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by triyambakam 1373 days ago
type Equal<A, B> = A extends B ? (B extends A ? true : false) : false;
2 comments

Actually, this won't work with union types! The definition of `Equal` I use is this one:

type Equal<X, Y> = (<T>() => T extends X ? 1 : 2) extends < T >() => T extends Y ? 1 : 2 ? true : false;

Understanding this requires a bit more context, but I'll explain why we need something so complicated in the Advanced Union Types chapter :)

I picked it from https://github.com/type-challenges/type-challenges which is an awesome resource too

Nice.