typescript-conditional-types

The short a answer is you can’t. No value will be assignable to an unresolved conditional type (a conditional type that still depends on a free generic type variable). The only thing you can do is use a type assertion. function test<T extends boolean>(a: T): T extends true ? string : number { return (a … Read more

Typescript now comes with a predefined Parameters<F> type alias in the standard library which is almost the same as ArgumentTypes<> below, so you can just use that instead of creating your own type alias. type TestParams = Parameters<(a: string, b: number) => void> // [string, number] Then to get for example the second parameter’s type … Read more