Silly Binary Logic in TypeScript's Type System

binary.ts

type Bit = 0 | 1;

type BitFlip<A> = A extends 0
  ? 1
  : 0;

type BitOr<A, B> = [A, B] extends [0, 0]
  ? 0
  : 1;

type BitAnd<A, B> = [A, B] extends [1, 1]
  ? 1
  : 0;

type BitXor<A, B> = [A, B] extends [0, 0] | [1, 1]
  ? 1
  : 0;

// Output: [Xor, Carry]
type BitAdd<A, B> = [BitXor<A, B>, BitAnd<A, B>];

// This snippet doesn't take care of all the edge cases, but doing so is kind of unreadable at first...
// See https://gist.github.com/JoshuaKGoldberg/7543c2b3258fdce0a4ad70fd854ff7ff for the full thing.