no, my driving ability wasn't impaired. well, if it was more than if I had zero alcohol I'd still be less of a threat than most elderly and young people with licenced. but that's neither here not there not the point of the thread. but back to the point please, maybe, shall we?
You admittedly had been drinking and smoking (marijuana, I presume). You also admit to not being completely sober .. by definition, that would mean you were impaired. You WERE impaired, my friend. You may not believe you were, but as a matter of medical fact, you were. The question would not have been impairment, but whether you were too impaired to safely operate a motor vehicle.
You got DARN lucky. You were stopped either by an inexperienced, incompetent, or lazy cop. If you appeared to be impaired, and the odor of marijuana was present, he should have investigated further. Had you gotten into a collision after he let you go, he could be held personally liable for any damage you might have done after that. Had he been one of my officers, I would have had his tail in a sling!
You got darn lucky.
Do yourself and the rest of the public a favor - if you must smoke dope and drink, do it at home and do not drive!