UnionIntersection.md

typelab / utils / UnionIntersection

type UnionIntersection<U1, U2> = U1 extends U1 ? U2 extends U2 ? IsEqual<U1, U2> extends true ? U1 : never : never : never;

Get the intersection of two union types, combining only the types that exist in both unions.

Type Parameters

Type Parameter	Description
U1	The first union type.
U2	The second union type.

Returns

The intersection of U1 and U2.

Example

// 'b'
type Result = UnionIntersection<'a' | 'b', 'b' | 'c'>;