Well public intoxication is illegal, and the legalization of the possession of drugs wouldn't change that. I'm firmly in the drug-use-is-a-human-right camp, but I don't think that you have a right to use drugs in public. I think it's OK to be under the influence in public as long as your intoxication is subtle enough to be unnoticeable to a casual passerby, but I would oppose getting rid of public intoxication laws.

You have a right to drug use in private or where everyone present consents to your using drugs, like in group psychedelic rituals.