export declare class Radix<A> {
    private depth;
    private size;
    private block;
    private suffix;
    private suffixSize;
    private constructor();
    space(): number;
    append(value: A): Radix<A>;
    nth(index: number): A | undefined;
    static empty(): Radix<any>;
}
export declare function empty(): Radix<any>;