type ElementType<A> = A extends ReadonlyArray<infer T> ? T | undefined : never;
type ElementsOfAll<Inputs, R extends ReadonlyArray<unknown> = []> = Inputs extends readonly [infer F, ...infer M] ? ElementsOfAll<M, [...R, ElementType<F>]> : R;
type CartesianProduct<Inputs> = ElementsOfAll<Inputs>[];
/**
 * Get the cross product or Cartesian product of a list of groups. The
 * implementation is copied, with some modifications, from
 * https://stackoverflow.com/a/72059390/159388.
 * @param sets A list of groups of elements
 * @returns A list of all possible combinations of one element from each group
 * in sets. Empty groups will result in undefined in that slot in each
 * combination.
 */
export declare function crossProduct<Sets extends ReadonlyArray<ReadonlyArray<unknown>>>(sets: Sets): CartesianProduct<Sets>;
export {};