Extracting return types from functions while mapping types?

[JasonKleban]

I don't recognize any examples of this in the docs. Can we map to a type that holds the return types of key-indexed functions? Is there a syntax for that?

var ex = {
    One<S>(x : S) { return x; }
    
    Two<T>(y : T) { return "foo"; }
    
    Three() { return false; }
}

 // Bad because all return types would have to be the same `T`
type BadMappedOutputs<T, O extends { [k : string] : () => T }> = {
    [K in keyof O] : T
}

// Something like this?
type MappedOutputs<O> = {
    <T>[K in keyof O where O[K] extends () => T] : T
}

var baz = MappedOutputs<typeof ex>;

baz.One; // any
baz.Two; // string
baz.Three; // boolean

[aluanhaddad]

I believe this is a duplicate of #6606.

[mhegazy]

You should be able to get this working today with Conditional Types

type ReturnType<T> = T extends (...args: any[]) => infer R ? R : never;

type MappedOutputs<T> = {
    [P in keyof T]: ReturnType<T[P]>
}