export declare const isObject: (value: unknown) => value is Record<string | number | symbol, unknown>;
export declare function isPlainObject(value: unknown): value is Record<string, unknown>;
export declare const isFunction: (value: unknown) => value is (...args: unknown[]) => boolean;
export declare const isString: (value: unknown) => value is string;
export declare const isBoolean: (value: unknown) => value is boolean;
export declare const isNumber: (value: unknown) => value is number;
export declare const isUndef: (value: unknown) => value is undefined;