import { type FlattenTuple } from "https://deno.land/x/deepmergets@v7.0.3/dist/deno/types/utils.ts";
Flatten a tuple of tuples into a single tuple.
definition: T extends readonly [] ? [] : T extends readonly [infer T0] ? [...FlattenTuple<T0>] : T extends readonly [infer T0, ...infer Ts] ? [...FlattenTuple<T0>, ...FlattenTuple<Ts>] : [T]