TypeScript：我可以推断数字索引值类型吗？

Question

I created a helper function to convert an object of numbered keys to a Map:

interface IndexedObject {
    [index: number]: unknown;
};

const objectToIndexedMap = (indexedObject: IndexedObject) => new Map(
    Object.entries(indexedObject).map(
        ([ index, field ]) => [ Number(index), field ]
    )
);

I use it to convert objects I'm getting from the API to a more convenient Map, where I don't need to deal with string keys anymore. The problem is that the returned type is Map<number, any> , while I'd like to use the type of those values in IndexedObject .

Is it possible to get that type and make my function return this specific type for Map values?

So for example this would throw an error:

interface IndexedNumbers {
    [index: number]: number;
}

const indexedNumbers: IndexedNumbers = api.numbers; // pseudocode
const map = objectToIndexedMap(indexedNumbers);
const foo = map.get(0)!.toUpperCase(); // This should throw an error

Of course I know I can hard-type it:

const map: Map<number, number> = objectToIndexedMap(indexedNumbers);

But I'd love TypeScript to do that for me. Is it possible?