TypeScript types memo
T1 extends T2 ? F<T1> : never similar to
f(t1 as T2) circularly references
{0: T1}[T extends any ? 0 : 0] {0: T1, 1: T2}[CONDITION ? 0 : 1] CONDITION ? T1 : T2 ts// type GET_LAST<X extends LIST> =
// X extends [BIN, LIST] ? CAR<X> : GET_LAST<CDR<X>>
// NG: Type alias 'GET_LAST' circularly references itself.
type GET_LAST<X extends LIST> = {
0: CAR<X>,
1: GET_LAST<CDR<X>>
}[X extends [BIN, LIST] ? 0 : 1]
// OKCONDITION
N extends any true
any extends any does not worktrue: any, false: never
N extends M ? ... : ... の形でしか使えない"Engineer's way of creating knowledge" the English version of my book is now available on [Engineer's way of creating knowledge]
(C)NISHIO Hirokazu / Converted from [Scrapbox] at [Edit]