Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
3.7k views
in Technique[技术] by (71.8m points)

typescript - Cannot be dynamically inferred after passing some generic parameters

const a = <
  T extends any = any,
  B extends boolean = true,
  R extends T | undefined = B extends true ? T : T | undefined
>(
  v: B = true as B // not use "as" will trigger type argument assign error
): R => '' as R;

const x = a<string>(); // ok! type is string
const y = a<string>(false); // error! `TS2345: Argument of type 'false' is not assignable to parameter of type 'true | undefined'.`, but the type inferred by webstorm is string | undefined

Is this because generics can only be passed parameters or dynamically inferred and cannot be use simultaneously the two?


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)
等待大神解答

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...