export declare class SinglyLinkedListNode<T> {
    private element;
    private next;
    /**
     * Creates new SinglyLinkedListNode
     * @param {T} element value of list node
     * @param {SinglyLinkedListNode<T>} next reference to the next node
     */
    constructor(element: T, next: SinglyLinkedListNode<T>);
    /**
     * Returns the value of the node
     * @returns {T} value of the node
     */
    getElement(): T;
    /**
     * Returns reference to the next node
     * @returns {SinglyLinkedListNode<T> | null} reference to the next node
     */
    getNext(): SinglyLinkedListNode<T> | null;
    /**
     * Sets next of current node to provided node
     * @param {SinglyLinkedListNode<T>} next next list node
     */
    setNext(next: SinglyLinkedListNode<T>): void;
}
export declare class SinglyLinkedList<T> {
    private head;
    private tail;
    private size;
    /**
     * Adds new node to the head of the list
     * @param {T} element value to be added
     */
    addFirst(element: T): void;
    /**
     * Adds new node to the tail of the list
     * @param {T} element value to be added
     */
    addLast(element: T): void;
    /**
     * Removes node from the head of the list
     * @returns {T} value of first node
     */
    removeFirst(): T;
    /**
     * Removes node from the tail of the list
     * @returns {T} value of the last node
     */
    removeLast(): T;
    /**
     * Returns value of the first node
     * @returns {T} value of the first node
     */
    first(): T;
    /**
     * Returns value of the last node
     * @returns {T} value of last node
     */
    last(): T;
    /**
     * Returns size of the list
     * @returns {number} size of the list
     */
    getSize(): number;
    /**
     * Returns true if list size is zero, false otherwise
     * @returns {boolean} true if list is empty
     */
    isEmpty(): boolean;
}