import { OverlayRef } from '../overlay-ref';
/**
 * Describes a strategy that will be used by an overlay
 * to handle scroll events while it is open.
 */
export interface ScrollStrategy {
    enable: () => void;
    disable: () => void;
    attach: (overlayRef: OverlayRef) => void;
}
/**
 * Returns an error to be thrown when attempting to attach an already-attached scroll strategy.
 */
export declare function getMdScrollStrategyAlreadyAttachedError(): Error;