import React from 'react';
/**
 * An async wrapper around a heavy-weight React dependency
 *
 * The component should only be loaded once.
 */
export declare function asyncComponent<T extends asyncComponent.TImportable>(doImport: asyncComponent.IImporter<T>, onError?: asyncComponent.IErrorHandler): asyncComponent.TImportable;
/**
 * A namespace for relevant interfaces
 */
export declare namespace asyncComponent {
    /**
     * The type of thing that can be lazily loaded
     */
    type TImportable = React.ComponentClass | React.StatelessComponent;
    /**
     * A lazy loader that uses `await import`
     *
     * Should probably also specify a webpackChunkName
     * https://webpack.js.org/guides/code-splitting/#dynamic-imports
     */
    interface IImporter<T> {
        (): Promise<T>;
    }
    /**
     * An error handler (can't have any particular side effects
     */
    interface IErrorHandler {
        (err: any): void;
    }
    /**
     * The state of the wrapper component.
     *
     * Apparently this can't be <T> yet...
     */
    interface IState {
        __async_component: TImportable | null;
    }
}