unwrapOrForUndefinable
Return input as T if the passed input is not undefined.
Otherwise, return defaultValue.
- defaultValue must not be
Undefinable<*>. - If the result of defaultValue is
undefined, throwTypeError.
function unwrapOrForUndefinable<T>(input: Undefinable<T>, defaultValue: NotUndefined<T>): NotUndefined<T>;