Interview questions should be trivial examples so you can see if the candidate know what programming is or how to program on the language, not what libraries he

Interview questions should be trivial examples so you can see if the candidate know what programming is or how to program on the language, not what libraries he/she knows. Ideally nothing that depends on any particular OS std libraries as well. Of course this does not apply if you are hiring someone for a position where knowledge on a particular library is a requirement, but in my experience that is usually not the case for either junior nor senior positions, maybe only for in-between. If you need anything more advanced you should do an assignment to allow time for proper design and reasoning, otherwise you'll never be able to fully evaluate what the candidate really can do and how he/she approaches problems.