (on prototype)
         *     result = Reflect.hasOwnMetadata("custom:annotation", Example.prototype, "property");
         *
         *     // method (on constructor)
         *     result = Reflect.hasOwnMetadata("custom:annotation", Example, "staticMethod");
         *
         *     // method (on prototype)
         *     result = Reflect.hasOwnMetadata("custom:annotation", Example.prototype, "method");
         *
         */
        function hasOwnMetadata(
            metadataKey: any,
            target: any,
            propertyKey?: string | symbol,
        ): boolean {
            if (!IsObject(target)) throw new TypeError();
            if (!IsUndefined(propertyKey)) propertyKey = ToPropertyKey(propertyKey);
            return OrdinaryHasOwnMetadata(metadataKey, target, propertyKey);
        }

        exporter("hasOwnMetadata", hasOwnMetadata);

        // 4.1.6 Reflect.getMetadata(metadataKey, target [, propertyKey])
        // https://rbuckton.github.io/reflect-metadata/#reflect-getmetadata

        function getMetadata(metadataKey: any, target: any): any;
        function getMetadata(
            metadataKey: any,
            target: any,
            propertyKey: string | symbol,
        ): any;

        /**
         * Gets the metadata value for the provided metadata key on the target object or its prototype chain.
         * @param metadataKey A key used to store and retrieve metadata.
         * @param target The target object on which the metadata is defined.
         * @param propertyKey (Optional) The property key for the target.
         * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     result = Reflect.getMetadata("custom:annotation", Example);
         *
         *     // property (on constructor)
         *     result = Reflect.getMetadata("custom:annotation", Example, "staticProperty");
         *
         *     // property (on prototype)
         *     result = Reflect.getMetadata("custom:annotation", Example.prototype, "property");
         *
         *     // method (on constructor)
         *     result = Reflect.getMetadata("custom:annotation", Example, "staticMethod");
         *
         *     // method (on prototype)
         *     result = Reflect.getMetadata("custom:annotation", Example.prototype, "method");
         *
         */
        function getMetadata(
            metadataKey: any,
            target: any,
            propertyKey?: string | symbol,
        ): any {
            if (!IsObject(target)) throw new TypeError();
            if (!IsUndefined(propertyKey)) propertyKey = ToPropertyKey(propertyKey);
            return OrdinaryGetMetadata(metadataKey, target, propertyKey);
        }

        exporter("getMetadata", getMetadata);

        // 4.1.7 Reflect.getOwnMetadata(metadataKey, target [, propertyKey])
        // https://rbuckton.github.io/reflect-metadata/#reflect-getownmetadata

        function getOwnMetadata(metadataKey: any, target: any): any;
        function getOwnMetadata(
            metadataKey: any,
            target: any,
            propertyKey: string | symbol,
        ): any;

        /**
         * Gets the metadata value for the provided metadata key on the target object.
         * @param metadataKey A key used to store and retrieve metadata.
         * @param target The target object on which the metadata is defined.
         * @param propertyKey (Optional) The property key for the target.
         * @returns The metadata value for the metadata key if found; otherwise, `undefined`.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     result = Reflect.getOwnMetadata("custom:annotation", Example);
         *
         *     // property (on constructor)
         *     result = Reflect.getOwnMetadata("custom:annotation", Example, "staticProperty");
         *
         *     // property (on prototype)
         *     result = Reflect.getOwnMetadata("custom:annotation", Example.prototype, "property");
         *
         *     // method (on constructor)
         *     result = Reflect.getOwnMetadata("custom:annotation", Example, "staticMethod");
         *
         *     // method (on prototype)
         *     result = Reflect.getOwnMetadata("custom:annotation", Example.prototype, "method");
         *
         */
        function getOwnMetadata(
            metadataKey: any,
            target: any,
            propertyKey?: string | symbol,
        ): any {
            if (!IsObject(target)) throw new TypeError();
            if (!IsUndefined(propertyKey)) propertyKey = ToPropertyKey(propertyKey);
            return OrdinaryGetOwnMetadata(metadataKey, target, propertyKey);
        }

        exporter("getOwnMetadata", getOwnMetadata);

        // 4.1.8 Reflect.getMetadataKeys(target [, propertyKey])
        // https://rbuckton.github.io/reflect-metadata/#reflect-getmetadatakeys

        function getMetadataKeys(target: any): any[];
        function getMetadataKeys(target: any, propertyKey: string | symbol): any[];

        /**
         * Gets the metadata keys defined on the target object or its prototype chain.
         * @param target The target object on which the metadata is defined.
         * @param propertyKey (Optional) The property key for the target.
         * @returns An array of unique metadata keys.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     result = Reflect.getMetadataKeys(Example);
         *
         *     // property (on constructor)
         *     result = Reflect.getMetadataKeys(Example, "staticProperty");
         *
         *     // property (on prototype)
         *     result = Reflect.getMetadataKeys(Example.prototype, "property");
         *
         *     // method (on constructor)
         *     result = Reflect.getMetadataKeys(Example, "staticMethod");
         *
         *     // method (on prototype)
         *     result = Reflect.getMetadataKeys(Example.prototype, "method");
         *
         */
        function getMetadataKeys(
            target: any,
            propertyKey?: string | symbol,
        ): any[] {
            if (!IsObject(target)) throw new TypeError();
            if (!IsUndefined(propertyKey)) propertyKey = ToPropertyKey(propertyKey);
            return OrdinaryMetadataKeys(target, propertyKey);
        }

        exporter("getMetadataKeys", getMetadataKeys);

        // 4.1.9 Reflect.getOwnMetadataKeys(target [, propertyKey])
        // https://rbuckton.github.io/reflect-metadata/#reflect-getownmetadata

        function getOwnMetadataKeys(target: any): any[];
        function getOwnMetadataKeys(
            target: any,
            propertyKey: string | symbol,
        ): any[];

        /**
         * Gets the unique metadata keys defined on the target object.
         * @param target The target object on which the metadata is defined.
         * @param propertyKey (Optional) The property key for the target.
         * @returns An array of unique metadata keys.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     result = Reflect.getOwnMetadataKeys(Example);
         *
         *     // property (on constructor)
         *     result = Reflect.getOwnMetadataKeys(Example, "staticProperty");
         *
         *     // property (on prototype)
         *     result = Reflect.getOwnMetadataKeys(Example.prototype, "property");
         *
         *     // method (on constructor)
         *     result = Reflect.getOwnMetadataKeys(Example, "staticMethod");
         *
         *     // method (on prototype)
         *     result = Reflect.getOwnMetadataKeys(Example.prototype, "method");
         *
         */
        function getOwnMetadataKeys(
            target: any,
            propertyKey?: string | symbol,
        ): any[] {
            if (!IsObject(target)) throw new TypeError();
            if (!IsUndefined(propertyKey)) propertyKey = ToPropertyKey(propertyKey);
            return OrdinaryOwnMetadataKeys(target, propertyKey);
        }

        exporter("getOwnMetadataKeys", getOwnMetadataKeys);

        // 4.1.10 Reflect.deleteMetadata(metadataKey, target [, propertyKey])
        // https://rbuckton.github.io/reflect-metadata/#reflect-deletemetadata

        function deleteMetadata(metadataKey: any, target: any): boolean;
        function deleteMetadata(
            metadataKey: any,
            target: any,
            propertyKey: string | symbol,
        ): boolean;

        /**
         * Deletes the metadata entry from the target object with the provided key.
         * @param metadataKey A key used to store and retrieve metadata.
         * @param target The target object on which the metadata is defined.
         * @param propertyKey (Optional) The property key for the target.
         * @returns `true` if the metadata entry was found and deleted; otherwise, false.
         * @example
         *
         *     class Example {
         *         // property declarations are not part of ES6, though they are valid in TypeScript:
         *         // static staticProperty;
         *         // property;
         *
         *         constructor(p) { }
         *         static staticMethod(p) { }
         *         method(p) { }
         *     }
         *
         *     // constructor
         *     result = Reflect.deleteMetadata("custom:annotation", Example);
         *
         *     // property (on constructor)
         *     result = Reflect.deleteMetadata("custom:annotation", Example, "staticProperty");
         *
         *     // property (on prototype)
         *     result = Reflect.deleteMetadata("custom:annotation", Example.prototype, "property");
         *
         *     // method (on constructor)
         *     result = Reflect.deleteMetadata("custom:annotation", Example, "staticMethod");
         *
         *     // method (on prototype)
         *     result = Reflect.deleteMetadata("custom:annotation", Example.prototype, "method");
         *
         */
        function deleteMetadata(
            metadataKey: any,
            target: any,
            propertyKey?: string | symbol,
        ): boolean {
            if (!IsObject(target)) throw new TypeError();
            if (!IsUndefined(propertyKey)) propertyKey = ToPropertyKey(propertyKey);
            const metadataMap = GetOrCreateMetadataMap(
                target,
                propertyKey, /*Create*/
                false,
            );
            if (IsUndefined(metadataMap)) return false;
            if (!metadataMap.delete(metadataKey)) return false;
            if (metadataMap.size > 0) return true;
            const targetMetadata = Metadata.get(target);
            targetMetadata.delete(propertyKey);
            if (targetMetadata.size > 0) return true;
            Metadata.delete(target);
            return true;
        }

        exporter("deleteMetadata", deleteMetadata);

        function DecorateConstructor(
            decorators: ClassDecorator[],
            target: Function,
        ): Function {
            for (let i = decorators.length - 1; i >= 0; --i) {
                const decorator = decorators[i];
                const decorated = decorator(target);
                if (!IsUndefined(decorated) && !IsNull(decorated)) {
                    if (!IsConstructor(decorated)) throw new TypeError();
                    target = <Function> decorated;
                }
            }
            return target;
        }

        function DecorateProperty(
            decorators: MemberDecorator[],
            target: any,
            propertyKey: string | symbol,
            descriptor: PropertyDescriptor | undefined,
        ): PropertyDescriptor | undefined {
            for (let i = decorators.length - 1; i >= 0; --i) {
                const decorator = decorators[i];
                const decorated = decorator(target, propertyKey, descriptor);
                if (!IsUndefined(decorated) && !IsNull(decorated)) {
                    if (!IsObject(decorated)) throw new TypeError();
                    descriptor = <PropertyDescriptor> decorated;
                }
            }
            return descriptor;
        }

        // 2.1.1 GetOrCreateMetadataMap(O, P, Create)
        // https://rbuckton.github.io/reflect-metadata/#getorcreatemetadatamap
        function GetOrCreateMetadataMap(
            O: any,
            P: string | symbol | undefined,
            Create: true,
        ): Map<any, any>;
        function GetOrCreateMetadataMap(
            O: any,
            P: string | symbol | undefined,
            Create: false,
        ): Map<any, any> | undefined;
        function GetOrCreateMetadataMap(
            O: any,
            P: string | symbol | undefined,
            Create: boolean,
        ): Map<any, any> | undefined {
            let targetMetadata = Metadata.get(O);
            if (IsUndefined(targetMetadata)) {
                if (!Create) return undefined;
                targetMetadata = new _Map<string | symbol | undefined, Map<any, any>>();
                Metadata.set(O, targetMetadata);
            }
            let metadataMap = targetMetadata.get(P);
            if (IsUndefined(metadataMap)) {
                if (!Create) return undefined;
                metadataMap = new _Map<any, any>();
                targetMetadata.set(P, metadataMap);
            }
            return metadataMap;
        }

        // 3.1.1.1 OrdinaryHasMetadata(MetadataKey, O, P)
        // https://rbuckton.github.io/reflect-metadata/#ordinaryhasmetadata
        function OrdinaryHasMetadata(
            MetadataKey: any,
            O: any,
            P: string | symbol | undefined,
        ): boolean {
            const hasOwn = OrdinaryHasOwnMetadata(MetadataKey, O, P);
            if (hasOwn) return true;
            const parent = OrdinaryGetPrototypeOf(O);
            if (!IsNull(parent)) return OrdinaryHasMetadata(MetadataKey, parent, P);
            return false;
        }

        // 3.1.2.1 OrdinaryHasOwnMetadata(MetadataKey, O, P)
        // https://rbuckton.github.io/reflect-metadata/#ordinaryhasownmetadata
        function OrdinaryHasOwnMetadata(
            MetadataKey: any,
            O: any,
            P: string | symbol | undefined,
        ): boolean {
            const metadataMap = GetOrCreateMetadataMap(O, P, /*Create*/ false);
            if (IsUndefined(metadataMap)) return false;
            return ToBoolean(metadataMap.has(MetadataKey));
        }

        // 3.1.3.1 OrdinaryGetMetadata(MetadataKey, O, P)
        // https://rbuckton.github.io/reflect-metadata/#ordinarygetmetadata
        function OrdinaryGetMetadata(
            MetadataKey: any,
            O: any,
            P: string | symbol | undefined,
        ): any {
            const hasOwn = OrdinaryHasOwnMetadata(MetadataKey, O, P);
            if (hasOwn) return OrdinaryGetOwnMetadata(MetadataKey, O, P);
            const parent = OrdinaryGetPrototypeOf(O);
            if (!IsNull(parent)) return OrdinaryGetMetadata(MetadataKey, parent, P);
            return undefined;
        }

        // 3.1.4.1 OrdinaryGetOwnMetadata(MetadataKey, O, P)
        // https://rbuckton.github.io/reflect-metadata/#ordinarygetownmetadata
        function OrdinaryGetOwnMetadata(
            MetadataKey: any,
            O: any,
            P: string | symbol | undefined,
        ): any {
            const metadataMap = GetOrCreateMetadataMap(O, P, /*Create*/ false);
            if (IsUndefined(metadataMap)) return undefined;
            return metadataMap.get(MetadataKey);
        }

        // 3.1.5.1 OrdinaryDefineOwnMetadata(MetadataKey, MetadataValue, O, P)
        // https://rbuckton.github.io/reflect-metadata/#ordinarydefineownmetadata
        function OrdinaryDefineOwnMetadata(
            MetadataKey: any,
            MetadataValue: any,
            O: any,
            P: string | symbol | undefined,
        ): void {
            const metadataMap = GetOrCreateMetadataMap(O, P, /*Create*/ true);
            metadataMap.set(MetadataKey, MetadataValue);
        }

        // 3.1.6.1 OrdinaryMetadataKeys(O, P)
        // https://rbuckton.github.io/reflect-metadata/#ordinarymetadatakeys
        function OrdinaryMetadataKeys(
            O: any,
            P: string | symbol | undefined,
        ): any[] {
            const ownKeys = OrdinaryOwnMetadataKeys(O, P);
            const parent = OrdinaryGetPrototypeOf(O);
            if (parent === null) return ownKeys;
            const parentKeys = OrdinaryMetadataKeys(parent, P);
            if (parentKeys.length <= 0) return ownKeys;
            if (ownKeys.length <= 0) return parentKeys;
            const set = new _Set<any>();
            const keys: any[] = [];
            for (const key of ownKeys) {
                const hasKey = set.has(key);
                if (!hasKey) {
                    set.add(key);
                    keys.push(key);
                }
            }
            for (const key of parentKeys) {
                const hasKey = set.has(key);
                if (!hasKey) {
                    set.add(key);
                    keys.push(key);
                }
            }
            return keys;
        }

        // 3.1.7.1 OrdinaryOwnMetadataKeys(O, P)
        // https://rbuckton.github.io/reflect-metadata/#ordinaryownmetadatakeys
        function OrdinaryOwnMetadataKeys(
            O: any,
            P: string | symbol | undefined,
        ): any[] {
            const keys: any[] = [];
            const metadataMap = GetOrCreateMetadataMap(O, P, /*Create*/ false);
            if (IsUndefined(metadataMap)) return keys;
            const keysObj = metadataMap.keys();
            const iterator = GetIterator(keysObj);
            let k = 0;
            while (true) {
                const next = IteratorStep(iterator);
                if (!next) {
                    keys.length = k;
                    return keys;
                }
                const nextValue = IteratorValue(next);
                try {
                    keys[k] = nextValue;
                } catch (e) {
                    try {
                        IteratorClose(iterator);
                    } finally {
                        throw e;
                    }
                }
                k++;
            }
        }

        // 6 ECMAScript Data Typ0es and Values
        // https://tc39.github.io/ecma262/#sec-ecmascript-data-types-and-values
        function Type(x: any): Tag {
            if (x === null) return Tag.Null;
            switch (typeof x) {
                case "undefined":
                    return Tag.Undefined;
                case "boolean":
                    return Tag.Boolean;
                case "string":
                    return Tag.String;
                case "symbol":
                    return Tag.Symbol;
                case "number":
                    return Tag.Number;
                case "object":
                    return x === null ? Tag.Null : Tag.Object;
                default:
                    return Tag.Object;
            }
        }

        // 6.1 ECMAScript Language Types
        // https://tc39.github.io/ecma262/#sec-ecmascript-language-types
        const enum Tag {
            Undefined,
            Null,
            Boolean,
            String,
            Symbol,
            Number,
            Object,
        }

        // 6.1.1 The Undefined Type
        // https://tc39.github.io/ecma262/#sec-ecmascript-language-types-undefined-type
        function IsUndefined(x: any): x is undefined {
            return x === undefined;
        }

        // 6.1.2 The Null Type
        // https://tc39.github.io/ecma262/#sec-ecmascript-language-types-null-type
        function IsNull(x: any): x is null {
            return x === null;
        }

        // 6.1.5 The Symbol Type
        // https://tc39.github.io/ecma262/#sec-ecmascript-language-types-symbol-type
        function IsSymbol(x: any): x is symbol {
            return typeof x === "symbol";
        }

        // 6.1.7 The Object Type
        // https://tc39.github.io/ecma262/#sec-object-type
        function IsObject<T>(
            x: T | undefined | null | boolean | string | symbol | number,
        ): x is T {
            return typeof x === "object" ? x !== null : typeof x === "function";
        }

        // 7.1 Type Conversion
        // https://tc39.github.io/ecma262/#sec-type-conversion

        // 7.1.1 ToPrimitive(input [, PreferredType])
        // https://tc39.github.io/ecma262/#sec-toprimitive
        function ToPrimitive(
            input: any,
            PreferredType?: Tag,
        ): undefined | null | boolean | string | symbol | number {
            switch (Type(input)) {
                case Tag.Undefined:
                    return input;
                case Tag.Null:
                    return input;
                case Tag.Boolean:
                    return input;
                case Tag.String:
                    return input;
                case Tag.Symbol:
                    return input;
                case Tag.Number:
                    return input;
            }
            const hint: "string" | "number" | "default" = PreferredType === Tag.String
                ? "string"
                : PreferredType === Tag.Number
                    ? "number"
                    : "default";
            const exoticToPrim = GetMethod(input, toPrimitiveSymbol);
            if (exoticToPrim !== undefined) {
                const result = exoticToPrim.call(input, hint);
                if (IsObject(result)) throw new TypeError();
                return result;
            }
            return OrdinaryToPrimitive(input, hint === "default" ? "number" : hint);
        }

        // 7.1.1.1 OrdinaryToPrimitive(O, hint)
        // https://tc39.github.io/ecma262/#sec-ordinarytoprimitive
        function OrdinaryToPrimitive(
            O: any,
            hint: "string" | "number",
        ): undefined | null | boolean | string | symbol | number {
            if (hint === "string") {
                const toString = O.toString;
                if (IsCallable(toString)) {
                    const result = toString.call(O);
                    if (!IsObject(result)) return result;
                }
                const valueOf = O.valueOf;
                if (IsCallable(valueOf)) {
                    const result = valueOf.call(O);
                    if (!IsObject(result)) return result;
                }
            } else {
                const valueOf = O.valueOf;
                if (IsCallable(valueOf)) {
                    const result = valueOf.call(O);
                    if (!IsObject(result)) return result;
                }
                const toString = O.toString;
                if (IsCallable(toString)) {
                    const result = toString.call(O);
                    if (!IsObject(result)) return result;
                }
            }
            throw new TypeError();
        }

        // 7.1.2 ToBoolean(argument)
        // https://tc39.github.io/ecma262/2016/#sec-toboolean
        function ToBoolean(argument: any): boolean {
            return !!argument;
        }

        // 7.1.12 ToString(argument)
        // https://tc39.github.io/ecma262/#sec-tostring
        function ToString(argument: any): string {
            return "" + argument;
        }

        // 7.1.14 ToPropertyKey(argument)
        // https://tc39.github.io/ecma262/#sec-topropertykey
        function ToPropertyKey(argument: any): string | symbol {
            const key = ToPrimitive(argument, Tag.String);
            if (IsSymbol(key)) return key;
            return ToString(key);
        }

        // 7.2 Testing and Comparison Operations
        // https://tc39.github.io/ecma262/#sec-testing-and-comparison-operations

        // 7.2.2 IsArray(argument)
        // https://tc39.github.io/ecma262/#sec-isarray
        function IsArray(argument: any): argument is any[] {
            return Array.isArray
                ? Array.isArray(argument)
                : argument instanceof Object
                    ? argument instanceof Array
                    : Object.prototype.toString.call(argument) === "[object Array]";
        }

        // 7.2.3 IsCallable(argument)
        // https://tc39.github.io/ecma262/#sec-iscallable
        function IsCallable(argument: any): argument is Function {
            // NOTE: This is an approximation as we cannot check for [[Call]] internal method.
            return typeof argument === "function";
        }

        // 7.2.4 IsConstructor(argument)
        // https://tc39.github.io/ecma262/#sec-isconstructor
        function IsConstructor(argument: any): argument is Function {
            // NOTE: This is an approximation as we cannot check for [[Construct]] internal method.
            return typeof argument === "function";
        }

        // 7.2.7 IsPropertyKey(argument)
        // https://tc39.github.io/ecma262/#sec-ispropertykey
        function IsPropertyKey(argument: any): argument is string | symbol {
            switch (Type(argument)) {
                case Tag.String:
                    return true;
                case Tag.Symbol:
                    return true;
                default:
                    return false;
            }
        }

        // 7.3 Operations on Objects
        // https://tc39.github.io/ecma262/#sec-operations-on-objects

        // 7.3.9 GetMethod(V, P)
        // https://tc39.github.io/ecma262/#sec-getmethod
        function GetMethod(V: any, P: any): Function | undefined {
            const func = V[P];
            if (func === undefined || func === null) return undefined;
            if (!IsCallable(func)) throw new TypeError();
            return func;
        }

        // 7.4 Operations on Iterator Objects
        // https://tc39.github.io/ecma262/#sec-operations-on-iterator-objects

        function GetIterator<T>(obj: Iterable<T>): Iterator<T> {
            const method = GetMethod(obj, iteratorSymbol);
            if (!IsCallable(method)) throw new TypeError(); // from Call
            const iterator = method.call(obj);
            if (!IsObject(iterator)) throw new TypeError();
            return iterator;
        }

        // 7.4.4 IteratorValue(iterResult)
        // https://tc39.github.io/ecma262/2016/#sec-iteratorvalue
        function IteratorValue<T>(iterResult: IteratorResult<T>): T {
            return iterResult.value;
        }

        // 7.4.5 IteratorStep(iterator)
        // https://tc39.github.io/ecma262/#sec-iteratorstep
        function IteratorStep<T>(iterator: Iterator<T>): IteratorResult<T> | false {
            const result = iterator.next();
            return result.done ? false : result;
        }

        // 7.4.6 IteratorClose(iterator, completion)
        // https://tc39.github.io/ecma262/#sec-iteratorclose
        function IteratorClose<T>(iterator: Iterator<T>) {
            const f = iterator["return"];
            if (f) f.call(iterator);
        }

        // 9.1 Ordinary Object Internal Methods and Internal Slots
        // https://tc39.github.io/ecma262/#sec-ordinary-object-internal-methods-and-internal-slots

        // 9.1.1.1 OrdinaryGetPrototypeOf(O)
        // https://tc39.github.io/ecma262/#sec-ordinarygetprototypeof
        function OrdinaryGetPrototypeOf(O: any): any {
            const proto = Object.getPrototypeOf(O);
            if (typeof O !== "function" || O === functionPrototype) return proto;

            // TypeScript doesn't set __proto__ in ES5, as it's non-standard.
            // Try to determine the superclass constructor. Compatible implementations
            // must either set __proto__ on a subclass constructor to the superclass constructor,
            // or ensure each class has a valid `constructor` property on its prototype that
            // points back to the constructor.

            // If this is not the same as Function.[[Prototype]], then this is definately inherited.
            // This is the case when in ES6 or when using __proto__ in a compatible browser.
            if (proto !== functionPrototype) return proto;

            // If the super prototype is Object.prototype, null, or undefined, then we cannot determine the heritage.
            const prototype = O.prototype;
            const prototypeProto = prototype && Object.getPrototypeOf(prototype);
            if (
                prototypeProto == null || prototypeProto === Object.prototype
            ) {
                return proto;
            }

            // If the constructor was not a function, then we cannot determine the heritage.
            const constructor = prototypeProto.constructor;
            if (typeof constructor !== "function") return proto;

            // If we have some kind of self-reference, then we cannot determine the heritage.
            if (constructor === O) return proto;

            // we have a pretty good guess at the heritage.
            return constructor;
        }

        // naive Map shim
        function CreateMapPolyfill(): MapConstructor {
            const cacheSentinel = {};
            const arraySentinel: any[] = [];

            class MapIterator<K, V, R extends (K | V | [K, V])>
                implements IterableIterator<R> {
                private _keys: K[];
                private _values: V[];
                private _index = 0;
                private _selector: (key: K, value: V) => R;
                constructor(keys: K[], values: V[], selector: (key: K, value: V) => R) {
                    this._keys = keys;
                    this._values = values;
                    this._selector = selector;
                }
                "@@iterator"() {
                    return this;
                }
                [iteratorSymbol]() {
                    return this;
                }
                next(): IteratorResult<R> {
                    const index = this._index;
                    if (index >= 0 && index < this._keys.length) {
                        const result = this._selector(
                            this._keys[index],
                            this._values[index],
                        );
                        if (index + 1 >= this._keys.length) {
                            this._index = -1;
                            this._keys = arraySentinel;
                            this._values = arraySentinel;
                        } else {
                            this._index++;
                        }
                        return { value: result, done: false };
                    }
                    return { value: <never> undefined, done: true };
                }
                throw(error: any): IteratorResult<R> {
                    if (this._index >= 0) {
                        this._index = -1;
                        this._keys = arraySentinel;
                        this._values = arraySentinel;
                    }
                    throw error;
                }
                return(value?: R): IteratorResult<R> {
                    if (this._index >= 0) {
                        this._index = -1;
                        this._keys = arraySentinel;
                        this._values = arraySentinel;
                    }
                    return { value: <never> value, done: true };
                }
            }

            return class Map<K, V> {
                private _keys: K[] = [];
                private _values: (V | undefined)[] = [];
                private _cacheKey = cacheSentinel;
                private _cacheIndex = -2;
                get size() {
                    return this._keys.length;
                }
                has(key: K): boolean {
                    return this._find(key, /*insert*/ false) >= 0;
                }
                get(key: K): V | undefined {
                    const index = this._find(key, /*insert*/ false);
                    return index >= 0 ? this._values[index] : undefined;
                }
                set(key: K, value: V): this {
                    const index = this._find(key, /*insert*/ true);
                    this._values[index] = value;
                    return this;
                }
                delete(key: K): boolean {
                    const index = this._find(key, /*insert*/ false);
                    if (index >= 0) {
                        const size = this._keys.length;
                        for (let i = index + 1; i < size; i++) {
                            this._keys[i - 1] = this._keys[i];
                            this._values[i - 1] = this._values[i];
                        }
                        this._keys.length--;
                        this._values.length--;
                        if (key === this._cacheKey) {
                            this._cacheKey = cacheSentinel;
                            this._cacheIndex = -2;
                        }
                        return true;
                    }
                    return false;
                }
                clear(): void {
                    this._keys.length = 0;
                    this._values.length = 0;
                    this._cacheKey = cacheSentinel;
                    this._cacheIndex = -2;
                }
                keys() {
                    return new MapIterator(this._keys, this._values, getKey);
                }
                values() {
                    return new MapIterator(this._keys, this._values, getValue);
                }
                entries() {
                    return new MapIterator(this._keys, this._values, getEntry);
                }
                "@@iterator"() {
                    return this.entries();
                }
                [iteratorSymbol]() {
                    return this.entries();
                }
                private _find(key: K, insert?: boolean): number {
                    if (this._cacheKey !== key) {
                        this._cacheIndex = this._keys.indexOf(this._cacheKey = key);
                    }
                    if (this._cacheIndex < 0 && insert) {
                        this._cacheIndex = this._keys.length;
                        this._keys.push(key);
                        this._values.push(undefined);
                    }
                    return this._cacheIndex;
                }
            };

            function getKey<K, V>(key: K, _: V) {
                return key;
            }

            function getValue<K, V>(_: K, value: V) {
                return value;
            }

            function getEntry<K, V>(key: K, value: V) {
                return [key, value] as [K, V];
            }
        }

        // naive Set shim
        function CreateSetPolyfill(): SetConstructor {
            return class Set<T> {
                private _map = new _Map<any, any>();
                get size() {
                    return this._map.size;
                }
                has(value: T): boolean {
                    return this._map.has(value);
                }
                add(value: T): Set<T> {
                    return this._map.set(value, value), this;
                }
                delete(value: T): boolean {
                    return this._map.delete(value);
                }
                clear(): void {
                    this._map.clear();
                }
                keys() {
                    return this._map.keys();
                }
                values() {
                    return this._map.values();
                }
                entries() {
                    return this._map.entries();
                }
                "@@iterator"() {
                    return this.keys();
                }
                [iteratorSymbol]() {
                    return this.keys();
                }
            };
        }

        // naive WeakMap shim
        function CreateWeakMapPolyfill(): WeakMapConstructor {
            const UUID_SIZE = 16;
            const keys = HashMap.create<boolean>();
            const rootKey = CreateUniqueKey();
            return class WeakMap<K, V> {
                private _key = CreateUniqueKey();
                has(target: K): boolean {
                    const table = GetOrCreateWeakMapTable<K>(target, /*create*/ false);
                    return table !== undefined ? HashMap.has(table, this._key) : false;
                }
                get(target: K): V {
                    const table = GetOrCreateWeakMapTable<K>(target, /*create*/ false);
                    return table !== undefined
                        ? HashMap.get(table, this._key)
                        : undefined;
                }
                set(target: K, value: V): WeakMap<K, V> {
                    const table = GetOrCreateWeakMapTable<K>(target, /*create*/ true);
                    table[this._key] = value;
                    return this;
                }
                delete(target: K): boolean {
                    const table = GetOrCreateWeakMapTable<K>(target, /*create*/ false);
                    return table !== undefined ? delete table[this._key] : false;
                }
                clear(): void {
                    // NOTE: not a real clear, just makes the previous data unreachable
                    this._key = CreateUniqueKey();
                }
            };

            function CreateUniqueKey(): string {
                let key: string;
                do key = "@@WeakMap@@" + CreateUUID(); while (HashMap.has(keys, key));
                keys[key] = true;
                return key;
            }

            function GetOrCreateWeakMapTable<K>(
                target: K,
                create: true,
            ): HashMap<any>;
            function GetOrCreateWeakMapTable<K>(
                target: K,
                create: false,
            ): HashMap<any> | undefined;
            function GetOrCreateWeakMapTable<K>(
                target: K,
                create: boolean,
            ): HashMap<any> | undefined {
                if (!hasOwn.call(target, rootKey)) {
                    if (!create) return undefined;
                    Object.defineProperty(
                        target,
                        rootKey,
                        { value: HashMap.create<any>() },
                    );
                }
                return (<any> target)[rootKey];
            }

            function FillRandomBytes(buffer: BufferLike, size: number): BufferLike {
                for (let i = 0; i < size; ++i) buffer[i] = Math.random() * 0xff | 0;
                return buffer;
            }

            function GenRandomBytes(size: number): BufferLike {
                if (typeof Uint8Array === "function") {
                    if (typeof crypto !== "undefined") {
                        return crypto.getRandomValues(new Uint8Array(size)) as Uint8Array;
                    }
                    if (typeof msCrypto !== "undefined") {
                        return msCrypto.getRandomValues(new Uint8Array(size)) as Uint8Array;
                    }
                    return FillRandomBytes(new Uint8Array(size), size);
                }
                return FillRandomBytes(new Array(size), size);
            }

            function CreateUUID() {
                const data = GenRandomBytes(UUID_SIZE);
                // mark as random - RFC 4122 § 4.4
                data[6] = data[6] & 0x4f | 0x40;
                data[8] = data[8] & 0xbf | 0x80;
                let result = "";
                for (let offset = 0; offset < UUID_SIZE; ++offset) {
                    const byte = data[offset];
                    if (offset === 4 || offset === 6 || offset === 8) result += "-";
                    if (byte < 16) result += "0";
                    result += byte.toString(16).toLowerCase();
                }
                return result;
            }
        }

        // uses a heuristic used by v8 and chakra to force an object into dictionary mode.
        function MakeDictionary<T>(obj: T): T {
            (<any> obj).__ = undefined;
            delete (<any> obj).__;
            return obj;
        }
    });
}