export type StateUpdater<ValueType> = (value: ValueType) => void;
export type SharedStateNext<ValueType> = (nextValue: ValueType) => void;
export type SharedStateMiddleware<ValueType> = (value: ValueType, next: SharedStateNext<ValueType>) => void;
export declare function readSharedState<ValueType>(key: string, defaultValue?: ValueType): any;
export declare function storeSharedState<ValueType>(key: string, value?: ValueType): void;
export declare function useSharedState<ValueType = any>(key: string, defaultValue?: ValueType): [
    ValueType | undefined,
    any
];
export declare function update<ValueType = any>(key: string, value: ValueType): void;
export declare function registerMiddleware<ValueType = any>(key: string, middleware: SharedStateMiddleware<ValueType>): void;
export declare function removeMiddleware<ValueType = any>(key: string, middleware: SharedStateMiddleware<ValueType>): void;