Why `combineLatest` returns OperatorFunction<{}, number>

Question

I am using RxJS 6 I have two observables in my code

import { combineLatest } from 'rxjs/operators';

loading$: Observable<boolean>;
loaded$: Observable<boolean>;

The observables are not coming from http request but from the store

I need to combine/convert the sequences into one single observable value based on this logic:
If the sequence true, true or false, false - need to return new observable true otherwise need to return false

I tried to use combineLatest to achieve that:

combineLatest(
    this.loaded$, this.loading$,
    (val1, val2) => Number(val1) + Number(val2) === 1
)

But the problem is that my combineLatest returns 'OperatorFunction<> and not Observable<> so I cannot subscribe. Do you have any ideas on how to fix that? Or if there is another approach that can be taken?

UPDATE:
Seems like that is the answer to my question import { combineLatest } from 'RxJS';
currently testing

Answer 1

With RxJS 5.5 it's most likely because you're using combineLatest from rxjs/operators while you want to use it as an Observable "creation method" which means you need to use rxjs/observable/combineLatest.

I mean you need to use this:

import { combineLatest } from 'rxjs/observable/combineLatest';

... instead of this:

import { combineLatest } from 'rxjs/operators';

Edit: Since you mentioned you're using RxJS 6 you can import the static variant from rxjs.

import { combineLatest } from 'rxjs';

If you're looking for combineLatest operator you have to import it like this:

import { combineLatest } from 'rxjs/operators';

Answer 2

I am guessing I just need this

import { combineLatest } from 'rxjs';