type Path = (string | number)[];
export declare function optional<T>(obj: any, fn: (obj: any) => T): T | undefined;
export declare function iface<T>(input: any, path: Path, fn: (obj: any) => T): T;
export declare function array<T>(input: any, path: Path, fn: (idx: number, obj: any) => T): T[];
export declare function string(input: any, path: Path): string;
export declare function number(input: any, path: Path): number;
export {};