UNPKG

426 BTypeScriptView Raw
1/**
2 * @hidden
3 */
4export declare type _UndefinableKeys<O extends object> = {
5 [K in keyof O]-?: [O[K] & (undefined)] extends [never] ? never : K;
6}[keyof O];
7/**
8 * Get the keys of `O` that are `undefined`
9 * (⚠️ needs `--strictNullChecks` enabled)
10 * @param O
11 * @returns [[Key]]
12 * @example
13 * ```ts
14 * ```
15 */
16export declare type UndefinableKeys<O extends object> = O extends unknown ? _UndefinableKeys<O> : never;