import { fromTemplateStrings } from "rx-template-strings";
const name = new BehaviorSubject("World");
const greeting = new BehaviorSubject("Hello");

// Non-unique observable will be processing only one time
fromTemplateStrings`${greeting}, ${name}-${name}!`
    .subscribe( (value) => console.log(value) ); // "Hello, World-World!"

fromTemplateStrings(strings: TemplateStringsArray, ...keys: any[]): Observable<string>;