What is the NoInfer utility (TS 5.4) for? function pick (colors: C[], fallback: NoInfer ) {} pick(['red', 'blue'], 'green');

It prevents inferring C from this argument - so there's an error

It disables type inference for the whole function and its arguments

It makes the fallback parameter optional with a default value

TypeScript · Senior · Question 12 of 75

What is the `NoInfer<T>` utility (TS 5.4) for?

function pick<C extends string>(colors: C[], fallback: NoInfer<C>) {}
pick(['red', 'blue'], 'green');

✓Correct answer: It prevents inferring C from this argument - so there's an error
2It disables type inference for the whole function and its arguments
3It makes the fallback parameter optional with a default value

Explanation

Without NoInfer, TS would infer C as 'red' | 'blue' | 'green' from both arguments, and there'd be no error. NoInfer says: "take C from elsewhere and only check this argument".

What is the `NoInfer<T>` utility (TS 5.4) for?

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What is the NoInfer<T> utility (TS 5.4) for?

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What is the `NoInfer<T>` utility (TS 5.4) for?