import { type Maybe } from '../value/maybe.type';
import { type StorageObject } from './storage.object';
/**
 * A StorageObject implementation that stores data in memory.
 * This is not persistent and will be cleared when the JavaScript context is lost.
 */
export declare class MemoryStorageInstance implements StorageObject {
    private _length;
    private _storage;
    /**
     * The number of items stored.
     *
     * @returns the current count of stored key-value pairs
     */
    get length(): number;
    /**
     * Returns the key at the given index.
     *
     * @param index The index of the key to retrieve.
     * @returns The key string if found, otherwise null.
     */
    key(index: number): string;
    /**
     * Checks if a key exists in the storage.
     *
     * @param key The key to check.
     * @returns True if the key exists, false otherwise.
     */
    hasKey(key: string): boolean;
    /**
     * Retrieves an item from storage.
     *
     * @param key The key of the item to retrieve.
     * @returns The item string if found, otherwise null or undefined.
     */
    getItem(key: string): Maybe<string>;
    /**
     * Sets an item in storage.
     * If the item is null or undefined, the key will be removed.
     *
     * @param key The key of the item to set.
     * @param item The item string to store.
     */
    setItem(key: string, item: Maybe<string>): void;
    /**
     * Removes an item from storage.
     *
     * @param key The key of the item to remove.
     */
    removeItem(key: string): void;
    /**
     * Clears all items from the storage.
     */
    clear(): void;
}
/**
 * A shared, global instance of MemoryStorageInstance.
 * Useful for singleton-like access to an in-memory store throughout an application.
 */
export declare const SHARED_MEMORY_STORAGE: MemoryStorageInstance;