export declare class Stack<T> {
	top: T[];
	bottom: T[];
	iterators: Generator<T, void, any>[];
	/**
	 * Construct a new `Stack<T>`
	 * @param sources are transformed into iterators, their values are returned from `.pop_top()`
	 */
	constructor(...sources: Iterable<T>[]);
	/**
	 * ### Last-In-First-Out
	 * Push items onto the top of this stack
	 * @returns the total number of pushed elements remaining
	 */
	push_top(...items: T[]): number;
	/**
	 * ### First-In-First-Out
	 * Push items below the bottom of this stack
	 * @returns the total number of remaining elements push to the bottom of this stack
	 */
	push_bottom(...items: T[]): number;
	/**
	 * Pop an element from the top of this stack
	 * @returns the popped element, or undefined if this stack is empty
	 */
	pop_top(): T | undefined;
	/**
	 * Pop an element from the bottom of this stack
	 * @returns the popped element, or undefined if no elements were pushed to the bottom of this stack
	 */
	pop_bottom(): T | undefined;
}