import * as React from "react";
export declare const FontSizeObserver: React.MemoExoticComponent<(props: {
    children: (fontSize: number) => string | number | boolean | {} | React.ReactElement<any, string | ((props: any) => React.ReactElement<any, string | any | (new (props: any) => React.Component<any, any, any>)>) | (new (props: any) => React.Component<any, any, any>)> | React.ReactNodeArray | React.ReactPortal | React.ReactNode[];
}) => JSX.Element>;