IsUnion TypeAlias

Returns true if T is a union and false if it is not.

This API is reserved for internal system use and should not be imported directly. It may change at any time without notice.

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Signature

export type IsUnion<T, T2 = T> = T extends unknown ? [T2] extends [T] ? false : true : "error";

Type Parameters

Parameter	Default	Description
T		Type to test if it is a union.
T2	T	Do not specify: default value used as implementation detail.