18220 - Filter

[sunupupup]

type Filter<T, Condition, Ret extends any[] = []> = T extends [
  infer First,
  ...infer Rest
]
  ? Filter<Rest, Condition, First extends Condition ? [...Ret, First] : Ret>
  : Ret;

[sunupupup]

type Filter<T, Condition> = T extends [infer First, ...infer Rest]
  ? First extends Condition
    ? [First, ...Filter<Rest, Condition>]
    : Filter<Rest, Condition>
  : [];