import type { Optic, TryA, TryT, A, B, S, T } from './optic.js';
import type { TupleExpected } from './errors.js';
export type Prec<N> = N extends 6 ? 5 : N extends 5 ? 4 : N extends 4 ? 3 : N extends 3 ? 2 : N extends 2 ? 1 : N extends 1 ? 0 : never;
export type AnyTuple<N extends number, Acc extends any[] = []> = N extends 0 ? Acc : AnyTuple<Prec<N>, [...Acc, any]>;
interface NthA<N extends number> extends A {
    0: TryA<this, S<this> extends [...AnyTuple<N>, infer Elem, ...any[]] ? Elem : TupleExpected<N, S<this>>>;
}
type SetNthRec<N extends number, B, S> = N extends 0 ? S extends [any, ...infer U] ? [B, ...U] : never : S extends [infer U, ...infer V] ? [U, ...SetNthRec<Prec<N>, B, V>] : never;
interface NthT<N extends number> extends T {
    0: TryT<this, S<this> extends [...AnyTuple<N>, any, ...any[]] ? SetNthRec<N, B<this>, S<this>> : TupleExpected<N, S<this>>>;
}
export type Nth<N extends number> = Optic<'Lens', NthA<N>, NthT<N>>;
export declare const nth: <N extends number>(n: N) => Nth<N>;
export {};