I flew a round-trip on Turkish (Atlanta-Istanbul-Vienna, then Budapest-Istanbul-Atlanta) while the ban was in effect. The ban was only in effect on the Istanbul to Atlanta flight. I believe I could have carried a laptop on the Budapest-Istanbul flight and "gate-checked" it at Istanbul; I didn't see anyone do this, but my carry-on bag was searched at the gate so I suppose that's when it would have happened. See http://liveandletsfly.boardingarea.com/2017/04/19/guide-elec... for an example of how this gate checking may have worked.