export declare class Stack {
    private items;
    get size(): number;
    constructor();
    /**
     * adds an entry to the stack
     * @param val the value to add to the stack
     * @returns {number} the new size of the stack
     */
    push(val: any): number;
    /**
     * removes and returns the next entry in the stack
     * @returns {any} the next entry in the stack
     */
    pop(): any;
}