README.md

This type would evaluate to union of "exclusive" shapes.

For example, the following type

type A = ExclusiveUnion<{a: number} | {b: string}>;

Evaluates to

type A = { a: number, b?: never } | { a?: never, b: string }

ExclusiveUnion.ts

type KeysOfUnion<T> = T extends T ? keyof T : never;
export type ExclusiveUnion<T> = KeysOfUnion<T> extends
  infer K extends PropertyKey
  ? T extends infer A ? A & Partial<Record<Exclude<K, keyof A>, never>>
  : never
  : never;